Reinforcement insert for tissue graft

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.