A sciatic nerve lesion secondary to compression by a heterotopic ossification in the hip and thigh region--an electrodiagnostic approach.

A sciatic nerve lesion secondary to compression by a heterotopic ossification is rare. Operative release of the encased sciatic nerve in some cases may restore the function of the nerve partially or completely. However, in some cases the injury may be permanent. An electrophysiologic study is very useful to determine the location and severity of nerve damage, including axonal loss, demyelination, or both. An electrophysiologic study can emphasize the portion of the sciatic nerve that has been involved the most (lateral versus medial or peroneal versus tibial). In some cases an electrophysiologic study can suggest whether surgery should be postponed if a recovery pattern from the nerve injury is obvious. The prognostic value of follow-up studies is considerable. The authors reviewed literature available to them since 1971 and found 6 cases, including their own. This is the first attempt to put together all the information available in the literature about this condition.