A brachial plexopathy due to myositis ossificans. Case report and review of the literature.

Myositis ossificans (MO) is a disorder characterized by the intramuscular proliferation of fibroblasts and osteoblasts, with subsequent deposition of bone and cartilage. A typical clinical presentation involves traumatic injury to a young adult, usually localized to the thigh, buttock, or upper arm, with resultant MO and mildly restricted range of motion in adjacent joints. Rarely, MO is associated with peripheral neuropathies involving the radial, median, sciatic, and sural nerves. The authors present an unusual case of MO causing a brachial plexopathy. To their knowledge, this is the first description of such a presentation.