Recurrent Extra- and Intra-articular Synovial Chondromatosis of the Ankle with Tarsal Tunnel Syndrome: A Rare Case Report.

INTRODUCTION: Synovial chondromatosis is a rare, benign monoarticular condition characterized by the metaplastic formation of cartilaginous nodules from the synovium of joints (intra-articular), tendons and bursae (extra-articular). These nodules have the potential to detach and form loose bodies within the joint space. The most common locations are the large joints such as the knees, hips, elbows, and shoulders, with less common locations being the foot and ankle joints. Synovial chondromatosis primarily occurs in men between the third and fifth decades of life, and it typically presents as chronic joint pain with swelling, decreased joint range of motion, and osteoarthritis. Treatment is usually centered on excision and retrieval of nodules and loose bodies. Prognosis is usually good with a low-moderate likelihood of recurrence.

CASE REPORT: We report the very rare case of a 27-year-old male with recurrent intra- and extra-articular ankle synovial chondromatosis, who also reported symptoms consistent with tarsal tunnel syndrome. His initial presentation was left ankle pain which was managed by open surgical debridement. Two years after, he re-presented with continued pain and tingling along the plantar aspect of his foot. On his second presentation, a dual approach was taken with arthroscopic as well as open debridement. He reported resolution of his symptoms postoperatively as well as at 3 years of follow-up.

CONCLUSION: Simultaneous extra- and intra-articular chondromatosis of the ankle is very rare and can be difficult to treat. It is important to recognize this disease as a rare but plausible cause of tarsal tunnel syndrome. Treatment may be complicated with early or late recurrence despite complete excision, highlighting the need for intentional follow-up of all cases.