A 17-year-old boy fractures his left tibia in a skiing accident. One year later, an X-ray of the leg discloses reactive bone formation in the calf muscle at the site of injury. Which of the following is the most likely diagnosis?

Myositis ossificans affects young persons and, although it is entirely benign, often mimics a malignant neoplasm. The lesion typically results from blunt trauma to the muscle and soft tissues, usually of the lower limb. Peripheral neovascularization of the resulting hematoma leads in a short time to the formation of bone spicules in the soft tissue because the local environment is similar to that of an initial hematoma in a healing fracture. Because myositis ossificans often occurs near a bone, on radiography, it may be misdiagnosed as a malignant bone-forming tumor. The other choices are unrelated to prior trauma.Diagnosis: Myositis ossificans