Mucoid degeneration of the posterior cruciate ligament in a college soccer player: a case report

BACKGROUND: To the best of our knowledge, arthroscopic treatment for symptomatic mucoid degeneration of the posterior cruciate ligament in young athletes has not been reported before. CASE PRESENTATION: An 18-year-old Asian male college soccer player presented with a 3-month history of right knee pain without episodes of trauma. Despite conservative treatment over the preceding 3 months, his symptoms persisted. Physical examination of the right knee revealed full range of motion, though posterior knee pain was induced when the knee approached full flexion. On ligament examination, posterior sagging and Lachman test were negative, and no clinical finding indicative of ligament insufficiency was noted. Magnetic resonance imaging showed a diffusely thickened posterior cruciate ligament with increased signal intensity on the T2-weighted sequence. A few intact fibers were observed with continuous margin from origin to insertion. Based on the patient's history and the magnetic resonance imaging findings, we suspected mucoid degeneration of the posterior cruciate ligament as the cause of the patient’s symptoms. Since conservative treatment had failed to relieve the symptoms, arthroscopic treatment was indicated. Arthroscopic examination revealed yellowish crumbly tissues along the thickened posterior cruciate ligament. Tension and bulk of the posterior cruciate ligament were well preserved. Curettage of degenerative tissue and decompression of the posterior cruciate ligament resulted in symptom relief without instability of the knee joint. The patient returned to play at 3 months. At 12 months, postoperative magnetic resonance imaging showed no evidence of recurrence and indicated that the remaining posterior cruciate ligament was thicker than before the surgery. At 2 years follow-up, the patient remained asymptomatic and could play soccer at the same level as before the onset of pain. CONCLUSIONS: Arthroscopic decompression of the posterior cruciate ligament may relieve knee pain and facilitate early return to play with good functional results.