Anterior and Posterior Arthroscopic Treatment of Primary Synovial Chondromatosis of the Ankle.

BACKGROUND: Primary synovial chondromatosis (PSC) is a progressive disorder of unknown etiology resulting in formation of multiple loose bodies. If left untreated, it may lead to degenerative changes or malignant transformation to chondrosarcoma.

METHODS: Seventeen patients who underwent combined posterior and anterior ankle arthroscopy within the same operative session and had histologically confirmed PSC were included in this retrospective study. American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot score was used to evaluate ankle function preoperatively and at a final follow-up. A 3-question survey was used to evaluate patient's satisfaction at the final follow-up.

RESULTS: In 14 patients, loose bodies were found in both compartments of the ankle, in 2 only in the anterior compartment, and in 1 only in the posterior compartment. All patients had evident signs of synovial inflammation in both compartments. The AOFAS Ankle-Hindfoot score increased from the preoperative median score of 65 (range, 29-90) to 95 (range, 65-100) at the final follow-up. Fourteen patients reported they were extremely satisfied with the outcome, 1 was moderately satisfied, and 2 were dissatisfied. No cases of recurrence of synovitis or loose body formation were noted, nor any signs of malignant transformation during the follow-up period.

CONCLUSION: We believe the risk of recurrence of PSC, which is in close relation to malignant transformation, can be minimized by performing a complete synovectomy of the ankle. Our experience and review of literature makes us believe that ankle PSC should be regarded as a whole joint disorder. Performing a combined posterior and anterior arthroscopic procedure within the same operative session should always be considered in patients with ankle PSC.

LEVEL OF EVIDENCE: Level IV, retrospective case series.