Midterm results of the Chiari pelvic ostetomy for acetabular dysplasia

Abstract

Objectives: We evaluated the midterm clinical and radiographic results of the Chiari pelvic osteotomy in the treatment of acetabular dysplasia.
Patients and methods: Forty-two hips of 36 patients (23 females, 13 males; mean age 17 years; range 12 to 42 years) were treated with the Chiari pelvic osteotomy for painful acetabular dysplasia. Six patients (16.7%) had bilateral surgery. Preoperatively, the mean duration of hip pain and/or limping was 34.6 months and 12 hips exhibited mild-to-moderate osteoarthrosis. Clinically, the patients were evaluated with the Harris hip score and correlations were sought between the hip scores and radiographic measurements. The mean follow-up was 88 months (range 48 to 164 months).
Results: After exclusion of one hip that required total hip arthroplasty 12 years after osteotomy, the mean Harris hip score increased from 73±5 preoperatively to 89±6 at the last follow-up. Postoperatively, 35 hips (85.4%) exhibited slight or no pain. Clinical results were excellent in 20 hips (48.8%), good in 15 hips (36.6%), and fair in six hips (14.6%). Thirty patients (83.3%) were satisfied with the operation. No significant correlations were found between Harris hip scores and the percentage coverage of the femoral head, center-edge angle, and acetabular angle. However, the percentage medialization of the distal fragment (r=0.28, p=0.042), the level of osteotomy (r= -0.6, p<0.0001), the severity of preoperative osteoarthrosis (r= -0.85, p<0.0001), and age (r= -0.66, p<0.0001) were significantly correlated with the hip scores. Complications included superficial infection in two hips, injury to the lateral femoral cutaneous nerve in 10 hips, and delayed union in two hips.
Conclusion: Our results suggest that the Chiari pelvic osteotomy provides a significant clinical improvement in patients with painful acetabular dysplasia.