Mechanical and histological response of carbon fibre pads implanted in the rabbit patella.

Small carbon fibre pads (3 mm in diameter) were implanted into rabbit patellae to ascertain the relationship between their mechanical and histological responses. After 3 months a highly vascularized collagenous matrix is formed within and around the implant securely anchored to the bone and providing a continuous layer to the articular surface. Mechanically, the resulting repair is much more compliant than the original articular cartilage/bone structure since the subchondral bone plate is not present within the implant; it also provides a functioning congruent surface with no evidence of fragmentation. This may be attractive in the long term by decreasing friction and the subsequent degeneration and wear commonly seen in fibrillated, disrupted articular cartilage.