Comparison of 3 Pediatric Pelvic Osteotomies for Acetabular Dysplasia Using Patient-specific 3D-printed Models

Abstract

Background: Children with developmental dysplasia of the hip may require a pelvic osteotomy to treat acetabular dysplasia. Three osteotomies are commonly performed in these patients (Pemberton, Dega, and San Diego), though comparative studies of each are limited. The purpose of this study was to compare changes in acetabular morphology (acetabular version, volume, and octant coverage angles) created by these 3 osteotomies using matched patient-specific 3D-printed pelvic models. Methods: Fourteen patients with developmental dysplasia of the hip and preoperative computed tomography (CT) imaging were retrospectively included. For each patient CT, bone and cartilage tissues were independently segmented, and 3 identical pelvises were 3D-printed using a dual material printer. Bone was printed with rigid material and cartilage with flexible material to simulate the flexibility of the triradiate cartilage and pubic symphysis. Pemberton, Dega, and San Diego acetabular osteotomies were performed on the triplicate set of 3D prints. Acetabular version, volume, and octant coverage angles (posterior, superior-posterior, superior, superior-anterior, and anterior) were determined before and after each mock surgery by morphologic assessment using preoperative and postoperative CT images. Results: San Diego osteotomy yielded a small increase (+3.34±1.71 degrees) in version, compared with decreases with Pemberton (−5.47±1.54 degrees) and Dega (−8.57±1.21 degrees, P<0.05). Acetabular volume decreased similarly for Pemberton (−13.36%±2.88%), Dega (−19.21%±2.73%), and San Diego (−19.29%±2.44%; P=0.215) osteotomies. San Diego osteotomy tended to have a larger postoperative increase in the posterior regions, and the Dega and Pemberton osteotomies tended to have larger postoperative increases in the anterior coverage regions. Conclusions: Quantifiable differences were identified in acetabular octant coverage angles and version between the 3 pelvic osteotomies. San Diego osteotomy increased acetabular coverage posteriorly resulting in acetabular anteversion, whereas Pemberton and Dega had greater superior-anterior coverage resulting in relative acetabular retroversion. This study is the first known to utilize 3D-printed models for comparison of surgical approaches in pediatric pelvic osteotomies.

Is acetabular dysplasia and pelvic deformity properly interpreted in patients with congenital femoral deficiency? A 3D analysis of pelvic computed tomography

“…7,18 Since the orientation of the acetabulum is skewed posteriorly and superiorly, we predict that the San Diego pelvic osteotomy (modification of Dega procedure, which enables better posterior coverage), or triple pelvic osteotomy in older children, might be better methods for the proper redirection of the acetabulum walls. 18,19 Despite this, further investigation including prospective studies comparing different surgical techniques or experimental models should be performed, as has been done previously in DDH cases by Caffrey et al 20 In conclusion, this study clearly shows that the acetabulum in CFD is distorted globally, with its axis skewed mainly posteriorly and superiorly. The severity of the disease influences the size of the acetabulum, making it smaller.…”

3-D acetabular morphology of the neuromuscular hip: implications for preoperative planning

“…With the advent of surgical techniques to address the deficient acetabulum, this can have significant clinical consequences. Acetabuloplasties do not all increase coverage in the same areas and may worsen coverage in some areas [30]. Tannast et al [16], for example, described iatrogenic retroversion following pelvic osteotomies causing poor patient outcomes requiring revision pelvic osteotomies in typical DDH.…”

MRI-based assessment of acetabular version and coverage after previous Pemberton osteotomy in skeletally mature patients

“…Using patient-specific 3D-printed models based on preoperative CT scans of 14 patients, Caffrey et al 32 performed mock surgeries, including Dega’s, San Diego as well as Pemberton osteotomies. The Pemberton osteotomy was found to have 5.47° ( sd 1.54°) of decreased version, albeit an increased coverage in the anterior acetabular region when compared with the preoperative status.…”