TOOLS FOR CREATING A VERTEBRAL TUNNEL FOR USE IN RF ABLATION AND METHODS OF MAKING AND USING

A tool arrangement for forming a tunnel in a vertebra to perform nerve ablation includes a tamp having a distal end portion that includes a tip for creating the tunnel in the vertebra and a curvable portion to direct the tip along a curved path within the vertebra; a first cannula including a cannula body that is straight along an entire length of the cannula body and configured to receive the curvable portion of the tamp and straighten the curvable portion; and a tool hub including a stationary cannula attachment coupled to the first cannula and a movable head coupled to the tamp and configured to move toward or away from the stationary cannula attachment to extend or retract, respectively, the curvable portion of the tamp from or into, respectively, the first cannula.

FIELD

The present disclosure is directed to the area of radiofrequency (RF) ablation and methods of preparing for RF ablation. The present disclosure is also directed to a tool for creating a vertebral tunnel for use in RF ablation, as well as methods of making and using the same.

BACKGROUND

Radiofrequency (RF) generators and electrodes can be used for pain relief or functional modification. Radiofrequency ablation (RFA) is a safe, proven means of interrupting pain signals, such as those coming from irritated facet joints in the spine, genicular nerves in the knee, and femoral and obturator nerves in the hip. Radiofrequency current is used to heat up a small volume of nerve tissue, thereby interrupting pain signals from that specific area. Radiofrequency ablation is designed to provide long-lasting pain relief.

Basivertebral nerve ablation (BVN) can be used to, for example, treat discogenic back pain or other conditions. The basivertebral nerve is ablated using RF energy. Typically, the root of the basivertebral nerve is located in the near center of the patient's vertebral body (for example, approximately 50%/50% cranial-to-caudal, 50%/50% left-to-right, and 60%-75%/25%-40% anterior-to-posterior.) In at least some embodiments, to access this ablation target the clinician can traverse the pedicle of the vertebrae (either left or right side) and then make a turn towards midline. Instead of transpedicular, an extrapedicular approach can be used. A tunnel is created through the bone and then an electrode is inserted into the bone for ablation. It can be challenging to create a curved tunnel within the vertebrae to access the basivertebral nerve.

BRIEF SUMMARY

One aspect is a tool arrangement for forming a tunnel in a vertebra to perform nerve ablation. The tool arrangement including a tamp having a distal end portion and a proximal end portion, wherein the distal end portion includes a tip configured for creating the tunnel in the vertebra and a curvable portion coupled to the tip and configured to direct the tip along a curved path within the vertebra; a first cannula including a cannula body defining a lumen through which the tamp is extendable, wherein the cannula body is straight along an entire length of the cannula body and the first cannula is configured to receive the curvable portion of the tamp and straighten the curvable portion when the curvable portion is received in the first cannula; and a tool hub including a stationary cannula attachment coupled to the first cannula and a movable head coupled to the tamp and configured to move toward or away from the stationary cannula attachment to extend or retract, respectively, the curvable portion of the tamp from or into, respectively, the first cannula.

In at least some aspects, the first cannula is a tamp cannula, the tool arrangement further including an access tool having an access tool handle and an access tool cannula, wherein the access tool cannula is straight along an entire length of the access tool cannula and the access tool is configured to receive the tamp cannula within the access tool cannula.

In at least some aspects, the tool arrangement further includes an access tool having an access tool handle and the first cannula.

In at least some aspects, the tool hub further includes a rotatable collar disposed between the stationary cannula attachment and the movable head. In at least some aspects, the movable head includes a threaded post. In at least some aspects, the rotatable collar includes a lumen with a threaded portion configured to receive and interact with the threaded post of the movable head. In at least some aspects, rotating the collar moves the movable head away from or toward the stationary cannula attachment depending on a direction of rotation. In at least some aspects, the stationary cannula attachment includes a shaft and the movable head or rotatable collar slide along the shaft as the movable head moves toward the stationary cannula attachment to extend the curvable portion of the tamp out of the first cannula.

In at least some aspects, the movable head includes an impact element to receive impacts from a hammer or mallet. In at least some aspects, the curvable portion of the tamp is defined, relative to the shaft and the tip, by a cutout and is offset relative to a central axis of at least one of the shaft or the tip of the tamp. In at least some aspects, the curvable portion bends away from the cutout. In at least some aspects, the curvable portion of the tamp defines a relieved channel along the curvable portion. In at least some aspects, the tool arrangement further includes at least two pull wires attached to the tip of the tamp to manually guide the tamp in forming the tunnel.

A further aspect is a method for forming a tunnel in a vertebra to perform nerve ablation. The method includes inserting an access tool cannula of an access tool into the vertebra of a patient, wherein the access tool cannula is straight; inserting a tamp cannula of a tamp tool into the access tool cannula of the access tool, wherein the tamp cannula is straight; and operating a tool hub of the tamp tool to extend a distal end portion of a tamp out of a distal end of the tamp cannula to form the tunnel, wherein the distal end portion of the tamp includes a tip configured for creating the tunnel in the vertebra and a curvable portion coupled to the tip and configured to direct the tip along a curved path within the vertebra, wherein the curvable portion is biased to curve when outside of the tamp cannula, wherein the curvable portion is straightened within the tamp cannula prior to extending out of the distal end of the tamp cannula.

In at least some aspects, operating the tool hub includes driving a movable head of the tool hub toward a stationary cannula attachment of the tool hub, wherein the tamp is coupled to the movable head. In at least some aspects, the method further includes after forming the tunnel, operating the tool hub of the tamp tool to retract the curvable portion of the tamp into the tamp cannula and straightening the curvable portion within the tamp cannula. In at least some aspects, operating the tool hub to retract the curvable portion includes rotating a rotatable collar of the tool hub to move a movable head of the tool hub away from a stationary cannula attachment of the tool hub, wherein the tamp is coupled to the movable head.

Another aspect is a tamp tool for forming a tunnel in a vertebra to perform nerve ablation. The tamp tool includes a tamp having a distal end portion and a proximal end portion, wherein the distal end portion includes a tip configured for creating the tunnel in the vertebra and a curvable portion coupled to the tip and configured to direct the tip along a curved path within the vertebra; a tamp cannula including a cannula body defining a lumen through which the tamp is extendable, wherein the tamp cannula is configured to receive the curvable portion of the tamp, wherein the curvable portion of the tamp is biased to curve when outside of the tamp cannula; and a tool hub including a stationary cannula attachment coupled to the tamp cannula, a movable head coupled to the tamp, and a rotatable collar configured to move the movable head toward or away from the stationary cannula attachment to extend or retract, respectively, the curvable portion of the tamp from or into, respectively, the tamp cannula.

In at least some aspects, the movable head includes a threaded post and the rotatable collar includes a lumen with a threaded portion configured to receive and interact with the threaded post. In at least some aspects, the stationary cannula attachment includes a shaft and the movable head or rotatable collar slide along the shaft as the movable head moves toward the stationary cannula attachment to extend the curvable portion of the tamp out of the tamp cannula. In at least some aspects, the tamp cannula is straight and is configured to straighten the curvable portion of the tamp when the curvable portion is received in the tamp cannula.

Yet another aspect is a method for forming a tunnel in a vertebra to perform nerve ablation. The method includes inserting an access tool cannula of an access tool into the vertebra of a patient; inserting the tamp cannula of one of the tamp tools described above into the access tool cannula of the access tool; and driving the movable head of the tool hub toward the stationary cannula attachment of the tool hub to extend a distal end portion of a tamp out of a distal end of the tamp cannula to form the tunnel, wherein the distal end portion of the tamp includes a tip configured for creating the tunnel in the vertebra and a curvable portion coupled to the tip and configured to direct the tip along a curved path within the vertebra, wherein the curvable portion is biased to curve when outside of the tamp cannula.

DETAILED DESCRIPTION

The present disclosure is directed to the area of radiofrequency (RF) ablation and methods of preparing for RF ablation. The present disclosure is also directed to a tool for creating a vertebral tunnel for use in RF ablation, as well as methods of making and using the same.

FIG.1illustrates one embodiment of a conventional RF ablation system100that includes a RF generator102, a RF electrode104, a cannula106, a ground pad107, and an optional extension cable109. The cannula106includes a cannula hub108, an insulated shaft110, and an active tip112. The insulated shaft110is hollow for receiving the RF electrode104. When inserted, the RF electrode104contacts, and energizes, the active tip112of the cannula106to produce RF ablation. The RF electrode104includes an electrode shaft114, an electrode hub116, a cable118that is electrically coupled to the electrode shaft114, and a connector120for connecting to a port122of the RF generator102to energize the electrode shaft114via the cable118and connector120. The optional adapter or extension109includes a cable119and connectors117a,117bfor coupling the RF electrode104to the RF generator102. It will be recognized that other RF ablation systems utilize the RF electrode104for ablation instead of, or in addition to, the cannula106.

The RF generator102can include one or more ports122and at least one screen130. In at least some embodiments, each port122is associated with a portion of the screen130(or a different screen) and can receive the connector120from an RF electrode104. Information such as current, voltage, status, time, temperature, power, impedance, or the like or any combination thereof can be displayed on the screen130. In at least some embodiments, each port122corresponds to an independent channel for operating a RF electrode104. The RF generator102also includes a ground port121for attachment of the ground pad107.

Examples of RF generators and RF ablation systems and methods of making and using the RF generators and RF ablation systems can be found at, for example, U.S. Pat. Nos. 9,717,552; 9,956,032; 10,111,703; 10,136,937; 10,136,942; 10,136,943; 10,194,971; 10,342,606; 10,363,063; 10,588,687; 10,631,915; 10,639,098; and 10,639,101; and U.S. Patent Application Publications Nos. 2014/0066917; 2014/081260; 2014/0121658; 2021/0121224; 2021/0236191; 2022/0202484; 2022/0202485; and 2022/0226039, all of which are incorporated herein by reference in their entireties.

Basivertebral nerve ablation (BVN) can be used to, for example, treat discogenic back pain or other conditions. The basivertebral nerve is ablated using RF energy. Typically, the root or central confluence of the major basivertebral nerve intravertebral body branches is located in the near center of the patient's vertebral body (for example, approximately 50%/50% cranial-to-caudal, 50%/50% left-to-right, and 60%-75%/25%-40% anterior-to-posterior.) In at least some embodiments, to access this ablation target a tunnel is created through the vertebral bone and then an electrode is inserted into the vertebral bone for ablation. In at least some embodiments, to form the tunnel the clinician uses a tool to traverse the pedicle of the vertebrae (either left or right side) and then make a turn towards midline. Instead of transpedicular, an extrapedicular approach can be used.

In at least some embodiments, an access tool is used to create a straight tunnel through the pedicle to the vertebral body. Instead of transpedicular, an extrapedicular approach can be used. A tamp tool is then used to create a curved tunnel in the bone. The tamp tools described herein can be used to create a curved tunnel within a hard tough media such as bone. In at least some embodiments, the tamp tool is capable of creating a curved tunnel with enough curve for the various anatomies presented by patient diversity (for example, differences in age, gender, size, or the like or the presence of a disease or disorder, such as scoliosis, which may alter bone shape, density, homogeneity, vertebral form, or the like.) In at least some embodiments, the tamp tool is capable of creating a curved tunnel throughout a range of vertebral levels (for example, at least L3 through S1).

In at least some embodiments, the tamp of the tamp tool is straightened to travel down the pedicle. In at least some embodiments, when the tamp enters the vertebral body a portion of the tamp curves. For example, a portion of the tamp curves toward the midline. In at least some embodiments, the tamp tool is sufficiently durable to survive the tunneling action performed by a clinician with a mallet and is also sufficiently flexible to turn.

In at least some embodiments, the tamp tool retains the ability to carve a curved tunnel throughout multiple uses. Many ablation procedures involve ablating 2, 3, 4, or more vertebral levels. Moreover, on occasion tunneling is unsuccessful due to bone deformities, anatomy, or other factors and the tamp tool may be used multiple times at a single vertebral level.

FIG.2illustrates one embodiment of an access tool232with a stylet234inserted into an open lumen of an access tool cannula235of the access tool leaving a stylet handle236of the stylet outside of the access tool and adjacent to an access tool cannula handle238of the access tool. A tip237of the stylet234can have any suitable shape including, but not limited to, bevel, diamond, trocar, or the like.

FIG.3illustrates one embodiment of a tamp tool240that includes a tamp cannula242fits into the open lumen of the access tool cannula235, a tamp244that extends through the tamp cannula and is retractable into, and extendable out of, a distal end of the tamp cannula, and a tool hub246attached to a proximal end of the tamp cannula. The tamp cannula242and access tool cannula235are straight and do not curve. In particular, the distal end portions of the tamp cannula242and access tool cannula235do not curve.

The distal portion260of the tamp244includes a tip262, a curvable portion264, and a shaft266(see, also,FIG.5.) In at least some embodiments, the tamp244, or at least the curvable portion264of the tamp, is constructed of nitinol, spring steel, or any other suitable flexible metal or other material. In at least some embodiments, the curvable portion264is biased to curve unless a force is applied to straighten the curvable portion. In at least some embodiments, the curvable portion264of the tamp244can be bent and held by a jig and then heat set in an oven (for example, heat set at 520° C. (or any other suitable temperature) for 8 minutes in a bath of heated salt) to bias the curvable portion264to curve. In at least some embodiments, a polymeric material can be overmolded, heat shrunk, or otherwise disposed over the curvable portion264to provide consistent cross-sectional dimension(s).

FIG.3illustrates one embodiment of one type of tool hub246that includes a stationary cannula attachment248, a rotatable collar250, and a movable head252. In at least some embodiments, the tamp cannula242is attached to the stationary cannula attachment248of the tool hub246. As illustrated inFIG.4A, the movable head optionally includes an impact element253attached to a threaded post254and optionally includes a grip251. The collar250includes a lumen256with a threaded portion that interacts with the threaded post254and the stationary cannula attachment248comprises a shaft249that fits within the lumen256of the collar. The threaded post254is attached to a proximal portion258of the tamp244.

In operation, the stylet234is inserted into the access tool232, as illustrated inFIG.2, and then this combination is inserted into either the left or right pedicle. After passing through the pedicle, the stylet234is removed. Instead of transpedicular, an extrapedicular approach can be used with the access tool232, where the stylet234is removed after entry into the vertebra.

The tamp tool240is then obtained with the tamp244retracted into the tamp cannula242. The tamp cannula242of the tamp tool240is inserted into the access tool cannula235of the access tool232, as illustrated inFIG.4A.

In at least some embodiments, the tamp cannula242and the access tool cannula235of the access tool232are arranged so that the distal ends of the tamp cannula242and the access tool cannula235terminate at or near the same position in the vertebra when the tamp cannula242is fully inserted into the access tool cannula235. In at least some embodiments, the tamp cannula242and the access tool cannula235of the access tool232are arranged so that the distal end of the tamp cannula242extends out of the distal end of the access tool cannula235when the tamp cannula242is fully inserted into the access tool cannula235.

The collar250is rotated to retract the collar away from the stationary cannula attachment248, as illustrated inFIG.4B. The movable head252is then hammered (with a hammer or mallet) or otherwise operated to push the movable head252and collar250toward the stationary cannula attachment248, as illustrated inFIG.4C. The combination of the movable head252and the collar250slide along the shaft249of the stationary cannula attachment248. In at least some embodiments, the shaft249or other part of the stationary cannula attachment248acts as a stop when the collar250is pushed against the stationary cannula attachment248, as illustrated inFIG.4C.

Pushing the movable head252and the collar250towards the stationary cannula attachment248extends the tamp244out of the tamp cannula242, as illustrated inFIG.3, to form the tunnel into the vertebral bone. As the tamp244extends out of the tamp cannula, the curvable portion264of the tamp244curves to form a curved tunnel in the vertebra.

After the tunnel is created, the collar250is rotated, while maintaining contact with the stationary cannula attachment248, so that the movable head252moves away from the collar250as the collar250rotates and the threaded post254translates upward, as illustrated inFIG.4D. This retracts the tamp244back into the tamp cannula242. The retraction of the tamp244straightens the tamp within the straight tamp cannula242. The tamp tool240is then removed from the access tool232. In at least some embodiments, the access tool232may also be used for the cannula106or RF electrode(s)104(or both) of the RF ablation system100(see,FIG.1.) In at least some embodiments, the tamp244can include one or more electrodes, for example, on or near a distal tip262(FIG.5) and can act as a monopolar or bipolar RF electrode to perform RF ablation. In at least some embodiments, the tamp cannula242can act as a return electrode.

In at least some embodiments, the tamp tool240can include a stop that prevents the tamp244from being drawn too far into the tamp cannula242. This may prevent or hinder the tip262(FIG.5) of the tamp244from digging into the interior wall of the tamp cannula242.

FIG.4Eillustrates another embodiment of a tool hub246including a movable head252with an impact element253and a threaded post254, a stationary cannula attachment248, and a rotatable collar250with a lumen256having a threaded portion. In at least some embodiments, as illustrated inFIG.4E, the rotatable collar250may not move up or down relative to the stationary cannula attachment248. InFIG.4E, the left illustration is the tool hub246with the tamp retracted into the tamp cannula and the right illustration is the tool hub with the tamp extended out of the tamp cannula.

FIG.4Fillustrates a further embodiment of a tool hub246including a movable head252with an optional impact element253, a stationary cannula attachment248with a threaded post254, and a rotatable collar250that functions similar to the tool hub246illustrated inFIG.4E. In at least some embodiments, as illustrated inFIG.4F, the rotatable collar250does not move up or down relative to the stationary cannula attachment248. InFIG.4F, the left illustration is the tool hub246with the tamp retracted into the tamp cannula and the right illustration is the tool hub with the tamp extended out of the tamp cannula.

FIG.4Gillustrates yet another embodiment of a tool hub246including a movable head252with an optional impact element253, a stationary cannula attachment248, and a cam handle255. In at least some embodiments, as illustrated inFIG.4G, the rotatable handle255is operated to translate the movable head252(which is attached to the tamp) up or down. InFIG.4G, the left illustration is the tool hub246with the tamp retracted into the tamp cannula and the right illustration is the tool hub with the tamp extended out of the tamp cannula.

Although the examples described herein include a tamp cannula242, it will be understood that in other embodiments, the tamp cannula is not present and the access tool cannula235can be used, instead, for any of the functions described herein for the tamp cannula. For example, the access tool cannula235can straighten the tamp244as the tamp is received in the access tool cannula.

Turning toFIG.5and the tamp244, in at least some embodiments, the tip262of the tamp is pointed. In at least some embodiments, the tip262includes a slanted face261in the direction of the bend259of the curvable portion264, as illustrated inFIG.5, to aid in curving. Examples of other slanted faces261of the tip262are illustrated inFIG.6A to6Gand include a beveled tip (FIG.6A), a curved tip (FIG.6B, which may facilitate a sharp point), a multi-faced tip (FIG.6C), a splayed tip (FIG.6D), a double wedge tip (FIG.6E), a curved double wedge tip (FIG.6F), or a blunted tip (FIG.6G). It will be recognized that any other suitable tip262can also be used. Similar tips can be used for the tip237of the stylet234ofFIG.2.

In at least some embodiments, the curvable portion264has a smaller thickness263in the plane of the bend as compared to the portions of the tip262and the shaft266immediately adjacent to the curvable portion, as illustrated inFIG.5. In at least some embodiments, the lateral width263is at least 0.042 inches (or approximately 1 mm). In at least some embodiments, the curvable portion264has a smaller thickness263in the plane of the bend than a width of the curvable portion perpendicular to the plane of the bend.

In at least some embodiments, the curvable portion264, when fully extended out of the tamp cannula242, bends at an angle of at least 60, 65, 70, 75, 80, 85, or 90 degrees. In at least some embodiments, the curvable portion264, when fully extended out of the tamp cannula242, bends at an angle of no more than 100 or 90 degrees.

In at least some embodiments, a smaller or larger length of the curvable portion264can result in a smaller or larger radius of curvature. In at least some embodiments, a smaller radius of curvature may be desirable for a vertebral level with smaller or more laterally oriented pedicle or a smaller vertebral body. In at least some embodiments, a larger radius may be desirable for a vertebral level with a larger or more medially oriented pedicle or a larger vertebral body.

In at least some embodiments, at least a portion of edges267of the curvable portion264are relieved inwardly toward a center of the curvable portion264relative to adjacent portions of the tip262and the shaft266, as illustrated inFIG.7A. In at least some embodiments, the edges267of the curvable portion264are relieved. This may facilitate retraction of the tamp244back into the tamp cannula242.

In at least some embodiments, the distal portion260of the tamp244defines a cutout265between the tip262and the shaft266. The cutout265can be described as a portion of the tamp264that is removed or absent when considered relative to the adjacent parts of the tip262and the shaft266. This results in the curvable portion264having a thinner part of the tamp244as compared to the adjacent parts of the tip262and the shaft266. In at least some embodiments, the curvable portion264is defined by the cutout265which facilitates curving. In at least some embodiments, the curvable portion264curves away from the cutout265, as illustrated inFIGS.5and7A.

In at least some embodiments, the cross-section of the curvable portion264can have a D-shape or be roughly D-shaped. In at least some embodiments, the straight portion of the D-shape is defined by the cutout265. In at least some other embodiments, the cross-section of the curvable portion264can be circular, oval, square, rectangular, tetrahedral, hexagonal, octagonal, or any other suitable shape. In at least some embodiments, a circular or other shape with similar dimensions in multiple directions (e.g., square, hexagonal, octagonal or the like) may facilitate actively steering the bending of the curvable portion264in different directions. A rectangular or oval cross-section may result in preferential bending directions.

In at least some embodiments, the curvable portion264includes a relieved channel243extending along at least a portion of the curvable portion264, as illustrated inFIG.7B. The lateral cross-sectional contour of the relieved channel264can be curved, as illustrated inFIG.7B, square, triangular, pentagonal, hexagonal, octagonal, or any other suitable regular or irregular shape.

In at least some embodiments, the curvable portion264is offset relative to the center axis277of the adjacent part of the shaft266, as illustrated inFIGS.5and8A. In at least some embodiments, the curvable portion264is offset relative to the center axis277′ of the adjacent part of the tip262, as illustrated inFIG.8A. In at least some embodiments, the curvable portion264is offset toward the inside of the bend, as illustrated inFIGS.5and8A. In at least some embodiments, this direction of bending or curving has been found to create a smooth tunnel. It will be understood, however, that the curvable portion264can be designed to bend in the other direction so that the offset is toward the outside of the bend.

In at least some embodiments, the curvable portion264of the tamp244can be offset in one direction from the central axis of the shaft266and offset in the opposite direction from the tip262, as illustrated inFIG.8B. In at least some embodiments, such an arrangement may reduce strain on the curvable portion264.

In at least some embodiments, the tamp244includes a supplemental cutout265′ opposite the cutout265, as illustrated inFIG.8C. In at least some embodiments, the curvable portion264remains offset relative to the center axis277of the adjacent part of the shaft266or may be centered relative to the center axis of the adjacent part of the shaft.FIG.8Dillustrates one embodiment of a cross-section for the curvable portion264defined by a cutout265and supplemental cutout265′.

In at least some embodiments, the curvable portion264has a uniform thickness along a length of the curvable portion264(optionally, except for relatively short region(s) adjacent the tip262or the shaft266or both the tip and shaft.) In at least some embodiments, the curvable portion264has a variable thickness along the length of the curvable region, as illustrated inFIG.8E. InFIG.8E, the thickness of the curvable portion264decreases from the distal end to the proximal end of the curvable portion. Such an arrangement may facilitate more aggressive curving as the tamp244exits the tamp cannula242with increased flexibility as the tamp continues to exit the tamp cannula. It will be recognized that other patterns of thickness variability can be used including, but not limited to, increasing thickness from the distal end to the proximal end or increasing thickness followed by decreasing thickness (or vice versa) along the length of the tamp. These variations in thickness can occur along the entire curvable portion264or along one or more parts of the curvable portion.

In at least some embodiments, the cutout265also defines at least one straight section269, in addition to the curvable portion264, as illustrated inFIG.9A. In at least some embodiments, a straight section269may be disposed adjacent the shaft266, as illustrated inFIG.9A. In at least some embodiments, this positioning of a straight section269may provide strain relief for the tamp244, particularly when the tamp244is positioned or retracted into the tamp cannula242.

In at least some embodiments, a straight section269′ may be disposed adjacent the tip262, as illustrated inFIG.9B. In at least some embodiments, this positioning of a straight section269′ may facilitate clearing the tunnel formed by the tamp244as the tamp is retracted into the tamp cannula242. In at least some embodiments, this positioning of a straight section269′ may facilitate forming a tunnel with an elliptical cross-section.

Other arrangements for a curvable portion264can be used. For example, the curvable portion264can be made of a tube of curvable material, such as nitinol, as illustrated inFIGS.10A and10B. In at least some embodiments, the curvable portion264is defined, at least in part, by multiple cutout teeth271, as illustrated inFIG.10C, or a set of microcuts273, as illustrated inFIG.10D.

Another embodiment of a tamp244includes a curvable portion264that is made of a curvable tube (such as a nitinol tube) and a stylet280that extends through the curvable portion264and forms the tip262, as illustrated inFIG.10E. In at least some embodiments, the stylet280can also be extended further out of the curvable portion264, as illustrated inFIG.10F. In at least some embodiments, the portion281of the stylet280that extends out of the curvable portion is straight, as illustrated inFIG.10F.

In at least some embodiments, the tamp244can include one or more pull-wires275, as illustrated inFIG.11A. In at least some embodiments, each pull wire275is attached to the tip262(or the curvable portion264) and extends through the shaft266(or outside the shaft but within the tamp cannula242) to the tool hub246. The pull wire(s)275can be used to steer the tip262or curvable portion264. A tamp244may include one or more of the pull wires275a,275b,275c,275dillustrated inFIG.11A.

As an example, inFIG.11A, a tamp244can include one or both of pull wires275a,275bwhich can be used to alter the amount of bending of the curvable portion264. Pulling pull wire275amay increase bending. Pulling pull wire275bmay decrease bending. As another example, inFIG.11A, a tamp244can include one or both of pull wires275c,275dwhich can be used to alter the lateral direction (lateral relative to the direction of bending) of the curvable portion264.FIG.11Billustrates one embodiment of a handle283that is rotatable relative to a fixed element285and is attached to two pull wires275(for example, pull wires275a,275bor pull wires275c,275d) for operating the pull wires. In at least some embodiments, the handle283and fixed element285can be part of a tool hub (or adjacent to a tool hub).

In at least some embodiments, the tamp244can include an opening265in the proximal end of the tip262, as illustrated inFIG.11C. As the tamp244is retracted into the tamp cannula242, bone fragments or other particles can be gathered into the opening265for at least partially clearing the tunnel created by the tamp.

Other arrangements of a tool hub246can be used. For example,FIGS.12A and12Billustrate a tool hub246with a rack and pinion mechanism in the deployed (left) and retracted (right) states. The tool hub246ofFIGS.12A and12Bincludes a movable head252with an impact elements253, as well as a stationary cannula attachment248with a rack249(e.g., a shaft) have teeth249a. The movable head252is attached to a proximal portion of the tamp244. Instead of a collar, the tool hub246ofFIGS.12A and12Bhas a pinion250′ with a handle250aand a circular gear250bwith teeth250cthat engage the teeth249aof the shaft249. The pinion250′ is attached to the movable head252and operation of the pinion250′ can move the movable head252up to the retracted state (FIG.12B) or down to the deployed state (FIG.12A). In at least some embodiments, the pinion250′ disengages from the rack249as the tamp244is extended out of the tamp cannula242.

In at least some embodiments, the stationary cannula attachment248of the tool hub246ofFIGS.12A and12Bincludes a movement limiting shaft270with a stop272, such as a pin, bar, or the like and the movable head252includes a track274along which the stop272moves. Movement of the movable head252away from the stationary cannula attachment248is limited by the track274and the stop272. When the stop272reaches an end of the track274, the movable head252can move no further from the stationary cannula attachment248.

Another arrangement of a tool hub246is illustrated inFIGS.12C and12Din the deployed (left) and retracted (right) states. The tool hub246ofFIGS.12C and12Dincludes a movable head252with an optional impact element253and a grip251(or handle), as well as a stationary cannula attachment248. The movable head252is attached to a proximal portion of the tamp244. In at least some embodiments, the stationary cannula attachment248of the tool hub246ofFIGS.12C and12Dincludes a movement limiting shaft270with a stop272, such as a pin, bar, or the like and the movable head252includes a lumen278along which the stop272moves. Movement of the movable head252away from the stationary cannula attachment248is limited by the stop272. When the stop272reaches a stop portion279of the lumen278, the movable head252can move no further from the stationary cannula attachment248. A clinician can use the grip251of the movable head252to separate the movable head from the stationary cannula attachment.

In at least some embodiments, the tool hub246includes a locking mechanism288to lock the tool hub to the access tool232, as illustrated inFIG.13. For example, the stationary cannula attachment248of the tool hub246can be locked to the handle238of the access tool232. Any suitable locking mechanism288including, for example, a detent panels and a groove on the handle238, panels that create a friction attachment or other attachment, or the like or any combination thereof. In at least some embodiments, the locking mechanism288can prevent or reduce rotational or axial misalignment between the stationary cannula attachment248and the handle238.