SURGICAL BITING PUNCH
TECHNICAL FIELD
[0001] This invention relates to medical devices, and more particularly to a surgical biting punch.
BACKGROUND
[0002] The meniscus is a C-shaped piece of fibro cartilage that is located at the peripheral aspect of the knee joint, between the femur and the tibia. There are two menisci in each knee, the medial meniscus, and the lateral meniscus. The two menisci absorb shock and spread the force of weight bearing on the joint over a larger area. They also stabilize the ligaments of the knee. The majority of the meniscus has little or no blood supply. For that reason, when damaged, the meniscus does not heal as quickly as other tissue. In addition, the meniscus begins to deteriorate over time, often developing degenerative tears.
[0003] Typically, when the meniscus is damaged, the torn piece begins to move abnormally within the joint. Because the space between the bones of the joint is very small, as the abnormally mobile piece of meniscal tissue moves, it may become caught between the femur and tibia. Usually this situation requires that the torn piece be removed. A surgeon can use an instrument, often referred to as a "biter" to remove the tear. The instrument is referred to as a biter because its cutting edges are typically in the shape of a semi-circle or a square and part of jaws that open and close. The cutting edges therefore cut a piece of the meniscus in the shape of a semi-circle or a square when the jaws are closed, giving the appearance of taking a bite.
SUMMARY
[0004] In one aspect there is a surgical punch including a first jaw having a first cutting edge, a second jaw having a second cutting edge and a coupling member. The coupling member is disposed at proximal end portions of the first and second cutting edges and configured to bring the first and second jaws towards each other when actuated. Further, the jaws are configured to cause cutting from distal ends towards proximal ends of the jaws when the jaws are brought towards each other.
[0005] In other examples, the surgical punch can include one or more of the following features. A portion of the first cutting edge can be disposed distal to the second cutting edge. The first cutting edge can further include a first distal portion that is closest to the second jaw at a distal end of the first distal portion and farthest from the second jaw at a proximal end of the first distal portion when the first jaw is parallel to the second jaw. The second cutting edge can further include a second distal portion that is closest to the first jaw at a distal end of the second distal portion and farthest from the first jaw at a proximal end of the second distal portion when the first jaw is parallel to the second jaw.
[0006] The surgical punch can also include a projected point of rotation of the cutting located outside of the coupling member. The first jaw can be an upper jaw and the second jaw can be a lower jaw, and the surgical punch can further include a projected point of rotation of the cutting that is located above an initial cutting point of the second cutting edge. The first jaw can further include a leading edge
having a reverse slope. The leading edge can be configured to guide the first jaw between a meniscus and a femoral chondyle associated with the meniscus.
[0007] The coupling member can include a pivot pin. The coupling member can include a pinless hinge, wherein the first jaw is slidably coupled to the second jaw. The coupling member can include one of an arcuate flange and an arcuate groove.
[0008] The surgical punch can be configure where the coupling member further comprises the following:
[0009] one of the jaws comprising at least one first arcuate flange and the other of the jaws comprising at least one first arcuate groove, the at least one first arcuate flange being slidably disposed in the at least one first arcuate groove so as to pivotally couple the first jaw to the second jaw, whereby the first jaw is capable of pivotal movement towards and away from the second jaw, with the at least one first arcuate flange and the at least one first arcuate groove having a first center of curvature that is fixed in position relative to the second jaw when the at least one first arcuate flange is disposed in the at least one first arcuate groove, and
[0010] one of the first jaw and an actuating member comprising at least one second arcuate flange and the other of the first jaw and the actuating member comprising at least one second arcuate groove, the at least one second arcuate flange being slidably disposed in the at least one second arcuate groove so as to pivotally couple the actuating member to the first jaw, with the at least one second arcuate flange and the at least one second arcuate groove having a second center of curvature that is fixed in position relative to the actuating member and is not fixed in position relative to the second jaw when the at least one second arcuate flange is disposed in the at least one second arcuate groove, and one of the centers of curvature is displaced laterally from the second stationary jaw and the actuating member,
[0011] whereby (a) when the actuating member is actuated in a first direction relative to the second jaw, the first j aw will open away from the second j aw, and (b) when the actuating member is moved in a second opposite direction relative to the second jaw, the first jaw will close towards the second jaw, the first and second jaws being arranged so that body tissue located between the first and second jaws may be severed in a punching motion as the jaws are opened and closed relative to one another by actuating the actuating member.
[0012] The coupling member can also include a pin coupled to the first jaw and an actuating member and a slot to receive the pin, where the slot is configured to allow free passage of the pin as the actuating member is actuated. The slot can include an arcuate portion. The first jaw can be a movable j aw and the second j aw can be a stationary j aw. The first jaw can be a stationary jaw and the second jaw can be a movable jaw.
[0013] In another aspect, there is a surgical punch that includes a first movable jaw, a second stationary jaw and a coupling member. The first movable jaw has a first cutting
edge and a leading edge including a reverse slope. The second stationary jaw has a second cutting edge disposed proximal to a portion of the first cutting edge. The coupling member slidably couples the first jaw to the second jaw. The coupling member is disposed at proximal end portions of the first and second cutting edges, and configured to bring the first and second jaws towards each other when actuated. The jaws are configured to cause cutting from distal ends towards proximal ends of the jaws when the jaws are brought towards each other.
[0014] In another aspect, there is a surgical punch including an actuating rod, a fist jaw, a second jaw, a pin, and a coupling member. The first jaw has a first cutting edge. The pin movably couples the first jaw to the actuating rod. The second jaw has a second cutting edge and a slot configured to allow free passage of the pin as the actuating member is actuated. The coupling member is disposed at proximal end portions of the first and second cutting edges. The coupling member includes a flange and a groove configured to bring the first and second jaws towards each other when actuated.
[0015] In another aspect, there is a surgical punch including a first jaw, a second jaw and a coupling member. The upper jaw has a first cutting edge. The lower jaw has a second cutting edge. The coupling member couples the upper jaw to the lower jaw. The coupling member includes a center of rotation, where the center of rotation is configured to cause a predefined vertical cut in target tissue. In one example, the predefined cut is more distal, with respect to the surgical punch, at an end of the tissue closest to the upper jaw than at an end of the tissue closest to the lower jaw. The surgical punch can also include one or more of the features listed above.
[0016] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0017] FIG. 1 is a side view of a surgical punch with closed jaws.
[0018] FIG. 2 is a perspective view of the surgical punch.
[0019] FIG. 3 is a side view of the surgical punch with open jaws.
[0020] FIGS. 4A and 4B are side views of the surgical punch with jaws closing.
[0021] FIG. 5 is a transparent side view of the surgical punch.
[0022] FIG. 6 is a side view of another example of a surgical punch.
[0023] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0024] FIG. 1 illustrates a surgical punch 100 for use in repairing a meniscus 205 having a tear 210. Surgical punch 100 includes a moveable upper jaw 105 having a sloped leading edge 215 with a reverse slope. In other words, the slope of leading edge 215 from the distal end to the proximal
end is negative. This reverse sloped leading edge 215 enables a surgeon to guide the distal end of surgical punch 100 between meniscus 205 and a femoral chondyle 220, as indicated by arrow 225. Leading edge 215 also enables a surgeon to easily position upper jaw 105 above meniscus 205 for a cutting procedure.
[0025] Referring to FIG. 2 surgical punch 100 also includes a stationary lower jaw 110 and an actuating rod 115. Actuating rod 115 is connected to handles (not shown), such as scissor-like handles typically seen on biting punches and other similar surgical instruments. The handles move actuating rod 115 towards and away from moveable jaw 105 and stationary jaw 110. During use, when actuating rod 115 is moved away from the distal end of the punch, jaws 105 and 110 move toward each other (i.e., close). As a surgeon moves actuating rod 115 away from jaws 105 and 110, upper jaw 105 moves away from lower jaw 110 (i.e., open). When viewed from above, upper jaw 105 is "U" shaped and has an opening 118. This opening 118 allows a surgeon to view the portion of the target tissue that will be cut by surgical punch 100.
[0026] To enable upper jaw 105 to move, surgical punch 100 includes a sliding coupling mechanism 120. Sliding mechanism 120 has a groove 120a, in the shape of a semi-circle, located on the inner walls of upper jaw 105. Sliding mechanism 120 also has a corresponding flange 120fc, also in the shape of a semi-circle, located on the outer walls of lower jaw 110. As upper jaw 105 moves, groove 120a slides along and is guided by flange 120fc. To connect upper jaw 105 to actuating rod 115, feature 125 includes a pin 520 (FIG. 5). The pin 520 extends from one side of upperjaw 105, through actuating rod 115, to the other side of upperjaw 105. To accommodate this pin 520, lower jaw 110 includes a slot 525 (FIG. 5) so that there is no obstructing material as the pin 520 moves with upper jaw 105 as actuating rod 115 moves.
[0027] The pin 520 at feature 125 is not a pivot pin about which upperjaw 105 rotates. Unlike the alternative example described below, sliding mechanism 120 does not include a pivot pin. Because upper jaw 105 slides, the cutting trajectory 130 has a projected center of rotation 135 that is outside of and above the jaws 105 and 110. As described in more detail below, having a projected center of rotation 135 above the initial cutting point of lower jaw 110 allows cutting by upperjaw 105, along trajectory 130, to be more distal when jaws 105 and 110 are furthest apart (as shown) than when jaws 105 and 110 are closed.
[0028] FIG. 3 illustrates jaws 105 and 110 in an open position around meniscus 205, ready to begin a cutting procedure. Meniscus 205 attaches at point 305 to the tibial plateau. The meniscus 205 can also attach along the vertical rear edge (from point 305 and up). Arrow 310 represents the distance along the top of meniscus 205 from the plane of attachment to the cut, at the cutting trajectory 130, made by surgical punch 100. Similarly, arrow 315 represents the distance along the bottom of meniscus 205 from the plane of attachment to the cut, at the cutting trajectory 130, made by surgical punch 100. The larger the difference between distance 315 and distance 310, the more stable the remaining meniscus will be. As described above, the projected center of rotation 135 for cutting trajectory 130 is above lower jaw 110 for surgical punch 100. This means that the cutting
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