Mid-Term Outcomes of Acetabular Reconstruction Using a Rapid Prototyping Pelvic Model in Complex Total Hip...

Total hip arthroplasty (THA) is challenging in cases of acetabular deficiency, implant loosening after primary THA, and osteoarthritis secondary to hip dysplasia. Three-dimensional (3D) prototyping models from CT scans enhance preoperative planning and anatomical understanding, particularly in complex acetabular reconstruction. The purpose of this study was to determine the effectiveness of the rapid prototyping pelvic model in THA.

This retrospective study included 20 hips in 18 patients (8 male, 10 female; mean age 60.9 years). Acetabular defects were classified using Paprosky types: 2B (1 case), 2C (11 cases), 3A (5 cases), along with pseudo-acetabular formation (2 hips) and metastatic bone defects (1 hip). 3D models were printed using fused deposition modeling (FDM) with polylactic acid filament. Preoperative simulations of acetabular reaming and cup positioning were performed on the models. Radiographic outcomes included acetabular cup inclination, anteversion, osteolysis, and implant loosening. Surgical complications such as dislocation, infection, and fracture were analyzed.

Mean acetabular cup inclination was 49.1° [43.5-54.7], and anteversion was 15.0° [2.0-28.0]. None of the cases showed implant loosening, osteolysis progression, or surgical complications during a mean follow-up of 71.5 months. Trabecular metal augment (7 cases) and acetabular cages (3 cases) were used for defect management, with additional bone screw stabilization in most cases.

Preoperative planning using 3D prototyping pelvic models resulted in accurate cup positioning and stable outcomes in complex THA cases. Further studies with larger cohorts and longer follow-up are necessary to confirm these findings.