Arthroscopic excision of juxta-articular giant-cell tumor arising from the patellar tendon sheath.

Most giant-cell tumors of the tendon sheath are found on the flexor surface of the hand, in the fingers, wrist, or palm. The isolated discrete lesion involving tendon sheaths (localized giant-cell tumor of the tendon sheath) is rarely located intra-articularly, especially in the knee joint. To the best of my knowledge, this is the first reported case of a large, localized, juxta-articular giant-cell tumor of the patellar tendon sheath that was treated successfully with arthroscopic excision.