Heterotopic ossification after rhizotomy and femoral osteotomy.

In 15 patients with cerebral palsy who underwent selective posterior rhizotomy (SPR) and subsequent proximal femoral varus derotation osteotomy (VDO), heterotopic ossification (HO) around the hip after VDO was noted in four of eight patients with spastic quadriplegia (seven of 26 hips, 27%). HO was not noted in the seven patients with spastic diplegia. A radiographic review of 118 hips with a femoral VDO in the 69 patients with cerebral palsy who did not undergo SPR during the same period showed no HO. Frequent evaluation of postrhizotomy patients with cerebral palsy quadriplegia after a femoral VDO is necessary to recognize HO as a possible etiology for late-onset pain and limited hip range of motion (ROM).