Hip reconstruction in cerebral palsy: Lessons from a single center and 137 hips

BACKGROUND: This large, retrospective, single-center study aimed to compare the outcomes of unilateral hip reconstruction and bilateral hip reconstruction in children with non-ambulatory cerebral palsy and ascertain risk factors for recurrent instability and reoperation. METHOD: We performed a retrospective review of 137 hip reconstructions performed for patients with cerebral palsy. Preoperative and postoperative clinical and radiological parameters were documented, including hip migration percentage, acetabular index, the Gross Motor Function Classification System, the Melbourne Cerebral Palsy Hip Classification System, hip abduction, and pelvic obliquity. RESULTS: Overall, 49 patients underwent bilateral hip reconstruction, and 37 patients underwent unilateral hip reconstruction. In the unilateral hip reconstruction group, the reconstructed hip remained stable (with a migration percentage < 33%) in 59% of patients compared to 74.4% of the more affected hips in the bilateral hip reconstruction group (p = 0.02). Of the unreconstructed hip in the unilateral hip reconstruction group, 74.4% remained stable (with a migration percentage < 33%), compared to 78.8% of the less affected hips in the bilateral hip reconstruction group. A level pelvis was maintained at final follow-up in significantly more patients in the bilateral hip reconstruction group than the unilateral hip reconstruction group (p = 0.002). Further surgical intervention was performed in 41% of the unilateral hip reconstruction group, compared with 11.5% in the bilateral hip reconstruction group (p = 0.001). Surgery performed under the age of 8 years and not performing an acetabular osteotomy were found to be risk factors for recurrent instability in all groups. CONCLUSION: Our series suggests that in terms of recurrent instability after hip reconstruction in cerebral palsy, protective factors against this complication include bilateral hip reconstruction, hip reconstruction after 8 years of age, and the use of an acetabular osteotomy.