Intraarticular heterotopic ossification in the knee following intramedullary nailing of the fractured femur using a retrograde method.

The cases of a forty-five-year-old woman and a twenty-year-old man who developed severe intraarticular and periarticular heterotopic ossification around the knee following intramedullary nailing of a femur fracture using a retrograde technique. The association of musculoskeletal heterotopic ossification with closed head injuries seems well established and can occur in and around the knee following retrograde intramedullary nailing. This complication may occur more often than has been reported.