KR20090043472A - Specialized cutter blades for preparing intervertebral disc spaces - Google Patents

Abstract

The cutter blade is made of a shape memory material. The cutter blade as part of the cutter assembly in the intervertebral disc space is rotated 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. The use of concave polishes to enhance the cutting action of the blade edges has been described in connection with the creation of cutter blades. Various thin cutter blades that can be used inside thin intervertebral discs (with reduced distance between end plates of adjacent vertebral bodies) are described.

Cutter Blade, Intervertebral Space, Range of Motion, Blade Edge

Description

Specialized cutter blades to create intervertebral disc space {SPECIALIZED CUTTER BLADES FOR PREPARING INTERVERTEBRAL DISC SPACES}

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.

[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, making them harder and less susceptible to breakage 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 rupture itself may be just a morphological change beyond the generalized degenerative changes in the connective tissue of the disc, and nevertheless the rupture of the disc 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.

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.

The use of concave polishes to enhance the cutting action of the blade edges has been described in connection with the creation of cutter blades.

Various thin cutter blades that can be used inside thin intervertebral discs (with reduced distance between end plates of adjacent vertebral bodies) are described.

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.

8A-8D are views of the closed loop cutter blade viewed from various directions to scrape the cartilage end plates to roughen the vascular vertebral body to cause bleeding.

9A to 9D show four forms of the cutter blade shown in FIG. 8 having a concave abrasive portion.

10 is a lateral view of the human spine portion.

11 is a perspective view from above of a thin cutter blade for use in the case of a thin disk.

12A-12D are additional views of the thin cutter blade of FIG.

FIG. 13 is an exploded perspective view of the thin cutter blade shown in FIG. 11.

14 is a side view of the thin cutter blade at a 45 degree angle between the blade arm portion of the proximal arm and the longitudinal portion of the proximal arm.

15 shows a thin cutter blade with cutting edges recessed from the outer surface of the thin cutter blade by having adjacent blade edges from the distal and proximal arms.

16 shows an "L" cutter blade using a single arm rather than a pair of arms.

FIG. 17 shows various forms of an "L" cutter blade similar to an "L" cutter blade except that the cutting edge is on the proximal side of the "L" cutter blade.

18 and 19 show focusing on the use of the cutter shaft and the cutter shaft extension.

20 shows the distal end of the cutter shaft.

21 is an enlarged detailed view of FIG. 20.

22 is a cross-sectional view of the distal end of the cutter shaft shown in FIG. 20.

23 is a view showing the distal end of the cutter shaft.

24 is an enlarged detailed view of FIG. 23.

25 is a cross-sectional view of the distal end of the cutter shaft shown in FIG. 23.

26A and 26B show a cutter blade attached to a cutter shaft by rivets.

FIG. 26C shows a cutter blade attached to the cutter shaft by rivets when the cutter shaft has a cutter shaft extension. FIG.

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.

2 shows the blunt tip stylet 204 being "walked" over the anterior side of the sacrum 116 to the intended position 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 by a subsequent step so that the length of the axial channel shown in one view may differ from that shown in the other view so that the axial tube may include additional vertebral or intervertebral spaces. 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 extend in the axial direction. Those skilled in the art will appreciate that they can escape the 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 not 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 securing 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 provided at 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 in the covered state and is to be covered again. It allows relative movement of the slotted portion (grooved portion) of the longitudinal portion 406 relative to it.

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, intervertebral disc space 312 (including intervertebral disc 334 and interstitial nucleus 338 and including intervertebral discs (intervertebral discs 330) joined by end plates) and the proximal vertebral body ( A moving segment 316 is shown that includes 308. 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 of ordinary skill in the art appreciates 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. You can do it. 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 this short movement is compared to the movement of the windshield wiper of 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 anatomical structure of the patient will determine the maximum operating range of the cutter blade 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 (stired), and similarly in the vicinity of the axial channel Cartilage 356 portion (also, cartilage 346 and end plate 342 of distal vertebral body 304 is disturbed when axial channel 212 (see FIG. 2C) extends to distal vertebral body 304). Being tongued (agitated) 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.

FIG. 8 shows a closed loop cutter blade viewed from various directions in which cartilage end plates are scraped to roughen the vascular vertebral body to cause bleeding. The cutter blade hole 407 and cutter blade slot 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 of breakage in the cutter blade 500 while being inserted into the intervertebral disc space, the cutter blade 500 having a portion of the cutter blade having a slot 427 ( In this case, the cutter shaft 500 is connected to the cutter shaft via a distal arm 560 of the cutter blade 500 or a portion of the cutter blade with a hole 407 (in this case, the proximal arm 564 of the cutter blade 500). Will be maintained. (A person skilled in the art will recognize that the distal arm 560 meets the proximal arm 564 at the blade tip portion 548.) All parts of the cutter blade may be damaged in the event of breakage in the cutter blade. Since it is connected to the cutter shaft, 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 by the naked eye as indicated by the change in the operation of the cutter and the real-time fluoroscopy imaging. Even when the cutter blade and the process for using the cutter blade are formed to avoid breakage of the cutter blade in the patient's body, it is useful to provide the characteristic features given in the safe use of the cutter blade in contact with the vertebral body. can do.

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. The edges 504, 516 are more prone to the handle 416 than the other portions of the closed loop, the proximal portion 536 of the blade arm 402 of the cutter blade 500, ie the distal portion 542 of the blade arm 402 ( In part of the blade arm (see FIG. 4A).

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 blade arm 402. 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 connect distal arm 560 and proximal arm 564 and are at tip 548 of the cutter blade between proximal 536 and distal 542 of blade arm 402.

The cutting edge along the distal portion 542 and proximal portion 536 of the blade arm 402 does not extend over the entire blade arm 402. As shown in FIG. 7, it is conceivable that a series of cutter blades of increased length will be used so that the cutter blade edge does not need to extend over the entire range previously cut by the previous cutter blade.

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 six cutting edges are at the outer circumference 556 of the closed loop than at the inner circumference 552 because the outer circumference 556 is a better choice for edge placement to contact the cartilage of the end plate. . By positioning the cutting edge at the outer periphery 556 of the closed loop, the cutter blade 500 is cartilage of the proximal end plate 352 (which is likely to be the bottom end plate when viewed in relation to the intervertebral disc space 312). 356 (see FIG. 7) or the cartilage 346 (see FIG. 7) of the distal end plate 342 (which is likely to be the upper end plate when viewed in relation to the intervertebral disc space 312) to cut the cutter blade. Maximize the validity.

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. 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 beneficial for some cutter blades to have blade edges at the tip of the cutter blade, but some cutter blades may not have blade edges at the tip or tip 548 rather than at distal 542 and proximal 536. ) May have other blade edges.

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.

[Cutter Blades with Concave Polishing]

9A-9D illustrate four forms of cutter blade 560 similar to cutter blade 500 described above. Cutter blade holes or cutter blade slots are not shown in this figure because they are not centered. Some cutter blades may be connected to the cutter shaft through the cutter blade holes or holes or a combination of the cutter blade holes and the cutter blade slots in other ways that do not include pins or rivets.

What is in the new cutter blade 560 compared to the cutter blade 500 is the configuration between the blade edges 524, 512 and the components 564 between the blade edges 508, 520 on top of the cutter blade 560. It is a hollow ground, which can be represented as element 568. Although not shown in this figure, the recessed abrasive portion may be added between the edge 516 and the edge 504 (not shown here) of the proximal portion 536 of the blade arm 402.

FIG. 9D is a detailed cross-sectional view according to A-A of FIG. 9C, showing that the tilt angle 576 of some cutter blades may be in the range of 15 degrees to 60 degrees. 9D also shows the removed material 580 removed such that the concave abrasive portion may be exemplarily in the range from 0.001 inch to 0.020 inch, depending on the portion of the thickness of the blade stock. Is obtained by enhancing the cutting action near the blade edge. In that the surface of the cutter blade is recessed near the blade edge, the blade edge has a more aggressive interaction with materials such as cartilage or end plates of the vertebral body. This aggressive interaction facilitates the efficiency of cutter blades and facilitates bleeding when scraping / cutting the material.

Using a concave abrasive portion to reinforce the cutter blade may be used with the cutter blade using serrated edges in addition to the cutter blade, such as the cutter blade 560 having a straight slanted edge.

[Thin disc cutter blade]

10 shows the lateral direction of a portion of the human spine 700. Disk 704 is a normal healthy disk. Disk 708 is a deteriorated disk. Disk 712 is an expanded disk. Disk 716 is a herniated disk. The disc 720 is a thin disc and is remarkable in that the space between the end plates 730, 734 is greatly reduced compared to the normal disc 704. Similarly, disc 724, which is a degenerated disc having a pole layer, is also a thin disc. Closed loop cutter blades such as the cutter blades 453 shown in FIGS. 3 and 5 may not be thin enough to operate in thin disks.

11 is a perspective view from above of a thin cutter blade 800 for use in the case of a thin disk. The thin cutter blade 800 has several features similar to the cutter blade 500 described with reference to FIG. 8. The thin cutter blade 800 has blade edges 808 and 820 at the distal arm 860 and blade edges 804 and 816 (not shown here) at the proximal arm 864.

Unlike the closed loop cutter blade 500, there is no gap between the distal arm 860 and the proximal arm 864 near the blade edge. Thus, the thickness of the cutter blade is only about 0.050 inches in size, which is considerably smaller than that shown in a closed loop cutter blade such as the cutter blade of FIG. 8.

Two rivets 874 are added to maintain the same side (same height) relationship between the distal arm 860 and the proximal arm 864. After the rivet 874 is pressed, the rivet 874 causes the surface of the distal arm 860 and the surface of the proximal arm 864 to be flush (the lower side of the rivet is not shown here). The tip portion 848 does not have a cutting edge but is rounded or inclined.

12A-12D illustrate additional forms of the thin cutter blade 800. 12A is a perspective view from above of a thin cutter blade 800 very similar to FIG. 11. As shown in FIG. 12A, the entire thin cutter blade 800, the blade 800 includes a cutter blade slot 427. 12B is a front view of the thin cutter blade 800, wherein the cutter blade slot 427 is in the proximal arm 864 and what is visible through the cutter blade slot 427 is the cutter blade hole in the distal arm 860. (407). Since the thin cutter blade 800 is surrounded by a cutter cover to suppress movement away from the shape shown in FIG. 12, the combination of the slot and hole allows the proximal arm 864 to distal arm 860. It is possible to move. Since the shape of the thin cutter blade 800 changes, the curved portion in the transition portion 870 is changed. 12C is a side view of the thin cutter blade 800, and FIG. 12D is a top view of the thin cutter blade 800.

13 is a perspective view of the disassembled thin cutter blade 800 viewed from above. Rivets 874 may be visible before being inserted and pressed. Distal arm 860 and cutter blade hole 407 are shown to be visible, and proximal arm 864 and cutter blade slot 427 are also shown.

[Retaining film]

13 also shows an optional element 880 that is a retaining film. The retaining film 880 is positioned between the proximal arm 864 and the distal arm 860 and attached to join each arm. Rivets 874 and pins or rivets that attach the thin cutter blade 800 to the cutter shaft pass through the slit 884 of the retaining film 880. When the thin cutter blade 880 breaks both the proximal arm 864 and the distal arm 860, the retaining film 880 begins to operate. When operated as intended, the retaining film 9880 may be broken in relation to the remainder of the cutter blade 800 such that the broken portion can be removed from the intervertebral space and the axial channel 212 (see FIG. 2). Will keep the part without destroying it.

The retaining film 880 may be made of a high tensile strength, dimensional stability, biocompatible, sterile polymer film. The retaining film 880 may be made of, for example, a biaxially-oriented polyethylene terephthalate (boPET) polyester film. In some cases, it may be difficult to properly attach the retaining film 880 to a shape memory alloy such as Nitinol ^™ . However, when the retaining film 880 is mechanically connected to the distal arm 860 and the proximal arm 864 via a connection to the rivet 874 and the cutter shaft, the rivet 874 and the tip portion 848. The retaining film 880 may serve a useful purpose in maintaining the broken portion of the thin cutter blade 800 if there are no breaks in between.

The thickness of the retaining film 880 may range from about 0.08 mm to about 0.40 mm. In addition to retaining the broken portion, the retaining film 880 serves to exclude shear and / or lateral movement of the distal arm 560 relative to the proximal arm 564.

14 is a side view of the thin cutter blade 890 at a 45 degree angle between the blade arm portion 402 of the proximal arm 564 and the longitudinal portion 406 of the proximal arm 564. Cutter blades having an angular range refer to end plates (end plates 342 and 352 of FIG. 7) which partially form the intervertebral disc space when the end plates are not substantially perpendicular to the centerline 262 of the cutter assembly as in FIG. 7. It may be useful to work on thin disks in. The angle may range from 25 to 155 degrees, but angles ranging from 40 degrees to 140 degrees may be required.

15 shows a thin cutter blade 904 having a cutting edge recessed from the outer surface of the thin cutter blade by having adjacent blade edges from the distal arm 560 and the proximal arm 564. Although shown at an angle of approximately 90 degrees, thin cutter blades of this type can be made in an angle ranging from 30 degrees to 120 degrees.

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, a surgeon may choose to use a short 135 degree cutter blade to cut inaccessible nuclear material using a 90 degree or 45 degree cutter blade, followed by one or more long 135 degree cutter blades. have.

FIG. 16 shows an “L” cutter blade 910 using a single arm rather than a pair of arms (560, 564 as shown in FIG. 15). The “L” cutter blade 910 shown in FIG. 16 has a pair of cutting edges 914, 918 at the distal surface 922 of the “L” blade 910. The cutting edge may be cut at an inclination angle of about 25 degrees to 80 degrees as shown in FIG. 16D. The “L” cutter blade 910 of FIG. 16 may be used to scrape the end plate of the distal end plate 730 and the cartilage (see FIG. 10). The advantage of the "L" cutter blade 910 over the thin cutter blade 800 shown in Figure 11 is that the "L" cutter blade effectively uses one arm instead of two piles (proximal and distal arms). The height of the “L” cutter blade is approximately half the height of the thin cutter blade 800. Thus, the "L" cutter blade can work on thinner disks that are thinner than thin cutter blades.

FIG. 17 shows various forms of “L” cutter blades similar to “L” cutter blades except that the cutting edges 934, 938 are proximal to the “L” cutter blade 930. The “L” cutter blade 930 may be used to scrape the end plate 734 of the closer proximal vertebral body (indicative of the trans-sacral access shown in FIG. 2). The range and inclination angle of the cutter blade angle relative to the "L" cutter blade 930 may be the same as the "L" cutter blade 910.

In FIG. 18 and FIG. 19, the description about the characteristic of the cutter shaft 410 shown to FIG. 5A and FIG. 5B is taken into consideration. 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.

When creating and obtaining cutter assemblies for use with thin cutter blades or "L" cutter blades, in addition to controlling the height of the cutter blades, there is no cutter shaft extension 480 to minimize the height of the cutter shaft. It may be desirable to use a cutter shaft.

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.

20 shows a distal end of a cutter shaft, such as cutter shaft 610. 21 is an enlarged detailed view of FIG. 20. 22 is a cross-sectional view of the distal end of the cutter shaft 610. 23-25, cutter shaft 410 without cutter shaft extension 480 is shown.

[Material selection and other description]

In the description of the present invention, the term "biocompatible" refers to a cell in which or when the biochemical tissue is in contact with, or exposed to (eg, abrasive particles) to, the device and material of the present invention. Indicates no toxicity 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 (ie, 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 (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; Progressive die 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

In FIGS. 26A and 26B, the cutter blades 453 are cutter shafts 410 by rivets 429 entering the cutter shaft holes 411 through the cutter blade slots 427 and the cutter blade holes 407 (not shown here). At the distal end of shaft slot 413. When using rivets, a shaft sleeve (compared to the components 418 of FIGS. 5A and 5B) is not necessary. FIG. 26C shows that this fixation method can be combined with the goal post described above.

The cutter blade described above used the cutter blade hole 407 of the proximal arm and the cutter blade slot 427 of the distal arm, but without departing from the scope of the present invention, the cutter blade slot and the proximal arm It will be appreciated by those skilled in the art that the cutter blade and cutter shaft may be modified to utilize the cutter blade holes of the distal arm. Similarly, the example showing the cutter blade slot of the proximal arm and the cutter blade hole of the distal arm can be changed by changing the hole and the slot.

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 formed to be able to rotate or be 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 two cutter thin cutter blades shown above comprise two rivet connections at the blade arm. It will be appreciated by those skilled in the art that a single rivet or more may be used rather than two rivets. Likewise, other mechanical connections can be replaced with rivets.

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. While shown in the context of a closed loop cutter blade, it can be used with thin cutter blades by processing concave abrasives to enhance the cutting performance of the blade edges. 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 (25)

A thin cutter blade for use in an intervertebral disc space, the cutter blade having a shape memory of the shape represented by the cutter blade when not restrained and generating at least a portion from a shape memory material, Proximal Arm-The proximal arm has a first longitudinal portion with a first cutter blade connection for use in attaching the proximal arm to a cutter assembly, the proximal arm also having a blade arm with at least one cutting edge. Ham-; Distal Arm-The distal arm has a second longitudinal portion with a second cutter blade connection for connecting and utilizing a second longitudinal portion to the cutter assembly, the proximal arm having a blade having at least one cutting edge. With a dark part; And Connection between the blade arm of the proximal arm and the blade arm of the distal arm Thin cutter blade comprising. The method of claim 1, The first cutter blade connection portion is a slot Cutter blade. The method of claim 1, The second cutter blade connection portion is a slot Cutter blade. The method of claim 1, The connection between the blade arms is riveted Cutter blade. The method of claim 1, The connection between the blade arms is at least two rivets Cutter blade. The method of claim 1, And a retention film layer positioned between the distal and proximal arms and attached to both the distal and proximal arms. Cutter blade. The method of claim 6, The retaining film is attached to both distal and proximal arms. Cutter blade. The method of claim 6, The connection between the proximal arm and the distal arm passes through the retaining film to attach the retaining film to both the proximal and distal arms. Cutter blade. The method of claim 1, The distal arm has a cutting edge on an outer surface of the distal arm that is a surface on an opposite side of the proximal arm. Cutter blade. The method of claim 9, The outer surface has a concave polished portion Cutter blade. The method of claim 9, The distal arm has a second cutting edge on the outer surface of the distal arm such that the distal arm is connected to the cutter shaft and the distal arm is clocked when the cutter blade extending around the centerline of the long axis of the cutter shaft is rotated. With a cutting edge for use with directional rotation and a cutting edge for use with counterclockwise rotation Cutter blade. The method of claim 1, The distal arm has a cutting edge recessed from an outer surface of the distal arm that is a surface on an opposite side of the proximal arm. Cutter blade. The method of claim 1, The proximal arm has a cutting edge on an outer surface of the proximal arm that is a surface on an opposite side of the distal arm. Cutter blade. The method of claim 13, The outer surface has a concave polished portion Cutter blade. The method of claim 13, The proximal arm has a second cutting edge on the outer surface of the proximal arm such that the proximal arm is connected to the cutter shaft and the proximal arm is clocked when the cutter blade extending around the centerline of the long axis of the cutter shaft is rotated. With at least one cutting edge for use with directional rotation and at least one cutting edge for use with counterclockwise rotation Cutter blade. The method of claim 1, The proximal arm has a cutting edge recessed from an outer surface of the proximal arm that is a surface on the opposite side of the distal arm. Cutter blade. The method of claim 1, The angle between the blade arm portion of the proximal arm and the longitudinal portion of the proximal arm is in the range of about 25 degrees to 155 degrees. Cutter blade. The method of claim 1, The angle between the blade arm portion of the proximal arm and the longitudinal portion of the proximal arm is in the range of about 25 degrees to 90 degrees. Cutter blade. The method of claim 1, The angle between the blade arm portion of the proximal arm and the longitudinal portion of the proximal arm is in the range of about 90 degrees to 155 degrees. Cutter blade. A closed loop cutter blade for use in an intervertebral disc space, the closed loop cutter blade having a shape memory of an extended position with respect to a blade arm extending approximately transverse to the longitudinal portion of the closed loop cutter blade, The closed loop cutter blade has an outer periphery comprising a blade arm; The blade arm comprises a first face and a second face, wherein the first face is a leading face and the second face is a trailing face when the closed loop cutter blade is connected to the cutter assembly. trailing face), wherein the cutter assembly is rotated in a first direction about the long axis of the cutter assembly; The closed loop cutter blade has a first cutting edge at a portion of the blade arm comprising a first face and an outer periphery; The cutter blade has a concave abrasive portion between the second face and the first face on the outer circumference adjacent to the cutting edge of the portion of the blade arm including the first face and the outer circumference. Closed loop cutter blade. The method of claim 20, The closed loop cutter blade has a second cutting edge at a portion of the blade arm that includes a second face and an outer circumference such that a concave abrasive portion lies between the first cutting edge and the second cutting edge. Closed loop cutter blade. The method of claim 20, The concave polish has a maximum depth not less than about 0.001 inches. Closed loop cutter blade. The method of claim 20, The first cutting edge is jagged Closed loop cutter blade. The method of claim 20, The closed loop cutter blade has a longitudinal portion that can be used to connect a closed loop cutter blade to the cutter blade assembly, the blade arm has a proximal and distal portions, the proximal portion of the blade arm being in the longitudinal portion. Closer to the longitudinal portion than the corresponding distal portion, the angle formed by the proximal and longitudinal portions being between about 25 degrees and about 155 degrees. Closed loop cutter blade. Invention as described and shown in the description and drawings.

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