RETROGRADE CUTTING INSTRUMENT

Abstract

A retrograde cutting instrument and method of retrograde drilling using such an instrument. A method of forming a socket includes providing a retrograde cutter, inserting the cutter into a joint with a blade of the cutter in a straight position, pivoting the blade to a non-straight flip position, locking the blade in the flip position, and retrograde drilling a socket using the blade in the flip position.

Claims

1. A retrograde cutting instrument for forming a bone socket in a first bone articulating with a second bone at an articular joint, comprising: a cannulated elongated shaft having a distal end, a proximal end, and a longitudinal axis; and a cutting tip pivotably coupled to the distal end of the shaft, the cutting tip being capable of movement from a first position, which is generally aligned with the longitudinal axis of the shaft, to a second position, which is not aligned with the longitudinal axis, the cutting tip extending beyond the distal end of the shaft when the cutting tip is in the first position; and wherein the cutting tip is configured such that, when the cutting tip is in an articular joint space of the articular joint, the cutting tip is pivotable from the first position to the second position for retrograde drilling of the bone socket when the shaft of the retrograde cutting instrument is rotated and the retrograde cutting instrument is pulled proximally, such that the bone socket faces the articular joint space.

2. The cutting instrument of claim 1, wherein the shaft includes an articulating mechanism for pivoting the cutting tip between the first and second positions.

3. The cutting instrument of claim 1, wherein the cutting tip is pivotably coupled to the shaft by a cross-pin near the distal end of the shaft.

4. The cutting instrument of claim 3, wherein the cutting tip is at least partially received in a slot at the distal end of the shaft, the slot being sized to allowing the cutting tip to pivot to the second position.

5. The cutting instrument of claim 1, wherein the angle of the cutting tip in the second position is about 90 degrees.

6. The cutting instrument of claim 1, wherein the distal end of the shaft has an open end face.

7. The cutting instrument of claim 1, wherein, when in the second position, the cutting tip has cutting edges facing the proximal end of the shaft.

8. The cutting instrument of claim 1, wherein a locking mechanism is provided at the proximal end of the shaft, the locking mechanism being configured to lock the cutting tip in the second position.

9. The cutting instrument of claim 1, wherein a hub member is attached to the proximal end of the shaft.

10. A method of retrograde drilling for forming a bone socket in a first bone articulating with a second bone at an articular joint, comprising: inserting a retrograde cutting instrument through a pre-formed tunnel in the first bone and into an articular joint space of the articular joint, the retrograde cutting instrument comprising a cannulated shaft having a distal end, a proximal end, and a longitudinal axis, the shaft further comprising a cutting tip at the distal end, the cutting tip being pivotably engaged to the shaft and capable of movement from a straight position to a pivoted position, the retrograde instrument being inserted through the pre-formed tunnel with the cutting tip disposed in the straight position; subsequently pivoting the cutting tip while the cutting tip is within the articular joint space, from the straight position, where the cutting tip is aligned with the longitudinal axis of the shaft, to the flip position, where the cutting tip is not aligned with the longitudinal axis of the shaft; and pulling the retrograde cutting instrument proximally while rotating the shaft so that the cutting tip, in the flip position, forms the bone socket in the first bone in a retrograde manner from the articular joint space towards an outer surface of the first bone, and the formed bone socket faces the articular joint space.

11. The method of claim 10, further comprising the step of locking the cutting tip in the flip position after articulating the cutting tip to the flip position.

12. The method of claim 10, further comprising the step of inserting a graft into the bone socket.

13. The method of claim 12, further comprising the step of securing the graft in the bone socket.

14. The method of claim 10, wherein the step of articulating the cutting tip to the flip position includes articulating the cutting tip to about a 90 degree angle with respect to the longitudinal axis of the shaft.

15. The method of claim 10, wherein the cutting tip is pivotably coupled to the shaft by a cross-pin near the distal end of the shaft

16. The method of claim 10, further comprising the step of measuring a depth of the bone socket during retrograde drilling.

17. The method of claim 10, wherein the distal end of the shaft has an open end face and the cutting tip extends through the open face when the cutting tip is in the straight position.

18. A method of retrograde drilling for forming a bone socket in a first bone articulating with a second bone at an articular joint, comprising: inserting a retrograde cutting instrument through a pre-formed tunnel in the first bone and into an articular joint space of the articular joint in a straight position, the retrograde cutting instrument comprising a cannulated shaft having a distal end, a proximal end, and a longitudinal axis, the shaft further comprising a cutting tip at the distal end, the cutting tip extending beyond the distal end of the shaft when the cutting tip is in the straight position, and the cutting tip being pivotably engaged to the shaft and capable of movement from the straight position to a flip position; subsequently, while the cutting tip is in the straight position, articulating the cutting tip within the articular joint space, from the straight position, where the cutting tip is aligned with the longitudinal axis of the shaft, to the flip position, where the cutting tip is at an angle of about 90 degrees with respect to the longitudinal axis of the shaft; locking the cutting tip in the second position while in the articular joint space; and pulling the flip retrograde cutting instrument proximally and rotating the shaft so that the cutting tip in the flip position drills the bone socket in the first bone in a retrograde manner from the articular joint space towards an outer surface of the first bone, and the formed bone socket faces the articular joint space.

19. The method of claim 18, further comprising the steps of inserting a graft into the bone socket and securing the graft in the bone socket.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 illustrates a side view of the combined flip cutter and drill of the present invention;

[0012] FIG. 2 illustrates an enlarged view of the combined flip cutter and drill of FIG. 1, with the drill end in the “straight” (or drilling mode) configuration;

[0013] FIG. 3 illustrates an enlarged view of the actuating mechanism of the combined flip cutter and drill of FIG. 1;

[0014] FIG. 4 illustrates an enlarged view of the combined flip cutter and drill of FIG. 1, with the drill end in the “flip” (or cutting mode) configuration;

[0015] FIGS. 5A and 5B illustrate another perspective view and an exploded view, respectively, of the combined flip cutter and drill of the present invention;

[0016] FIG. 6 illustrates an enlarged view of the distal end of the combined flip cutter and drill of FIG. 1, with the drill end in the “straight” (or drilling mode) configuration;

[0017] FIG. 7 illustrates an enlarged view of the distal end of the combined flip cutter and drill of FIG. 1, with the drill end in the “flip” (or cutting mode) configuration; and

[0018] FIG. 8 illustrates an enlarged view of the distal end of the combined flip cutter and drill of FIG. 1, with the outer tube in a retracted position to show the pivoting axis.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventors of carrying out their invention. Various modifications, however, will remain readily apparent to those skilled in the art.

[0020] The present invention provides a combined flip cutter and drill instrument that is designed to function in either a drilling mode or a cutting mode. The flip cutter and drill of the present invention is provided with a drill which has a conical, multi-blade configuration and which engages the shaft of the instrument to articulate between at least a first “straight” position (for example, about parallel to the longitudinal axis of the instrument) and at least a second “flip” position (for example, a non-parallel position relative to the longitudinal axis of the instrument).

[0021] The flip cutter and drill of the present invention may be employed in a regular manner (when in the drilling mode or “straight” position, for example), or in a retrograde manner (when in the cutting mode or “flip” position for example) to form a recipient socket (to accommodate an osteochondral transplant, or to allow retrograde fixation of a graft within two sockets, for example).

[0022] Referring now to the drawings, where like elements are designated by like reference numerals, FIGS. 1-8 illustrate various components of a combined flip cutter and drill 100 of the present invention. The flip cutter and drill 100 of the present invention is similar to the flip retrograde cutting instrument 100 of U.S. Pat. No. 8,652,139 (the disclosure of which is incorporated in its entirety herewith) but differs in that blade 5 of the flip retrograde cutter 100 is replaced by a drill or cutter 50 which is conical with a plurality of edges 52 (FIGS. 2 and 4) and/or has a plurality of blades with sharp cutting edges 52 (FIGS. 6-8), as described in more detail below, to allow drilling both in a regular manner (in an antegrade manner) and in a retrograde manner.

[0023] The flip cutter and drill 100 includes a cannulated elongated body 10 having a distal end 12 and a proximal end 13, as shown in FIGS. 1, 5A and 5B. The body 10 of the flip cutter and drill 100 includes a cannulated shaft or outer tube 11 provided at its distal end 12. The outer tube 11 houses an inner tube or inner member 17 (as shown in more detail in FIG. 8, for example) provided with a drill 50 having a plurality of cutting edges 52 (as shown in FIG. 2, for example). Details of specific exemplary embodiments of the drill 50 of the flip cutter and drill 100 are illustrated in FIGS. 2, 4 and 6-8; however, the invention contemplates other shapes and geometries for the drill 50.

[0024] Drill 50 illustrated in detail in FIGS. 2, 4 and 6-8 is configured to engage the shaft or inner tube 17 of the instrument 100 and to articulate between at least first and second positions. In an exemplary embodiment, drill 50 engages inner tube 17 in a first or “straight” position (for example, about parallel to the longitudinal axis of the cutting instrument 100), as shown in FIGS. 1, 2 and 6. In the “straight” configuration, instrument 100 functions in the antegrade drilling mode.

[0025] In an exemplary embodiment, drill 50 engages the shaft of the instrument in a second or “flip” position (for example, a non-parallel position relative to the longitudinal axis of the cutting instrument 100), as shown in FIGS. 4, 5A, 5B and 7. In the “flip” configuration, instrument 100 functions in the cutting mode (for example, retrograde cutting). The non-parallel position shown in FIGS. 4, 5 and 7 is about perpendicular to the longitudinal axis of the cutting instrument 100; however, the present invention contemplates embodiments wherein drill 50 forms any angle with the shaft (for example, an angle between about 10 to about 170 degrees relative to the longitudinal axis of the cutting instrument 100, as shown in FIG. 8, for example).

[0026] In use, once the drilling/cutting instrument 100 is inserted into a joint, for example, a knee joint, the surgeon rotates (in the direction of arrow “A” of FIG. 3) actuating mechanism 60 to pivot the cutting drill 50 into the “flip” configuration (i.e., into a position other than the “straight” position), wherein the cutting tip is disposed at an angle of about 90 degrees with respect to the shaft of the instrument. The surgeon may also gradually increase or decrease the angle, as desired and in accordance with the characteristics of the surgical site. Once the drill is articulated in the desired “flip” position, the drill is preferably locked in position by tightening the tube 11. A drilling operation (when the instrument is in the “straight” position) or a retrograde cutting operation (when the instrument is in the “flip” position) may be subsequently carried, as desired and as known in the art.

[0027] As seen in FIGS. 5A and 5B, actuating mechanism 60 comprises a driver end 1, a nut 2, a hub 3, a retainer ring 7, two pins (a slotted spring pin 9 and a pin 10), and the shaft 11. The flip cutter and drill 100 is preferably assembled by first pressing the shaft 11 into the hub 3 until the shaft 11 bottoms out. The retainer ring 7 is then inserted into a groove of the hub 3 to form a first sub-assembly. Next, the inner member 17 is inserted into an end of the driver end 1 and securely engaged using the pin 10. The first sub-assembly, described above, is slid over the assembled inner member 17 and driver end 1. Next, the drill 50 is slid into slot of the inner member 17 and securely engaged using cross pin 8. The nut 2 is then screwed onto the other end of the driver end 1. Next, the hub 3 is pulled back while advancing the nut 2 until the retainer ring 7 engages and the slotted spring pin 9 is inserted into a through hole in the driver end 1 to secure the driver end 1 against the nut 2. An O-Ring 20 may be slid over the shaft 11, having laser etches on its circumference. The O-Ring 20 may be used to measure depth during retrograde drilling.

[0028] The present invention may be used to form various sockets or tunnels to allow fixation of a graft (for example, a semitendonosus allograft) or to allow replacement of osteochondral cores or implants in a retrograde manner, to obviate inserting harvesters into the joint. For example, drilling/cutting instrument 100 of the present invention may be employed for the formation of sockets during an “all-inside ACL RetroConstruction™” for ligament repair, which may comprise, for example, the steps of: (i) drilling at least a femoral and tibial tunnel or socket using a retrograde drill technique employing the drilling/cutting instrument 100 of FIGS. 1-8; (ii) providing a graft (soft tissue graft or BTB graft) in the vicinity of the sockets; and (iii) securing the graft within the femoral and tibial tunnels (sockets).

[0029] According to yet another embodiment, an exemplary method of ACL RetroConstruction™ of the present invention comprises, for example, the steps of: (i) drilling a femoral socket; (ii) drilling a tibial tunnel or socket using a retrograde drill technique employing the drilling/cutting instrument 100 of FIGS. 1-8; (iii) providing a graft (soft tissue graft or BTB graft) in the vicinity of the sockets; (iv) securing the graft (soft tissue graft or BTB graft) to a continuous loop/button construct comprising a button with an oblong configuration and provided with an inside eyelet that allows the passage of the continuous loop, preferably a suture loop; (v) passing the graft with the button through the femoral tunnel; (vi) securing the button to the femoral cortex once the button exits the femoral socket; and (vii) securing the graft in the tibial tunnel or socket.

[0030] Although the present invention has been described in connection with preferred embodiments, many modifications and variations will become apparent to those skilled in the art. While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.