Mucoid degeneration of the anterior cruciate ligament.

A case of intraligamentous mucoid degeneration of the anteromedial band of the anterior cruciate ligament (ACL) is presented. The patient had knee pain without clinical or diagnostic evidence of instability. Isolated debridement of the anteromedial band resulted in immediate pain relief with rapid return to athletic activities without instability. We present this case to demonstrate the presence of intraligamentous mucoid degeneration in the ACL as a source of knee pain without instability. Partial ACL debridement did not preclude adequate knee stability.