DISLOCATION OF THE HIP MYELOMENINGOCELE - THE MCKAY HIP STABILIZATION

We reviewed the clinical and radiographic results of varus osteotomy o f the proximal aspect of the femur and transfer of the adductor and ex ternal oblique muscles (the McKay procedure) in thirty-four children ( sixty-six hips) who had an unstable hip secondary to a myelomeningocel e at the middle or caudad lumbar level, The average age at the time of the operation was twenty months (range, seven to forty-two months), T he average duration of follow-up was 10.9 years (range, 0.7 to 20.0 ye ars), An open reduction was performed in ten hips, None of the childre n had had any previous operative treatment. The index operation helped to maintain the stability of thirty-seven of the fifty-one hips in tw enty-six children who remained neurologically stable: seventeen of nin eteen hips that were at risk, two of three hips with acetabular dyspla sia, fifteen of sixteen subluxated hips, one of three dislocated hips that had been previously reduced with a Pavlik harness, one of two dis locatable hips, and one of seven previously untreated dislocated hips, The index operation was not successful for one dislocated hip that ha d been treated with closed reduction and application of a spica cast, The operation was a success for eight of the fifteen hips in eight chi ldren who had a progressive loss of neurological function: three of fi ve hips that were at risk, one hip with acetabular dysplasia, two of f our subluxated hips, one of two hips that had been previously reduced with a Pavlik harness, and one dislocatable hip, Two dislocated hips r edislocated. Initially the index operation was performed on all childr en who had a myelomeningocele at the third or fourth lumbar level. Rec ent data have shown that the hips in these children are not all at ris k, and we now perform the operation only if there is documented instab ility of the hip.