Arthroscopic management of calcific tendonitis of the medial collateral ligament.

Calcific tendinitis most commonly occurs to the shoulder, but may also involve other structures of the locomotor system. It is a rare cause of knee pain. We report a 46-year-old woman with severe medial knee pain and limitation of movement in her right knee. There was a marked tenderness site at the proximal insertion of the medial collateral ligament (MCL). Flexion was able to provoke the painful symptoms in the medial knee. The involvement of differentiated diagnoses were excluded by history, laboratory and radiograph examinations, while X-ray, CT and MRI suggested calcific tendonitis of the MCL. Due to the failure of conservative treatments, we offered her arthroscopic excision of calcific deposit which was sent for biopsy. Histopathological evaluation confirmed the diagnosis of calcific tendinitis. This patient recovered shortly afterwards with immediate resolution of symptoms following excision. Thus far, calcifications involving the MCL have been documented thrice. Calcific tendonitis of the MCL diagnosed and treated by arthroscopy has not previously been reported, which can be challenging to diagnose and treat because of its rarity. Although conservative treatment appears to be frequently satisfactory, arthroscopic excision may be a better option for the refractory or severe cases.