Intra-articular ganglion cyst arising from the anterior cruciate ligament: a case report

Intra-articular ganglion cysts have been reported in the medical literature but are extremely rare. A MEDLINE search from 1966 to July 1995 revealed no reported cases in the Physical Medicine literature. This case report details the presentation, evaluation and treatment course of a patient with knee complaints who was subsequently diagnosed to have a ganglion cyst arising from the anterior cruciate ligament. The patient was a 38-year-old woman with a 6-month history of knee swelling and pain. She had difficulty walking. Non-steroidal anti-inflammatory agents had not alleviated her symptoms significantly. Physiatric evaluation revealed a supra-patellar effusion and a mass lateral to the patellar tendon. MRI evaluation revealed an intra-articular cyst. The patient underwent surgical removal of what was subsequently determined to be an intra-articular ganglion cyst arising from the anterior cruciate ligament. The patient has had progressive resolution of her knee symptoms post-operatively. Physiatrists need to be aware of this cause of mechanical knee symptoms.