KR20080111461A - Cutter to create intervertebral disc space - Google Patents

Abstract

A cutter assembly for use with a cutter blade made of shape memory material. The cutter blade may be deployed inside the intervertebral disc space and may be rotated about the central axis of the cutter assembly to cut to remove material present from the intervertebral disc space. Cutter blades with other characteristics (such as operating range section, cutter blade angle, type and position of blade edge) are applied to achieve other purposes within the intervertebral disc space. Some cutter blades are applied to promote bleeding of the vertebral end plates and cartilage, and some cutter blades are applied to avoid the occurrence of such bleeding. Closed loop cutter blades are described that have certain desired characteristics, including the ability to remove the entire cutter blade from the intervertebral disc space after breakage of the blade. Details including the sawtooth pattern using the trapezoid sawtooth shape are described in the description of the sawtooth pattern.

Description

Cutter to create intervertebral disc space {CUTTER FOR PREPARING INTERVERTEBRAL DISC SPACE}

The present invention generally relates to the spine in the intervertebral space between these two adjacent vertebral bodies for subsequent therapeutic procedures, including therapies that do not require fusion of two adjacent vertebral bodies, such as therapies for implanting an exercise preservation device into the spine. An improved cutter and a method for preparing a treatment site within.

This application is based on a series of applications filed on behalf of the assignee. In particular, the present application discloses US patent application Ser. No. 10 / 972,077 filed on Oct. 22, 2004 and later published US patent application US 2005, which discloses a method and apparatus for manipulating materials in a spine that is pending and commonly assigned. / 0149034 A1 and February 28, 2006 extends innovative methods in the area for manipulating materials in the spine proposed in US Provisional Application No. 60 / 778,035, filed as a method and apparatus for tissue manipulation and extraction. This application incorporates by reference both the '077 application and the' 035 application as a priority claim application for the '035 application.

This application is pending US patent application Ser. No. 11 / 586,338, filed Oct. 24, 2006, and commonly assigned spinal motion preservation assembly, and tools and methods for delivery of the spinal motion preservation assembly on October 24, 2006. It extends an innovative method in the area of spinal motion preservation assembly proposed in US patent application Ser. No. 11 / 586,486, filed with. This application incorporates by reference both the '338 application and the' 486 application as priority claims applications.

Although many applications have been incorporated by reference to provide additional details, previous other applications (including later registered patents) have been described at the time of filing and may have a different viewpoint than the present application. Accordingly, this application controls the extent to which any application incorporated herein differs from the use of any technology or technology.

[summary]

The present invention extends the method in a series of patent applications (some currently registered patents) with conventional assignees. Many of these methods are incorporated herein by reference and are described in detail in the many applications referenced above. Thus, the background of the invention provided herein does not repeat all the details described in the prior application, but instead highlights how the invention is added to this method.

The spinal column is a complex system of bone segments (vertebral bodies and other bone segments) that are separated from each other in most cases by disks in the intervertebral space (excluding the sacrum). 1 illustrates several segments of the human spinal column as viewed from the side. In the context of the present invention, the "motion segment" refers to the intervertebral space, which separates the adjacent vertebrae, i.e., the lower and upper vertebral bodies and the two vertebral bodies into spaces in which the nucleus has been removed or intact or damaged vertebral discs. (Interpolated disk space). Unless pre-fused (or damaged), each segment of motion contributes to the overall flexibility of the spine and contributes to the overall bendability of the spine to provide support for the movement of the trunk and head.

The spinal cord of the spinal cord is generally subdivided into several sections. When viewed from head to tailbone, the sections are cervical spine 104, thoracic spine 108, lumbar spine 112, sacrum (sacrum) 116 and tailbone 120. Individual vertebral bodies within the section are identified numerically starting at the vertebral body closest to the head. The trans-sacral approach is quite suitable for accessing the lumbar section and the vertebral bodies of the sacrum section. Since the various vertebral bodies of the sacrum sections are usually fused to each other in adults, it is more fully described that they are represented only by the sacrum rather than the individual sacral components.

It is useful to explain some of the standard medical terms before describing the background of the invention in more detail. In the context of this description: the anterior represents the front of the spinal column; (Abdomen) and posterior represent spinal column posterior (dorsal); The cephalad indicates towards the head of the patient (sometimes "upward"); The caudal (sometimes "down") represents a direction or position close to the foot. Since the present invention contemplates access to various vertebral bodies and intervertebral spaces through the preferred approach of moving from the sacrum towards the head, the proximal and distal are defined in relation to the access channel. Thus, the proximal is close to the beginning of the channel towards the foot or the surgeon, and the distal away from the beginning of the channel toward the head or further away from the surgeon. In the context of a tool comprising a cutter, the distal is the end intended for insertion into the access channel and the proximal represents the other end, generally the end close to the handle for the tool.

Each motor segment in the spinal column moves within limited limits and serves to protect the spinal cord. The disc is important for relieving and distributing the great force through the spinal column when a person walks, bends, lifts or otherwise exercises. Unfortunately, for several reasons to be described later, for some people one or more discs in the spinal column will not work as intended. The reasons for disc problems range from degeneratives that can be attributed to birth defects, diseases, wounds, or aging. Sometimes when the disc does not work properly, the gaps between adjacent vertebral bodies are reduced, which causes additional problems with pain.

Therapies continue to be developed to alleviate the pain associated with the disc problem. One class of solutions is to remove the damaged disc and then fuse two adjacent vertebral bodies together into a permanent but inflexible space, also referred to as static stabilization. It is estimated that approximately 300,000 fusion operations were performed in 2004 around the world. Fusion of one section with each other results in flexible (bendability) in the movement segment. Loss of normal physiological disc function to the motor segment through fusion of the motor segment may be better than sustained pain, but alleviates the pain and further maintains normal function of all or a substantial portion of the healthy motor segment. It would be desirable to.

Other classes of therapies have been attempted to treat the disc so that operation with the intended intervertebral space and physical properties is resumed. One type of treatment is to replace the original damaged disk with an artificial disk. This type of therapy is called by other names, such as dynamic stabilization or spinal motor conservation.

[Spine works]

The continuous bodies of the lumbar, thoracic and cervical vertebrae are segmented from each other and separated by intervertebral vertebral discs. Each vertebral disc includes a fibrous cartilage shell surrounding a central mass and "nucleus pulposus" (or "nucleus" herein) to buffer and relieve compressive forces on the spinal column. ) Is provided. The shell surrounding the nucleus comprises a cartilage end plate attached to the opposing cortical end plates (endplates) of the head and tail vertebral bodies and includes "annulus fibrosus" (or, herein, "rings"). ") Comprises multiple layers of opposing collagen fibers circumferentially surrounding said nucleus pulposus and connecting said cartilage end plates. Natural and physiological nuclei include hydrophilic (water aspirated) mucopolysacharides and fibrous strands (protein polymers). The nucleus is relatively inelastic, but the ring may expand slightly outward to accommodate the axial load on the spinal motion segment.

The intervertebral disc (intervertebral disc) is located in front of the spinal canal and is located between the end plate or the opposite end face on the head side and the tail vertebral body. The lower articulation process is segmented with the upper articulation process of the next continuous spine in the tail side (ie foot or lower) direction. Multiple ligaments (supraspinous, interspinous, anterior and posterior longitudinal and ligamenta flava) properly maintain the spine and allow only a limited degree of movement. The assembly of the two vertebral bodies, the inserted, intervertebral, intervertebral discs and attached ligaments, the muscles and the facet joints are referred to as "spine movement segments".

The relatively large vertebral body located at the anterior portion of the intervertebral disc and the spine provides the majority of weight to withstand the support of the spinal column. Each vertebral body has a relatively strong cortical bone layer that forms the outer surface of the exposed body, including the end plates, and a weak spongy bone at the center of the vertebral body.

The nucleus pulposus, which forms the central part of the intervertebral disc, consists of 80% of water absorbed by the proteoglycans of the healthy adult spine. As aging develops, the nucleus becomes less fluid, more viscous, and often even dehydrates and contracts (sometimes referred to as "isolated disc resorption"), causing severe pain in many cases. The vertebral disc acts as a "buffer" between each vertebral body, which minimizes the impact of spinal movement, and disc degeneration, expressed as a decrease in the amount of water in the nucleus, transfers the load to the annulus layer. This makes the disk inefficient. In addition, the rings tend to be thick and dry, which makes them harder and less susceptible to rupture or fracture by reducing the ability of elastic deformation under load, and when the rings rupture or tear, a form of disc degeneration occurs. The rupture may or may not be accompanied by ejecting nuclear material into and out of the ring. The tear itself may be only a morphological change beyond the generalized degenerative changes in the connective tissue of the disc, and nevertheless the disc tear may be painful and debilitating. Biochemicals contained within the nucleus can escape through rupture and stimulate structures near them.

Various other surgical treatments that preserve the intervertebral vertebral discs and simply relieve pain may involve removing a majority or a portion of internal nuclei to reduce and reduce external pressure in the annulus, such as "discectomy" or "disc disc decompression." decompression) ". In a less invasive microsurgical procedure known as "microlumbar discectomy" and "automated percutaneous lumbar discectomy", the needles extend laterally through the ring. The nucleus is removed by suction. Although the procedure is less invasive than open surgery, it is nevertheless likely to be injured by instability due to excessive bone removal, nerve roots and dura sac, wound formation around the nerve and relocation of the surgical site. . In addition, this will generally include the perforation of the ring.

Damaged discs and vertebral bodies can be identified by sophisticated diagnostic imaging, but existing surgical procedures and clinical results are consistently unsatisfactory. In addition, patients undergoing this fusion surgery experience significant complications, discomfort, and long-term care. For example, surgical complications include disk space infection; Nerve root damage; Hematoma formation; Proximal spinal instability, and muscle, tendon and ligament rupture.

Several companies are pursuing the development of prosthetics, or artificial discs, for the human spine that can completely replace physiological discs. In individuals whose degree of degeneration does not progress to the destruction of the rings, it may be a desirable treatment option to replace or increase the nucleus pulposus, including the placement of the artificial disc nucleus, rather than to replace the entire artificial disc. As described above, a normal nucleus is contained within a fibrous frame circumferentially surrounding the nucleus and within a space bounded by bone vertebrae at the top and bottom of the nucleus. In this way, the nucleus, together with the spinal column known as the endplate, is completely encapsulated with the fluid exchange occurring through the bone boundary by optimal delivery to the body.

Despite sufficient physiological loads carried across the disk in normal activity, the hydroscopic material present in the physiological nucleus is strong enough to distort (ie, excite or "expand" the intervertebral disc space). Affinity for moisture (and volume expansion). These loads, ranging from 0.4 to 1.8 times the body weight, generate local pressure above normal blood pressure, and in fact the nucleus and internal ring tissue become avascular.

Detailed descriptions of specific exercise preservation devices and advantages, including methods for implanting exercise preservation devices, have been proposed in various pending applications including the aforementioned 11 / 586,338 and 11 / 586,486. You may choose to present these details, but you will not need to repeat them here.

On the other hand, the cutter to be described later can be used in other surgical procedures, including spinal surgery to reach the intervertebral space through the front or rear access, rather than to access the intervertebral space through the axial approach. The cutter is disk space surgically denuclearized from an access point across the treatment area via a cannula docked against the sacrum along a partial or complete nucleectomy. Can be used in surgical procedures with an axially inserted motion preservation device in the spine. In such a procedure, the introduction of the spinal motion preservation assembly of the present description is accomplished without the need to surgically create or deleteriously expand the holes present in the fiber frame of the disc.

The shape of the cutter blade is considered such that the cutter blade is efficient in many cases of preparing the nuclear material for removal by cutting (slicing, tearing or some combination thereof). In order to reduce the cost of manpower, such as surgical teams and their medical centers, and to reduce the duration of patient anesthesia, it is generally desirable for a surgeon to perform a procedure quickly while efficiently reducing the length of the procedure.

Cutter blades, which can be replaced frequently, may be less desirable than cutter blades with similar characteristics that are more durable and can be used for a long time without having to be replaced.

Cutter blades that do not operate in a mode where all parts of a broken cutter blade can be easily removed from the intervertebral space and the patient body may be desirable over similar cutter blades that do not have this feature.

Described herein is a cutter assembly for use with a cutter blade made of shape memory material. The cutter blade may be developed inside the intervertebral disc space and may be rotated about the central axis of the cutter assembly approximately aligned with the centerline of the axial channel. The cutter blade as part of the cutter assembly in the intervertebral disc space is rotated to remove material present from the intervertebral disc space. Cutter blades with other characteristics (such as operating range section, cutter blade angle, type and position of blade edge) are applied to achieve other purposes within the intervertebral disc space. Some cutter blades are applied to facilitate bleeding of the vertebral endplates and cartilage, and some cutter blades are applied to avoid the occurrence of such bleeding or to avoid such bleeding by pursuing other treatment procedures.

Closed loop cutter blades are described that have certain desired characteristics, including the ability to remove the entire cutter blade from the intervertebral disc space after breakage of the blade. Details including the sawtooth pattern using the trapezoid sawtooth shape are described in the description of the sawtooth pattern.

Other systems, methods, features and advantages of the present invention will become more apparent from the accompanying drawings and the description. All such additional systems, methods, features, and advantages are included within this description, are included within the scope of the invention, and will be covered by the appended claims.

1 is a cross-sectional view of the human spine.

2A-2C illustrate an anterior trans-sacral axial approach method of forming an axial channel of the spine that can be used to provide an axial channel in the spine for use with the present invention.

3 shows a cutter assembly with a cutter blade inserted into an axial channel in an extended position.

4A and 4B show a cutter assembly.

5A and 5B illustrate one method of connecting a cutter blade to a cutter shaft.

6A-6D are additional views of the cutter assembly including stops that limit the reciprocating range of the cutter cover.

FIG. 7 illustrates the concept of sections of different operating ranges of a series of cutter blades in an intervertebral disc space. FIG.

FIG. 8 illustrates a problem that occurs when the axial channel is not approximately perpendicular to the end plate for the intervertebral disc space.

9 shows a blade arm for a cutter blade having angles of 45 degrees, 90 degrees, and 135 degrees with respect to the longitudinal portion of the cutter blade.

10A to 10C are views showing cutter blades viewed in three directions.

11 shows a cross section of a cutter blade with a blade edge.

12 shows the cutter blade in the first cutter shaft without the cutter shaft extension.

13 shows a cutter blade in a cutter shaft with a cutter shaft extension.

14-16 show a cutter shaft without cutter shaft extensions.

17 to 19 show cutter shafts with cutter shaft extensions.

20A to 20C are diagrams illustrating a cutter blade having a round sawtooth shape on one side of the cutter blade.

21A to 21C illustrate a cutter blade having a round sawtooth shape at one side of the cutter blade and a different sawtooth pattern at the tip of the cutter blade.

22A-22C show cutter blades viewed from different directions with serrated cutting edges on both the clockwise and counterclockwise sides of the cutter blade.

23 and 24 are detailed views of adding the sawtooth shape to a flat stock of appropriate size to produce a cutter blade.

FIG. 25 shows material removed from a flat stock to form a cutter blade using a trapezoidal sawtooth pattern.

FIG. 26 shows a cutter blade having a trapezoidal sawtooth pattern as the cutter blade of the cutter assembly. FIG.

27A-27D illustrate blade stock with a trapezoidal sawtooth pattern.

28A-28D illustrate a round toothed sawtooth pattern cut in a blade stock.

29A-29G are views of a cutter blade made from blade stock in a saw form from various directions, with a sawtooth pattern as shown in FIGS. 28A-28D.

30 and 31 show two exemplary forms of cutter blades with an angle of 135 degrees between the proximal portion of the blade arm and the longitudinal portion of the cutter blade.

32A-32C show connection of a cutter blade to a cutter shaft based on rivets.

The foregoing objects, features, and advantages will become more apparent from the following examples taken in conjunction with the accompanying drawings. The components of the drawings are not drawn to scale, but rather represent important parts of the principles of the invention. In the drawings, like reference numerals designate corresponding parts in different drawings throughout. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Even if the cutter of the present invention to be described below can be used for other surgical procedures, it is useful to describe here how such a cutter can be used in a trans-sacral approach. As noted above, there are several advantages with regard to minimally invasive, less traumatic trans-sacral axial approach. The trans-sacral axial approach (commonly assigned U.S. Pat. While there are a number of advantages over other paths for transmission, there are logical problems in providing intervertebral disc space through axial access channels. In dealing with this problem, one encounters certain aspects of the cutter intended for use as described above.

[Trans-Sacral Axial Access]

The trans-sacral axial approach shown in FIG. 2 provides for the treatment procedure including stabilization, exercise preservation, and fixation device / fusion system over the course of treatment in the procedure and during the deployment (deployment) of the newly improved instrument shape and There is no need for other invasive steps and muscle incisions associated with traditional spinal surgery.

FIG. 2 shows a "blunt tip stylet" 204 "walked" to the intended position of the sacrum 116 over the anterior side of the sacrum 116 during monitoring with one or more fluoroscopy (not shown). 2a and 2b illustrating the process of "walking" to provide an overview of the process. This process moves the rectum 208 out of the way so that a straight path is established for the next step. 2C shows an exemplary trans-sacral axial channel 212 formed in the L5 vertebrae 216 through the sacrum 116, the L5 / sacral intervertebral space. If a treatment regimen is provided to the L4 / L5 motor segment, the channel will extend through the L5 spine 216 and the L4 / L5 intervertebral space to the L4 spine 220.

The description of FIG. 2 provides a context for the present invention. Previous applications with conventional assignees (now part of which are registered in the US patent) include a description of another approach that is a posterior trans-sacral axial vertebral approach rather than an anterior trans-sacral axial vertebral approach. (For example, US Pat. No. 6,558,386 for an axial spinal implant and apparatus and method for implanting an axial spinal implant into the spinal column as a patent describing the anterior trans-sacral axial approach shown in FIG. Note that the whole is incorporated by reference)

As shown in FIG. 3, the axial direction, which is difficult to see with the naked eye because the dilator sheath 380 passes through the sacrum 116, substantially fills the axial channel 212. The cutter 400 is inserted through an axially aligned anterior tract 372 formed by the lumen of the channel 212 and the dilator cover 380. (The axial channel 212 may be replaced at a later stage so that the length of the axial channel shown in one figure may be different from that shown in the other figure so that the axial tube may include additional vertebral or intervertebral space. It will be appreciated by the ordinary person skilled in the art (hereinafter referred to as "the person skilled in the art") that it can be extended in the axial direction by the axial channel for some treatment due to anatomical differences. Those skilled in the art will appreciate that they can escape this sacrum and enter through other parts of the spine.

As shown in FIG. 3, the exercise segment 316 is a proximal vertebra 308 (sacral 116), an intervertebral space 312 (in this case, a disc 330, a fibrous 334, and a nucleus ( L5-S1 space with 338), distal vertebra 304 (in this case L5 216). The cutter 400 includes a remotely operable cutting blade (eg, cutter blade 453 collectively depicting any blade configuration). Manipulating the cutter blade 453 may include retracting the cutter blade 453 into the cutter assembly 400, whereby the maximum radius of the cutter assembly 400 is reduced and the retracting is performed. The cutter assembly with the blade 453 may be advanced through the axial channel 212. After reaching the position where the cutter blade 453 is to be operated, the cutter blade 453 may be extended.

As shown in FIG. 3, the center line 262 of the cutter 400 is axial because the cutter 400 is inserted into the expander cover 380 and the expander cover 380 is inserted into the axial channel 212. Very close to the centerline of channel 212. When the cutter blade 453 extends as shown in FIG. 3, the cutter blade is approximately traversed (crossed) with respect to the centerline 262 of the cutter 400. The extended cutter blade 453 extends laterally to the nucleus 338 of the spinal disc 330.

After the cutter blade 453 is retracted into the cutter cover, the cutter blade 453 and the cutter shaft 410 "push-pull", if necessary, to extend the cutter blade 453 from the distal end of the cutter cover. The cutter shaft 410, cutter lid 430 (shown in FIG. 4) and handle components are preferably configured together so as to enable "pushed-pulled" attachment. More specifically, the cutter blade edge of the cutter blade 453 is retracted into the cutter cover 430 (see FIG. 4) for delivery to the intervertebral disc space (intervertebral disc space) 312. Once the cutter 400 is in position, the cutter blade 453 extends distal and is rotated using a handle to cut tissue in the intervertebral disc space 312. After the task of cutting is completed or when the cutter blade does not need to be replaced, the cutter blade 453 is moved from the axial channel 212 to the cutter cover 430 to remove the cutter assembly unit 400. It is retracted again.

The cutter assembly 400, cutter blade 453 and cutter assembly shaft 410 are schematically illustrated in FIGS. 4A and 4B, which are shown proportionally to each other or to the axial channel 212. Did.

Nucleotomy (nucleus) through insertion into the disc space to delete, disassemble and otherwise relieve nucleus pulposus or cartilage from the endplates from the disc cavity and from the lower and upper bone endplates. a cutter can be used to perform nucleectomy. As can be seen from this description, cartilage damage or cartilage removal tends to cause bleeding in the intervertebral disc space 312. Bleeding is likely to promote bone growth, which may be desirable in a fusion type of treatment regimen, but may not be desirable in other treatment regimens, including the treatment regimen needed to implant an exercise preservation device in exercise segment 316.

In connection with the exemplary embodiment of FIGS. 4A and 4B, the cutter assembly 400 (also simply referred to as a cutter) is a cutter having a distal end 412 and a proximal end 414. Shaft 410; A cutter blade 453 connected to the distal end 412 of the cutter shaft 410; A handle 416 connected to the proximal end 414 of the cutter shaft by an attachment method such as a set screw or a pin; A cutter cover (430) positioned at the same central axis above the shaft (410); And shaft sleeve 418 (shown in the following figure).

5A and 5B illustrate one method of connecting the cutter blade 453 to the cutter shaft 410. Prior to inserting the pin 409, a longitudinal portion 406 of the cutter blade 453 is located in a slot 413 close to the distal end 412 of the cutter shaft 410. The cutter blade slot 427 may be aligned with the cutter shaft hole 411 in the shaft slot 413. The pin 409 is optimally shown in the cutter blade slot 427 (shown in FIG. 5A), ie, the cutter blade hole 407 on the opposite side of the longitudinal portion 406 of the cutter blade 453 (FIG. 10A). And shaft shaft hole 419 of shaft sleeve 418. The pin passes through the cutter blade hole 407 and enters the cutter shaft hole 411 of the cutter shaft slot 413.

The shaft slot 413 is dimensioned to accommodate the cutter blade 453. The width of the slot 413 is approximately equal to the width of the longitudinal portion 406 of the cutter blade 453. The bend 428 at the distal end of the slot 413 may extend (part of the cutter blade 453 or the portion of the cutter blade 402) which may extend (which forms a throw of the cutter blade). And a curved portion of the cutter blade 453 between the cutter blade arm 402) and the longitudinal portion 406. While the curved portion 428 at the distal end of the slot 413 provides axial support for the cutter blade arm 402 that acts in conjunction with the cutter blade edge structure to reinforce the cutter blade 453, the Slot 413 provides torsional support for cutter blade arm 402. The cutter shaft extension 480, which will be discussed in more detail below, to provide additional support for the cutter blade 453 to reduce the tendency of the cutter blade to bend when rotated in tissue.

The shaft sleeve 418, when pinned, plays an effective role in aligning and securing the longitudinal portion 406 of the shaft 410 and the cutter blade 453. To this end, the pin 409 fixing the cutter blade 453 to the shaft 410 may be approximately 0.06 inches (1.5 mm) in diameter.

When the cutter blade hole 407 is fixed to the cutter blade shaft 410, the cutter blade 453 is attached to the cutter blade shaft 410. The cutter blade slot 427 is a fixed portion of the longitudinal portion 406 so as to accommodate the shape change of the cutter blade 453 when the cutter blade is extended and covered again in the covered state. To allow relative movement of the slotted portion (grooved portion) of the longitudinal portion 406 relative to.

The remaining components of the cutter 400 can be stably fixed to each other using any suitable fastening mechanism known in the art.

6A-6D illustrate a series of cutter assemblies 400. 6A is a top view of the cutter assembly 400. 6B is a rear view of the cutter assembly 400. 6C is a cross-sectional view of FIG. 6B. FIG. 6D is an enlarged view of the expanded portion of FIG. 6C.

As shown in FIGS. 6A and 6D, the slots in the cutter shaft 410 may be placed in specific positions such that the handle 416 (if extended) is aligned with the blade arm 402. Although not required, the relationship between the handle and the blade is a useful method for the surgeon to know the rotational position of the handle 416 to sustain the position trajectory of the extended blade arm 402.

As shown in FIG. 6D, the reciprocating range (movement range) 440 of the cutter cover 430 is limited at the proximal end by the proximal end stop 444 attached to the cutter shaft 410. The reciprocating range 440 of the cutter cover 430 is limited at the distal end by the shoulder 448 of the cutter shaft 410.

Those skilled in the art will appreciate that certain components, such as the handle 416, cutter shaft 410 and cutter lid 430 may be reused even when the cutter blade 453 is processed after being used by only one patient. You can do it. The handle and the cutter shaft can be made as one integral component.

A sleeve or inner cover liner (not shown) may be inserted inside the cutter cover to reduce friction. The cutter blade 453 is nickel, such as Nitinol ^TM (Nitinol ^TM) - may be formed of a shape memory alloy containing titanium shape memory alloy. The cutter cover 430 may be made of stainless steel of a suitable grade. In order to reduce friction between the cutter blade 453 and the inner surface of the cutter cover 430, a dry lubricant such as polytetrafluoroethylene (PTFE) may be used. In addition, the sleeve or inner cover liner may be made of a material having a lower coefficient of friction than the cutter blade. When such components are reused, the components can be selected to have properties that can withstand multiple sterilization cycles. One such material is ultra-high molecular weight polyethylene (UHMWPE).

It is useful to explain why the cutter can be used continuously during the preparation of the interior of the intervertebral disc space 312 after introducing the cutter and its components. 7 shows a first example. 7 shows the distal vertebral body 304, the intervertebral disc space 312 (including the intervertebral disc 334 and interstitial nucleus 338 and including an intervertebral disc (intervertebral disc) 330 joined by an end plate) and the proximal vertebral body 308. A moving segment 316 is shown, which includes. For this example, it is not critical that the vertebral body be involved beyond the extent necessary to become adjacent vertebral bodies.

7 shows the cartilage layer 346 located at the end plate 342, which includes the end plate 342 of the distal vertebral body 304 and forms part of the intervertebral disc space 312. If the access path is a trans-sacral axial approach from the point of reference of the intervertebral disc space 312, the end plate 342 may be an upper end plate. Also shown in FIG. 7 is a cartilage layer 356 positioned at the end plate 352 that includes the end plate 352 of the proximal vertebral body 308 and forms part of the intervertebral disc space 312. If the access path is a trans-sacral axial approach from the reference point of the intervertebral disc space 312, the end plate 352 may be a lower end plate.

Inclusion of the cartilage layers 346 and 356 is intended to illustrate the use of cutters, which will be appreciated by those skilled in the art that are not intended to be anatomically accurate and do not represent the proper dimensions of cartilage.

The position of the cutter in the intervertebral disc space can be seen by the surgeon under real-time fluoroscopy imaging (both front / rear and lateral imaging are possible).

To illustrate the features, FIG. 7 includes showing different throw lengths of three different cutter blades 504, 508, 512. One skilled in the art will recognize that one method for cutting the nucleus 338 can use a series of cutter blades 504, 508, 512 and possibly other long blades to progressively cut the nucleus 338. Could be. The sections of different operating ranges (sometimes called reach) of these three blades can be used continuously from short to long states, which is only characteristic of the three different blade sections being shown simultaneously in FIG. It will be appreciated by those skilled in the art that the description is intended as. To illustrate this relationship, the range of cutter blades used in a particular procedure ranges from 0.40 inch for small cutter blades to 0.70 inch for long cutter blades. Those skilled in the art will recognize that such ranges may be varied by way of example. The optimal range of motion for the cutter blade depends on several factors including the patient's anatomy and the (axial) entry point into the disc space and also the problems associated with sagittal symmetry of the spinal disc. Further, for safety reasons, it would be desirable to limit the length of the cutter blade to exclude the operating range that is too close to the disc edge, i.e. to prevent contact between the cutter blade and the fiber frame to exclude damaging the fiber frame. Can be.

The cutter blades 504, 508, 512 in the extended case traverse about the center line 262 of the cutter and are parallel to an axis 266 perpendicular to the cutter blade center line 262. The cutter blade is also close to parallel with the end plates 342, 352 and the cartilage layers 346, 356.

In this example, the continuously elongated cutter blades 504, 508, 512 may be rotated more than 360 degrees around the centerline 262. For some surgeons to rotate the cutter handle at a predetermined angle (approximately 90 degrees) of 360 degrees and then act on one segment at a time by rotating the cutter handle in the opposite direction to return to the position occupied by the cutter. It may be desirable. Thus, this process proceeds during operation at radial quadrants. Sometimes these short movements are likened to the movement of the windshield wipers on the vehicle.

In addition to using a series of cutter blades with a sequentially increasing range of motion, the surgeon may also move the cutter blade to move further closer to the cartilage 346 at the end plate 342 of the distal vertebral body 304. It will be necessary to adjust the axial position of the cutter blade by sliding the cutter forward (distal to the segment) relative to the segment. By continuously using the cutter's increasing range of motion and repeating the process of further extension of the cutter into the nucleus (and subsequently repeating the increasing range of motion of the blades), the surgeon chooses to create a first space relatively close to the proximal vertebral body. Can be.

In addition, the surgeon may choose to use one or more cutters having a first operating range to create a space that approaches a cylinder that is approximately the same height as the first blade operating range and the approximate height of the space between the two cartilage layers. This process uses a radial cutter blade with a section of the given operating range, followed by one or more cutter blades at a different blade angle (eg 45 degrees) in addition to the section of the range of operation as described above. It may include. When the cut is complete for a given range of motion, the surgeon moves to the cutter blade for a longer range of motion to start over with the radial cutter blade. This process can be repeated with cutter blades of increasing blade operating range until the required amount of space is created.

The nature of the treatment procedure and the anatomy of the patient will determine the maximum operating range of cutter blades required. In some procedures, multiple cutter blade operating ranges are used to increase the range of operating ranges in small increments. In other procedures, a small range of motion range is simply utilized and moved to the maximum range of motion range required to provide the intervertebral disc space.

When the nuclear material is cut, the surgeon may periodically remove the cutter from the axial channel and use any suitable tissue extraction tool. Several retractable tissue extractors that can be used for this purpose are proposed in US patent application Ser. No. 10 / 972,077 (see above).

US patent application Ser. No. 10 / 972,077 (see above) describes bleeding which may be desirable for facilitating bone growth and facilitating fusion of the vertebral bodies of related motor segments when arranging intervertebral space for fusion procedures. It is proposed that using such a cutter to scrape the cartilage end plates to coarse the vascular vertebral body to produce coarse) may be advantageous.

However, not all treatment procedures attempt to obtain such bleeding to promote fusion. When the axial channel is created through the end plate 352, it is inevitable that the end plate 352 portion of the proximal vertebral body is disturbed (stirred), and likewise cartilage in the immediate vicinity of the axial channel A portion 356 (also cartilage 346 and end plate 342 of the distal vertebral body 304 is disturbed when the axial channel 212 (see FIG. 2C) extends to the distal vertebral body 304). Losing (agitating) is inevitable. However, the inevitable disturbance of the endplates and small parts of the cartilage does not eliminate the advantages within any procedure to avoid damaging the cartilage and other parts of the endplates.

8 shows another alignment between the end plates of the two vertebral bodies and the axial channel 212. In FIG. 8, the cutter assembly 400 partially passed through the dilator cover 380 in the axial channel 212 is either the end plate 352 of the proximal vertebral body 308 or the end plate 342 of the distal vertebral body (intervertebral space). And a cutter centerline 262 at an angle that is not near perpendicular to the lower and upper end plates of 312.

A cutter blade 353 having an angle of about 90 degrees between the cutter shaft 310 and the cutter blade 353 can be used to cut a portion of the nucleus, but cannot remove other portions of the nucleus. . Cutter blades with an angle of 90 degrees are sometimes referred to as radial cutters.

8 is to emphasize the need for a cutter blade having a blade angle different from 90 degrees. 8 does not show the optimal alignment of the axial channel for any particular treatment procedure. In practical medical procedures, while considering the placement of the axial channel, the surgeon evaluates and selects an alignment to provide adequate spacing from the anatomical structure for safe and efficient implantation, including effective processes within the associated vertebral body. will be.

9 illustrates matters that may be useful when describing other characteristics of the cutter blade. In this case, the cutter blade 460 is a 90 degree cutter blade when the length between the longitudinal portion 406 of the cutter blade 460 and the proximal portion of the blade arm is nominal at 90 degrees. A portion of the 45 degree cutter blade 464 is shown as the more proximal portion of the portion of the cutter blade 464 about 45 degrees relative to the back of the longitudinal portion 406. Although not shown here, the middle portion connects a portion of the cutter blade 464 to the longitudinal portion 406.

Likewise, a portion of the 135 degree cutter blade 468 is shown as the proximal portion of the portion of the 135 degree cutter blade 468 about 135 degrees relative to the back of the longitudinal portion 406.

As can be seen based on FIGS. 5 and 6, the longitudinal portion 406 of the cutter blade is approximately parallel to the length of the cutter shaft 410 and cutter cover 430 and the centerline axis 262 of the cutter, This line can be used to measure the cutter blade angle.

A complete 45 degree cutter blade is shown in FIG. 21. A complete 135 degree cutter blade is shown in FIGS. 30 and 31.

In some cutter blades, the proximal portion of the cutter blade is not continuously parallel to any angular reference line. In such a case, it may be useful to simply measure the cutter blade angle based on the proximal portion (most proximal portion) of the extended blade arm.

In that the cutter blade is made with a finite number of nominal cutter blade angles, the actual angle measured can deviate a few degrees (about 5 degrees) from the nominal angle value. This actual angle may deviate over a cycle of moving from the covered position to the extended position.

In many cases, a set of cutter blades with various combinations of range of motion and angles (such as 45 degrees, 90 degrees and 135 degrees) may be sufficient. Some surgeons may feel that using 90 and 45 degree cutter blades will yield adequate results for some treatments. Other angles may be used, including angles that deviate less from 90 degrees, such as 60 degrees and 120 degrees, or angles that deviate significantly from 90 degrees, such as 25 degrees and 155 degrees. An angle closer to 90 degrees, such as an angle of about 105 degrees, may be useful in some applications. The kit may comprise more than three angle values for the cutter blades. For example, the kit can include blades at 25, 45, 60, 90, 105, 120, 135 and 155 degree angles. With respect to this range of blade angles, there is a wide range of variation in which the extended blade traverses the long axis of the cutter assembly, but in all such cases the cutter blade is the long axis of the cutter assembly and the length of the cutter blade. It crosses substantially with respect to the direction part.

Gradually longer 90 degree cutter blade (at least one long cutter blade) after initially using a short 90 degree cutter blade to cut a large amount of material that can be safely processed within the intervertebral space 312 using a 90 degree cutter blade. By using, some surgeons can work in the case as shown in FIG. 8. At this point, the surgeon may want to work with one or more long 45 degree cutter blades after working with a short 45 degree cutter blade to remove material that may be difficult to access using a 90 degree cutter blade. As a result, in some cases, surgeons may choose to use short 135 degree cutter blades to cut inaccessible nuclear material using 90 or 45 degree cutter blades, followed by one or more long 135 degree cutter blades. Can be.

10 shows the cutter blade 500 seen in three directions. Cutter blade holes 407 and cutter blade slots 427 are shown to be visible. The cutter blade arm 402 is joined to the longitudinal portion 406 by a pair of transitional sections 470. The exact position in the area where the two transitions 470 meet the two longitudinal portions 406 is not particularly relevant, but the two ends of the cutter blades meet. This point of contact can be considered a position where the loop is closed. However, when the cutter blade is attached to the cutter assembly in the blade shaft, the two ends of the cutter blade are joined (see FIG. 5), so that the cutter blade hole 407 and the cutter blade slot 427 are currently adjacent to each other. Closing the loop at the point 500 located at the portion can be made simpler. The closed loop includes an extra layer in case breakage occurs in the cutter blade 500 while being inserted into the intervertebral disc space, and all parts of the cutter blade 500 have a cutter blade having a slot 427. It will remain connected to the cutter shaft through a portion of the cutter blade having a portion or hole 407. Since all parts of the cutter blade are connected to the cutter shaft even after breakage occurs in the cutter blade, all parts of the cutter blade can be removed from the intervertebral disc space by immediate removal of the cutter assembly.

The surgeon can see that a break has occurred in the cutter blade due to the change of the cutter blade, which can be seen visually as seen in the change of the cutter and in real-time fluoroscopy imaging.

The cutter blade 500 may have six different cutting edges 504, 508, 512, 516, 520, 524. There are three cutting edges 504, 508, 512 on one side and three cutting edges 516, 520, 524 on the other side. Edges 504 and 516 are closer to the handle 416 (see FIG. 4A) than other portions of the closed loop, the proximal portion 536 of the cutter blade 500, ie the distal portion 542 of the cutter blade 500. It is in part of the cutter blade 500. When inserted into the intervertebral disc space, the outside of the proximal portion 536 (whether or not the proximal portion is parallel to the end plate) will generally face the end plate of the proximal vertebral body. Edges 508 and 520 are at the distal portion 542 of the cutter blade 500. When inserted into the intervertebral disc space, the exterior of the distal portion 542 will generally face the end plate of the distal vertebral body (whether or not the distal portion 542 is parallel to the end plate). Edges 512 and 524 are at tip 548 of the cutter blade between distal portion 542 and proximal portion 536.

The sides of the cutter blade need not be flat. The side (sometimes called a face) is the side or object (as is seen when a sawtooth formed from a pair of die on one of the six faces of a single die looks at the face or side of the die). If you look at the surface of the feature you can see.

In each case, the cartilage of the end plate and the outer periphery may contact, so that the cutting edge is at the inner periphery 552 of the closed loop rather than the outer periphery 556. By recessing the cutting edge with respect to the outer circumference 556 of the closed loop, the cutter blade 500 is likely to be a lower end plate when viewed in relation to the intervertebral disc space 312. Cartilage 356 of the proximal end plate 352 (see FIG. 8) or cartilage 346 of the distal end plate 342 (which is likely to be the upper end plate in view of the intervertebral disc space 312) (see FIG. 8). Minimizes trauma to the body.

As shown in FIG. 8, even when the cutter blade 500 has a nominal blade angle of 90 degrees, such cutter blade 500 may not be impossible to contact the cartilage of the upper end plate.

By having cutting edges on both sides of the cutter blade 500, the surgeon may cut the nuclear material while the cutter blade rotates clockwise and while the cutter blade rotates counterclockwise. (Clockwise and counterclockwise depend on azimuth. One method of defining clockwise direction may be seen in the cutter when looking from the proximal end to the distal end of the cutter assembly. This coincides with the rotation of the cutter handle.)

Being bidirectional is a useful feature, but not all cutter blades need to have cutting edges on both sides. Similarly, as will be described later, some cutter blades may have one type of cutting edge on one side and an auxiliary type cutter blade on the secondary side. It may be advantageous that some cutter blades have blade edges (such as blade edges 512, 524 shown in FIG. 10) at the tip of the cutter blade, but some cutter blades may not have blade edges at the tip or Or may have different blade edges at tip 548 than at distal 542 and proximal 536.

The cutter blade 500 has a gap 528 in a closed loop so that material can pass through the gap while the cutter blade 500 is rotated in the intervertebral disc space 312. This reduces resistance to the cutter blade 500 moving through the intervertebral space 312 and thus may include other aspects of the cutting action. Other cutter blades may have smaller gaps or no gaps between the distal and proximal portions. Cutter blades that do not have a gap large enough to allow material to pass through the gap at the inner circumference of the closed loop have a closed loop connected to the cutter shaft providing two points for the cutter blade and breakage occurs at the cutter blade. In the case of gaining from the closed loop as can be seen above in that it provides at least one point from each part of the cutter blade to the cutter shaft 410.

The cutter blade 500 may be marked as having a reverse bevel to position the cutting edge away from the outer circumference. Although blade edges 504, 508, 512, 516, 520 and 524 of the cutter blade 500 are recessed in the inner circumference 552 of all ranges of the closed loop, other means to avoid damage to cartilage or endplates The cutter blade may recess the blade edges away from the outer circumference 556 of the closed loop instead of the entire inner circumference 552 of the closed loop. For example, the blade edge may be sufficiently recessed midway between the outer periphery 556 and the inner periphery 552 to avoid cartilage damage.

11 shows a cross section of a cutter blade 500 having blade edges 508, 520. Tilt angle 532 may be in the range of 15 to 80 degrees, usually in the range of 15 to 40 degrees, usually in the range of 20 to 35 degrees, and sometimes 30 degrees.

12 and 13 illustrate two important concepts. Looking at the cutter blade 600 shown in FIG. 12 and comparing the cutter blade with the cutter blade 500 shown again in FIGS. 10 and 13 described above, one difference is that the cutter blade 600 has a proximal blade edge ( 604 and distal blade edge 608 are not approximately parallel. Extensions of the two blade edges are joined and formed at an angle of about 12 degrees. This is in contrast to cutter blade 500 having a proximal blade edge 504 approximately parallel with distal blade edge 508.

12 and 13, description of the features of the cutter shaft 410 shown in FIGS. 5A and 5B will be referred to. The cutter shaft 610 may receive a longitudinal portion of the cutter blade 600 in a slot, and the cutter blade 600 may be fixed to the cutter shaft 610 in the manner described with respect to FIGS. 5A and 5B. . However, the cutter shaft 610 is different from the cutter shaft 410 in that there is no cutter shaft extension 480. The cutter shaft extension 480 (sometimes referred to as a goal post) provides additional support for the cutter blade 500. Such additional support may be particularly desirable for cutter blades having a long operating range.

For some cutter blades, especially cutter blades with a short range of motion, a cutter shaft similar to the cutter shaft 610 is in contact with the cartilage 346 (see FIG. 8) of the end plate 342 of the distal vertebral body 304. It may be desirable to avoid having the shaft extension 480. This risk may be more relevant when used with cutter blades having an angle less than 90 degrees, for example cutter blades having an angle of 45 degrees.

A second reason for using the cutter shaft 610 without the cutter shaft extension 480 is that larger bending in the blade can be advantageously made when using a cutter blade with a short operating range. For example, additional bending in the cutter blade of short operating range helps the cutter blade cut more efficiently.

14 is a distal end of a cutter shaft, such as cutter shaft 610. FIG. 15 is an enlarged view of FIG. 14 in detail. 16 is a cross-sectional view of the distal end of the cutter shaft 610. A similar view of the cutter shaft 410 with the cutter shaft extension 480 is shown in FIGS. 17-19.

[Serrated blade]

Although the cutter blades with the blade edges shown in FIGS. 10A-10C are effective for cutting the nucleus material, in some cases other blade types may be effective or more efficient in preparing for removal of the nucleus material.

20A-20C show cutter blade 704 viewed in three directions with one serrated side 708 and a flat (blunt) side 712 that is not intended for cutting. 20A is a perspective view of the cutter blade showing the sawtooth side 708 seen from above. 20B is a front view of a blade arm having a longitudinal portion 406 of the cutter blade 704 and a cutter blade hole 407. 20C is a perspective view from above of the flat side 712. The sawtooth pattern utilizes a round serration 716.

21A-21C show the cutter blade 720 viewed in three directions (the figure does not include cutter blade holes or cutter blade slots because the focus is on a sawtooth pattern). In addition, there are a side 724 cut into a sawtooth shape and a non-cutting side (side not cut) 728. Fig. 21 shows a sawtooth pattern at the outer circumference of the closed loop (sawtooth cut portions 732, 734, 736) at the sawtooth pattern at the inner circumference of the closed loop (sawtooth cut portions 742, 744, 746). 21A-21C are intended to emphasize that the sawtooth pattern at the cutter blade tip 750 is often different from other sawtooth patterns.

22A-22C show cutter blades viewed from different directions with serrated cutting edges on both the clockwise side 764 of the cutter blade 760 and the counterclockwise side 768 of the cutter blade 760. . 22B is a front view of the cutter blade 760 showing the cutter blade hole 407 in the longitudinal portion 406. The sawtooth pattern lasts from one end 772 at the distal portion of the cutter blade 760 around the blade tip 776 to the other end 780 of the proximal portion of the cutter blade 760. (The proximal and distal portions each have a relationship with the cutter handle 416 (proximal) when the cutter blade 760 (distal) is part of the cutter assembly.) Serrated shape used in the cutter blade 760 The pattern has a double slope so that the tip of the sawtooth tooth is close to the level line of material thickness used to make the cutter blade 760. The saw tooth shape is not a round saw tooth shape as shown in Fig. 21 but a triangular saw tooth shape having a sawtooth valley between the tooth tip portions having a "V" shape. For example, since a cutter blade having a V-shaped serrated valley is moved relative to the nuclear material, the movement of the V-shaped serrated bone relative to the nuclear material causes local compression of the nuclear material, thereby Is pinched. This effect is such that the sawtoothed bones may occur when the cutter blade continues to move and tear the nuclear material away from the cutter blade to enhance the action of the cutter blade in preparing for removal of the nuclear material from the intervertebral disc space. It can help you catch nuclear material.

The final result of the tooth pattern and the double bevel as seen from different directions in FIGS. 22A-22C is to cut each part of the two sides of the cutter blades on both sides to cut the outer periphery of the closed loop and the inner periphery of the closed loop. It is essentially a series of tetrahedral pyramids with the vertices of the pyramids aligned in between, forming a pair of cutting faces.

It will be appreciated by those skilled in the art that the cutter blade may have blade edges cut in flat stock before the stock is processed to represent the closed loop configuration. It will be appreciated by those skilled in the art that blade stock or formed blades may require a post-processing step to remove material by polishing or similar processes.

23 and 24 show in detail the addition of a sawtooth shape to a flat stock of appropriate size. Figure 23 shows the part associated with the sharp stock before bending in the shape of the cutter blade.

FIG. 24 shows the pattern used to remove metal on each side of the blade stock to create a sawtooth pattern as shown in FIG. Since the one marked on the right of the removal pattern at the top of the 100% blade stock material is removed, the amount is reduced by the depth cut in the blade stock. The angle of the amount of material removed thus reduced may be about 20 degrees. In order to help visualize the interaction between these shapes, markings for the removal of material from the first side 802, 804, 806, 808 are provided on the second side 812, 814, 186, 181, 820, 822. Are shown with indications for the removal of material. In FIG. 23 only one toothed set is shown in the blade stock. Thus, such blades can only be cut if they are rotated in one direction (rather than in both clockwise and counterclockwise directions).

Figure 25, similar to Figure 24, shows that the material is removed to form a sawtooth pattern for the cutter blade. 25 illustrates an example of a trapezoidal sawtooth pattern 830. Each trapezoid 834 has a pair of parallel lines (upper and lower side) and a pair of non-parallel lines. Trapezoidal corners 838 cut at the blade stock may be rounded as shown herein. With the sawtooth pattern shown in FIG. 24, the material left after forming the tip of the toothed tooth 842 is offset so that the tooth tip on one side is aligned with the midpoint of the trapezoid on the opposite side. .

In the sawtooth pattern in Fig. 25 and the present description, one pattern of X repetitions on one side is combined with X + 1 repetitions on the opposite side as part of the effort to stagger the toothed tips. Instead of having five trapezoidal patterns and six trapezoidal second patterns all aligned at the same intermediate point in order to achieve the required sawtooth pattern, each side removes the trapezoid 840 or the one adjacent to the trapezoid 844. By adding it can have the same number of trapezoids.

26 illustrates an example of a trapezoidal sawtooth pattern of the cutter blade 850. This type of serrated pattern has an alternating serrated tooth between the inner circumference of the closed loop (such as toothed tip 854) and the outer circumference of the closed loop (such as toothed tip 862). Makes a very aggressive serrated blade.

27A-27D show blade stock 866 with trapezoidal serrated pattern 868. In this pattern 868, five trapezoids are cut on one side of the blade stock 866 and six trapezoids are cut on the opposite side where the pattern is offset so that the teeth on one side are at the midpoint of the trapezoid on the opposite side. Sort it. Those skilled in the art will appreciate that other combinations of five trapezoids and six or more trapezoids are possible and can be made into a fine tooth pattern by increasing the number of trapezoids cut from each side over a defined length to accommodate the sawtooth pattern. Could be. Conversely, reducing the number of trapezoids per side over a given length to accommodate the sawtooth pattern will result in a coarser tooth pattern. In some cases, fine tooth patterns may be desirable over thick tooth patterns.

As can be seen in FIG. 26, the sawtooth pattern can be cut across the face such that the depth of the trapezoid varies from the maximum depth of the blade stock to zero. This angle of inclination may be about 20 degrees but other angles may be used.

In the case of deep cutting at the blade stock to produce an aggressive sawtooth pattern, either no cutting surface is provided on the opposite side (clockwise versus counterclockwise side of the cutter blade), or as shown in FIGS. 10A-10C. It may be desirable to provide a sawtooth cutting edge (a sawtooth free cutting edge) to create a strong and durable cutter blade. Such hybrid cutter blades (sawtooth on one side and non-toothed on the other side) may be desirable because they provide two different types of cutting action (rip / tooth actuation and sawing) for one cutter blade.

28A-28D show round toothed cuts to 0.140 inch (3.5 mm) diameter, 3 inch (76 mm) long, and 0.025 inch (0.64 mm) deep in blade stock (874); Shape pattern 870 is shown. The saw tooth pattern 870 is less rigid than some of the saw tooth patterns described above.

29A-29C show cutter blades 880 made from blade stock in various views, with a sawtooth pattern similar to that shown by sawtooth pattern 870 in FIGS. 28A-28D. The blade stock is bent to position the cutting edge at outer perimeter 884. Cutter blades 880 are more suitable for arranging intervertebral disc spaces for fusion procedures than for treatments that do not require bleeding of the cartilage and endplates (such as providing dynamic stabilization therapies, eg providing exercise preservation devices). Can make By reversing the bending direction of the blade stock (and making the necessary modifications to the process of adding the cutter blade hole 407 and the cutter blade slot 427), the cutting edge is placed on the inner circumference 888 of the cutter blade. Those skilled in the art will recognize that the blade stock can be used to make a cutter blade having (not shown). Such cutter blades may be suitable for use in procedures where bleeding from cartilage and endplates is not desired.

30 is a side view of cutter blade 492 having a 135 degree blade angle. 31 is a side view of the cutter blade 496 having a blade angle of 134 degrees where the proximal portion of the blade arm 402 is not parallel to the distal portion of the blade arm 402.

[Material selection and other description]

In the description of the present invention, the term "biocompatible" is used when or when the biochemical tissue is in contact with or exposed to (eg, abrasion particles) to the device and material of the present invention. No cytotoxicity or chronic inflammatory response. In addition to biocompatibility, in another aspect of the invention, a tool comprising an instrument is sterile; It is preferred that the visualization and / or imaging may be possible, for example fluoroscopy.

The cutter shaft and cutter cover are generally made of metal or metal alloys, for example stainless steel, and can be machined or injection molded.

Due to the limited disk height of a patient, for example, if the fusion is due to a herniated or collapsed disk, it is desirable that the cutter blade is configured to have a low profile during extension, use and retraction.

In the sense of the present invention, the separation distance (distant distance) between the first and second cutting edges is visually controllable during manufacturing (i.e. predetermined through heat treatment fixed during the formation of the cutter blade, preferably nickel Titanium shape memory alloys such as Nitinol ^™ . The separation distance between the cutting edges varies from about 2 mm to 8 mm, and usually from about 3 mm to 4 mm. Some cutter blades have a tear drop shape. The maximum separation distance between the cutting edges may be located within a maximum of one third in the radially outward direction of the total blade length. In addition, the maximum separation distance can be positioned within a maximum 1/3 of the blade length or within a central region of the blade length, depending on the desired development and cutting properties.

According to the consistency of the embodiments described herein, the cutter blade and blade arm are generally super-elastic or austenite phases in strip material, preferably at room temperature and body temperature and are about 0.10 inch (2.5 in width). mm) at about 0.20 inch (5 mm) and a thickness of about 0.015 inch (0.38 mm) to about 0.050 inch (1.3 mm). The blade arm formed according to this embodiment has bendability without significant shape deformation even over 100 cycles, and is twisted at maximum 1 and 1/2 rotation (about 540 degrees) without breakage. This is the twist of one end of the cutter blade relative to the other part of the cutter blade.

The shape memory feature is rotated within the intervertebral space and helps to resume the cutter blade to its intended shape after being deformed while receiving a unilateral resistance to movement, but also to resume the cutter blade to an extended position in shape memory. It is useful for everyone who can.

In one embodiment, the cutting blade and the cutter blade edges are formed to have a shape memory alloy that preferably exhibits superelasticity, biocompatibility, and a substantial shape recovery when stretched to 12%. Suitable materials close to the desired biocompatibility properties for cutter blades and cutter blade edges and blade arms include, for example, nickel and titanium, such as nitinol strip material # SE508 available from Nitinol Device and Components, Inc. of Fremont, Canada. Alloys (eg, alloys of Ni _56- Ti ₄₅ and other elements by weight). Such materials generally exhibit complete shape restoration (i.e. elongation restored when elongated from about 6% -10%, which is approximately better than elongation restored at elongation of stainless steel).

The shape and length of the cutter blades formed will generally vary for different cutting modes. Securing the alloy material to a particular shape fixture, and then positioning and bolting the nitinol strip (along with the cutting edge of the blade already ground) to the shape fixture; Temperature range of about 500 ° C. to about 550 ° C. (eg, for one fixture) for a time range between about 15 to 40 minutes (eg, the optimal time for one fixture is about 20 minutes). The shape memory material can be formed in the desired cutter blade by a heat-setting, time-temperature process that places the entire fixture in the oven at an optimum temperature of about 525 ° C.). In this way a bendable (flexible) cutter blade formed of nitinol is particularly suitable for retracting into a shaft sleeve and can extend perpendicular to the disk space. In addition, the cutter blade can mechanically withstand a number of cutting "cycles" before failure occurs.

The cutting blade edges are preferably polished to be exactly reproducible. The range of about 5 degrees to about 70 degrees of the angle of the inclined surface of the blade relative to the flat side of the blade is usually in the range of about 20 degrees to about 50 degrees. In one embodiment, the blade angle is about 30 degrees with respect to the side of the blade.

In a consistent aspect of the present invention, a cutter blade configured to have a sawtooth shape is formed by a wire electric discharge machining (EDM) process to optimize a shape profile. In order to manufacture more, the cutter blades are profile polished; Gradual die tooth stamping; It is formed by machining or general EDM.

In one embodiment, the shaft of the assembly is formed of solid stainless steel or other known suitable material. In one embodiment, the shaft has a diameter of about 0.25 inches (6.3 mm). The cutter shaft cover may be formed of a stainless steel rod or bar or other known suitable tubing material and has a length of about 0.7 inches (17.8 mm).

As will be appreciated by those skilled in the art, certain components or subassemblies of the assembly of the present invention may also be made of a suitable (eg biocompatible; sterile) polymer material, for example where appropriate or necessary Can be coated (eg with PTFE) to reduce friction.

For example, the cutter cover can be made of a polymer material, stainless steel, or a combination of stainless steel with a low friction polymer sleeve such as UHMWPE, HDPE, PVDF, PTFE loaded polymer. This cover has an outer diameter (O.D.) of about 0.31 inch (7 mm) to about 0.35 inch (9 mm).

[Alternative]

Alternative method of attaching the blade to the blade shaft

32A and 32B, cutter blade 453 is cutter shaft 410 by rivet 429 entering cutter shaft hole 411 through cutter blade slot 427 and cutter blade hole 407 (not shown here). In the shaft slot 413 at the distal end. When using rivets, a shaft sleeve (compared to the components 418 of FIGS. 5A and 5B) is not necessary. 32C shows that this fixation method can be combined with the goal post described above.

The closed loop cutter blade described above includes a cutter blade hole 407 in the longitudinal portion that is most directly connected to the proximal portion of the blade arm and a cutter blade slot 427 in the longitudinal portion most directly connected to the distal portion of the blade arm. Cutter blade slot of the longitudinal portion most directly connected to the proximal portion of the blade arm without departing from the scope of the technology of the present invention, and cutter of the longitudinal portion most directly connected to the distal portion of the blade arm It will be appreciated by those skilled in the art that the cutter blade and cutter shaft can be modified to utilize blade holes.

Similarly, the cutter blades described above can be modified such that at least some types of cutter blades have holes in both longitudinal portions so that once fixed, there is no relative movement of one longitudinal portion relative to the other portion. Other attachment options that do not use pins may be used to not allow relative movement. This alternative is further dependent on the performance of the shape memory material to resume a given shape since the fixed longitudinal portions cannot move relative to each other to contribute to the deformation.

The cutter shaft can be embodied to work with a particular cutter blade having a particular blade angle. For example, it may be advantageous to use a cutter shaft for 45 degree blades such that the 45 degree blade starts at a downward angle while still in contact with the cutter shaft. Also, standard cutter blades can be used over a range of cutter blade angles, and changes in blade angle can be processed at the cutter blade after the cutter blade is in contact with the cutter shaft. The combination of both methods can represent several different cutter shafts, such as 45 degree cutter shafts and 90 degree cutter shafts, using the characteristics of the cutter blades to provide an extended range of cutter blade angles.

The cutter assembly described herein may be combined with other methods, such as hydro-ablation or laser, as two examples to partially perform or complete nucleotomy or to facilitate other tissue manipulation (eg, crushing and / or extraction). Can also be used together.

[Other handles]

According to the consistency of the embodiments described herein, a handle is provided, for example as a pistol grip or lever attached to the proximal end of the cutter shaft. As shown in FIG. 4B, the illustrated handle 416 is attached to the proximal end 414 of the cutter shaft 410 by a cross-pin or a set screw, which is loosened by a rotational operation during cutting. Reduce the risk of the handle being disengaged from the shaft 410. As noted above, the handle 416 is preferably attached to be in rotational position alignment with the blade arm and to serve as a reference marker for the blade arm in a situ orientation.

In addition, the handle of the cutter assembly consists of a rotary knob (not shown) made of a polymer material such as, for example, ABS polymer, the handle can be injection molded and machined, and the cutter shaft It is attached to the cutter shaft by screws or other coupling means about its proximal end.

[Rotation stop part]

According to the consistency of the embodiments described herein, there is provided a blade arm and a cutter which are configured to be rotated or used in one direction (ie clockwise or counterclockwise), ie in one direction only (ie clockwise). The rotational movement of the blade arm will begin to provide nuclear material. The intended movement during the use of this blade is similar to the lateral movement of the windshield wiper and the incision relative to the cutter occurs in a clockwise range.

In one embodiment (not shown), one or more stops are located within the cutter shaft to control the range of motion or blade arc. In another embodiment (not shown), one or more stops are fitted to the cutter cover to control the range of motion or blade arc.

[Variation of tooth height]

The example provided above used a pattern to create a toothed tip of uniform height, but those skilled in the art will be able to modify the pattern used as an example to create a pattern when some teeth are larger than other teeth.

[Kit]

Various combinations of the aforementioned devices and tools may be provided to form a kit, such that all tools desired to perform a particular procedure will be available in a single package. The kit according to the invention may comprise a preparation kit for the required treatment area, ie the tools necessary for disc preparation are provided. The disc preparation kit may vary depending on whether the procedure is prepared for treatment of one or more spine levels or motor segments. The disk preparation kit may include a plurality of cutters. In a single level kit, generally three to seven cutters are provided, and in one embodiment five cutters are provided. Two level kits may generally be provided with 5 to 14 cutters, in one embodiment 10 cutters. The cutter assembly will include several types of cutter blades. The type will depend on the particular procedure that may possibly be performed based on the anatomical structure of the patient (which may affect the range of operating range sections of the cutter blade required).

In general, the kit will include a cutter assembly having a small radial cutter blade, an intermediate radial cutter blade and a large radial cutter blade. The kit will also include three or more cutter assemblies with small, medium and large cutter blades having a blade angle of 45 degrees. Certain surgical kits may include other cutter assemblies with specific cutter blades for special applications, including, for example, cutter blades selected to be capable of causing bleeding and cutting at the lower or upper endplates. All cutter blades are used once, ie discarded after use. Certain other components included within the cutter assembly may be discarded or reused after use.

The disc preparation kit may additionally (optionally) comprise one or more tissue extraction tools for removing debris from the nucleus. In one level kit three to eight tissue extraction tools are provided, and in one embodiment six tissue extraction tools are provided. Two level kits are generally provided with about 8 to 14 tissue extraction tools, and in one embodiment 12 tissue extraction tools. The tissue extraction tool may be discarded after use.

The cutters described above have been described in connection with their use in the intervertebral disc space. A desirable property of the cutter of the invention is that the material is to be cut (which must be removed before subsequent treatment) by the transfer of the cutter blade while covered through the lumen before estimating the extended position the cutter blade has as shape memory. It will be appreciated by those skilled in the art that the present invention can be used in other medical procedures to access. It will be appreciated by those skilled in the art that the dimensions of the cutter blades and associated components need to be adjusted to correspond with the dimensions of the lumen used to provide access and the dimensions of the associated anatomical structure. There may be no cartilage covering the vertebral endplate to preserve or scrape (depending on the desired result), but other anatomy that needs to be protected from the cutting edge or needs to be scraped as part of the site preparation. There may be a structure, and thus various characteristic techniques related to the present invention may be made.

It will be appreciated by those skilled in the art that some of the other implementations described above are not universally mutually exclusive, and in some cases additional implementations may be made that employ the aspects of the two or more changes described above. Likewise, the description is not limited to the specific examples or specific embodiments provided to enhance understanding of the various techniques of this description. In addition, the following claims protect the scope of changes, modifications and substitutions for the components described herein, as known to those skilled in the art.

Claims (45)

A cutter for crushing material in an intervertebral space between two vertebral end plates, the cutter extending through an axial channel having a centerline axis, the axial channel comprising at least one vertebral end plate and extending into the intervertebral space, A cutter blade made of a shape memory material; A first side surface at the cutter blade that generally faces one of the vertebral end plates when the cutter blade is positioned substantially transverse to the centerline axis; A second side surface at the cutter blade separated by a blade thickness from the first side surface; A clockwise side at the cutter blade that is the leading side when the cutter is rotated clockwise in the axial channel; A counterclockwise side at the cutter blade that is a trailing side when the cutter is rotated clockwise in an axial channel; And At least one cutting edge formed on at least one of the clockwise and counterclockwise sides Cutter comprising. As a cutter blade formed from the formation memory material and used in the intervertebral disc space, A first longitudinal portion of the cutter blade having a cutter blade hole for attaching and using a closed loop cutter blade to the cutter assembly; And A second longitudinal portion having a cutter blade slot for connecting and utilizing a second longitudinal portion to the cutter assembly via a slotted connection allowing a limited range of motion of the second longitudinal portion; Including, The closed loop cover blade may be retractable and extendable from a cutter cover including a portion of a cutter assembly. Cutter blade. The method of claim 2, The extended and closed loop cutter blade forms a closed loop that is tied when connected to the cutter assembly by connection points extending through the first and second lengthwise portions. Closed loop cutter blade. The method of claim 3, All cutting edges are recessed from the outer periphery Closed loop cutter blade. The method of claim 3, All cutting edges follow the inner circumference of the closed loop Closed loop cutter blade. The method of claim 2, The closed loop cutter blade has two faces, the first face and the second face, when the closed loop cutter blade is attached to the cutter assembly that is rotated in the first direction, the first face being the leading face and the second face being the second face. The face is a trailing face and the closed loop cutter blade has a cutting edge on at least a portion of the first face and a blunt side of the second face. Closed loop cutter blade. The method of claim 2, The closed loop cutter blade has two faces, the first face and the second face, when the closed loop cutter blade is attached to the cutter assembly that is rotated in the first direction, the first face being the leading face and the second face being the second face. The face is a trailing face, and the closed loop cutter blade has a cutting edge on at least a portion of the first face and a cutting edge on at least a portion of the second face. Closed loop cutter blade. The method of claim 7, wherein The cutting edge on the first surface uses a sawtooth cutting edge having a first pattern and the cutting edge on the second surface is different from the cutting edge on the first surface. Closed loop cutter blade. The method of claim 7, wherein The cutting edge on the first surface uses a sawtooth cutting edge having a first pattern, and the cutting edge on the second surface uses a sawtooth cutting edge having a pattern different from the first pattern. Closed loop cutter blade. The method of claim 7, wherein The cutting edge on the first surface uses a sawtooth cutting edge and does not use the cutting edge on the second surface. Closed loop cutter blade. The method of claim 21, The closed loop cutter blade has two faces, the first face and the second face, when the closed loop cutter blade is attached to the cutter assembly that is rotated in the first direction, the first face being the leading face and the second face being the second face. The face is a trailing face, and the closed loop cutter blade has a cutting edge on at least a portion of the first face, and the cutting edge at the first face is a portion of the first face and an inner circumference of the closed loop. Formed by repetition of the pattern added to the corresponding part and the pattern added to the part of the first surface and the corresponding part of the outer circumference of the closed loop; Closed loop cutter blade. The method of claim 2, The closed loop cutter blade has two faces, the first face and the second face, when the closed loop cutter blade is attached to the cutter assembly that is rotated in the first direction, the first face being the leading face and the second face being the second face. The face is a trailing face, the closed loop cutter blade having a cutting edge on at least a portion of the first face, the first face being approximately halfway between the outer periphery of the closed loop and the inner periphery of the closed loop. With a series of tetrahedral pyramids with the vertices of the aligned pyramids Closed loop cutter blade. The method of claim 2, The closed loop includes a cutting edge proximal to the cutter blade and the angle between the proximal portion of the cutter blade and the first longitudinal portion when in the extended position is between about 25 degrees and about 90 degrees. Closed loop cutter blade. The method of claim 2, The closed loop includes a cutting edge proximal to the cutter blade, and the angle between the proximal portion of the cutter blade and the first longitudinal portion when in the extended position is between about 90 degrees and about 155 degrees. Closed loop cutter blade. The method of claim 2, The closed loop includes a cutting edge proximal to the cutter blade and the angle between the proximal portion of the cutter blade and the first longitudinal portion when in the extended position is between about 80 degrees and about 100 degrees. Closed loop cutter blade. A closed loop cutter blade for use in intervertebral disc space with shape memory in an extended position, An inner surface forming at least a portion of an inner circumference of the closed loop; An outer surface forming at least a portion of an outer circumference of the closed loop; A first surface outside of the closed loop cutter blade between the inner surface and the outer surface, where the first surface is attached to the closed loop cutter blade and is rotated in a first direction about the long axis of the cutter assembly On the leading edge-; A second face on the outside of the closed loop cutter blade between the inner and outer surfaces, wherein the second face is attached to the cutter assembly and rotated in a first direction about the long axis of the cutter assembly; On the trailing side-; And At least a portion of the first surface with a cutting edge having a set of serrated shapes Closed loop cutter blade comprising a. The method of claim 16, The first surface has a first set of sawtooth shapes extending to the outer surface and a second set of sawtooth shapes extending to the inner surface Closed loop cutter blade. The method of claim 17, The first set of toothed shapes has a toothed tooth tip and the second set of toothed shapes has a toothed tooth tip that is not aligned with the first set of toothed toothed tips. Closed loop cutter blade. The method of claim 18, The first set of sawtooth shapes have a sawtooth pattern, and the second set of sawtooth shapes have the same sawtooth pattern except that the toothed tip portions are offset so as not to align. Closed loop cutter blade. The method of claim 18, The first set of sawtooth shapes have a first sawtooth pattern, and the second set of sawtooth shapes have a second sawtooth pattern different from the first sawtooth pattern in addition to being offset so as not to align the toothed tip portion. Closed loop cutter blade. The method of claim 18, The first face has a valley between the tooth tooth on the outer surface and the tooth tooth on the inner surface. Closed loop cutter blade. The method of claim 21, The valley comprises V formed by an acute angle Closed loop cutter blade. The method of claim 16, The tooth set includes a round tooth shape Closed loop cutter blade. The method of claim 16, The serrated set includes an inclined round serrated shape Closed loop cutter blade. The method of claim 16, The serrated set includes a set of polygons Closed loop cutter blade. The method of claim 16, The serrated set includes a set of trapezoids Closed loop cutter blade. The method of claim 16, The serrated set is cut at an angle across the first face such that the depth of the saw tooth is in the range from the thickness of the first face to zero. Closed loop cutter blade. A cutter for crushing material in the intervertebral space between the end plate of the distal vertebral body and the end plate of the proximal vertebral body, the cutter through a bore along an axis extending through at least the end plate of the proximal vertebral body to position one end of the cutter in the intervertebral space. Prolonged, Cutter shaft; A cutter cover surrounding at least a portion of the cutter shaft; Cutter Blade-The cutter is retracted into the cutter cover and is configured to extend from the cutter cover, the cutter blade having a shape memory of an extended position, the extended cutter blade being substantially transverse to the long axis of the cutter shaft. Diameter-; A distal surface of the cutter blade at the extended cutter blade side that is closer to the end plate of the distal vertebral body than the end plate of the proximal vertebral body when the cutter blade extends into the intervertebral space; A proximal surface of the cutter blade at the side of the inserted cutter blade that extends closer to the end plate of the proximal vertebral body than the end plate of the distal vertebral body when the cutter blade extends into the intervertebral space; A first edge at the cutter blade, which may be the leading edge of the cutter blade when the elongated cutter blade is rotated in a first direction about the long axis of the cutter shaft; A second edge in the cutter blade, which may be the leading edge of the cutter blade when the extended cutter blade is rotated in a second direction around the long axis of the cutter shaft, the second direction being opposite to the first direction; ; And At least one cutting edge formed on at least one of the first and second edges, the cutting edge being recessed with respect to the distal surface of the cutter blade Cutter comprising. The method of claim 28, The cutting edge is recessed against the proximal surface of the cutter blade. cutter. The method of claim 28, The cutter blade comprising a loop extending from a portion of the cutter blade connected to the cutter shaft, the first portion of the loop comprising a distal surface and the second portion of the loop comprising a proximal surface, the loop And a loop tip connecting the first and second parts, wherein the loop forms an open area when the cutter blade is rotated around the long axis of the cutter shaft. cutter. The method of claim 28, The cutter blade comprising a loop extending from a portion of the cutter blade connected to the cutter shaft, the first portion of the loop comprising a distal surface and the second portion of the loop comprising a proximal surface, the loop Also includes a loop tip connecting the first and second portions, wherein the loop forms an open area when the cutter blade is rotated around the long axis of the cutter shaft, and material can pass through the open area. cutter. The method of claim 28, The extended cutter blade, which is substantially transverse to the long axis of the cutter shaft, is positioned to be between about 25 and about 155 degrees away from the long axis of the cutter shaft. cutter. The method of claim 28, The distal portion of the cutter blade is approximately parallel with the proximal portion of the cutter blade. cutter. The method of claim 28, The protrusion of the distal portion of the cutter blade intersects the protrusion of the proximal portion of the cutter blade to form an acute angle. cutter. The method of claim 28, The cutting edge at the first edge of the cutter blade is sawtooth shaped. cutter. 36. The method of claim 35 wherein The cutter blade has a series of teeth, the teeth of approximately the same height cutter. 36. The method of claim 35 wherein The cutter blade has a series of teeth having a set of teeth at a first tooth height and a set of teeth at a second tooth height, wherein the second tooth height is greater than the first tooth height. cutter. 36. The method of claim 35 wherein The cutter blade has a sawtooth-shaped pattern with valleys in a sawtooth-shaped pattern with an acute angle. cutter. 36. The method of claim 35 wherein The distal and proximal surfaces are joined by a loop tip such that the cutter with cutter blades in the extended position forms a closed loop, and the cutting edge at the first edge of the cutter blade is the first edge. With a sawtooth pattern along the loop tip which is different from the sawtooth shape at other parts of the cutter. 36. The method of claim 35 wherein The cutting edge at the second edge of the cutter blade is not serrated cutter. A cutter for pulverizing material in the intervertebral space between the end plate of the distal vertebral body and the end plate of the proximal vertebral body, the cutter axial bore along an axis extending through at least the end plate of the proximal vertebral body for positioning one end of the cutter in the intervertebral space. Extending through, A cutter shaft having a long axis; A cutter cover surrounding at least a portion of the cutter shaft; A cutter blade, the cutter retracted with a cutter cover and configured to extend from the cutter cover, the cutter blade extending generally across the long axis of the cutter shaft; A distal surface of the cutter blade at the extended cutter blade side that is closer to the end plate of the distal vertebral body than the end plate of the proximal vertebral body when the cutter blade extends into the intervertebral space; And Proximal surface of the cutter blade at the inserted and extended cutter blade side closer to the end plate of the proximal vertebral body than the end plate of the distal vertebral body when the cutter blade extends into the intervertebral space. Including, The distal surface and the proximal surface are joined by a loop tip such that the cutter with the cutter blades in the extended position forms a closed loop; The cutter shaft has an extension such that a portion of the extended cutter blade that generally crosses the long axis of the cutter shaft is located between the cutter shaft extensions. cutter. Kit for freeing up intervertebral space for treatment A cutter assembly having a radial cutter blade in a first operating range section; A cutter assembly having a cutter blade having the first operating range section and a blade angle smaller than 90 degrees; A cutter assembly having a radial cutter blade in a second operating range section longer than the first operating range section; And A cutter assembly having a cutter blade having a blade angle of less than 90 degrees and said second range of motion Kit comprising a. The method of claim 42, wherein A cutter assembly having a radial cutter blade in a third operating range section longer than the second operating range section; And A cutter assembly having a cutter blade having the third operating range section and a blade angle smaller than 90 degrees Kit comprising a. The method of claim 42, wherein The blade angle for the cutter assembly with the cutter blade having the first operating range section and a blade angle smaller than 90 degrees is about 45 degrees. Kit. Invention as described and shown in the description and drawings.

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