Reinforcement insert for tissue graft
Devices and methods for reinforcing tissue grafts are described herein. In one embodiment, an implant is described that includes a proximal end portion having a through-hole formed therein, a distal end portion, and a reinforcing insert disposed in the through-hole. The insert includes a proximal face, a distal face opposed to the proximal face, a first upper surface extending between the proximal and distal faces and having a generally convex shape that abuts against at least a portion of a sidewall of the through-hole, and a second lower surface extending between the proximal and distal faces and having a generally concave shape. The second lower surface and portions of the sidewall of the through-hole not abutted by the first upper surface form a reinforced through-hole of the implant.
1. An implant, comprising:
a proximal end portion formed of bone and having a through-hole formed therein;
a distal end portion formed of bone;
a tendon coupled to the proximal end portion distal to the through-hole and extending between the proximal end portion and the distal end portion; and
a reinforcing insert disposed in the through-hole, the insert comprising:
a proximal face;
a distal face opposed to the proximal face;
a first upper surface extending between the proximal and distal faces, the upper surface having an upward-facing generally convex shape that abuts against at least a portion of a sidewall of the through-hole; and
a second lower surface extending between the proximal and distal faces, the lower surface being opposed to and disposed below the first upper surface, the lower surface having at least a portion with a downward-facing generally concave shape, and the second lower surface and portions of the sidewall of the through-hole not abutted by the first upper surface forming a reinforced through-hole of the implant,
wherein a cross-section of the through-hole has a non-circular shape and a cross-section of the reinforced through-hole has a circular shape.
2. The implant of claim 1 , wherein a radius of curvature of the first upper surface of the reinforcing insert associated with the generally convex shape is approximately equal to a radius of curvature of the portion of the sidewall of the through-hole against which the first upper surface abuts.
3. The implant of claim 1 , wherein a radius of curvature of the at least portion of the second lower surface of the reinforcing insert associated with the generally concave shape is approximately equal to a radius of the through-hole.
4. The implant of claim 1 , wherein the distance between a midpoint of the convex surface and a midpoint of the concave surface is about 1 millimeter.
5. The implant of claim 1 , wherein at least one of the proximal and distal faces has a cavity formed therein for receiving an insertion tool.
6. The implant of claim 1 , further comprising a suture disposed in the reinforced through-hole.
7. The implant of claim 1 , wherein the tendon, the proximal end portion, and the distal end portion are aligned along a longitudinal axis of the implant; and
wherein the tendon is coupled to a distal-most end of the proximal end portion and a proximal-most end of the distal end portion.
8. A reinforced bone plug, comprising:
a bone plug having a substantially cylindrical shape with a proximal end and a distal end, and a through-hole extending transversely across a longitudinal axis of the bone plug; and
an insert movable relative to the bone plug and positioned within the through-hole such that a proximally-facing convex surface of the insert abuts against at least a portion of a sidewall of the through-hole and a second surface of the insert that includes at least a distally-facing portion that is concave intersects at least a second portion of the sidewall of the through-hole to define a reinforced through-hole in the bone plug;
wherein a cross-section of the through-hole is oblong and a cross-section of the reinforced through-hole is a substantially circular.
9. The reinforced bone plug of claim 8 , wherein a radius of curvature of the convex surface is substantially equal to a radius of curvature of the portion of the sidewall of the through-hole against which it abuts.
10. The reinforced bone plug of claim 8 , wherein a radius of curvature of the at least portion of the second surface that is concave is substantially equal to a radius of curvature of the second portion of the sidewall of the through-hole.
11. The reinforced bone plug of claim 10 , further comprising a suture disposed in the reinforced through-hole.
12. The implant of claim 1 , wherein the second lower surface further includes a first planar portion and a second planar portion that each intersect at least a portion of the sidewall of the through-hole not abutted by the first upper surface; and
wherein the portion with a generally concave shape is disposed between the first planar portion and the second planar portion.
13. The reinforced bone plug of claim 8 , wherein the bone plug is formed of bone.
14. The reinforced bone plus of claim 8 , wherein the second surface further includes a first planar portion and a second planar portion that each intersect the at least second portion of the sidewall of the through-hole; and
wherein the concave portion of the second surface is disposed between the first planar portion and the second planar portion.
15. The implant of claim 1 , wherein the proximal end portion, distal end portion, and tendon are aligned along a longitudinal axis of the implant; and
wherein the through-hole is transverse to the longitudinal axis of the implant.
16. The implant of claim 1 , wherein the reinforcing insert is movable relative to the through-hole.
17. The implant of claim 1 , wherein the reinforcing insert and the proximal end portion are formed of different materials.
18. The reinforced bone plug of claim 8 , wherein the insert is formed of a different material than the bone plug.