Synovial chondromatosis of the foot: Two case reports and literature review

BACKGROUND: Primary synovial chondromatosis (PSC) is a rare arthropathy of the synovial joints characterized by the formation of cartilaginous nodules, which may detach and become loose bodies within the joint and may undergo secondary proliferation. PSC of the foot and ankle is exceedingly rare, with only a few cases reported in the literature. The diagnosis may be difficult and delayed until operative treatment, when it is confirmed by histological assessment. PSC may degenerate into chondrosarcoma. Operative treatment is the gold standard aiming to minimize pain, improve function, prevent or limit progression of arthritis. Surgical treatment consists in debridement by arthrotomic or arthroscopic management, but there is no consensus in the literature about timing of surgery and surgical technique. Thus, the aim of this study is to report the outcomes of the surgical treatment of two cases, together with a literature review. CASE SUMMARY: We report two cases of patients affected by PSC of the foot in stage III, according to the Milgram classification: the former PSC localized in the ankle that underwent open surgery consisted of loose bodies removal; the latter in the subtalar joint, and the choice of treatment was the arthrotomy and debridement from loose bodies, in addition to the subtalar arthrodesis. Both patients returned to complete daily and working life after surgery. CONCLUSION: Synovial chondromatosis is a rare benign pathology, even rarer in the ankle joint and especially in the foot. Surgery should be minimal in patients with ankle PSC, choosing the correct timing, waiting if possible until stage III. More aggressive and early surgery should be performed in patients with PSC of the foot, particularly the subtalar joint, due to the high risk of arthritic evolution.