Mucoid Degeneration of Posterior Cruciate Ligament Leads to Roof Impingement with Anterior Cruciate Ligament: Case Report

Mucoid degeneration of cruciate ligament is rare cause of knee pain, however there are some cases causing pain and restriction of extension. A 60-year-old man came to our clinic complaining of pain in knee joint on full range of extension about 3 months ago. The range of motion (ROM) was a flexion contracture of 5 degree and a further flexion of 140 degree with pain aggravation by forced extension. Magnetic resonance imaging of the knee joint showed thickened posterior cruciate ligament (PCL) mucoid degeneration. Arthroscopic treatment consists of PCL reduction-plasty by debridement of yellowish material in the PCL fiber and reduces the volume of the hypertrophied PCL. Immediately after surgery, patient gain the full ROM without any symptom of impingement. Enlarged PCL can make impingement in femoral notch with anterior cruciate ligament (ACL). Then, Partial debulking surgery of PCL is an effective treatment to pain relief and restore ROM of knee.