WO2025174829A1

WO2025174829A1 - Surgical tools for implanting a tissue scaffold

Info

Publication number: WO2025174829A1
Application number: PCT/US2025/015517
Authority: WO
Inventors: Luke Aram; Nathan CASTRO; Douglas Snell; Benjamin HOLMES; Sean CHURCHILL
Original assignee: Nanochon Inc
Current assignee: Nanochon Inc
Priority date: 2024-02-13
Filing date: 2025-02-12
Publication date: 2025-08-21
Anticipated expiration: 2026-08-13
Also published as: WO2025174792A1

Abstract

A surgical tool kit and a method of installing a tissue, the method comprising positioning an alignment guide to ensure proper alignment of surgical tools relative to a lesion in a host tissue; inserting a guide pin into the host tissue to provide a reference point; using a punch to score the host tissue at the location of the guide pin; utilizing a cannulated reamer to prepare a socket in the host tissue; evaluating the prepared socket in the host tissue with a trial implant to ensure proper fit and alignment; employing an undercut tool to prepare at least one groove in the host tissue; and placing the tissue scaffold into the prepared socket using an insertion tool.

Description

SURGICAL TOOLS FOR IMPLANTING A TISSUE SCAFFOLD

CROSS-REFERENCE

[0001] This application claims the benefit of U.S. Provisional Application No. 63/553,044, filed February 13, 2024, and U.S. Provisional Application No. 63/716,611, filed November 5, 2024, each of which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] Focal and full-thickness cartilage lesions can be a significant source of pain and impairment to a patient's quality of life. Over 250,000 patients undergo surgical treatment for cartilage lesions each year, which is often associated with a low rate of treatment success (-60% treatment failure) due to the complex nature of the tissue. In recent years, researchers have begun to use both complex biomimetic nanomaterials and three-dimensional (3D) printing to create highly effective strategies for complex joint repair. However, while these materials work well in a controlled laboratory setting, they are limited in their adaptability for clinical medical device fabrication. More importantly, the materials as they are designed now can only be printed using extrusion-based 3D printing techniques, so called bioplotting or bio-printing, where an extrusion tool slowly deposits material from a reservoir and then cures each layer of material using a crosslinking agent. This type of additive manufacturing is limited by resolution and print speed / volume when compared to commercial systems such as fused filament fabrication (FFF) or laserbased systems. Furthermore, current biologically complex approaches (incorporating live cells, growth factors and biologies) have had good outcomes, but are prohibitively expensive ($10,000 or more for treatment, no reimbursement).

SUMMARY

[0003] There is an unmet need for improving clinical outcomes with a more mechanically and biologically stable implant, while also addressing manufacturing costs. This application provides meets this unmet need by providing devices and methods directed towards tissue scaffolds and methods of implantation.

[0004] In one aspect, provided herein is a tissue scaffold comprising: (a) a scaffold region; and (b) at least one press-fit ring configured to engage with at least one socket prepared on a host tissue. In some cases, the tissue scaffold is configured to have an interference fit with the host tissue. In some cases, the socket is a bone socket. In some cases, the at least one press-fit ring is at least two press-fit rings. In some cases, each press-fit ring of the at least two press-fit rings is separated by a distance of at least 0.05mm. In some cases, the at least one press-fit ring has a ring-like structure. In some cases, the at least one press-fit ring is disposed along the outer circumference of the tissue scaffold. In some cases, an outer surface of the at least one press-fit ring is configured to contact the host tissue and anchor the tissue scaffold into the host tissue. In some cases, the at least one press-fit ring is solid. In some cases, the at least one press-fit ring has an infill density of about 100%. In some cases, the scaffold region and at least one press-fit ring are integrally formed as a single unit. In some cases, the scaffold region and the at least one press fit ring are manufactured using a three-dimensional printing process.

[0005] In another aspect, provided herein is a tissue scaffold comprising: (a) a scaffold region; and (b) a fixation region, wherein the fixation region comprises at least one retention tab configured to engage with at least one groove or socket prepared on a host tissue. In some cases, the tissue scaffold is compressible to a compressed state. In some cases, the tissue scaffold is, after being compressed, capable of expanding to an expanded state. In some cases, the tissue scaffold in the expanded state is within at least about 90% of an original size of the tissue scaffold. In some cases, the at least one retention tab is configured to engage the groove or socket prepared in the host tissue when the tissue scaffold is in the expanded state. In some cases, the fixation region has two retention tabs, each retention tab of the two retention tabs disposed on opposing sides of the tissue scaffold. In some cases, the fixation region comprises three or more retention tabs. In some cases, the fixation region is circular or substantially circular in shape. In some cases, the at least one retention tab comprises a protrusion which extends in a radial direction from the fixation region. In some cases, the protrusion is configured to contact the groove or socket and anchor the tissue scaffold into the groove or socket. In some cases, a top surface of the fixation region is attached to a bottom surface of the scaffold region. In some cases, the fixation region is solid. In some cases, the fixation region has an infill density of about 100%. In some cases, the fixation region comprises a plurality of layers. In some cases, the fixation region comprises 2 to 10 layers. In some cases, the fixation region comprises 2 to 80 layers. In some cases, the fixation region is about 0.8 mm to about 8.0 mm in thickness. In some cases, the fixation region comprises a cylindrical pocket. In some cases, the cylindrical pocket is sized and shaped to accept a bone post in the host tissue. In some cases, the fixation region is a substantially circular body having an upper surface, a lower surface, a thickness extending between the upper and lower surfaces, and a central through-hole extending along an axis perpendicular to the plane of the fixation region. In some cases, the scaffold region and the fixation region are integrally formed as a single unit. In some cases, the scaffold region and the fixation region are manufactured using a three-dimensional printing process. [0006] In yet another aspect, a tissue scaffold is provided comprising: (a) a scaffold region; and (b) a fixation region comprising at least one circumferential thread configured to engage with at least one groove or socket prepared on a host tissue. In some cases, the at least one circumferential thread is configured for secure fixation of the tissue scaffold on the host tissue. In some cases, the at least one circumferential thread comprises at least two circumferential threads. In some cases, the at least two circumferential threads are extended along an outer surface of the scaffold region and an outer surface of the fixation region. In some cases, the at least two circumferential threads are two helical threads extended symmetrically around a central axis of the scaffold region and a central axis of the fixation region. In some cases, the two helical threads are extended along an outer surface of the scaffold region and an outer surface of the fixation region, wherein the helical threads have a predetermined pitch and/or lead angle. In some cases, the two helical threads have two opposite cut-out portions configured to provide two insertion slots for engaging a tool to facilitate the rotation of the tissue scaffold. In some cases, the two opposite cut-out portions are extended partially along the outer surface of the scaffold region and the outer surface of the fixation region, wherein the two opposite cut-out portions are parallel with the central axis of the scaffold region and the central axis of the fixation region. [0007] In yet another aspect, a tissue scaffold is provided comprising: a scaffold region; and an attachment element that encapsulates at least a portion of the scaffold region, wherein the attachment element is configured to engage a tissue and hold the tissue scaffold in place. In some cases, the attachment element is a density that is greater than a density of the scaffold region. In some cases, the attachment element engages a groove or socket in the tissue. In some cases, the groove or socket is circular. In some cases, the attachment element engages the tissue by expanding from a compressed state. In some cases, the attachment element comprises a radial geometry. In some cases, the attachment element comprises a threaded geometry.

[0008] In yet another aspect, a tissue scaffold is provided comprising: a scaffold region; and an attachment element, wherein the attachment element extends in a radial direction from the scaffold. In some cases, the attachment element extends in a radial direction from a longitudinal axis of the scaffold region. In some cases, the scaffold region comprises a cylindrical geometry. In some cases, the attachment element comprises at least one radial protrusion. In some cases, the attachment element comprises a toroidal shape. In some cases, the attachment element is attached to an end of the scaffold region. In some cases, the attachment element encapsulates a portion of the scaffold region. In some cases, the attachment element is configured to engage a tissue. In some cases, the attachment element has a density that is greater than a density of the scaffold region. [0009] In another aspect, a tissue scaffold is provided comprising: a scaffold region; and an attachment element, wherein the scaffold region and the attachment element are elastically compressible, and wherein the attachment element holds the scaffold within a tissue. In some cases, the scaffold region and the attachment element are elastically compressible by 20%. In some cases, the scaffold region and the attachment element comprise a Young’s modulus of at least 200 kilopascals. In some cases, the scaffold is porous, and the attachment element is solid. In some cases, attachment element is attached to an end of the scaffold region. In some cases, the attachment element encapsulates a portion of the scaffold region.

[0010] In another aspect, a tissue scaffold is provided comprising: a cylindrical scaffold region, wherein an end of the cylindrical scaffold comprises a recessed portion; and an attachment element. In some cases, the recess is configured to mate to a portion of a tissue. In some cases, the portion of the tissue has been cut to the shape of the recess. In some cases, the portion of a tissue comprises bone or cartilage. In some cases, the attachment element encapsulates at least a portion of the end of the cylindrical scaffold region. In some cases, the attachment element engages a tissue.

[0011] In another aspect, a tissue scaffold is provided comprising: a porous region; and a solid threaded element that encapsulates at least a portion of the porous region. In some cases, the solid threaded element comprises a compressible material. In some cases, the porous region comprises a scaffold region. In some cases, the scaffold region comprises a plurality of layers. In some cases, the plurality of layers comprises at least one rotational offset between a first layer of the plurality of layers and a second layer of the plurality of layers. In some cases, the scaffold region comprises a plurality of layer densities.

[0012] In another aspect, a method of inserting a tissue scaffold is provided, the method comprising: forming a socket comprising a groove in a bone of a patient; and inserting the tissue scaffold. In some cases, the forming further comprises: drilling a guide pin into a bone of a patient; reaming a socket into the bone of the patient; and cutting a groove at a bottom of the socket. In some cases, the inserting further comprises: compressing the tissue scaffold; inserting the tissue scaffold into the socket; and releasing the tissue scaffold to engage the groove of the socket.

[0013] In another aspect, a method of inserting a tissue scaffold is provided, the method comprising: forming a socket in a bone of a patient; and inserting the tissue scaffold. In some cases, the forming further comprises: drilling a guide pin into a bone of a patient; reaming a socket into the bone of the patient; and cutting a groove at a bottom of the socket. In some cases, the inserting further comprises: compressing the tissue scaffold; inserting the tissue scaffold into the socket; and releasing the tissue scaffold to engage the groove of the socket.

[0014] In another aspect, a method of inserting a tissue scaffold is provided, the method comprising: forming a threaded socket; and threading the tissue scaffold into the socket. In some cases, the forming further comprises: tapping a thread along the socket. In some cases, the forming further comprises drilling a guide pin into a bone of a patient. In some cases, the tapping is guided by the guide pin. In some cases, the tissue scaffold comprises at least one cutout slot in the threaded portion. In some cases, the tissue scaffold is inserted using an insertion tool configured to engage the at least one cutout slot of the tissue scaffold.

[0015] In another aspect, a kit is provided comprising any tissue scaffold described herein.

[0016] In yet another aspect, a bone preparation tool is provided, comprising: a cylindrical shaft; an end of the cylindrical shaft comprising two cutting teeth, wherein the end is hollow and compressible; and a cannula that extends from the center of the cylindrical shaft. In some cases, the bone preparation tool further comprises a handle portion opposite the hollow and compressible end of the cylindrical shaft. In some cases, the hollow and compressible end of the cylindrical shaft comprises cutouts for compression. In some cases, the two cutting teeth are configured to cut a groove in a bone of a patient. In some cases, the cannula extends past the end of the cylindrical shaft.

[0017] In yet another aspect, a scaffold insertion tool is provided, comprising: a cylindrical shaft; an end of the cylindrical shaft comprising a receiving end configured to receive a scaffold implant; and at least two engagement tines running parallel to the length of the cylindrical shaft and each comprising a proximal end, a middle portion, and a distal end, wherein the distal end of the engagement tines are configured to engage at least a portion of the received scaffold implant. In some cases, the engagement tines are configured to release the received scaffold implant when depressed at the middle portion.

[0018] In yet another aspect, a scaffold insertion tool is provided, comprising: a shaft; an end of the cylindrical shaft comprising a receiving end configured to receive a scaffold implant; and at least two engagement tines running parallel to the length of the cylindrical shaft and each comprising a proximal end, a middle portion, and a distal end, and wherein the engagement tines are configured to release the received scaffold implant when depressed at the middle portion. In some cases, the distal ends of the engagement tines are configured to engage at least a portion of the received scaffold implant.

[0019] In yet another aspect, a scaffold insertion tool is provided, comprising: a cylindrical shaft; a hollow distal end of the cylindrical shaft configured to receive and hold an inserted scaffold implant; a pushing portion located in the cylindrical shaft, wherein a distal end is configured to be in contact with the inserted scaffold implant; and a button on the external surface of the cylindrical shaft, connected to the pushing portion; wherein the button is configured engage the pushing portion to push the inserted scaffold out of the hollow distal end of the cylindrical shaft. In some cases, hollow distal end comprises a plurality of cutouts such that the hollow distal end flexes to receive the inserted scaffold implant. In some cases, the flex of the hollow distal end holds the inserted scaffold implant in place.

[0020] In yet another aspect, a scaffold insertion tool is provided, comprising: a first lever portion comprising a first distal end, a first middle portion, and a first proximal end, wherein the first distal end comprises a first compression tine; and a second lever portion comprising a second distal end, a second middle portion, and a second proximal end, wherein the second distal end comprises a second compression tine; wherein the first lever portion and second lever portion are pivotally coupled at the first middle portion and the second middle portion, wherein the first compression tine and the second compression tine are configured to engage a portion of a tissue scaffold.

[0021] In another aspect, a guide pin for providing a reference point in a host tissue is provided, comprising: an elongated, cylindrical member featuring a tapered tip for facilitating insertion into the host tissue; and depth indicators along a length to assist a user in determining an appropriate insertion depth. In some cases, the guide pin is made of a biocompatible material. In some cases, tapered tip is designed to minimize tissue damage during insertion. In some cases, the guide pin is drilled into the host tissue. In some cases, the host tissue comprises a femur bone. In some cases, the guide pin is inserted through an alignment guide. In some cases, the guide pin comprises markings or indicators for a depth measurement. In some cases, the guide pin is configured to establish an orientation of a tissue scaffold. In some cases, the guide pin is designed to be removed after a socket preparation is completed.

[0022] In another aspect, a punch for scoring a host tissue is provided, comprising: a body designed to score the host tissue; and an opening configured to be placed over a guide pin for accurate positioning. In some cases, the punch is sized to match dimensions of a host tissue lesion. In some cases, the punch is configured to apply axial pressure while rotating to score the host tissue. In some cases, the punch is made of a biocompatible material. In some cases, the punch includes markings or indicators to assist in proper alignment during use.

[0023] In another aspect, a cannulated reamer for preparing a socket in a host tissue is provided, comprising: a hollow, cylindrical body designed to create a socket in the host tissue; and at least one cutting tooth configured to facilitate a reaming process. In some cases, the reamer comprises a depth stop to prevent over-reaming beyond a predetermined cutting depth. In some cases, a hollow inside the reamer allows for a passage of a guide pin during use. In some cases, the reamer is made of a biocompatible material. In some cases, the reamer is configured to create a cylindrical socket that matches dimensions of a tissue scaffold. In some cases, the reamer is designed to be used in conjunction with an alignment guide to ensure accurate positioning during the reaming process.

[0024] In another aspect, an undercut tool for preparing at least one groove in a host tissue is provided, comprising: a cylindrical body featuring two cutting teeth designed to create at least one groove in a socket of the host tissue; and a cannula configured to allow for a placement of a guide pin during use. In some cases, each cutting tooth is disposed on an outer end of a first arm and a second arm extending from a vertex of the undercut tool. In some cases, an outer diameter of an end of the undercut tool containing the cutting teeth is larger than the socket of the host tissue, requiring compression to fit into the socket. In some cases, the undercut tool comprises a compression mechanism that allows a user to compress the two cutting teeth for retraction during placement over the guide pin and into the socket. In some cases, the cutting teeth extend to prepare the at least one groove in the host tissue upon release, wherein the undercut tool requires a compression to retract the teeth for removal. In some cases, the undercut tool is made of a biocompatible material.

[0025] In another aspect, an insertion tool for placing a tissue scaffold in a host tissue is provided, comprising: a gripping instrument to compress the tissue scaffold during insertion; and a tube with a pocket to hold the tissue scaffold during insertion. In some cases, insertion tool comprises two tips for gripping the tissue scaffold. In some cases, the insertion tool is used for compressing the tissue scaffold. In some cases, the insertion tool comprises at least four relief flutes that allow the tube to receive the tissue scaffold while applying a clamping force to hold the tissue scaffold. In some cases, the insertion tool further comprises a release button that retracts the tube. In some cases, the insertion tool is made of a biocompatible material. In some cases, the insertion tool is designed to provide tactile feedback to a user during the insertion process. In some cases, the pocket is cylindrical. In some cases, the pocket is about 0 mm to about 12 mm deep. In some cases, the tube holds a top half of the tissue.

[0026] In yet another aspect, a surgical tool kit for installing a tissue scaffold is provided, the surgical tool kit comprising: an alignment guide for ensuring proper positioning of surgical tools; a guide pin for providing a reference point in a host tissue; a punch for scoring the host tissue; a cannulated reamer for preparing a socket in the host tissue; a trial implant for evaluating the prepared socket in the host tissue; an undercut tool for preparing at least one groove in the host tissue; and an insertion tool for placing the tissue scaffold in the host tissue. In some cases, the surgical tool kit is made of a biocompatible material. In some cases, the host tissue comprises a femur bone. In some cases, the alignment guide is a cylindrical tube with both ends open, positioned perpendicular to a lesion in the host tissue to ensure accurate alignment of the surgical tools during the installation of the tissue scaffold. In some cases, the guide pin is drilled into the host tissue. In some cases, the guide pin is an elongated, cylindrical member, featuring a tapered tip for facilitating insertion into the host tissue, and includes depth indicators along its length to assist a user in determining an appropriate insertion depth. In some cases, the punch is designed for scoring the host tissue, wherein the punch is configured to be placed over the guide pin while applying axial pressure and rotating. In some cases, the cannulated reamer is a hollow, cylindrical tool with at least one cutting tooth designed for creating the socket of varying diameters in the host tissue, and includes a depth stop to prevent over-reaming over at least one predetermined cutting depth. In some cases, the trial implant is designed to match a thickness and a diameter of a final tissue scaffold implant, wherein the trial implant comprises visual indicators on an outer body of the trial implant to assist a user in evaluating a fit and alignment. In some cases, the trial implant has a Imm-mark on an outer surface of the trial implant, wherein the Imm-mark is visible to the user for evaluating the fit and alignment of the trial implant within the prepared socket in the host tissue. In some cases, the undercut tool is a cylindrical instrument featuring two cutting teeth and a cannula, designed to prepare a groove in the socket of the host tissue, wherein the undercut tool is configured to be placed concentrically over the guide pin. In some cases, each cutting tooth of the two cutting teeth is disposed on an outer end of a first arm and second arm extending from a vertex of the undercut tool. In some cases, an outer diameter of an end of the undercut tool containing the cutting teeth is larger than the socket of the host tissue, requiring a compression to fit into the socket. In some cases, the undercut tool comprises a compression mechanism that allows a user to compress the two cutting teeth for retraction during placement over the guide pin and into the socket, and upon release, the cutting teeth extend to prepare the groove in the bone, with the tool requiring compression to retract the teeth for removal. In some cases, the insertion tool is a gripping instrument that functions similarly to needle nose pliers, designed to compress the tissue scaffold during insertion. In some cases, the insertion tool includes two tips that are optimized for a shape of the tissue scaffold, ensuring a secure grip and effective compression during placement. In some cases, the tissue scaffold comprises at least one solid snap ring designed for secure fixation of the tissue scaffold on the host tissue. In some cases, the insertion tool comprises a tube with a cylindrical pocket that is about 2 mm deep, designed to hold a top half of the tissue scaffold during insertion. In some cases, the insertion tool comprises at least four relief flutes that allow the tube to flex and receive the tissue scaffold while applying a clamping force to hold the tissue scaffold, and further comprises a release button that retracts the tube to facilitate the complete placement of the tissue scaffold into the socket. In some cases, the insertion tool allows a user to place the tissue scaffold into the socket halfway, press the release button to retract the tube, and then fully insert the tissue scaffold, enabling the user to perform a procedure with at least one hand. In some cases, the tissue scaffold comprises at least one press-fit ring designed for secure fixation of the tissue scaffold on the host tissue. In some cases, the surgical tool kit further comprises an implant tap that feature cutting threads, is cannulated to fit over the guide pin, and comprises at least six flutes designed to trap bone removed by the cutting threads during a threading process. In some cases, the implant tap is rotated to cut threads in the host tissue, and further comprises an insertion tool with two tines designed to engage two insertion slots of the tissue scaffold, wherein the tissue scaffold is opened by pressing on two press points, allowing the insertion tool to rotate the tissue scaffold and screw it into the prepared socket. In some cases, the host tissue comprises bones, cartilages, or other tissues. In some cases, the tissue scaffold comprises at least one thread designed for secure fixation of the tissue scaffold on the host tissue. In some cases, the surgical tool kit is sterilized before use. In some cases, the surgical tool kit is sterilized by steam autoclaving. In some cases, the tissue scaffold is sterilized before use. In some cases, the tissue scaffold is sterilized by steam autoclaving. In some cases, the installation of the tissue scaffold is conducted within about 2 hours post sterilization. In some cases, the tissue scaffold is hydrated prior to installation. In some cases, the tissue scaffold is packed in a container prior to installation. In some cases, the container is made of glass, polymer, or metal. In some cases, the container is filled with an aqueous solution. In some cases, the surgical tool kit is organized and fixed in place within a metal container. In some cases, the metal container can be sterilized. In some cases, the surgical tool kit comprises at least one size of each tool.

[0027] In another aspect, a method of installing a tissue scaffold is provided, the method comprising: positioning an alignment guide to ensure proper alignment of surgical tools relative to a lesion in a host tissue; inserting a guide pin into the host tissue to provide a reference point; using a punch to score the host tissue at the location of the guide pin; utilizing a cannulated reamer to prepare a socket in the host tissue; evaluating the prepared socket in the host tissue with a trial implant to ensure proper fit and alignment; employing an undercut tool to prepare at least one groove in the host tissue; and placing the tissue scaffold into the prepared socket using an insertion tool. In some cases, the lesion in the host tissue is a chondral lesion. In some cases, the host tissue comprises a femur bone. In some cases, the method further comprises measuring the chondral lesion with the alignment guide to assess dimensions of the lesion. In some cases, the method further comprises assessing a position of the tissue scaffold to ensure that intact tissue is fully surround the tissue scaffold. In some cases, the alignment guide is positioned to fully cover the host tissue. In some cases, the host tissue is an articular cartilage lesion. In some cases, the alignment guide is oriented perpendicular to the lesion and is fitted to a surface of the host tissue. In some cases, the method further comprises placing the guide pin into the alignment guide. In some cases, an orientation of the guide pin is aligned with an orientation of the tissue scaffold. In some cases, the method further comprises drilling the guide pin into the host tissue until the depth stop line on the guide pin is aligned with an opening of the alignment guide. In some cases, the method further comprises selecting the punch from a plurality of predefined-size punches to score the host tissue. In some cases, the punch is placed over the guide pin. In some cases, the method further comprises applying axial pressure to the punch while rotating the punch to score the host tissue. In some cases, the method further comprises selecting the reamer from a plurality of predefined-size reamers to prepare a cylindrical socket for receiving the tissue scaffold. In some cases, a depth stop is assembled onto a shaft of the reamer, wherein the reamer is turned until the reamer is locked before use. In some cases, the depth stop is designed to ensure that the tissue scaffold sits recessed within the prepared socket. In some cases, the method further comprises preparing to assess a depth and orientation of the socket with applying the trial implant. In some cases, the method further comprises employing the undercut tool to prepare at least one groove in the host tissue to enhance the fixation of the tissue scaffold. In some cases, the method further comprises placing the tissue scaffold into the prepared socket using the insertion tool, wherein the insertion tool ensures a proper placement and secure fixation of the tissue scaffold within the host tissue.

[0028] In one aspect, provided herein is a tissue scaffold, comprising: a scaffold region; and an attachment element that encapsulates at least a portion of the scaffold region, wherein the attachment element is configured to engage a tissue and hold the tissue scaffold in place. In some embodiments, the attachment element is a density that is greater than a density of the scaffold region. In some embodiments, the attachment element engages a groove in the tissue. In some embodiments, the groove is circular. In some embodiments, the attachment element engages the tissue by expanding from a compressed state. In some embodiments, the attachment element comprises a radial geometry. In some embodiments, the attachment element comprises a threaded geometry.

[0029] In another aspect, provided herein is a tissue scaffold, comprising: a scaffold region; and an attachment element, wherein the attachment element extends in a radial direction from the scaffold. In some embodiments, the attachment element extends in a radial direction from a longitudinal axis of the scaffold region. In some embodiments, the scaffold region comprises a cylindrical geometry. In some embodiments, the attachment element comprises at least one radial protrusion. In some embodiments, the attachment element comprises a toroidal shape. In some embodiments, the attachment element is attached to an end of the scaffold region. In some embodiments, the attachment element encapsulates a portion of the scaffold region. In some embodiments, the attachment element is configured to engage a tissue. In some embodiments, the attachment element has a density that is greater than a density of the scaffold region.

[0030] In another aspect, provided herein is a tissue scaffold, comprising: a scaffold region; and an attachment element, wherein the scaffold region and the attachment element are elastically compressible, and wherein the attachment element holds the scaffold within a tissue. In some embodiments, the scaffold region and the attachment element are elastically compressible by 20%. In some embodiments, the scaffold region and the attachment element comprise a Young’s modulus of at least 200 kilopascals. In some embodiments, the scaffold is porous, and the attachment element is solid. In some embodiments, the attachment element is attached to an end of the scaffold region. In some embodiments, the attachment element encapsulates a portion of the scaffold region.

[0031] In some embodiments, the scaffold region and the attachment element comprise a equilibrium modulus of at least about 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, or at least about 6.0 megaPascals (MPa). In some embodiments, the scaffold region and the attachment element comprise an equilibrium modulus of less than about 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, or less than about 6.0 megaPascals (MPa).

[0032] In some embodiments, the scaffold region and the attachment element comprise a relaxation constant of at least about 134.8, 140, 150, 160, 170, 180, 190, 200, 210, or at least about 219.9 seconds (s). In some embodiments, the scaffold region and the attachment element comprise a relaxation constant of less than about 134.8, 140, 150, 160, 170, 180, 190, 200, 210, or less than about 219.9 seconds (s).

[0033] In some embodiments, the scaffold region and the attachment element comprise a dynamic modulus of at least about 18.4, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 ,41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, or at least about 51.2 megaPascals (MPa). In some embodiments, the scaffold region and the attachment element comprise a dynamic modulus of less than about 18.4, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 ,41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, or less than about 51.2 megaPascals (MPa).

[0034] In some embodiments, the scaffold region and the attachment element comprise a phase angle of at least about 1.9, 2.0, 2.1, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6,

3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8,

5.8, 5.9, 6.0, 6.1, or at least about 6.2 hertz (Hz). In some embodiments, the scaffold region and the attachment element comprise a phase angle of less than about 1.9, 2.0, 2.1, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8,

4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.8, 5.9, 6.0, 6.1, or less than about 6.2 hertz (Hz).

[0035] In another aspect, provided herein is a tissue scaffold, comprising: a cylindrical scaffold region, wherein an end of the cylindrical scaffold comprises a recessed portion; and an attachment element. In some embodiments, the recess is configured to mate to a portion of a tissue. In some embodiments, the portion of the tissue has been cut to the shape of the recess. In some embodiments, the portion of a tissue comprises bone or cartilage. In some embodiments, the attachment element encapsulates at least a portion of the end of the cylindrical scaffold region. In some embodiments, the attachment element engages a tissue.

[0036] In yet another aspect, provided herein is a tissue scaffold, comprising: a porous region; and a solid threaded element that encapsulates at least a portion of the porous region. In some embodiments, the solid threaded element comprises a compressible material. In some embodiments, the porous region comprises a scaffold region. In some embodiments, the scaffold region comprises a plurality of layers. In some embodiments, the plurality of layers comprises at least one rotational offset between a first layer of the plurality of layers and a second layer of the plurality of layers. In some embodiments, the scaffold region comprises a plurality of layer densities.

[0037] In yet another aspect, provided herein is a bone preparation tool, comprising: a cylindrical shaft; an end of the cylindrical shaft comprising two cutting teeth, wherein the end is hollow and compressible; and a cannula that extends from the center of the cylindrical shaft. In some embodiments, the bone preparation tool further comprises a handle portion opposite the hollow and compressible end of the cylindrical shaft. In some embodiments, the hollow and compressible end of the cylindrical shaft comprises cutouts for compression. In some embodiments, the two cutting teeth are configured to cut a groove in a bone of a patient. In some embodiments, the cannula extends past the end of the cylindrical shaft.

[0038] In another aspect, provided herein is a scaffold insertion tool, comprising: a cylindrical shaft; an end of the cylindrical shaft comprising a receiving end configured to receive a scaffold implant; and at least two engagement tines running parallel to the length of the cylindrical shaft and each comprising a proximal end, a middle portion, and a distal end, wherein the distal end of the engagement tines are configured to engage at least a portion of the received scaffold implant. In some embodiments, the engagement tines are configured to release the received scaffold implant when depressed at the middle portion.

[0039] In yet another aspect, provided herein is a scaffold insertion tool, comprising: a shaft; an end of the cylindrical shaft comprising a receiving end configured to receive a scaffold implant; and at least two engagement tines running parallel to the length of the cylindrical shaft and each comprising a proximal end, a middle portion, and a distal end, and wherein the engagement tines are configured to release the received scaffold implant when depressed at the middle portion. In some embodiments, the distal ends of the engagement tines are configured to engage at least a portion of the received scaffold implant.

[0040] In yet another aspect, provided herein is a scaffold insertion tool, comprising: a cylindrical shaft; a hollow distal end of the cylindrical shaft configured to receive and hold an inserted scaffold implant; a pushing portion located in the cylindrical shaft, wherein a distal end is configured to be in contact with the inserted scaffold implant; and a button on the external surface of the cylindrical shaft, connected to the pushing portion; wherein the button is configured engage the pushing portion to push the inserted scaffold out of the hollow distal end of the cylindrical shaft. In some embodiments, the hollow distal end comprises a plurality of cutouts such that the hollow distal end flexes to receive the inserted scaffold implant. In some embodiments, the flex of the hollow distal end holds the inserted scaffold implant in place.

[0041] In yet another aspect, provided herein is a scaffold insertion tool, comprising: a first lever portion comprising a first distal end, a first middle portion, and a first proximal end, wherein the first distal end comprises a first compression tine; and a second lever portion comprising a second distal end, a second middle portion, and a second proximal end, wherein the second distal end comprises a second compression tine; wherein the first lever portion and second lever portion are pivotally coupled at the first middle portion and the second middle portion, wherein the first compression tine and the second compression tine are configured to engage a portion of a tissue scaffold.

[0042] In yet another aspect, provided herein is a method of inserting a tissue scaffold, the method comprising: forming a socket comprising a groove in a bone of a patient; and inserting the tissue scaffold. In some embodiments, forming further comprises: drilling a guide pin into a bone of a patient; reaming a socket into the bone of the patient; and cutting a groove at a bottom of the socket. In some embodiments, inserting further comprises: compressing the tissue scaffold; inserting the tissue scaffold into the socket; and releasing the tissue scaffold to engage the groove of the socket. In some embodiments, the tissue scaffold is compressed using a scaffold insertion tool.

[0043] In yet another aspect, provided herein is a method of inserting a tissue scaffold, the method comprising: forming a socket in a bone of a patient; and inserting the tissue scaffold. In some embodiments, forming further comprises: drilling a guide pin into a bone of a patient; reaming a socket into the bone of the patient; and cutting a groove at a bottom of the socket. In some embodiments, inserting further comprises: compressing the tissue scaffold; inserting the tissue scaffold into the socket; and releasing the tissue scaffold to engage the groove of the socket. In some embodiments, the tissue scaffold is compressed using a scaffold insertion tool. [0044] In yet another aspect, provided herein is a method of inserting a tissue scaffold, the method comprising: forming a threaded socket; and threading the tissue scaffold into the socket. In some embodiments, the forming further comprises: tapping a thread along the socket. In some embodiments, the forming further comprises drilling a guide pin into a bone of a patient. In some embodiments, the tapping is guided by the guide pin. In some embodiments, the tissue scaffold comprises at least one cutout slot in the threaded portion. In some embodiments, the tissue scaffold is inserted using an insertion tool configured to engage the at least one cutout slot of the tissue scaffold. In some embodiments, the tissue scaffold is threaded into the socket with a scaffold insertion tool.

[0045] Additional aspects and advantages of the present disclosure will become readily apparent to those skilled in this art from the following detailed description, wherein only illustrative embodiments of the present disclosure are shown and described. As will be realized, the present disclosure is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

INCORPORATION BY REFERENCE

[0046] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. To the extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and/or take precedence over any such contradictory material. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings (also “Figure” and “FIG.” herein), of which:

[0048] FIGS. 1A-1C illustrate several embodiments of a tissue scaffold comprising a scaffold region and an attachment element.

[0049] FIGS. 2A and 2B illustrate a skew view and a side view of a tissue scaffold comprising a scaffold region and an attachment element in a snap ring configuration.

[0050] FIG. 3 illustrates a top view and a side view of a tissue scaffold comprising a scaffold region and an attachment element in a snap ring configuration.

[0051] FIGS. 4A and 4B illustrate a top view, a side view, and a cross section of a tissue scaffold comprising a scaffold region and an attachment element in a snap ring configuration. [0052] FIGS. 5A-5C illustrate additional side views and a skew view of a tissue scaffold comprising a scaffold region and an attachment element in a snap ring configuration.

[0053] FIG. 5D illustrates a top view (bottom left panel), a front view (top left panel), a left view (top right panel), and a trimetric view (bottom right panel) of the tissue scaffold with an attachment element in a snap ring configuration.

[0054] FIG. 6 illustrates drilling a socket into a bone of a patient.

[0055] FIG. 7 illustrates comparing a drilled socket to a tissue scaffold trial reference.

[0056] FIG. 8 illustrates a tool used to cut a groove in a socket.

[0057] FIG. 9 illustrates cutting a groove in a socket.

[0058] FIGS. 10A-10C illustrate the bone of a patient after drilling a socket, comparing the socket to an tissue scaffold trial reference, and after cutting a groove in the socket.

[0059] FIG. 11 illustrates a tissue scaffold retained in a tissue of a patient.

[0060] FIGS. 12A and 12B illustrate a skew view and a side view of a tissue scaffold comprising a scaffold region and an attachment element in a press-fit ring configuration.

[0061] FIG. 13 illustrates a top view and a side view of a tissue scaffold comprising a scaffold region and an attachment element in a press-fit ring configuration.

[0062] FIGS. 14A and 14B illustrate a top view, a side view, and a cross section of a tissue scaffold comprising a scaffold region and an attachment element in a press-fit ring configuration. [0063] FIGS. 15A and 15B illustrate skew views of additional embodiments of a tissue scaffold comprising a scaffold region and an attachment element in a press-fit ring configuration. [0064] FIGS. 16A and 16B illustrate additional side and skew views of a tissue scaffold comprising a scaffold region and an attachment element in a press-fit ring configuration. [0065] FIG. 16C illustrates a top view (bottom left panel), a front view (top left panel), a left view (top right panel), and a trimetric view (bottom right panel) of an exemplary tissue scaffold having an attachment element in a press-fit ring configuration.

[0066] FIG. 16D illustrates a top view (bottom left panel), a front view (top left panel), a left view (top right panel), and a trimetric view (bottom right panel) of an alternative exemplary tissue scaffold having an attachment element in a press-fit ring configuration.

[0067] FIGS. 17A and 17B illustrate a tool for insertion of a scaffold implant into a tissue of a patient.

[0068] FIGS. 18A and 18B illustrate skew views of a tissue scaffold comprising a threaded attachment element.

[0069] FIGS. 19A and 19B illustrate a top view and a side view of a tissue scaffold comprising a threaded attachment element.

[0070] FIGS. 20A and 20B illustrate a top view, a side view, and a cross section of a tissue scaffold comprising a threaded attachment element.

[0071] FIGS. 21A-21C illustrate additional side views and a skew view of a tissue scaffold comprising a threaded attachment element.

[0072] FIG. 21D illustrates a top view (bottom left panel), a front view (top left panel), a left view (top right panel), and a trimetric view (bottom right panel) of a tissue scaffold comprising a threaded attachment element.

[0073] FIG. 22 illustrates a tool used to tap a thread in a tissue of a patient.

[0074] FIG. 23 illustrates tapping a thread in a tissue of a patient.

[0075] FIG. 24 illustrates an insertion tool used to thread a tissue scaffold into a tissue of a patient.

[0076] FIG. 25 illustrates a tissue scaffold insertion tool configured to compress a tissue scaffold.

[0077] FIGS. 26A-26F summarize the histologically observed effects of 3D printed nTP.

[0078] FIG. 27 illustrates H&E staining of cartilage and nTP samples taken from goat medial femoral condyle implantation sites after 4 months.

[0079] FIGS. 28A-28C illustrate H&E, Masson’s Tri chrome and Safranin-0 staining of one of the microfracture groups, Animal 1502.

[0080] FIGS. 29A-29C illustrate H&E, Masson’s Tri chrome and Safranin-0 staining of one of the tissue scaffold implant groups, Animal 2503. [0081] FIG. 30 illustrates a three-month relook arthroscopy with gross morphology comparison of microfracture control and tissue scaffold.

[0082] FIG. 31 illustrates cartilage and bone observed at 8-month equine study.

[0083] FIG. 32 illustrates an instrument set designed for surgical purposes.

[0084] FIGS. 33A-33E illustrate the sequential use of the instrument set of FIG. 32 in a surgical procedure.

DETAILED DESCRIPTION

[0085] While various embodiments of the invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed.

[0086] Whenever the term “at least,” “greater than,” or “greater than or equal to” precedes the first numerical value in a series of two or more numerical values, the term “at least,” “greater than” or “greater than or equal to” applies to each of the numerical values in that series of numerical values. For example, greater than or equal to 1, 2, or 3 is equivalent to greater than or equal to 1, greater than or equal to 2, or greater than or equal to 3.

[0087] Whenever the term “no more than,” “less than,” or “less than or equal to” precedes the first numerical value in a series of two or more numerical values, the term “no more than,” “less than,” or “less than or equal to” applies to each of the numerical values in that series of numerical values. For example, less than or equal to 3, 2, or 1 is equivalent to less than or equal to 3, less than or equal to 2, or less than or equal to 1.

[0088] Certain inventive embodiments herein contemplate numerical ranges. When ranges are present, the ranges include the range endpoints. Additionally, every sub range and value within the range is present as if explicitly written out. The term “about” or “approximately” may mean within an acceptable error range for the particular value, which will depend in part on how the value is measured or determined, e.g., the limitations of the measurement system. For example, “about” may mean within 1 or more than 1 standard deviation, per the practice in the art. Alternatively, “about” may mean a range of up to 20%, up to 10%, up to 5%, or up to 1% of a given value. Where particular values are described in the application and claims, unless otherwise stated the term “about” meaning within an acceptable error range for the particular value may be assumed.

Detailed Description [0089] FIGS. 1A-1C illustrate several embodiments of a tissue scaffold comprising a scaffold region 101 and an attachment element 102. In some embodiments, the attachment element may be shaped to engage a tissue of a patient. In some embodiments, the scaffold region may be shaped to engage a tissue of a patient. The scaffold region and the attachment region may comprise a similar or dissimilar shape. A shape may comprise a cylinder, sphere, rectangular prism, hollow tube, toroid, or combinations thereof. A shape may be amorphous. A tissue scaffold may be at least about 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 ,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or at least about 30 millimeters (mm) in length or width. A tissue scaffold may be at least about 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 ,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or at least about 30 millimeters (mm) in depth. A tissue scaffold may be at least about 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 ,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or at least about 30 millimeters (mm) in diameter.

[0090] In some embodiments, the scaffold region is compressible. In some embodiments, the attachment element is compressible. In some embodiments, both the scaffold region and the attachment element are compressible. The scaffold region and the attachment element may comprise individual mechanical characteristics, such as rigidity or compressibility. The tissue scaffold may comprise an overall rigidity based at least in part on an interaction of the scaffold region with the attachment element. In some embodiments, the tissue scaffold may be compressible by at least about 5%, 10%, 15%, 20%, 25%, 30%, 40%, 45%, or at least about 50%. The tissue scaffold may comprise a Young’s modulus of at least about 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 400, 500, 600, 700, 800, 900, or at least about 1000 kiloPascals (kPa). The tissue scaffold may comprise a Young’s modulus of at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, or at least about 50 megaPascals (MPa).

[0091] In some embodiments, the scaffold region may comprise a polycarbonate, an aliphatic polyester, an aromatic polyester, a polyurethane, a polyamide, a polyvinyl alcohol (PVA), a lactide, a polyolefin, or combinations thereof. In some embodiments, a polyurethane may be a thermoplastic polyurethane. In some embodiments, a lactide may be a linear lactide. In some embodiments, a lactide may be an aromatic lactide. In some embodiments, the scaffold region may comprise a polyvinyl alcohol composite material. In some embodiments, the scaffold region may comprise a polymer with a solubility in an aqueous environment that is greater than polyvinyl alcohol. In some embodiments, the scaffold region may comprise a polymer with a degradation rate in an aqueous environment that is greater than polyvinyl alcohol. In some embodiments, the scaffold region may comprise a combination of a water soluble material and a material that is not water-soluble. In some embodiments, the scaffold region may comprise a combination of a material that degrades in water and a material that does not degrade in water. In some embodiments, the scaffold region may comprise a material with a degradation rate in water that is at least 5 times slower than the degradation rate of polyvinyl alcohol in water.

[0092] In some embodiments, the attachment element may comprise a polycarbonate, an aliphatic polyester, an aromatic polyester, a polyurethane, a polyamide, a polyvinyl alcohol (PVA), a lactide, a polyolefin, or combinations thereof. In some embodiments, a polyurethane may be a thermoplastic polyurethane. In some embodiments, a lactide may be a linear lactide. In some embodiments, a lactide may be an aromatic lactide. In some embodiments, the attachment element may comprise a polyvinyl alcohol composite material. In some embodiments, the attachment element may comprise a polymer with a solubility in an aqueous environment that is greater than polyvinyl alcohol. In some embodiments, the attachment element may comprise a polymer with a degradation rate in an aqueous environment that is greater than polyvinyl alcohol. In some embodiments, the attachment element may comprise a combination of a water soluble material and a material that is not water-soluble. In some embodiments, the attachment element may comprise a combination of a material that degrades in water and a material that does not degrade in water. In some embodiments, the attachment element may comprise a material with a degradation rate in water that is at least 5 times slower than the degradation rate of polyvinyl alcohol in water.

[0093] In some embodiments, the scaffold region and the attachment element comprise the same material. In some embodiments, the scaffold region may comprise a plurality of layers. In some embodiments, the scaffold region may comprise a one, two three, or more subregions. The subregions may comprise differences in porosities, densities, layer patterns, materials, mechanical characteristics, or combinations thereof. The subregions may be divided by differences between layers of the plurality of layers. In some embodiments, a subregion may be configured to support cell encapsulation, to support a cartilage defect, to facilitate engraftment of repair tissue to bone, to engage a tissue of a patient, or combinations thereof.

[0094] The attachment element may comprise a greater density than the scaffold region. The attachment element may comprise a lower density than the scaffold region. In some embodiments, the attachment element may be solid. In some embodiments, the scaffold region may be porous.

[0095] In some embodiments, the scaffold region and the attachment element may comprise a unitary body. In some embodiments, the scaffold region and the attachment element may be assembled together as a unitary body. The assembly may be accomplished by 3D printing the scaffold region and the attachment element as a unified body. 3D printing may include fused filament fabrication, fused layer deposition, stereolithography, selective laser sintering, or multijet fusion.

[0096] In some embodiments, the attachment element joins to the scaffold region at a face of the scaffold region. A face may comprise a flat portion of the scaffold region. In some embodiments, the attachment element joins to the scaffold region along a curved surface of the scaffold region. In some embodiments, an attachment element encapsulates at least a portion of a scaffold region. Encapsulation may comprise surrounding at least a portion of the scaffold region. The encapsulation may be partial or complete. The encapsulated scaffold region may be surrounded by the attachment element around a plane of the scaffold region. The encapsulated scaffold region may be surrounded by the attachment element along the intersection of an exterior surface of the scaffold region and a plane that intersects the scaffold region. The plane may intersect along an x, y, or z axis, or along a longitudinal or radial axis. In some embodiments, the attachment element comprises a geometry. The geometry may be a ring, a toroid, a thread, a rectangle, a shape rotated around a circumference of the scaffold region, or a combination thereof. The geometry may be a radial geometry.

[0097] In some embodiments, the tissue scaffold comprises a recessed portion. The recessed portion may comprise a cylindrical shape, a rectangular shape, an elliptical shape, or a combination thereof. The recessed portion may be formed by the scaffold region. The recessed portion may be formed by the attachment element. The recessed portion may be formed by the combination of the geometries of the scaffold region and the attachment element. The depth of the recess may be at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or at least about 20 millimeters (mm) thick. The recessed portion may be configured to engage a tissue of a patient. The recessed portion may be shaped to receive a tissue plug in a patient. A tissue plug in a patient may be shaped to insert into a recessed portion of a tissue scaffold. A tissue plug may comprise a bone plug. A tissue plug may comprise a socket.

[0098] FIG. 1A illustrates a tissue scaffold comprising an attachment element in a snap ring configuration. In some embodiments, the attachment element may comprise a geometry with at least one retaining tab. A retaining tab may be a protrusion from the attachment element. In some embodiments, the retaining tab comprises a face of the geometry extruded radially. In some embodiments, a retaining tab protrudes at least about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or at least about 2.0 millimeters (mm) from the surface of the scaffold region. In some embodiments, a retaining tab protrudes less than about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or less than about 2.0 millimeters (mm) from the surface of the scaffold region. The retaining tab may be extruded in a shape to engage a tissue of a patient. The retaining tab may be shaped to fit a groove in a patient. The groove may be cut in a tissue in a circular shape, an elliptical shape, a rectangular shape, or a shape resulting from the combinations of two or more shapes. The attachment element may comprise 1, 2, 3, 4, 5, 6, or more retaining tabs. The attachment element may join at a face of the scaffold region, or encapsulate at least a portion of the tissue scaffold.

[0099] FIG. IB illustrates a tissue scaffold comprising an attachment element in a press-fit configuration. In some embodiments, an attachment element comprises one or more press-fit rings. The press fit rings may encapsulate at least a portion of the scaffold region. In some embodiments, a press-fit ring protrudes at least about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or at least about 2.0 millimeters (mm) from the surface of the scaffold region. In some embodiments, a press-fit ring protrudes less than about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or less than about 2.0 millimeters (mm) from the surface of the scaffold region. In some embodiments, an attachment element comprises multiple press fit rings. The press fit rings may be spaced along the scaffold region. In some embodiments, a press-fit ring comprises a face rotated along the intersection of a surface of a scaffold region and a plane. The face may comprise a rectangle, a circle, an ellipse, a polygon, or a combination thereof. In some embodiments, a press-fit ring diameter is about 1 mm larger than the diameter of a prepared socket in a patient’s tissue. In some embodiments the difference in diameter between a press-fit ring and a prepared socket may provide press-fit fixation of the tissue scaffold in a patient’s tissue.

[0100] In some embodiments, an attachment element comprises a threaded portion. FIG. 1C illustrates a tissue scaffold comprising a threaded attachment element with two rectangular cutouts to receive an insertion tool. In some embodiments, the threaded portion encapsulates at least a portion of the scaffold region. In some embodiments, the threaded portion runs along the entire length of the scaffold region, or along part of the length of the scaffold region. In some embodiments, the thread is a double start thread. The threaded portion may comprise a 16mm diameter x 3 mm pitch thread. The threaded portion may comprise a SP4 Bottle thread. The threaded portion may comprise a Unified Thread Standard thread pitch and diameter. The threaded portion may comprise a Unified National Special Thread pitch and diameter. The thread pitch and diameter may be tapered or standard. The thread pitch and diameter may a modified Unified National Special Thread pitch and diameter. The thread pitch and diameter may a modified Unified Thread Standard thread pitch and diameter. In some embodiments, the tissue scaffold comprises one or more insertion slots. The insertion slot may be shaped according to a cutout in the tissue scaffold. The cutout may be a rectangular cutout, a circular cutout, a triangular cutout, or combinations thereof. The insertion slot may receive an insertion tool for rotating the tissue scaffold. In some embodiments the path of a threaded portion of the attachment element may be interrupted by a cutout.

[0101] In one aspect, provided herein is a tissue scaffold comprising an attachment element in a snap-ring configuration. In some cases, the tissue scaffold comprises a scaffold region; and a fixation region, wherein the fixation region comprises at least one retention tab configured to engage with at least one groove or socket prepared on a host tissue. In some cases, the tissue scaffold is compressible to a compressed state. In some cases, the tissue scaffold is, after being compressed, capable of expanding to an expanded state. In some cases, the tissue scaffold in the expanded state is within at least about 90% of an original size of the tissue scaffold. In some cases, the at least one retention tab is configured to engage the groove or socket prepared in the host tissue when the tissue scaffold is in the expanded state. In some cases, the fixation region has two retention tabs, each retention tab of the two retention tabs disposed on opposing sides of the tissue scaffold. In some cases, the fixation region comprises three or more retention tabs. In some cases, the fixation region is circular or substantially circular in shape. In some cases, the at least one retention tab comprises a protrusion which extends in a radial direction from the fixation region. In some cases, the protrusion is configured to contact the groove or socket and anchor the tissue scaffold into the groove or socket. In some cases, a top surface of the fixation region is attached to a bottom surface of the scaffold region. In some cases, the fixation region is solid. In some cases, the fixation region has an infill density of about 100%. In some cases, the fixation region comprises a plurality of layers. In some cases, the fixation region comprises 2 to 10 layers. In some cases, the fixation region comprises 2 to 80 layers. In some cases, the fixation region is about 0.8 mm to about 8.0 mm in thickness. In some cases, the fixation region comprises a cylindrical pocket. In some cases, the cylindrical pocket is sized and shaped to accept a bone post in the host tissue. In some cases, the fixation region is a substantially circular body having an upper surface, a lower surface, a thickness extending between the upper and lower surfaces, and a central through-hole extending along an axis perpendicular to the plane of the fixation region. In some cases, the scaffold region and the fixation region are integrally formed as a single unit. In some cases, the scaffold region and the fixation region are manufactured using a three-dimensional printing process.

[0102] FIGS. 2A and 2B illustrate a skew view and a side view of a tissue scaffold comprising a scaffold region and an attachment element in a snap ring configuration. The attachment element may comprise at least retention tab. In some embodiments the attachment element may comprise, 1, 2, 3, or more retention tabs. The attachment element may be shaped to engage a tissue of a patient. In some embodiments, the attachment element may comprise a convex top surface. The top surface may be flexible. The top surface may contour to a patient’s anatomy. FIG. 2A illustrates a skew view of a tissue scaffold comprising an attachment element in a snap ring configuration, in which a cylindrical recessed portion of the tissue scaffold can be seen. FIG. 2B illustrates a side view of a tissue scaffold comprising an attachment element in a snap ring configuration. The scaffold region 201 may comprise subregions. The subregions may comprise a top layer 202, and a layered lattice 203. The top layer 202 may comprise a thickness of 0.2 to 1.0 mm. The top layer 202 may comprise a thickness of 0.2 mm. The top layer 202 may comprise one layer, or multiple layers. The layered lattice 203 may comprise a thickness of 0.8 to 4.0 mm. The layered lattice 203 may comprise a thickness of 1.8 mm. The layered lattice 203 may comprise from about 4 layers to about 40 layers. The attachment element 204 may comprise a thickness of 0.8 to 8.0 mm. The attachment element 204 may comprise a thickness of 2.0 mm. The attachment element 204 may comprise from about 4 layers to about 80 layers.

[0103] FIG. 3 illustrates a top view and a side view of a tissue scaffold 300 comprising a scaffold region and an attachment element in a snap ring configuration. The attachment element may comprise a first retention tab 301 to engage a tissue of a patient, and may further comprises a second retention tab 302.

[0104] FIGS. 4A and 4B illustrate a top view, a side view, and a cross section of a tissue scaffold comprising a scaffold region and an attachment element in a snap ring configuration. FIG. 4A illustrates a side view and a cross section view of a tissue scaffold. The tissue scaffold can comprise at least two porous surfaces that facilitate cartilage ingrowth. These surfaces can be a tissue scaffold periphery 401, and a tissue scaffold bottom 402. The tissue scaffold shown comprises a recessed portion 403. FIG 4B illustrates a top view of the tissue scaffold.

[0105] FIGS. 5A-5D illustrate additional of a tissue scaffold comprising a scaffold region and an attachment element in a snap ring configuration. FIG. 5A is a first side view. FIG. 5B is a second side view rotated at 90 degrees to the first side view. FIG. 5C is skew view of the top of the tissue scaffold. FIG. 5D shows a top view (bottom left panel), a front view (top left panel), a left view (top right panel), and a trimetric view (bottom right panel) of the tissue scaffold.

[0106] FIG. 6 illustrates drilling a socket into a bone of a patient. A guide pin 601 may be drilled into a tissue of a patient 602. The tissue can comprise cartilage, bone, or a combination thereof. A tissue may comprise a femur, tibia, patella, acetabulum, or other bones. A reamer 603 may then drill a socket 604 into the tissue. The reamer may be guided by the guide pin. In some embodiments, a punch can be used to prepare the implantation site. This step involves sliding the punch over the Guide Pin to score the implantation site tissue, thereby separating it from the adjacent cartilage prior to reaming. The punch, slid over the Guide Pin, scores the implantation site tissue creating a small grove or depression. In some embodiments, the punch can be in a size of 10, 15, or 20. In some embodiments, a Sizing/ Alignment Guide ca be used, which serves two essential functions. Firstly, it can be used to measure the chondral lesion, providing the surgeon with the necessary information to choose an appropriately sized implant. Secondly, it can aid in establishing the orientation of the implant, ensuring its correct positioning. In some embodiments, the alignment guide can be in a size of 10, 12.5, 15, 17.5 or 20.

[0107] In some embodiments, the reamer may comprise teeth at a plurality of cutting depths. The reamer may comprise teeth at 1, 2, 3, 4, or more cutting depths. The reamer may comprise 1, 2, 3, 4, or more cutting teeth. In some embodiments, the reamer has 4 cutting teeth: two outer teeth, and two inner teeth. The outer teeth may prepare an annular (ring shaped) socket at a first depth. The inner teeth may prepare a flat inner region at a second depth. The first depth may be deeper that the second depth. In some embodiments the reamer comprises a depth stop. The depth stop may correspond to a tissue scaffold. The socket may be shaped to receive a tissue scaffold. The tissue scaffold and socket may comprise matching geometries. The socket may support a cylindrical recess in the tissue scaffold.

[0108] FIG. 7 illustrates comparing a drilled socket to a tissue scaffold trial reference 701. In some embodiments, the tissue scaffold trial reference can comprise an end matching the geometry of the tissue scaffold. The tissue scaffold trial reference may fit over the guide pin and into the socket. A surgeon can evaluate the size and depth of the socket based at least in part on the tissue scaffold trial reference. A surgeon can make an adjustment to the socket based on a comparison of the socket to the tissue scaffold trial reference.

[0109] FIG. 8 illustrates a bone preparation tool 800 used to cut a groove in a socket. In some embodiments, the bone preparation comprises an undercut tool. The bone preparation may comprise an end comprising at least 1, 2, 3, 4, 5, or 6 cutting teeth 801. The cutting teeth may be configured to cut bone. The teeth may face outward. The teeth may face inward. The bone preparation tool may comprise a cannula, the cannula may match the guide pin. The cannula may extend beyond the bone preparation end comprising teeth. The bone preparation end comprising teeth may be compressible. The bone preparation tool may comprise a plurality of cutouts 802 at the end comprising teeth. The cutouts may provide space for the bone preparation end comprising teeth to compress. The cutouts may be triangular.

[0110] FIG. 9 illustrates forming a groove in a socket. Forming a groove may comprise inserting the bone preparation tool; and cutting a groove. In some embodiments, inserting the bone preparation tool may comprise: compressing a bone preparation tool to retract the cutting teeth and inserting the bone preparation tool into the socket. Inserting may further comprise placing the bone preparation tool over a guide pin. Cutting a groove may comprise rotating the bone preparation tool to cut a groove in the bone. Cutting a groove may further comprise decompressing the bone preparation tool to extend the teeth. In some embodiments, the bone preparation tool may be compressed to retract the teeth and then removed from the socket.

[0111] FIG. 10A illustrates a cross sectional view of the bone 1001 of a patient after drilling a socket 1002, with a guide pin 1003 in place. FIG. 10B illustrates an exterior view of a tissue scaffold trial reference 1004 engaged in a socket 1002, and after cutting a groove in the socket. FIG. 10C illustrates a cross sectional view of the bone 1001 of a patient after drilling cutting a groove 1005 into a socket 1002, with a guide pin 1003 in place. The socket may be shaped to receive a tissue scaffold.

[0112] FIG. 11 illustrates a tissue scaffold 1101 retained in a tissue of a patient. The tissue scaffold may be engaged in the tissue of the patient based at least in part on the matching shape of the socket and the tissue scaffold.

[0113] In another aspect, provided herein is a tissue scaffold comprising an attachment element in a press-fit ring configuration. In some cases, the tissue scaffold comprises a scaffold region; and at least one press-fit ring configured to engage with at least one socket prepared on a host tissue. In some cases, the at least one press-fit ring is configured to have an interference fit with the host tissue. In some cases, the socket is a bone socket. In some cases, the at least one press- fit ring is at least two press-fit rings. In some cases, each press-fit ring of the at least two press- fit rings is separated by a distance of at least 0.05mm. In some cases, the at least one press-fit ring has a ring-like structure. In some cases, the at least one press-fit ring is disposed along the outer circumference of the tissue scaffold. In some cases, an outer surface of the at least one press-fit ring is configured to contact the host tissue and anchor the tissue scaffold into the host tissue. In some cases, the at least one press-fit ring is solid. In some cases, the at least one press- fit ring has an infill density of about 100%. In some cases, the scaffold region and the at least one press-fit ring are integrally formed as a single unit. In some cases, the scaffold region and the at least one press fit ring are manufactured using a three-dimensional printing process.

[0114] FIG. 12A illustrates a skew view of the top of a tissue scaffold comprising a scaffold region and an attachment element in a press-fit ring configuration. FIG. 12B illustrates a skew view of the bottom of the tissue scaffold. In some embodiments, a press-fit ring diameter is about 1 mm larger than the diameter of a prepared socket in a patient’s tissue. In some embodiments the difference in diameter between a press-fit ring and a prepared socket may provide press-fit fixation of the tissue scaffold in a patient’s tissue.

[0115] FIG. 13 illustrates a top view and a side view of a tissue scaffold comprising a scaffold region 1301 and an attachment element in a press-fit ring configuration 1302.

[0116] FIG. 14A illustrates a side view and a cross section view of a tissue scaffold with an attachment element comprising a press-fit ring configuration. In some embodiments, the tissue scaffold can comprise at least two porous surfaces that facilitate cartilage ingrowth. These surfaces can be a tissue scaffold periphery 1401, and a tissue scaffold bottom 1402. The tissue scaffold shown comprises a recessed portion 1403. FIG 14B illustrates a top view of the tissue scaffold.

[0117] FIG. 15A illustrates a skew view of the bottom an embodiment of a tissue scaffold comprising a scaffold region and an attachment element in a press-fit ring configuration, wherein there are three press-fit rings. FIG. 15B illustrates a skew view of the top of the tissue scaffold comprising three press-fit rings.

[0118] FIG. 16A illustrates a side view of a tissue scaffold comprising a scaffold region and an attachment element in a press-fit ring configuration. FIG. 16B illustrates a skew view of a tissue scaffold comprising a scaffold region and an attachment element in a press-fit ring configuration. FIG. 16C illustrates a top view (bottom left panel), a front view (top left panel), a left view (top right panel), and a trimetric view (bottom right panel) of a tissue scaffold with an attachment element in a press-fit ring configuration. FIG. 16D illustrates a top view (bottom left panel), a front view (top left panel), a left view (top right panel), and a trimetric view (bottom right panel) of an tissue scaffold with an attachment element in a press-fit ring configuration, wherein the bottom-most press-fit ring has a beveled edge.

[0119] FIG. 17A and FIG. 17B illustrates a tool 1700 for insertion of a scaffold implant into a tissue of a patient. The insertion tool may comprise a cylindrical shaft 1701 comprising: an inner pushing portion 1702; a hollow distal end comprising a pocket 1703 wherein the pushing portion 1702 contacts the pocket; and a button 1704 mechanically connected to the hollow distal end. The pocket may be configured to receive a tissue scaffold 1705. In some embodiments, the pocket can be cylindrical. The pocket can be about 1, 2, 3, 4, 5 or 6 mm deep. The pocket can be at most as deep as the length of a tissue scaffold. The pocket may hold the top half of a tissue scaffold. The tissue scaffold may comprise an attachment element in a press-fit ring configuration. The pushing portion may contact the tissue scaffold when inserted into the pocket. In some embodiments, the hollow distal end may comprise a tube 1706. The tube may comprise 1, 2, 3, 4, or more relief flutes 1707. The tube may flex and receive the implant while applying a clamping force to hold the implant. In some embodiments, pushing the button retracts the tube. The retraction of the tube may cause the tissue scaffold to be pushed out of the hollow distal end by the pushing portion. A surgeon can place the implant into a socket, press the button to retract the tube, and then place the implant all the way in. In some embodiments, the surgeon may place the implant halfway into the socket, or about 2mm into the socket. In some embodiments, the surgeon may place the implant with one hand while holding an arthroscopic camera (or other instrument) with their other hand.

[0120] In another aspect, provided herein is a tissue scaffold comprising a threaded attachment element. In some cases, the tissue scaffold comprises a scaffold region; and a fixation region comprising at least one circumferential thread configured to engage with at least one groove or socket prepared on a host tissue. In some cases, the at least one circumferential thread is configured for secure fixation of the tissue scaffold on the host tissue. In some cases, the at least one circumferential thread comprises at least two circumferential threads. In some cases, the at least two circumferential threads are extended along an outer surface of the scaffold region and an outer surface of the fixation region. In some cases, the at least two circumferential threads are two helical threads extended symmetrically around a central axis of the scaffold region and a central axis of the fixation region. In some cases, the two helical threads are extended along an outer surface of the scaffold region and an outer surface of the fixation region, wherein the helical threads have a predetermined pitch and/or lead angle. In some cases, the two helical threads have two opposite cut-out portions configured to provide two insertion slots for engaging a tool to facilitate the rotation of the tissue scaffold. In some cases, the two opposite cut-out portions are extended partially along the outer surface of the scaffold region and the outer surface of the fixation region, wherein the two opposite cut-out portions are parallel with the central axis of the scaffold region and the central axis of the fixation region.

[0121] FIGS. 18A and 18B illustrate skew views of a tissue scaffold comprising a threaded attachment element. In some embodiments, the thread is a double start thread. In some embodiments, the thread is a 16mm diameter x 3 mm pitch thread. In some embodiments, the thread is a SP4 Bottle thread. FIG. 18A illustrates a top skew view, and FIG. 18B illustrates a bottom skew view.

[0122] FIGS. 19A and 19B illustrate a top view and a side view of a tissue scaffold comprising a attachment element comprising threads 1901. In some embodiments, the tissue scaffold comprises one or more insertion slots 1902. The insertion slot may be a cutout in the tissue scaffold. The insertion slot may receive a tool for rotating the tissue scaffold. [0123] FIG. 20A illustrates a side view and a cross section view of a tissue scaffold comprising a threaded attachment element. In some embodiments, the tissue scaffold can comprise at least two porous surfaces that facilitate cartilage ingrowth. These surfaces can be a tissue scaffold periphery 2001, and a tissue scaffold bottom 2002. The tissue scaffold shown comprises a recessed portion 2003. FIG 20B illustrates a top view of the tissue scaffold.

[0124] FIGS. 21A-C illustrate additional side views and a skew view of a tissue scaffold comprising a threaded attachment element. FIG. 21A is a first side view. FIG. 21B is a second side view rotated at 90 degrees to the first side view. FIG. 21C is skew view of the top of the tissue scaffold. FIG. 21D illustrates a top view (bottom left panel), a front view (top left panel), a left view (top right panel), and a trimetric view (bottom right panel) of a tissue scaffold comprising a threaded attachment element.

[0125] FIG. 22 illustrates a tapping tool 2200 used to tap a thread in a tissue of a patient. The tool may comprise cutting threads 2201. The tool may be cannulated and may fit over a guide pin. The tool may comprise flutes 2202 to trap tissue removed by the cutting threads 2201. In some embodiments the tool comprises 4, 5, 6, 7, 8, or more flutes. The tool may cut threads in bone, cartilage, or other tissue by being rotated.

[0126] FIG. 23 illustrates tapping a thread in a tissue of a patient. A tapping tool 2301 may be inserted over a guide pin 2302 and rotated to cut a thread in a tissue of a patient 2303.

[0127] FIG. 24 illustrates an insertion tool 2400 used to thread a tissue scaffold into a tissue of a patient. The insertion tool may comprise a cylindrical shaft 2401; an end of the cylindrical shaft comprising a receiving end 2402 configured to receive a tissue scaffold 2403; and one or more engagement tines 2404 running parallel to the length of the shaft 2401 and each comprising a proximal end 2405, a middle portion 2406, and a distal end 2407. The one or more engagement tines may be configured to engage one or more insertion slots 2408 of a tissue scaffold. In some embodiments, applying pressure to the middle portion 2406 can engage or disengage a tissue scaffold from the distal end 2407 of the engagement tines. In some embodiments, the proximal ends 2405 may be connected to the shaft. The insertion tool may be used to engage an insertion slot 2408 and rotate a tissue scaffold 2403. The socket may be threaded. Rotating the tissue scaffold may screw the implant into the socket.

[0128] FIG. 25 illustrates a tissue scaffold insertion tool 2500 configured to compress a tissue scaffold 2501. In some embodiments, the insertion tool comprises tips or tines 2502 that are optimized for the shape of a tissue scaffold. In some embodiments, the tissue scaffold insertion tool comprises: a first lever portion 2503 comprising a first distal end 2504, a first middle portion 2505, and a first proximal end 2506, wherein the first distal end comprises a first compression tine 2507; and a second lever portion 2508 comprising a second distal end 2509, a second middle portion 2510, and a second proximal end 2511, wherein the second distal end comprises a second compression tine 2512; wherein the first lever portion 2503 and second lever portion 2508 are pivotally coupled at the first middle portion 2504 and the second middle portion 2510, wherein the first compression tine 2507 and the second compression tine 2512 are configured to engage a portion of a tissue scaffold 2501. In some embodiments, the tissue scaffold is compressible. In some embodiments, the tissue scaffold comprises a snap ring configuration.

[0129] A tissue scaffold may comprise a scaffold region. The scaffold region may be made from new tissue growth materials and designs compatible with fused filament fabrication additive manufacturing. The scaffold region may comprise 3D printable synthetic bone, vascular, and cartilage structure from these materials. The tissue scaffold may be efficacious and safe for a human clinical trial.

[0130] In some embodiments, the tissue scaffold may comprise printable materials. The printable materials may comprise polyurethane, thermoplastic polyamide (TP), polyvinyl alcohol composite materials, or combinations thereof. The materials may be optimized for 3D printing and biological use. In some cases, PVA dissolves in the presence of water, leaving only the soft TP material. This material may be processed and exhibit analogous mechanical properties to native cartilage as well as an aligned nonporous topography. The tissue scaffold be comprise a 3D printed microporous structure. The 3D printed microporous structure may comprise materials to create a hierarchical micro-to-nano porosity. The micro-to-nano porosity may be extremely advantageous for stem cell recruitment, growth and differentiation.. 3D printed microporous structure may have physical characteristics, compressive and elastic properties very similar to native cartilage at the osteochondral region. These characteristics may accelerate the formation of new bone and vascular networks. The tissue scaffold may be 3D printed to form a transitional structure which looks like osteochondral tissue. The tissue scaffold may replace the function of the lost cartilage. The tissue scaffold may induce new vascularized subchondral bone to form in the tissue scaffold, anchoring it permanently in place and repairing an articular surface of a patient. The tissue scaffold may support mechanical loading similar to native bone and cartilage. The tissue scaffold may promote fast and efficient fluid perfusion, namely of arterial blood, throughout the tissue scaffold.

Numbered Embodiments

[0131] The following embodiments recite nonlimiting permutations of combinations of features disclosed herein. Other permutations of combinations of features are also contemplated. In particular, each of these numbered embodiments is contemplated as depending from or relating to every previous or subsequent numbered embodiment, independent of their order as listed.

[0132] Embodiment 1 : A tissue scaffold comprising: (a) a scaffold region; and (b) at least one press-fit ring configured to engage with at least one socket prepared on a host tissue.

[0133] Embodiment 2: The tissue scaffold of embodiment 1, wherein the tissue scaffold is configured to have an interference fit with the host tissue.

[0134] Embodiment 3: The tissue scaffold of embodiment 1 or 2, wherein the socket is a bone socket.

[0135] Embodiment 4: The tissue scaffold of any one of embodiments 1-3, wherein the at least one press-fit ring is at least two press-fit rings.

[0136] Embodiment 5: The tissue scaffold of embodiment 4, wherein each press-fit ring of the at least two press-fit rings is separated by a distance of at least 0.05mm.

[0137] Embodiment 6: The tissue scaffold of any one of embodiments 1-5, wherein the at least one press-fit ring has a ring-like structure.

[0138] Embodiment 7: The tissue scaffold of any one of embodiments 1-6, wherein the at least one press-fit ring is disposed along the outer circumference of the tissue scaffold.

[0139] Embodiment 8: The tissue scaffold of any one of embodiments 1-7, wherein an outer surface of the at least one press-fit ring is configured to contact the host tissue and anchor the tissue scaffold into the host tissue.

[0140] Embodiment 9: The tissue scaffold of any one of embodiments 1-8, wherein the at least one press-fit ring is solid.

[0141] Embodiment 10: The tissue scaffold of any one of embodiments 1-9, wherein the at least one press-fit ring has an infill density of about 100%.

[0142] Embodiment 11 : The tissue scaffold of any one of embodiments 1-10, wherein the scaffold region and at least one press-fit ring are integrally formed as a single unit.

[0143] Embodiment 12: The tissue scaffold of any one of embodiments 1-11, wherein the scaffold region and the at least one press fit ring are manufactured using a three-dimensional printing process.

[0144] Embodiment 13: A tissue scaffold comprising: (a) a scaffold region; and (b) a fixation region, wherein the fixation region comprises at least one retention tab configured to engage with at least one groove or socket prepared on a host tissue.

[0145] Embodiment 14: The tissue scaffold of embodiment 13, wherein the tissue scaffold is compressible to a compressed state. [0146] Embodiment 15: The tissue scaffold of embodiment 14, wherein the tissue scaffold is, after being compressed, capable of expanding to an expanded state.

[0147] Embodiment 16: The tissue scaffold of embodiment 15, wherein the tissue scaffold in the expanded state is within at least about 90% of an original size of the tissue scaffold.

[0148] Embodiment 17: The tissue scaffold of embodiment 15 or 16, wherein the at least one retention tab is configured to engage the groove or socket prepared in the host tissue when the tissue scaffold is in the expanded state.

[0149] Embodiment 18: The tissue scaffold of any one of embodiments 13-17, wherein the fixation region has two retention tabs, each retention tab of the two retention tabs disposed on opposing sides of the tissue scaffold.

[0150] Embodiment 19: The tissue scaffold of any one of embodiments 13-18, wherein the fixation region comprises three or more retention tabs.

[0151] Embodiment 20: The tissue scaffold of any one of embodiments 13-19, wherein the fixation region is circular or substantially circular in shape.

[0152] Embodiment 21 : The tissue scaffold of any one of embodiments 13-20, wherein the at least one retention tab comprises a protrusion which extends in a radial direction from the fixation region.

[0153] Embodiment 22: The tissue scaffold of embodiment 21, wherein the protrusion is configured to contact the groove or socket and anchor the tissue scaffold into the groove or socket.

[0154] Embodiment 23: The tissue scaffold of any one of embodiments 13-22, wherein a top surface of the fixation region is attached to a bottom surface of the scaffold region.

[0155] Embodiment 24: The tissue scaffold of any one of embodiments 13-23, wherein the fixation region is solid.

[0156] Embodiment 25: The tissue scaffold of any one of embodiments 13-24, wherein the fixation region has an infill density of about 100%.

[0157] Embodiment 26: The tissue scaffold of any one of embodiments 13-25, wherein the fixation region comprises a plurality of layers.

[0158] Embodiment 27: The tissue scaffold of embodiment 26, wherein the fixation region comprises 2 to 10 layers.

[0159] Embodiment 28: The tissue scaffold of embodiment 26, wherein the fixation region comprises 2 to 80 layers.

[0160] Embodiment 29: The tissue scaffold of any one of embodiments 13-28, wherein the fixation region is about 0.8 mm to about 8.0 mm in thickness. [0161] Embodiment 30: The tissue scaffold of any one of embodiments 13-29, wherein the fixation region comprises a cylindrical pocket.

[0162] Embodiment 31 : The tissue scaffold of embodiment 30, wherein the cylindrical pocket is sized and shaped to accept a bone post in the host tissue.

[0163] Embodiment 32: The tissue scaffold of any one of embodiments 13-31, wherein the fixation region is a substantially circular body having an upper surface, a lower surface, a thickness extending between the upper and lower surfaces, and a central through-hole extending along an axis perpendicular to the plane of the fixation region.

[0164] Embodiment 33: The tissue scaffold of any one of embodiments 13-32, wherein the scaffold region and the fixation region are integrally formed as a single unit.

[0165] Embodiment 34: The tissue scaffold of any one of embodiments 13-33, wherein the scaffold region and the fixation region are manufactured using a three-dimensional printing process.

[0166] Embodiment 35: A tissue scaffold comprising: (a) a scaffold region; and (b) a fixation region comprising at least one circumferential thread configured to engage with at least one groove or socket prepared on a host tissue.

[0167] Embodiment 36: The tissue scaffold of embodiment 35, wherein the at least one circumferential thread is configured for secure fixation of the tissue scaffold on the host tissue. [0168] Embodiment 37: The tissue scaffold of embodiment 35 or 36, wherein the at least one circumferential thread comprises at least two circumferential threads.

[0169] Embodiment 38: The tissue scaffold of embodiment 37, wherein the at least two circumferential threads are extended along an outer surface of the scaffold region and an outer surface of the fixation region.

[0170] Embodiment 39: The tissue scaffold of embodiment 37, wherein the at least two circumferential threads are two helical threads extended symmetrically around a central axis of the scaffold region and a central axis of the fixation region.

[0171] Embodiment 40: The tissue scaffold of embodiment 39, wherein the two helical threads are extended along an outer surface of the scaffold region and an outer surface of the fixation region, wherein the helical threads have a predetermined pitch and/or lead angle.

[0172] Embodiment 41 : The tissue scaffold of embodiment 39, wherein the two helical threads have two opposite cut-out portions configured to provide two insertion slots for engaging a tool to facilitate the rotation of the tissue scaffold.

[0173] Embodiment 42: The tissue scaffold of embodiment 41, wherein the two opposite cut-out portions are extended partially along the outer surface of the scaffold region and the outer surface of the fixation region, wherein the two opposite cut-out portions are parallel with the central axis of the scaffold region and the central axis of the fixation region.

[0174] Embodiment 43: A tissue scaffold comprising: a scaffold region; and an attachment element that encapsulates at least a portion of the scaffold region, wherein the attachment element is configured to engage a tissue and hold the tissue scaffold in place.

[0175] Embodiment 44: The tissue scaffold of embodiment 43, wherein the attachment element is a density that is greater than a density of the scaffold region.

[0176] Embodiment 45: The tissue scaffold of embodiment 43 or 44, wherein the attachment element engages a groove or socket in the tissue.

[0177] Embodiment 46: The tissue scaffold of embodiment 45, wherein the groove or socket is circular.

[0178] Embodiment 47: The tissue scaffold of any one of embodiments 43-46, wherein the attachment element engages the tissue by expanding from a compressed state.

[0179] Embodiment 48: The tissue scaffold of any one of embodiments 43-47, wherein the attachment element comprises a radial geometry.

[0180] Embodiment 49: The tissue scaffold of any one of embodiments 43-48, wherein the attachment element comprises a threaded geometry.

[0181] Embodiment 50: A tissue scaffold comprising: a scaffold region; and an attachment element, wherein the attachment element extends in a radial direction from the scaffold.

[0182] Embodiment 51 : The tissue scaffold of embodiment 50, wherein the attachment element extends in a radial direction from a longitudinal axis of the scaffold region.

[0183] Embodiment 52: The tissue scaffold of embodiment 50 or 51, wherein the scaffold region comprises a cylindrical geometry.

[0184] Embodiment 53: The tissue scaffold of any one of embodiments 50-52, wherein the attachment element comprises at least one radial protrusion.

[0185] Embodiment 54: The tissue scaffold of any one of embodiments 50-53, wherein the attachment element comprises a toroidal shape.

[0186] Embodiment 55: The tissue scaffold of any one of embodiments 50-54, wherein the attachment element is attached to an end of the scaffold region.

[0187] Embodiment 56: The tissue scaffold of any one of embodiments 50-55, wherein the attachment element encapsulates a portion of the scaffold region.

[0188] Embodiment 57: The tissue scaffold of any one of embodiments 50-56, wherein the attachment element is configured to engage a tissue. [0189] Embodiment 58: The tissue scaffold of any one of embodiments 50-57, wherein the attachment element has a density that is greater than a density of the scaffold region.

[0190] Embodiment 59: A tissue scaffold comprising: a scaffold region; and an attachment element, wherein the scaffold region and the attachment element are elastically compressible, and wherein the attachment element holds the scaffold within a tissue.

[0191] Embodiment 60: The tissue scaffold of embodiment 59, wherein the scaffold region and the attachment element are elastically compressible by 20%.

[0192] Embodiment 61 : The tissue scaffold of embodiment 59 or 60, wherein the scaffold region and the attachment element comprise a Young’s modulus of at least 200 kilopascals.

[0193] Embodiment 62: The tissue scaffold of any one of embodiments 59-61, wherein the scaffold is porous, and wherein the attachment element is solid.

[0194] Embodiment 63: The tissue scaffold of any one of embodiments 59-62, wherein the attachment element is attached to an end of the scaffold region.

[0195] Embodiment 64: The tissue scaffold of any one of embodiments 59-63, wherein the attachment element encapsulates a portion of the scaffold region.

[0196] Embodiment 65: A tissue scaffold comprising: a cylindrical scaffold region, wherein an end of the cylindrical scaffold comprises a recessed portion; and an attachment element.

[0197] Embodiment 66: The tissue scaffold of embodiment 65, wherein the recess is configured to mate to a portion of a tissue.

[0198] Embodiment 67: The tissue scaffold of embodiment 66, wherein the portion of the tissue has been cut to the shape of the recess.

[0199] Embodiment 68: The tissue scaffold of embodiment 66 or 67, wherein the portion of a tissue comprises bone or cartilage.

[0200] Embodiment 69: The tissue scaffold of any one of embodiments 65-68, wherein the attachment element encapsulates at least a portion of the end of the cylindrical scaffold region. [0201] Embodiment 70: The tissue scaffold of any one of embodiments 65-69, wherein the attachment element engages a tissue.

[0202] Embodiment 71 : A tissue scaffold comprising: a porous region; and a solid threaded element that encapsulates at least a portion of the porous region.

[0203] Embodiment 72: The tissue scaffold of embodiment 71, wherein the solid threaded element comprises a compressible material.

[0204] Embodiment 73: The tissue scaffold of embodiment 71 or 72, wherein the porous region comprises a scaffold region. [0205] Embodiment 74: The tissue scaffold of embodiment 73, wherein the scaffold region comprises a plurality of layers.

[0206] Embodiment 75: The tissue scaffold of embodiment 74, wherein the plurality of layers comprises at least one rotational offset between a first layer of the plurality of layers and a second layer of the plurality of layers.

[0207] Embodiment 76: The tissue scaffold of embodiment 74, wherein the scaffold region comprises a plurality of layer densities.

[0208] Embodiment 77: A method of inserting a tissue scaffold according to any one of embodiments 43-49, the method comprising: forming a socket comprising a groove in a bone of a patient; and inserting the tissue scaffold.

[0209] Embodiment 78: The method of embodiment 77, wherein forming further comprises: drilling a guide pin into a bone of a patient; reaming a socket into the bone of the patient; and cutting a groove at a bottom of the socket.

[0210] Embodiment 79: The method of embodiment 77 or 78, wherein inserting further comprises: compressing the tissue scaffold; inserting the tissue scaffold into the socket; and releasing the tissue scaffold to engage the groove of the socket.

[0211] Embodiment 80: A method of inserting a tissue scaffold according to any one of embodiments 50-58, the method comprising: forming a socket in a bone of a patient; and inserting the tissue scaffold.

[0212] Embodiment 81 : The method of embodiment 80, wherein forming further comprises: drilling a guide pin into a bone of a patient; reaming a socket into the bone of the patient; and cutting a groove at a bottom of the socket.

[0213] Embodiment 82: The method of embodiment 80 or 81, wherein inserting further comprises: compressing the tissue scaffold; inserting the tissue scaffold into the socket; and releasing the tissue scaffold to engage the groove of the socket.

[0214] Embodiment 83: A method of inserting a tissue scaffold according to any one of embodiments 71-77, the method comprising: forming a threaded socket; and threading the tissue scaffold into the socket.

[0215] Embodiment 84: The method of embodiment 83, wherein the forming further comprises: tapping a thread along the socket.

[0216] Embodiment 85: The method of embodiment 83 or 84, wherein the forming further comprises drilling a guide pin into a bone of a patient.

[0217] Embodiment 86: The method of embodiment 85, wherein the tapping is guided by the guide pin. [0218] Embodiment 87: The method of embodiment 86, wherein the tissue scaffold comprises at least one cutout slot in the threaded portion.

[0219] Embodiment 88: The method of embodiment 87, wherein the tissue scaffold is inserted using an insertion tool configured to engage the at least one cutout slot of the tissue scaffold. [0220] Embodiment 89: A kit comprising the tissue scaffold of any one of embodiments 1-76. [0221] Embodiment 90: A bone preparation tool, comprising: a cylindrical shaft; an end of the cylindrical shaft comprising two cutting teeth, wherein the end is hollow and compressible; and a cannula that extends from the center of the cylindrical shaft.

[0222] Embodiment 91: The bone preparation tool of embodiment 90, further comprising a handle portion opposite the hollow and compressible end of the cylindrical shaft.

[0223] Embodiment 92: The bone preparation tool of embodiment 90 or 91, wherein the hollow and compressible end of the cylindrical shaft comprises cutouts for compression.

[0224] Embodiment 93 : The bone preparation tool of any one of embodiments 90-92, wherein the two cutting teeth are configured to cut a groove in a bone of a patient.

[0225] Embodiment 94: The bone preparation tool of any one of embodiments 90-93, wherein the cannula extends past the end of the cylindrical shaft.

[0226] Embodiment 95: A scaffold insertion tool, comprising: a cylindrical shaft; an end of the cylindrical shaft comprising a receiving end configured to receive a scaffold implant; and at least two engagement tines running parallel to the length of the cylindrical shaft and each comprising a proximal end, a middle portion, and a distal end, wherein the distal end of the engagement tines are configured to engage at least a portion of the received scaffold implant.

[0227] Embodiment 96: The scaffold insertion tool of embodiment 95, wherein the engagement tines are configured to release the received scaffold implant when depressed at the middle portion.

[0228] Embodiment 97: A scaffold insertion tool, comprising: a shaft; an end of the cylindrical shaft comprising a receiving end configured to receive a scaffold implant; and at least two engagement tines running parallel to the length of the cylindrical shaft and each comprising a proximal end, a middle portion, and a distal end, and wherein the engagement tines are configured to release the received scaffold implant when depressed at the middle portion.

[0229] Embodiment 98: The scaffold insertion tool of embodiment 97, wherein the distal ends of the engagement tines are configured to engage at least a portion of the received scaffold implant. [0230] Embodiment 99: A scaffold insertion tool, comprising: a cylindrical shaft; a hollow distal end of the cylindrical shaft configured to receive and hold an inserted scaffold implant; a pushing portion located in the cylindrical shaft, wherein a distal end is configured to be in contact with the inserted scaffold implant; and a button on the external surface of the cylindrical shaft, connected to the pushing portion; wherein the button is configured engage the pushing portion to push the inserted scaffold out of the hollow distal end of the cylindrical shaft.

[0231] Embodiment 100: The scaffold insertion tool of embodiment 99, wherein the hollow distal end comprises a plurality of cutouts such that the hollow distal end flexes to receive the inserted scaffold implant.

[0232] Embodiment 101 : The scaffold insertion tool of embodiment 99 or 100, wherein the flex of the hollow distal end holds the inserted scaffold implant in place.

[0233] Embodiment 102: A scaffold insertion tool, comprising: a first lever portion comprising a first distal end, a first middle portion, and a first proximal end, wherein the first distal end comprises a first compression tine; and a second lever portion comprising a second distal end, a second middle portion, and a second proximal end, wherein the second distal end comprises a second compression tine; wherein the first lever portion and second lever portion are pivotally coupled at the first middle portion and the second middle portion, wherein the first compression tine and the second compression tine are configured to engage a portion of a tissue scaffold.

[0234] Embodiment 103: A guide pin for providing a reference point in a host tissue, comprising: an elongated, cylindrical member featuring a tapered tip for facilitating insertion into the host tissue; and depth indicators along a length to assist a user in determining an appropriate insertion depth.

[0235] Embodiment 104: The guide pin of embodiment 103, wherein the guide pin is made of a biocompatible material.

[0236] Embodiment 105: The guide pin of embodiment 103 or 104, wherein the tapered tip is designed to minimize tissue damage during insertion.

[0237] Embodiment 106: The guide pin of any one of embodiments 103-105, wherein the guide pin is drilled into the host tissue.

[0238] Embodiment 107: The guide pin of any one of embodiments 103-106, wherein the host tissue comprises a femur bone.

[0239] Embodiment 108: The guide pin of any one of embodiments 103-107, wherein the guide pin is inserted through an alignment guide.

[0240] Embodiment 109: The guide pin of any one of embodiments 103-108, wherein the guide pin comprises markings or indicators for a depth measurement.

[0241] Embodiment 110: The guide pin of any one of embodiments 103-109, wherein the guide pin is configured to establish an orientation of a tissue scaffold. [0242] Embodiment 111: The guide pin of any one of embodiments 103-110, wherein the guide pin is designed to be removed after a socket preparation is completed.

[0243] Embodiment 112: A punch for scoring a host tissue, comprising: a body designed to score the host tissue; and an opening configured to be placed over a guide pin for accurate positioning. [0244] Embodiment 113: The punch of embodiment 112, wherein the punch is sized to match dimensions of a host tissue lesion.

[0245] Embodiment 114: The punch of embodiment 112 or 113, wherein the punch is configured to apply axial pressure while rotating to score the host tissue.

[0246] Embodiment 115: The punch of any one of embodiments 112-114, wherein the punch is made of a biocompatible material.

[0247] Embodiment 116: The punch of any one of embodiments 112-115, wherein the punch includes markings or indicators to assist in proper alignment during use.

[0248] Embodiment 117: A cannulated reamer for preparing a socket in a host tissue, comprising: a hollow, cylindrical body designed to create a socket in the host tissue; and at least one cutting tooth configured to facilitate a reaming process.

[0249] Embodiment 118: The cannulated reamer of embodiment 117, wherein the reamer comprises a depth stop to prevent over-reaming beyond a predetermined cutting depth.

[0250] Embodiment 119: The cannulated reamer of embodiment 117 or 118, wherein a hollow inside the reamer allows for a passage of a guide pin during use.

[0251] Embodiment 120: The cannulated reamer of any one of embodiments 117-119, wherein the reamer is made of a biocompatible material.

[0252] Embodiment 121 : The cannulated reamer of any one of embodiments 117-120, wherein the reamer is configured to create a cylindrical socket that matches dimensions of a tissue scaffold.

[0253] Embodiment 122: The cannulated reamer of any one of embodiments 117-121, wherein the reamer is designed to be used in conjunction with an alignment guide to ensure accurate positioning during the reaming process.

[0254] Embodiment 123: An undercut tool for preparing at least one groove in a host tissue, comprising: a cylindrical body featuring two cutting teeth designed to create at least one groove in a socket of the host tissue; and a cannula configured to allow for a placement of a guide pin during use.

[0255] Embodiment 124: The undercut tool of embodiment 123, wherein each cutting tooth is disposed on an outer end of a first arm and a second arm extending from a vertex of the undercut tool. [0256] Embodiment 125: The undercut tool of embodiment 123 or 124, wherein an outer diameter of an end of the undercut tool containing the cutting teeth is larger than the socket of the host tissue, requiring compression to fit into the socket.

[0257] Embodiment 126: The undercut tool of any one of embodiments 123-125, wherein the undercut tool comprises a compression mechanism that allows a user to compress the two cutting teeth for retraction during placement over the guide pin and into the socket.

[0258] Embodiment 127: The undercut tool of any one of embodiments 123-126, wherein the cutting teeth extend to prepare the at least one groove in the host tissue upon release, wherein the undercut tool requires a compression to retract the teeth for removal.

[0259] Embodiment 128: The undercut tool of any one of embodiments 123-127, wherein the undercut tool is made of a biocompatible material.

[0260] Embodiment 129: An insertion tool for placing a tissue scaffold in a host tissue, comprising: a gripping instrument to compress the tissue scaffold during insertion; and a tube with a pocket to hold the tissue scaffold during insertion.

[0261] Embodiment 130: The insertion tool of embodiment 129, wherein the insertion tool comprises two tips for gripping the tissue scaffold.

[0262] Embodiment 131 : The insertion tool of embodiment 129 or 130, wherein the insertion tool is used for compressing the tissue scaffold.

[0263] Embodiment 132: The insertion tool of any one of embodiments 129-131, wherein the insertion tool comprises at least four relief flutes that allow the tube to receive the tissue scaffold while applying a clamping force to hold the tissue scaffold.

[0264] Embodiment 133: The insertion tool of any one of embodiments 129-132, further comprising a release button that retracts the tube.

[0265] Embodiment 134: The insertion tool of any one of embodiments 129-133, wherein the insertion tool is made of a biocompatible material.

[0266] Embodiment 135: The insertion tool of any one of embodiments 129-134, wherein the insertion tool is designed to provide tactile feedback to a user during the insertion process.

[0267] Embodiment 136: The insertion tool of any one of embodiments 129-135, wherein the pocket is cylindrical.

[0268] Embodiment 137: The insertion tool of any one of embodiments 129-136, wherein the pocket is about 0 mm to about 12 mm deep.

[0269] Embodiment 138: The insertion tool of any one of embodiments 129-137, wherein the tube holds a top half of the tissue. [0270] Embodiment 139: A surgical tool kit for installing a tissue scaffold, the surgical tool kit comprising: an alignment guide for ensuring proper positioning of surgical tools; a guide pin for providing a reference point in a host tissue; a punch for scoring the host tissue; a cannulated reamer for preparing a socket in the host tissue; a trial implant for evaluating the prepared socket in the host tissue; an undercut tool for preparing at least one groove in the host tissue; and an insertion tool for placing the tissue scaffold in the host tissue.

[0271] Embodiment 140: The surgical tool kit of embodiment 139, wherein the surgical tool kit is made of a biocompatible material.

[0272] Embodiment 141 : The surgical tool kit of embodiment 139 or 140, wherein the host tissue comprises a femur bone.

[0273] Embodiment 142: The surgical tool kit of any one of embodiments 139-141, wherein the alignment guide is a cylindrical tube with both ends open, positioned perpendicular to a lesion in the host tissue to ensure accurate alignment of the surgical tools during the installation of the tissue scaffold.

[0274] Embodiment 143: The surgical tool kit of any one of embodiments 139-142, wherein the guide pin is drilled into the host tissue.

[0275] Embodiment 144: The surgical tool kit of any one of embodiments 139-143, wherein the guide pin is an elongated, cylindrical member, featuring a tapered tip for facilitating insertion into the host tissue, and includes depth indicators along its length to assist a user in determining an appropriate insertion depth.

[0276] Embodiment 145: The surgical tool kit of any one of embodiments 139-144, wherein the punch is designed for scoring the host tissue, wherein the punch is configured to be placed over the guide pin while applying axial pressure and rotating.

[0277] Embodiment 146: The surgical tool kit of any one of embodiments 139-145, wherein the cannulated reamer is a hollow, cylindrical tool with at least one cutting tooth designed for creating the socket of varying diameters in the host tissue, and includes a depth stop to prevent over-reaming over at least one predetermined cutting depth.

[0278] Embodiment 147: The surgical tool kit of any one of embodiments 139-146, wherein the trial implant is designed to match a thickness and a diameter of a final tissue scaffold implant, wherein the trial implant comprises visual indicators on an outer body of the trial implant to assist a user in evaluating a fit and alignment.

[0279] Embodiment 148: The surgical tool kit of embodiment 147, wherein the trial implant has a Imm-mark on an outer surface of the trial implant, wherein the Imm-mark is visible to the user for evaluating the fit and alignment of the trial implant within the prepared socket in the host tissue.

[0280] Embodiment 149: The surgical tool kit of any one of embodiments 139-148, wherein the undercut tool is a cylindrical instrument featuring two cutting teeth and a cannula, designed to prepare a groove in the socket of the host tissue, wherein the undercut tool is configured to be placed concentrically over the guide pin.

[0281] Embodiment 150: The surgical tool kit of any one of embodiments 139-149, wherein each cutting tooth of the two cutting teeth is disposed on an outer end of a first arm and second arm extending from a vertex of the undercut tool.

[0282] Embodiment 151 : The surgical tool kit of any one of embodiments 139-150, wherein an outer diameter of an end of the undercut tool containing the cutting teeth is larger than the socket of the host tissue, requiring a compression to fit into the socket.

[0283] Embodiment 152: The surgical tool kit of any one of embodiments 139-151, wherein the undercut tool comprises a compression mechanism that allows a user to compress the two cutting teeth for retraction during placement over the guide pin and into the socket, and upon release, the cutting teeth extend to prepare the groove in the bone, with the tool requiring compression to retract the teeth for removal.

[0284] Embodiment 153: The surgical tool kit of any one of embodiments 139-152, wherein the insertion tool is a gripping instrument that functions similarly to needle nose pliers, designed to compress the tissue scaffold during insertion.

[0285] Embodiment 154: The surgical tool kit of any one of embodiments 139-153, wherein the insertion tool includes two tips that are optimized for a shape of the tissue scaffold, ensuring a secure grip and effective compression during placement.

[0286] Embodiment 155: The surgical tool kit of any one of embodiments 139-154, wherein the tissue scaffold comprises at least one solid snap ring designed for secure fixation of the tissue scaffold on the host tissue.

[0287] Embodiment 156: The surgical tool kit of any one of embodiments 139-155, wherein the insertion tool comprises a tube with a cylindrical pocket that is about 2 mm deep, designed to hold a top half of the tissue scaffold during insertion.

[0288] Embodiment 157: The surgical tool kit of any one of embodiments 139-156, wherein the insertion tool comprises at least four relief flutes that allow the tube to flex and receive the tissue scaffold while applying a clamping force to hold the tissue scaffold, and further comprises a release button that retracts the tube to facilitate the complete placement of the tissue scaffold into the socket. [0289] Embodiment 158: The surgical tool kit of any one of embodiments 139-157, wherein the insertion tool allows a user to place the tissue scaffold into the socket halfway, press the release button to retract the tube, and then fully insert the tissue scaffold, enabling the user to perform a procedure with at least one hand.

[0290] Embodiment 159: The surgical tool kit of any one of embodiments 139-158, wherein the tissue scaffold comprises at least one press-fit ring designed for secure fixation of the tissue scaffold on the host tissue.

[0291] Embodiment 160: The surgical tool kit of any one of embodiments 139-159, further comprising an implant tap that feature cutting threads, is cannulated to fit over the guide pin, and comprises at least six flutes designed to trap bone removed by the cutting threads during a threading process.

[0292] Embodiment 161 : The surgical tool kit of embodiment 160, wherein the implant tap is rotated to cut threads in the host tissue, and further comprises an insertion tool with two tines designed to engage two insertion slots of the tissue scaffold, wherein the tissue scaffold is opened by pressing on two press points, allowing the insertion tool to rotate the tissue scaffold and screw it into the prepared socket.

[0293] Embodiment 162: The surgical tool kit of any one of embodiments 139-161, wherein the host tissue comprises bones, cartilages, or other tissues.

[0294] Embodiment 163: The surgical tool kit of any one of embodiments 139-162, wherein the tissue scaffold comprises at least one thread designed for secure fixation of the tissue scaffold on the host tissue.

[0295] Embodiment 164: The surgical tool kit of any one of embodiments 139-163, wherein the surgical tool kit is sterilized before use.

[0296] Embodiment 165: The surgical tool kit of any one of embodiments 139-164, wherein the surgical tool kit is sterilized by steam autoclaving.

[0297] Embodiment 166: The surgical tool kit of any one of embodiments 139-165, wherein the tissue scaffold is sterilized before use.

[0298] Embodiment 167: The surgical tool kit of any one of embodiments 139-166, wherein the tissue scaffold is sterilized by steam autoclaving.

[0299] Embodiment 168: The surgical tool kit of any one of embodiments 139-167, wherein the installation of the tissue scaffold is conducted within about 2 hours post sterilization.

[0300] Embodiment 169: The surgical tool kit of any one of embodiments 139-168, wherein the tissue scaffold is hydrated prior to installation. [0301] Embodiment 170: The surgical tool kit of any one of embodiments 139-169, wherein the tissue scaffold is packed in a container prior to installation.

[0302] Embodiment 171 : The surgical tool kit of embodiment 170, wherein the container is made of glass, polymer, or metal.

[0303] Embodiment 172: The surgical tool kit of embodiment 170 or 171, wherein the container is filled with an aqueous solution.

[0304] Embodiment 173: The surgical tool kit of any one of embodiments 139-172, wherein the surgical tool kit is organized and fixed in place within a metal container.

[0305] Embodiment 174: The surgical tool kit of embodiment 173, wherein the metal container can be sterilized.

[0306] Embodiment 175: The surgical tool kit of any one of embodiments 139-174, wherein the surgical tool kit comprises at least one size of each tool.

[0307] Embodiment 176: A method of installing a tissue scaffold, the method comprising: positioning an alignment guide to ensure proper alignment of surgical tools relative to a lesion in a host tissue; inserting a guide pin into the host tissue to provide a reference point; using a punch to score the host tissue at the location of the guide pin; utilizing a cannulated reamer to prepare a socket in the host tissue; evaluating the prepared socket in the host tissue with a trial implant to ensure proper fit and alignment; employing an undercut tool to prepare at least one groove in the host tissue; and placing the tissue scaffold into the prepared socket using an insertion tool.

[0308] Embodiment 177: The method of embodiment 176, wherein the lesion in the host tissue is a chondral lesion.

[0309] Embodiment 178: The method of embodiment 176 or 177, wherein the host tissue comprises a femur bone.

[0310] Embodiment 179: The method of embodiment 177, further comprising measuring the chondral lesion with the alignment guide to assess dimensions of the lesion.

[0311] Embodiment 180: The method of any one of embodiments 176-179, further comprising assessing a position of the tissue scaffold to ensure that intact tissue is fully surround the tissue scaffold.

[0312] Embodiment 181 : The method of any one of embodiments 176-180, wherein the alignment guide is positioned to fully cover the host tissue.

[0313] Embodiment 182: The method of embodiment 181, wherein the host tissue is an articular cartilage lesion.

[0314] Embodiment 183: The method of any one of embodiments 176-182, wherein the alignment guide is oriented perpendicular to the lesion and is fitted to a surface of the host tissue. [0315] Embodiment 184: The method of any one of embodiments 176-183, further comprising placing the guide pin into the alignment guide.

[0316] Embodiment 185: The method of embodiment 184, wherein an orientation of the guide pin is aligned with an orientation of the tissue scaffold.

[0317] Embodiment 186: The method of embodiment 184 or 185, further comprising drilling the guide pin into the host tissue until the depth stop line on the guide pin is aligned with an opening of the alignment guide.

[0318] Embodiment 187: The method of any one of embodiments 176-186, further comprising selecting the punch from a plurality of predefined-size punches to score the host tissue.

[0319] Embodiment 188: The method of embodiment 187, wherein the punch is placed over the guide pin.

[0320] Embodiment 189: The method of embodiment 188, further comprising applying axial pressure to the punch while rotating the punch to score the host tissue.

[0321] Embodiment 190: The method of any one of embodiments 176-189, further comprising selecting the reamer from a plurality of predefined-size reamers to prepare a cylindrical socket for receiving the tissue scaffold.

[0322] Embodiment 191 : The method of embodiment 190, wherein a depth stop is assembled onto a shaft of the reamer, wherein the reamer is turned until the reamer is locked before use.

[0323] Embodiment 192: The method of embodiment 190, wherein the depth stop is designed to ensure that the tissue scaffold sits recessed within the prepared socket.

[0324] Embodiment 193: The method of any one of embodiments 176-192, further comprising preparing to assess a depth and orientation of the socket with applying the trial implant.

[0325] Embodiment 194: The method of any one of embodiments 176-193, further comprising employing the undercut tool to prepare at least one groove in the host tissue to enhance the fixation of the tissue scaffold.

[0326] Embodiment 195: The method of any one of embodiments 176-194, further comprising placing the tissue scaffold into the prepared socket using the insertion tool, wherein the insertion tool ensures a proper placement and secure fixation of the tissue scaffold within the host tissue.

EXAMPLES

[0327] In the current care continuum for cartilage related knee injuries, a surgeon may first try to mitigate existing damage by removing diseased cartilage, performing microfracture surgery, or regrafting and transplanting healthy cartilage, or combinations thereof. When these treatments fail, the next step may be an osteochondral autograft (for example, OATS) or the implantation of a device made from processed cadaver tissue. If these treatments also fail, the last line of treatment may be a living tissue transplant from a donor, or the use of a premium implant, for example a premium implant composed of live cells or preserved tissue. If no treatment has long term success, the patient must then wait until they are a candidate for a metallic joint replacement. This can occur when the patient is at least 55 years old, or if pain and mobility loss are so severe that the patient cannot walk.

[0328] In some embodiments, a tissue scaffold improves clinical outcomes for patients suffering from large focal cartilage lesions in the knee. The tissue scaffold may utilize a more mechanically and biologically stable implant, while also addressing manufacturing costs.

[0329] A tissue scaffold was tested in a 4-month in vivo study. The tissue scaffold has been evaluated in a series of in vitro studies, a small animal osteochondral model, and a large animal chondral defect model in a goat study consisting of 12 total experimental groups. The goat study revealed initial implantation of the device and demonstrated that the tissue scaffold geometry was highly flexible and could be formed into place by a surgeon. This illustrated the flexibility of the tissue scaffold device in not requiring a high degree of customization. The also demonstrated that the device could be installed over the prepared and microfractured bone successfully, using chondral darts for fixation. FIGS. 26A-26F summarize the histologically observed effects of 3D printed nTP. The top row shows the three animals which received a solid nTP implant and microfracture control. The bottom row shows the three animals that received a 3D printed implant. In all six cases, the microfracture control showed little to no tissue repair activity, and mostly open defects. In the solid nTP groups, even though the devices failed, there was still chondrocyte stimulation and non-fibrotic tissue observed. The 3D printed implants showed the most complete filling of the defect, chondrocyte recruitment int the nTP material, and chondrogenic activity. Standard biodegradable pins were used to fix graft tissue in place. After 24 hours, all the animals recovered and began to ambulate. This was highly significant, as existing treatments require patients to remain immobile and non-weight bearing for 6 weeks postop. After the 4-month study, no animals contracted infections. At the 4-month endpoint, it was observed that the 3D printed nanoporous thermoplastic polyamide (nTP) implant was successful. [0330] The microfracture defects showed little to no visible tissue growth, and in some cases, led to deterioration of healthy tissue. The solid, non-3D printed implants failed and became dislodged from the injury site. The tissue scaffold 3D printed nTP implants remained in place and intact, leading to -70% tissue engraftment. Further mechanical testing showed that the 3D printed implant-based defect repair had statistically equivalent mechanical properties (i.e. Young's modulus) when compared to healthy osteochondral tissue samples. [0331] Histological staining demonstrated that the Nanochon implant continued to have the most effective defect repair process. A thin layer of fibrocartilage was observed on the microfracture defect samples, while the tissue scaffold stimulated the formation of new cartilage (FIG. 27), sometimes referred to as "nuvo cartilage”. Nuvo cartilage is characterized by an observable collagen matrix with tight clusters of chondrocytes embedded within. FIG. 27 illustrates H&E staining of cartilage and nTP samples taken from goat medial femoral condyle implantation sites after 4 months, (a-b) Nuvo cartilage characterized by chondrocyte clusters and new tissue at defect cite, (c-d) Chondrocytes growing on implant material.

[0332] Additional histological images showed chondrocytes partially invading and taking up residence in the nTP material. This is very advantageous as it shows that the tissue scaffold, as designed and validated, can support new healthy tissue growth, which would give a patient much longevity compared to the fibrocartilage that microfracture induces. Ongoing histochemistry is evaluating the quality and composition of the results observed in the goat study. The figures above show a snapshot of animal tissue analyzed for cartilage from one of the microfracture groups, as well as the 3D printed nTP implant. The first three panels of FIGS. 28A-28C contain H&E, Masson’s Trichrome and Safranin-0 staining of one of the microfracture groups. H&E shows the presence of fibrous tissue at the surface of the lesion and in the subchondral bone puncture, while Masson confirms the presence of chondrocytes, and Safranin-O shows limited cartilage tissue (red cartilage, blue bone and fibrosis). The next three panels (Figure 5 A-C) show the same staining protocol, performed on samples taken from one of the 3D nTP implant groups. These images show a well-preserved cartilage-like tissue and the implant material on H&E, while Masson’s demonstrates filling of the defect with a well-organized chondrocyte rich tissue, and Safran-0 confirms that there is a distinct separation between mature cartilage and subchondral bone.

[0333] FIG. 28A illustrates H&E staining from Animal 1502, the microfracture defect. Minimal activity can be observed at the defect site and at the subchondral bone. Fibrous tissue can be observed forming in the cavity where initial microfracture punctures were made. FIG. 28B illustrates Masson’s Tri chrome staining from Animal 1502, the microfracture defect. Chondrocytes are observed at the defect site at the subchondral bone and inside the cavity where initial microfracture punctures were made. FIG. 28C illustrates Safranin-0 staining from Animal 1502, the microfracture defect. Very limited collagen (cartilage) is detected at the defect site at the subchondral bone and inside the cavity where initial microfracture punctures were made. [0334] FIG. 29A illustrates H&E staining from Animal 2503, the 3D implant repaired defect. Dense organized tissue and implant material can be seen at the defect site. Fibrous tissue can be observed forming in the cavity where remnants of the PDS pins (JnJ Depuy) were placed and used to fix the device. FIG. 29B illustrates Masson’s staining from Animal 2503, the 3D implant repaired defect. A distinct difference between thick cartilage tissue (blue) and subchondral bone (red) can be seen at the defect site. Fibrous encapsulation of PDS fragments and a mature osteochondral region can be observed. FIG. 29C illustrates Safranin-0 staining from Animal 2503, the 3D implant repaired defect. Clearly defined healthy cartilage tissue (Red) can be seen at the defect site, along with a well-organized osteochondral interface. Intact subchondral bone is also observed along with the absorption of the PDS pins.

[0335] The safety and efficacy of first and second generation Nanochon tissue scaffolds were evaluated in animal models. A 2-month pilot and an 8-month pivotal equine study have been completed, testing the standard of care (microfracture) compared to tissue scaffold. The defect preparation was analogous to how defects are prepared for microfracture. Debridement of defective cartilage, scoring of subchondral bone or microfracture, were followed by implant placement. In the 2-month pilot study, 2 animals in each group were observed at 2 months. The control group, treated with microfracture surgery, showed consistent disorganized and lower- quality tissue, tissue scaffold-treated defects showed intact, fully integrated devices, evidence of cartilage ingrowth, some overgrowth, and high-quality tissue underneath (push test) (FIG. 30). The outcomes were measured using the International Cartilage Regeneration and Joint Preservation Society (ICRS) score. The tissue scaffold treated group received a score of 11.3/12, indicating nearly healthy tissue, while the microfracture treated group received a score of 4.1. FIG. 30 illustrates a three-month relook arthroscopy with gross morphology comparison of microfracture control and tissue scaffold.

[0336] In the 8-month study, 12 animals were evaluated at 8 months, again, comparing the tissue scaffold and microfracture treatment groups. The microfracture group showed disorganized and degrading tissue, tissue scaffold-treated defects showed intact, fully integrated devices, strong evidence of cartilage ingrowth, overgrowth, and high-quality tissue underneath (push test) (FIG. 31, panel A). The microfracture group also had soft, poorly integrated tissue, and significant bone thickening, while tissue scaffold treated animals demonstrated fully integrated devices and high- quality cartilage, normal bone, and cartilage surface (FIG. 31, panel B).

[0337] The primary findings of the preceding equine studies were two-fold: 1) illustrated longterm material stability and biocompatibility allowing for volumetric tissue infiltration, mature tissue engraftment, integration, and overgrowth; and 2) the need for implant redesigns specific to human clinical use cases. [0338] FIG. 32 illustrates an example of an instrument set used for surgical procedures. In some embodiments, the instrument set comprises a Sizing/ Alignment Guide 3201. This tool can assist in determining the appropriate dimensions for an implant and ensuring the correct positioning during the procedure. In some embodiments, the instrument set also includes a Guide Pin 3202. This tool can be used to assist with aligning the surgical instruments and establishing a pathway for the procedure. The instrument set also features a Punch 3203 in some embodiments. This tool may be used for creating an opening in the tissue or bone to facilitate implant insertion. In certain embodiments, the instrument set comprises a Reamer 3204. This tool can be utilized to smooth or enlarge the created opening to fit the implant accurately. In some embodiments, a Depth Stop 3205 is also included in the instrument set. This component is employed to limit the depth of penetration of other instruments to ensure accurate positioning and prevent damage to surrounding structures. Lastly, in some embodiments, the instrument set includes an Insertion Tube 3206. This tool is used to guide the implant into the prepared opening in a controlled and precise manner.

[0339] FIGS. 33A-33E depict the steps involved in using the instrument set from FIG. 32 for surgical procedures. In FIG. 33A, in some embodiments, the Sizing/ Alignment Guide 3301 is first used to determine the appropriate dimensions for the implant and to confirm its proper positioning. Following this, in FIG. 33B, in some embodiments, the Guide Pin 3302 is inserted to establish a pathway for the upcoming procedure. Then, in FIG. 33C, in some embodiments, the Punch 3303 is applied to create an opening in the tissue or bone where the implant will be placed. Next, in FIG. 33D, in some embodiments, the Reamer 3304 is used to smooth or widen the opening to ensure the implant fits accurately. Simultaneously, the Depth Stop 3305, in some embodiments, is implemented to control the depth of penetration and to safeguard surrounding structures from potential damage. Finally, in FIG. 33E, in some embodiments, the Insertion Tube 3306 is used to guide and insert the implant into the opening in a precise and controlled manner. This concludes the steps of using the instrument set in the depicted surgical procedure.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A bone preparation tool, comprising: a cylindrical shaft; an end of the cylindrical shaft comprising two cutting teeth, wherein the end is hollow and compressible; and a cannula that extends from the center of the cylindrical shaft.

2. The bone preparation tool of claim 1, further comprising a handle portion opposite the hollow and compressible end of the cylindrical shaft.

3. The bone preparation tool of claim 1 or 2, wherein the hollow and compressible end of the cylindrical shaft comprises cutouts for compression.

4. The bone preparation tool of any one of claims 1-3, wherein the two cutting teeth are configured to cut a groove in a bone of a patient.

5. The bone preparation tool of any one of claims 1-4, wherein the cannula extends past the end of the cylindrical shaft.

6. A scaffold insertion tool, comprising: a cylindrical shaft; an end of the cylindrical shaft comprising a receiving end configured to receive a scaffold implant; and at least two engagement tines running parallel to the length of the cylindrical shaft and each comprising a proximal end, a middle portion, and a distal end, wherein the distal end of the engagement tines are configured to engage at least a portion of the received scaffold implant.

7. The scaffold insertion tool of claim 6, wherein the engagement tines are configured to release the received scaffold implant when depressed at the middle portion.

8. A scaffold insertion tool, comprising: a shaft; an end of the cylindrical shaft comprising a receiving end configured to receive a scaffold implant; and at least two engagement tines running parallel to the length of the cylindrical shaft and each comprising a proximal end, a middle portion, and a distal end, and wherein the engagement tines are configured to release the received scaffold implant when depressed at the middle portion.

9. The scaffold insertion tool of claim 8, wherein the distal ends of the engagement tines are configured to engage at least a portion of the received scaffold implant.

10. A scaffold insertion tool, comprising: a cylindrical shaft; a hollow distal end of the cylindrical shaft configured to receive and hold an inserted scaffold implant; a pushing portion located in the cylindrical shaft, wherein a distal end is configured to be in contact with the inserted scaffold implant; and a button on the external surface of the cylindrical shaft, connected to the pushing portion; wherein the button is configured engage the pushing portion to push the inserted scaffold out of the hollow distal end of the cylindrical shaft.

11. The scaffold insertion tool of claim 10, wherein the hollow distal end comprises a plurality of cutouts such that the hollow distal end flexes to receive the inserted scaffold implant.

12. The scaffold insertion tool of claim 10 or 11, wherein the flex of the hollow distal end holds the inserted scaffold implant in place.

13. A scaffold insertion tool, comprising: a first lever portion comprising a first distal end, a first middle portion, and a first proximal end, wherein the first distal end comprises a first compression tine; and a second lever portion comprising a second distal end, a second middle portion, and a second proximal end, wherein the second distal end comprises a second compression tine; wherein the first lever portion and second lever portion are pivotally coupled at the first middle portion and the second middle portion, wherein the first compression tine and the second compression tine are configured to engage a portion of a tissue scaffold.

14. A guide pin for providing a reference point in a host tissue, comprising: an elongated, cylindrical member featuring a tapered tip for facilitating insertion into the host tissue; and depth indicators along a length to assist a user in determining an appropriate insertion depth.

15. The guide pin of claim 14, wherein the guide pin is made of a biocompatible material.

16. The guide pin of claim 14 or 15, wherein the tapered tip is designed to minimize tissue damage during insertion.

17. The guide pin of any one of claims 14-16, wherein the guide pin is drilled into the host tissue.

18. The guide pin of any one of claims 14-17, wherein the host tissue comprises a femur bone.

19. The guide pin of any one of claims 14-18, wherein the guide pin is inserted through an alignment guide.

20. The guide pin of any one of claims 14-19, wherein the guide pin comprises markings or indicators for a depth measurement.

21. The guide pin of any one of claims 14-20, wherein the guide pin is configured to establish an orientation of a tissue scaffold.

22. The guide pin of any one of claims 14-21, wherein the guide pin is designed to be removed after a socket preparation is completed.

23. A punch for scoring a host tissue, comprising: a body designed to score the host tissue; and an opening configured to be placed over a guide pin for accurate positioning.

24. The punch of claim 23, wherein the punch is sized to match dimensions of a host tissue lesion.

25. The punch of claim 23 or 24, wherein the punch is configured to apply axial pressure while rotating to score the host tissue.

26. The punch of any one of claims 23-25, wherein the punch is made of a biocompatible material.

27. The punch of any one of claims 23-26, wherein the punch includes markings or indicators to assist in proper alignment during use.

28. A cannulated reamer for preparing a socket in a host tissue, comprising: a hollow, cylindrical body designed to create a socket in the host tissue; and at least one cutting tooth configured to facilitate a reaming process.

29. The cannulated reamer of claim 28, wherein the reamer comprises a depth stop to prevent over-reaming beyond a predetermined cutting depth.

30. The cannulated reamer of claim 28 or 29, wherein a hollow inside the reamer allows for a passage of a guide pin during use.

31. The cannulated reamer of any one of claims 28-30, wherein the reamer is made of a biocompatible material.

32. The cannulated reamer of any one of claims 28-31, wherein the reamer is configured to create a cylindrical socket that matches dimensions of a tissue scaffold.

33. The cannulated reamer of any one of claims 28-32, wherein the reamer is designed to be used in conjunction with an alignment guide to ensure accurate positioning during the reaming process.

34. An undercut tool for preparing at least one groove in a host tissue, comprising: a cylindrical body featuring two cutting teeth designed to create at least one groove in a socket of the host tissue; and a cannula configured to allow for a placement of a guide pin during use.

35. The undercut tool of claim 34, wherein each cutting tooth is disposed on an outer end of a first arm and a second arm extending from a vertex of the undercut tool.

36. The undercut tool of claim 34 or 35, wherein an outer diameter of an end of the undercut tool containing the cutting teeth is larger than the socket of the host tissue, requiring compression to fit into the socket.

37. The undercut tool of any one of claims 34-36, wherein the undercut tool comprises a compression mechanism that allows a user to compress the two cutting teeth for retraction during placement over the guide pin and into the socket.

38. The undercut tool of any one of claims 34-37, wherein the cutting teeth extend to prepare the at least one groove in the host tissue upon release, wherein the undercut tool requires a compression to retract the teeth for removal.

39. The undercut tool of any one of claims 34-38, wherein the undercut tool is made of a biocompatible material.

40. An insertion tool for placing a tissue scaffold in a host tissue, comprising: a gripping instrument to compress the tissue scaffold during insertion; and a tube with a pocket to hold the tissue scaffold during insertion.

41. The insertion tool of claim 40, wherein the insertion tool comprises two tips for gripping the tissue scaffold.

42. The insertion tool of claim 40 or 41, wherein the insertion tool is used for compressing the tissue scaffold.

43. The insertion tool of any one of claims 40-42, wherein the insertion tool comprises at least four relief flutes that allow the tube to receive the tissue scaffold while applying a clamping force to hold the tissue scaffold.

44. The insertion tool of any one of claims 40-43, further comprising a release button that retracts the tube.

45. The insertion tool of any one of claims 40-44, wherein the insertion tool is made of a biocompatible material.

46. The insertion tool of any one of claims 40-45, wherein the insertion tool is designed to provide tactile feedback to a user during the insertion process.

47. The insertion tool of any one of claims 40-46, wherein the pocket is cylindrical.

48. The insertion tool of any one of claims 40-47, wherein the pocket is about 0 mm to about 12 mm deep.

49. The insertion tool of any one of claims 40-48, wherein the tube holds a top half of the tissue.

50. A surgical tool kit for installing a tissue scaffold, the surgical tool kit comprising: an alignment guide for ensuring proper positioning of surgical tools; a guide pin for providing a reference point in a host tissue; a punch for scoring the host tissue; a cannulated reamer for preparing a socket in the host tissue; a trial implant for evaluating the prepared socket in the host tissue; an undercut tool for preparing at least one groove in the host tissue; and an insertion tool for placing the tissue scaffold in the host tissue.

51. The surgical tool kit of claim 50, wherein the surgical tool kit is made of a biocompatible material.

52. The surgical tool kit of claim 50 or 51, wherein the host tissue comprises a femur bone.

53. The surgical tool kit of any one of claims 50-52, wherein the alignment guide is a cylindrical tube with both ends open, positioned perpendicular to a lesion in the host tissue to ensure accurate alignment of the surgical tools during the installation of the tissue scaffold.

54. The surgical tool kit of any one of claims 50-53, wherein the guide pin is drilled into the host tissue.

55. The surgical tool kit of any one of claims 50-54, wherein the guide pin is an elongated, cylindrical member, featuring a tapered tip for facilitating insertion into the host tissue, and includes depth indicators along its length to assist a user in determining an appropriate insertion depth.

56. The surgical tool kit of any one of claims 50-55, wherein the punch is designed for scoring the host tissue, wherein the punch is configured to be placed over the guide pin while applying axial pressure and rotating.

57. The surgical tool kit of any one of claims 50-56, wherein the cannulated reamer is a hollow, cylindrical tool with at least one cutting tooth designed for creating the socket of varying diameters in the host tissue, and includes a depth stop to prevent over-reaming over at least one predetermined cutting depth.

58. The surgical tool kit of any one of claims 50-57, wherein the trial implant is designed to match a thickness and a diameter of a final tissue scaffold implant, wherein the trial implant comprises visual indicators on an outer body of the trial implant to assist a user in evaluating a fit and alignment.

59. The surgical tool kit of claim 58, wherein the trial implant has a Imm-mark on an outer surface of the trial implant, wherein the Imm-mark is visible to the user for evaluating the fit and alignment of the trial implant within the prepared socket in the host tissue.

60. The surgical tool kit of any one of claims 50-59, wherein the undercut tool is a cylindrical instrument featuring two cutting teeth and a cannula, designed to prepare a groove in the socket of the host tissue, wherein the undercut tool is configured to be placed concentrically over the guide pin.

61. The surgical tool kit of any one of claims 50-60, wherein each cutting tooth of the two cutting teeth is disposed on an outer end of a first arm and second arm extending from a vertex of the undercut tool.

62. The surgical tool kit of any one of claims 50-61, wherein an outer diameter of an end of the undercut tool containing the cutting teeth is larger than the socket of the host tissue, requiring a compression to fit into the socket.

63. The surgical tool kit of any one of claims 50-62, wherein the undercut tool comprises a compression mechanism that allows a user to compress the two cutting teeth for retraction during placement over the guide pin and into the socket, and upon release, the cutting teeth extend to prepare the groove in the bone, with the tool requiring compression to retract the teeth for removal.

64. The surgical tool kit of any one of claims 50-63, wherein the insertion tool is a gripping instrument that functions similarly to needle nose pliers, designed to compress the tissue scaffold during insertion.

65. The surgical tool kit of any one of claims 50-64, wherein the insertion tool includes two tips that are optimized for a shape of the tissue scaffold, ensuring a secure grip and effective compression during placement.

66. The surgical tool kit of any one of claims 50-65, wherein the tissue scaffold comprises at least one solid snap ring designed for secure fixation of the tissue scaffold on the host tissue.

67. The surgical tool kit of any one of claims 50-66, wherein the insertion tool comprises a tube with a cylindrical pocket that is about 2 mm deep, designed to hold a top half of the tissue scaffold during insertion.

68. The surgical tool kit of any one of claims 50-67, wherein the insertion tool comprises at least four relief flutes that allow the tube to flex and receive the tissue scaffold while applying a clamping force to hold the tissue scaffold, and further comprises a release button that retracts the tube to facilitate the complete placement of the tissue scaffold into the socket.

69. The surgical tool kit of any one of claims 50-68, wherein the insertion tool allows a user to place the tissue scaffold into the socket halfway, press the release button to retract the tube, and then fully insert the tissue scaffold, enabling the user to perform a procedure with at least one hand.

70. The surgical tool kit of any one of claims 50-69, wherein the tissue scaffold comprises at least one press-fit ring designed for secure fixation of the tissue scaffold on the host tissue.

71. The surgical tool kit of any one of claims 50-70, further comprising an implant tap that feature cutting threads, is cannulated to fit over the guide pin, and comprises at least six flutes designed to trap bone removed by the cutting threads during a threading process.

72. The surgical tool kit of claim 71, wherein the implant tap is rotated to cut threads in the host tissue, and further comprises an insertion tool with two tines designed to engage two insertion slots of the tissue scaffold, wherein the tissue scaffold is opened by pressing on two press points, allowing the insertion tool to rotate the tissue scaffold and screw it into the prepared socket.

73. The surgical tool kit of any one of claims 50-72, wherein the host tissue comprises bones, cartilages, or other tissues.

74. The surgical tool kit of any one of claims 50-73, wherein the tissue scaffold comprises at least one thread designed for secure fixation of the tissue scaffold on the host tissue.

75. The surgical tool kit of any one of claims 50-74, wherein the surgical tool kit is sterilized before use.

76. The surgical tool kit of any one of claims 50-75, wherein the surgical tool kit is sterilized by steam autoclaving.

77. The surgical tool kit of any one of claims 50-76, wherein the tissue scaffold is sterilized before use.

78. The surgical tool kit of any one of claims 50-77, wherein the tissue scaffold is sterilized by steam autoclaving.

79. The surgical tool kit of any one of claims 50-78, wherein the installation of the tissue scaffold is conducted within about 2 hours post sterilization.

80. The surgical tool kit of any one of claims 50-79, wherein the tissue scaffold is hydrated prior to installation.

81. The surgical tool kit of any one of claims 50-80, wherein the tissue scaffold is packed in a container prior to installation.

82. The surgical tool kit of claim 81, wherein the container is made of glass, polymer, or metal.

83. The surgical tool kit of claim 81 or 82, wherein the container is filled with an aqueous solution.

84. The surgical tool kit of any one of claims 50-83, wherein the surgical tool kit is organized and fixed in place within a metal container.

85. The surgical tool kit of claim 84, wherein the metal container can be sterilized.

86. The surgical tool kit of any one of claims 50-85, wherein the surgical tool kit comprises at least one size of each tool.

87. A method of installing a tissue scaffold, the method comprising: positioning an alignment guide to ensure proper alignment of surgical tools relative to a lesion in a host tissue; inserting a guide pin into the host tissue to provide a reference point; using a punch to score the host tissue at the location of the guide pin; utilizing a cannulated reamer to prepare a socket in the host tissue; evaluating the prepared socket in the host tissue with a trial implant to ensure proper fit and alignment; employing an undercut tool to prepare at least one groove in the host tissue; and placing the tissue scaffold into the prepared socket using an insertion tool.

88. The method of claim 87, wherein the lesion in the host tissue is a chondral lesion.

89. The method of claim 87 or 88, wherein the host tissue comprises a femur bone.

90. The method of claim 88, further comprising measuring the chondral lesion with the alignment guide to assess dimensions of the lesion.

91. The method of any one of claims 87-90, further comprising assessing a position of the tissue scaffold to ensure that intact tissue is fully surround the tissue scaffold.

92. The method of any one of claims 87-91, wherein the alignment guide is positioned to fully cover the host tissue.

93. The method of claim 92, wherein the host tissue is an articular cartilage lesion.

94. The method of any one of claims 87-93, wherein the alignment guide is oriented perpendicular to the lesion and is fitted to a surface of the host tissue.

95. The method of any one of claims 87-94, further comprising placing the guide pin into the alignment guide.

96. The method of claim 95, wherein an orientation of the guide pin is aligned with an orientation of the tissue scaffold.

97. The method of claim 95 or 96, further comprising drilling the guide pin into the host tissue until the depth stop line on the guide pin is aligned with an opening of the alignment guide.

98. The method of any one of claims 87-97, further comprising selecting the punch from a plurality of predefined-size punches to score the host tissue.

99. The method of claim 98, wherein the punch is placed over the guide pin.

100. The method of claim 99, further comprising applying axial pressure to the punch while rotating the punch to score the host tissue.

101. The method of any one of claims 87-100, further comprising selecting the reamer from a plurality of predefined-size reamers to prepare a cylindrical socket for receiving the tissue scaffold.

102. The method of claim 101, wherein a depth stop is assembled onto a shaft of the reamer, wherein the reamer is turned until the reamer is locked before use.

103. The method of claim 101, wherein the depth stop is designed to ensure that the tissue scaffold sits recessed within the prepared socket.

104. The method of any one of claims 87-103, further comprising preparing to assess a depth and orientation of the socket with applying the trial implant.

105. The method of any one of claims 87-104, further comprising employing the undercut tool to prepare at least one groove in the host tissue to enhance the fixation of the tissue scaffold.

106. The method of any one of claims 87-105, further comprising placing the tissue scaffold into the prepared socket using the insertion tool, wherein the insertion tool ensures a proper placement and secure fixation of the tissue scaffold within the host tissue.