Fractured heterotopic bone in myositis ossificans traumatica.

OBJECTIVE

To discuss the case of a patient with an acute fracture occurring through preexisting, quiescent, posttraumatic heterotopic bone formation of the gastrocnemius muscle. The lesion demonstrated a previously unreported pattern of healing. This case serves to demonstrate an infrequent event with a rare and heretofore unreported sequella.

CLINICAL FEATURES: A 54-year-old man with preexisting, mature heterotopic bone within the left gastrocnemius muscle experienced reinjury to the site. The preexisting heterotopic bone was a result of a sporting injury that had occurred 32 years previously. At the time of the new injury, the patient experienced immediate, severe pain. Radiographs demonstrated a nondisplaced oblique fracture through the preexisting heterotopic bone.

INTERVENTION AND OUTCOME: The patient was treated with protective wrapping and physiotherapy modalities. Because only the heterotopic bone was involved, the leg was not placed in a cast. Follow-up radiographs obtained 14 weeks later showed callus formation about the fractured site and evidence of union.

CONCLUSION

Fractures occurring through mature heterotopic bone formations, such as those seen in myositis ossificans traumatica, are infrequent; callus formation with union of the fractured fragments is an even rarer occurrence.