Soft-tissue releases to treat spastic hip subluxation in children with cerebral palsy

Background: Spastic hip subluxation and dislocation are common problems in children with cerebral palsy. Soft-tissue releases have proved to be beneficial in the prevention of spastic hip dislocation. A protocol for treatment based on patient age, hip abduction, and hip migration percentage was established in 1988. The purpose of this study was to assess the outcome in sixty-five children treated according to this protocol and followed for a minimum of eight years. Methods: The medical records and radiographs of sixty-five children, from an original series of seventy-four patients, who met the inclusion criteria were available for review. Forty-seven children had spastic quadriplegia and were unable to walk; eighteen children had spastic diplegia and were able to walk independently or with assistive devices. The mean age at the time of the surgery was 4.4 years. Open adductor tenotomy and psoas muscle recession or iliopsoas tenotomy were performed on 129 hips, which were followed for a mean of 10.8 years. The mean age at the time of follow-up was fifteen years. Hips were grouped according to the hip migration percentage preoperatively, at one year postoperatively, and at the time of final follow-up. The final outcome for the patient was defined according to the worse hip. An analysis was performed to identify potential factors influencing outcome. Results: Thirty-two patients (49%) had a good result, eleven (17%) had a fair result, three (4%) had a poor result, and nineteen (30%) had a failure. The mean hip migration percentage was 34% preoperatively and 18% at the time of final follow-up. Nineteen patients required subsequent osseous reconstructive procedures, and eleven required repeat soft-tissue releases. The migration percentage at one year postoperatively was the most predictive of the final outcome (p = 0.001). Patients who had been able to walk preoperatively had a better long-term outcome (p = 0.01). Neither the preoperative hip migration percentage nor the age at surgery significantly affected the outcome. Conclusions: Soft-tissue release was effective for long-term prevention of hip dislocation in 67% (forty-three) of sixty-five children with spastic hip subluxation. Two preoperative factors that were related to a favorable outcome were a spastic diplegic pattern of involvement and the ability to walk. The hip migration percentage at one year postoperatively was a good predictor of final outcome.