[Post-traumatic ossification of the medial collateral ligament of the knee: about a case].

Heterotopic ossification is a pathological ossification of soft tissues. It is a benign, recurring disease with an unpredictable onset. We here report the case of a patient treated for a fracture of the left tibial tray with installation of a screwed plate. Two months after surgery the patient had a stiff left knee. Standard radiological examination showed ossification of the medial collateral ligament (MCL) confirmed by tomodensitometry. We do not currently know which factors determine the presence of tendon and ligamentous ossification. Although clinicians often prescribe prophylactic drugs, such as anti-inflammatory drugs and radiotherapy sessions to prevent heterotopic ossification in soft tissues, the physiopathology of heterotopic ossification is little known.