Hindfoot Endoscopy for the Treatment of Localized Pigmented Villonodular Synovitis

INTRODUCTION: Pigmented villonodular synovitis (PVNS) is a rare and benign proliferative lesion affecting synovial lining of joints, bursae, and tendon sheaths. Depending on the extent of synovial involvement, two forms are distinguished, diffuse, and localized. Intra-articular localized form of PVNS (LPVNS) presents as a nodular, well circumscribed, pedunculated, or sessile soft-tissue mass. CASE PRESENTATION: We report a case of an unusual localization of LPVNS in posterior ankle recess in a 42-year-old male with concomitant anterior ankle impingement syndrome. To address both the posterior and the anterior ankle disorders the patient was treated with combined two-portal endoscopic hindfoot approach and anterior ankle arthroscopy within the same operative session. The hindfoot endoscopy encompassed complete removal of the localized mass, partial synovectomy of the area at the base of the lesion, removal of os trigonum, and a loose body impinged in the interval between tibia and fibula. The anterior ankle arthroscopy included removal of the osteophytes from the anterior distal tibia and dorsal talus. Patient continued his normal daily and sporting activities without any restrictions and no recurrence of LPVNS 2 years after the surgery. CONCLUSION: PVNS is an important clinical entity that should always be thought of as a differential diagnosis when treating patients with ankle disorders. Hindfoot endoscopy, when performed by an experienced ankle surgeon, is a safe and effective procedure for LPVNS of the posterior ankle recess, when deemed amenable to complete resection.