Background
Tenosynovial giant cell tumor (TGCT) is a relatively rare disease often misdiagnosed as osteoarthritis. Synovectomy or arthroplasty is the recommended treatment option, but recurrence is common after surgery. This study aimed to determine the prognosis of patients with advanced TGCT that was diagnosed incidentally during total knee arthroplasty (TKA) for osteoarthritis and treated by synovectomy.