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Background: Surgical management to improve hip joint morphology in immature patients with acetabular dysplasia includes Pemberton, Dega, San Diego, and Salter acetabular osteotomies. This study evaluates acetabular morphology between these osteotomies using patient-specific 3-D printing technology.
Methods: Preoperative computed tomography scans (CTs) from patients with acetabular dysplasia were rendered into 3-D printable formats. Quadruplicate pelvis models for each patient received Pemberton, Dega, San Diego, and Salter osteotomies. CTs were obtained of each model before and after osteotomy. Acetabular volume and regional coverage angles were computed and compared before and after each osteotomy.
Results: Fourteen hips (14 patients) were included; 1 male, 13 female; age 5.4±1.3 years (3.9-7.5 years). Acetabular volume decreased following each osteotomy (Pemberton by 14%, Dega by 19%, San Diego by 19%, and Salter by 6%), with smaller volume reduction for Salter than the others (p<0.05). Volume change was similar between Pemberton, Dega, and San Diego (p=0.32). Pemberton increased coverage in Superior and Anterior regions, Dega increased coverage in Superior, Superior-Anterior, and Anterior regions, San Diego increased coverage in Posterior, Superior-Posterior, and Superior regions, and Salter increased coverage in Superior region (p<0.05).
Conclusions: Acetabular volume changes found in this study support the convention that redirectional osteotomies such as Salter are more volume neutral than incomplete osteotomies such as Pemberton, Dega, and San Diego. However, even the Salter decreased acetabular volume. This study re-demonstrated that each osteotomy studied changes acetabular coverage in different regions. Based on this, a surgeon’s osteotomy decision should be based on the dysplastic acetabulum morphology.