[go: up one dir, main page]

WO2018051228A1 - Vis à os à diamètre variable limité - Google Patents

Vis à os à diamètre variable limité Download PDF

Info

Publication number
WO2018051228A1
WO2018051228A1 PCT/IB2017/055494 IB2017055494W WO2018051228A1 WO 2018051228 A1 WO2018051228 A1 WO 2018051228A1 IB 2017055494 W IB2017055494 W IB 2017055494W WO 2018051228 A1 WO2018051228 A1 WO 2018051228A1
Authority
WO
WIPO (PCT)
Prior art keywords
proximal
longitudinal bore
head
shank
struts
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/IB2017/055494
Other languages
English (en)
Inventor
Mark Levy
Eran ISHAY
Ohn LEVY
Jaffar Hleihil
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Expanding Orthopedics Inc
Original Assignee
Expanding Orthopedics Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Expanding Orthopedics Inc filed Critical Expanding Orthopedics Inc
Publication of WO2018051228A1 publication Critical patent/WO2018051228A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws or setting implements
    • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
    • A61B17/84—Fasteners therefor or fasteners being internal fixation devices
    • A61B17/844—Fasteners therefor or fasteners being internal fixation devices with expandable anchors or anchors having movable parts
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws or setting implements
    • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
    • A61B17/84—Fasteners therefor or fasteners being internal fixation devices
    • A61B17/86—Pins or screws or threaded wires; nuts therefor
    • A61B17/8685—Pins or screws or threaded wires; nuts therefor comprising multiple separate parts
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws or setting implements
    • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
    • A61B17/70—Spinal positioners or stabilisers, e.g. stabilisers comprising fluid filler in an implant
    • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
    • A61B17/7035—Screws or hooks, wherein a rod-clamping part and a bone-anchoring part can pivot relative to each other

Definitions

  • the present invention generally relates to bone fasteners, such as pedicle screws, and particular to an expanding bone screw with superior pullout strength.
  • Pedicle screws have been the gold standard for internal fixation for the vast majority of surgical procedures in the thoracic and lumbar portions of the spine for more than two decades, and are generally considered a safe and effective treatment modality.
  • Implantation of short-term and long-term stable constructs for spine fixation is critical, especially when fusing more than one level.
  • bilateral pedicle screws are implanted in each vertebra since the pedicle isthmus is the strongest point of attachment to the bone, in addition to crossing through all three vertebral columns.
  • a strong bone-screw interface is of cardinal importance for screw-loosening prevention, particularly when dynamic loading is increased due to various clinical factors or when shorter fusion segments are selected.
  • the typical indications for pedicle screw systems include fracture fixation, treatment of spondylolisthesis, fixation after tumor resection, revision cases, correction of scoliosis and other congenital, idiopathic, developmental and/or degenerative deformations, and stabilization after spinal stenosis decompression and osteotomies.
  • the outer diameter of the screw has the largest influence on the pullout strength and resistance to loosening under cyclic loading.
  • Other factors that affect fixation strength to a lesser degree include screw length, inner diameter, pitch, core shape, use of single or double threads, coating and/or surface finish.
  • Screw fixation also depends on screw placement. Optimal fixation is achieved by use of convergent screws in a parallel transversal orientation, using the largest and longest screw possible without damaging the dorsal cortex or pedicle breach.
  • the surgical instruments used to prepare the pilot hole should be less than or equal to the inner screw diameter in order to preserve their maximum pullout force.
  • the present invention seeks to provide an expanding bone screw with superior pullout strength, as is described further in detail below.
  • the screw diameter is minimal at insertion to facilitate screw placement, using the smallest pilot hole possible, and the screw diameter is then expanded in place after insertion.
  • the diameter is expanded at the proximal end of the screw, within a limited range until a maximal diameter, where it will have the greatest effect as it is performed in the region of the bone with the highest density, i.e. the pedicle. This is in contrast with prior art screws that expand at the distal end, i.e., far from the screw head, which have had inferior pullout strength.
  • the screw can be made of any medical compatible material for bone utilization, such as but not limited to, titanium, titanium-aluminum-vanadium alloy, CoCr alloy, PEEK (polyetheretherketone), carbon fibers reinforced polymer, polymers, or any other metal, natural or synthetic material including resorbable materials.
  • the surfaces of such devices may be regular or irregular, including surfaces that may enhace attachment to bone.
  • a bone screw including a shank having a proximal spherical head and formed with a longitudinal bore that extends an entire length of the shank, the shank including three threaded portions, a distal portion, a middle portion and a proximal portion, the distal portion extending at least a third of the entire length of the shank, the middle portion and the proximal portion each including two or more expandable struts, and the struts of the middle portion being joined to the struts of the proximal portion by a bending region, wherein the longitudinal bore in the proximal portion is larger in diameter than in the distal portion and the longitudinal bore in the spherical head is larger in diameter than in the proximal portion and terminates distally in the spherical head as a shoulder, and a wedge element movably disposed in the longitudinal bore in the proximal portion and in the middle portion, the wedge
  • Figs. 1A and IB are simplified illustrations of a bone screw, constructed and operative in accordance with a non-limiting embodiment of the present invention, respectively in contracted and expanded orientations.
  • FIG. 1A-1B illustrate a bone screw 10, in accordance with a non-limiting embodiment of the present invention.
  • the bone screw 10 may be used in any bone including the vertebra, such as but not limited to, a pedicle screw.
  • screw 10 has a threaded shank 12 with a proximal spherical head 14 on which is mounted a polyaxial head 16.
  • Polyaxial head 16 may have a threaded opening 18.
  • Shank 12 may be hollow (cannulated), that is, formed with a longitudinal bore 20 (e.g., central bore) that extends the entire length of the shank 12 of screw 10.
  • Shank 12 of screw 10 has three threaded portions, a distal portion 22, a middle portion 24 and a proximal portion 26.
  • the distal portion 22 preferably does not expand, but other embodiments are contemplated in which the distal portion 22 is allowed to expand.
  • Distal portion 22 preferably extends at least a third of the entire length of shank 12 (the length of shank 12 being defined as the distance from the distal tip of the screw to the proximal face of spherical head 14).
  • the middle portion 24 and proximal portion 26 may each include two or more expandable struts 28, such as but not limited to, three struts 28 that are equally spaced (120° apart) circumferentially about the perimeter of shank 12.
  • the struts 28 of middle portion 24 may be joined to the struts 28 of proximal portion 26 by a bending region 30, such as a live hinge or pivot element.
  • the bending region 30 may mean the struts bend about a bending line (in which case, the struts are basically straight on either side of the bending line) or the bending region may be a curved region (in which case, the struts curve or bow outwards and are not necessarily straight after bending).
  • the longitudinal bore 20 in proximal portion 26 is larger in diameter than in distal portion 22 and middle portion 24.
  • the distal end of longitudinal bore 20 in proximal portion 26 may be conical.
  • the longitudinal bore 20 in spherical head 14 is larger in diameter than in proximal portion 26 and terminates distally in spherical head 14 as a shoulder 32.
  • a wedge element 34 is initially disposed in longitudinal bore 20 in proximal portion 26 and middle portion 24.
  • the wedge element 34 includes a distal shank 36 (with a chamfered distal end) and a proximal head 38.
  • wedge element 34 may be cannulated.
  • Wedge element 34 may slide in bore 20, or alternatively, the longitudinal bore 20 in spherical head 14 may be tapped (internally threaded) and head 38 may be threaded externally so that turning head 38 (such as with a screwdriver) either advances or retracts wedge element 34 in longitudinal bore 20 (that is, longitudinal bore 20 threadingly mates with a portion of wedge element 34).
  • wedge element 34 may move along a guide element 40, such as a rod 40 positioned in portions of middle portion 24 and proximal portion 26.
  • Fig. 1A shows screw 10 in its retracted state, before distal advancement of wedge element 34.
  • Fig. IB shows screw 10 in its expanded state, after distal advancement of wedge element 34.
  • Screw 10 has limited expansion, because wedge element 34 can advance distally only until its head 38 abuts against shoulder 32. Screw 10 can return from the expanded state to the retracted state by simply moving wedge element 34 proximally backwards (the struts 28 having undergone elastic deformation, which is fully reversible). This will allow the easy removal of the screw if needed. This limited expansion ensures that the bone screw cannot be expanded beyond a certain diameter, thus providing a safety feature.
  • the struts may have a certain degree of plastic deformation, producing some hysteresis so the reversibility may not be complete but small enough to allow the removal of the screws after moving the wedge element .
  • screw 10 may expand by a maximum of 1 mm in diameter (0.5mm in radius).
  • a 5.5 mm diameter screw is capable of increasing its diameter up to 6.5 mm (and 6.5 mm up to 7.5 mm).
  • the slits or gaps separating struts 28 from each other may be, without limitation, 0.4 mm in width or less and about 20 mm in length. Upon maximum expansion, the gap width may increase without limitation from 0.4 to 1.4 mm, while the length may remain substantially unchanged.
  • the maximum expansion is 1 mm, however, the user may choose to stop turning the wedge element 34 at any point to arrive at any desired partial expansion.

Landscapes

  • Health & Medical Sciences (AREA)
  • Orthopedic Medicine & Surgery (AREA)
  • Surgery (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Neurology (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Surgical Instruments (AREA)

Abstract

La présente invention concerne une fixation osseuse (10) comprenant une tige (12) qui a une tête sphérique proximale (14) et est formée avec un alésage longitudinal (20). La tige (12) comprend trois parties filetées, une partie distale (22), une partie médiane (24) et une partie proximale (26). La partie médiane (24) et la partie proximale (26) comprennent chacune deux entretoises extensibles ou plus (28). L'alésage longitudinal (20) a un diamètre plus grand dans la partie proximale (26) que dans la partie distale (22) et l'alésage longitudinal (20) a un diamètre plus grand dans la tête sphérique (14) que dans la partie proximale (26) et se termine de manière distale dans la tête sphérique (14) sous forme d'un épaulement (32). Un élément de coin (34) est disposé de façon mobile dans l'alésage longitudinal (20). L'élément de coin (34) comprend une tige distale (36) et une tête proximale (38), la tête proximale (38) étant conçue pour venir en butée contre l'épaulement (32).
PCT/IB2017/055494 2016-09-14 2017-09-12 Vis à os à diamètre variable limité Ceased WO2018051228A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201662394299P 2016-09-14 2016-09-14
US62/394,299 2016-09-14

Publications (1)

Publication Number Publication Date
WO2018051228A1 true WO2018051228A1 (fr) 2018-03-22

Family

ID=60191423

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2017/055494 Ceased WO2018051228A1 (fr) 2016-09-14 2017-09-12 Vis à os à diamètre variable limité

Country Status (1)

Country Link
WO (1) WO2018051228A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20210085510A (ko) * 2019-12-30 2021-07-08 주식회사 엔닥 팽창 복원 기능을 구비한 뼈 고정용 스크류
EP4464269A1 (fr) * 2023-05-16 2024-11-20 Sota Orthopaedics Limited Boulon pour la fixation d'os
JP2025502571A (ja) * 2022-01-26 2025-01-24 エーアイアールエス インク． プッシュ型の片側皮質骨固定アンカー

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5827285A (en) * 1996-12-12 1998-10-27 Bramlet; Dale G. Multipiece interfragmentary fixation assembly
WO2008004057A2 (fr) * 2006-07-05 2008-01-10 Implants International Limited Vis à os
US20120265258A1 (en) * 2011-04-14 2012-10-18 Brian Garvey Expanding Spinal Anchor

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5827285A (en) * 1996-12-12 1998-10-27 Bramlet; Dale G. Multipiece interfragmentary fixation assembly
WO2008004057A2 (fr) * 2006-07-05 2008-01-10 Implants International Limited Vis à os
US20120265258A1 (en) * 2011-04-14 2012-10-18 Brian Garvey Expanding Spinal Anchor

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20210085510A (ko) * 2019-12-30 2021-07-08 주식회사 엔닥 팽창 복원 기능을 구비한 뼈 고정용 스크류
KR102342948B1 (ko) * 2019-12-30 2021-12-24 주식회사 엔닥 팽창 복원 기능을 구비한 뼈 고정용 스크류
JP2025502571A (ja) * 2022-01-26 2025-01-24 エーアイアールエス インク． プッシュ型の片側皮質骨固定アンカー
JP7765133B2 (ja) 2022-01-26 2025-11-06 エーアイアールエス インク． プッシュ型の片側皮質骨固定アンカー
EP4464269A1 (fr) * 2023-05-16 2024-11-20 Sota Orthopaedics Limited Boulon pour la fixation d'os
WO2024236158A1 (fr) * 2023-05-16 2024-11-21 Sota Orthopaedics Limited Vis pour la fixation d'os

Similar Documents

Publication Publication Date Title
US11786279B2 (en) Modular spinal fixation device
US20250107832A1 (en) Bone anchors
EP2967582B1 (fr) Vis pédiculaire à découpe en spirale inverse
US7601166B2 (en) Stabilization device for the dynamic stabilization of vertebrae or bones and rod like element for such a stabilization device
EP2445426B1 (fr) Dispositif de stabilisation dynamique postérieure ayant une ancre mobile
US20110295319A1 (en) Dynamic pedicle screw
US20120290013A1 (en) Tapered spinal rod
US10327819B2 (en) Bone screw
MX2011004699A (es) Dispositivo de sujecion para cuerpos vertebrales de una columna vertebral.
Yaman et al. The Comparison of Pullout Strengths of Various Pedicle Screw Designs on Synthetic Foams and Ovine Vertebrae.
KR20140085360A (ko) 동적 뼈 고정기
US9168068B2 (en) Spinal stabilization system
WO2018051228A1 (fr) Vis à os à diamètre variable limité
CN104605903A (zh) 微创撑开加压器
RU2641376C2 (ru) Некруглый транспедикулярный винт
Koller et al. Impact of constrained dual-screw anchorage on holding strength and the resistance to cyclic loading in anterior spinal deformity surgery: a comparative biomechanical study

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17791730

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17791730

Country of ref document: EP

Kind code of ref document: A1