The patellar meniscus in total knee replacement.

Theoretically, because most patellar replacements are convex polyethylene structures subjected to high loads, considerable wear should occur. This has not been reported. A review of knee revisions had been carried out. The patella has been resurfaced on 12 occasions. It was revised on five occasions, and gross wear was seen in three of these cases, in all of which the patella had dislocated. The patella in all cases was surrounded by a meniscus of dense fibrous tissue. A small wear facet in the exposed area was present. This suggests that patellar articular surface geometry may not be critical as far as wear is concerned.