Objectives: We evaluated the effect of triple pelvic osteotomy on acetabular coverage and its clinical implications by clinical and radiographic parameters in patients with acetabular dysplasia.
Methods: Triple pelvic osteotomy was performed in 21 hips of 19 patients (13 females, 6 males; mean age during operation 16.3 years; range 8 to 32 years). Acetabular dysplasia was bilateral in two, and unilateral in 17 patients. Etiology was developmental dysplasia of the hip in 12 patients, Legg-Calve-Perthes disease in five patients, and diplegic and quadriplegic cerebral palsy in two patients, respectively. The patients were clinically evaluated by the modified Merle d'Aubigne-Postel system, and radiographic assessments were made using nine parameters. The mean follow-up period was 27.7 months (range 14 to 60 months).
Results: According to the modified Merle d'Aubigne-Postel system, preoperative and postoperative clinical scores were 13.14 and 15.29, respectively (p<0.001). The Trendelenburg test was positive in all (94.7%) but one patient preoperatively. At final follow-up, it was positive in six hips (28.6%), delayed positive in 12 hips (57.1%), and negative in three hips (14.3%). Of radiographical parameters, the mean corrections obtained in the center-edge angle, femoral head coverage, acetabular angle, and acetabular index angle were 21.6 degrees (p<0.05), 18% (p<0.05), 14.5 degrees (p<0.05), and 16.4 degrees (p<0.05), respectively, with an increase in lateralization (1.7 mm; p<0.05) and a decrease in cranialization (3.8 mm; p>0.05). The ratio of acetabular depth to width remained unchanged (p>0.05).
Conclusion: Triple pelvic osteotomy is successful in correcting biomechanics of the hip joint in most of the patients with acetabular dysplasia.