Heterotopic ossification in children after iliopsoas release.

Heterotopic calcification or ossification of the soft tissues adjacent to the lesser trochanter was observed in the radiographs of 4 patients during a retrospective review of the records of 68 patients with Perthes' disease. This abnormality has since been seen in one other patient with Perthes' disease and in five with spastic quadriplegia. All 10 patients are known to have undergone iliopsoas release as part of adductor tenotomy. The authors believe that the heterotopic ossification is related to the surgery.