Restoring Hip Symmetry and Its Impact on Outcomes: A Case Series on Megaprosthesis Use in Non-Oncological Patients with Complications After Total Hip Arthroplasty

Total hip arthroplasty (THA) is commonly performed for conditions like osteoarthritis, avascular necrosis, hip fractures, and hip dysplasia. Complications following THA can result in major proximal femoral defects (MPFD), which are challenging to manage. Megaprostheses provide a solution, offering stability and early weight-bearing, though they present their own challenges. However, maintaining hip symmetry with megaprostheses is challenging in accurately restoring femoral offset, acetabular orientation, and soft tissue tension. These factors can contribute to instability, altered biomechanics, and functional impairment. Therefore, achieving hip symmetry through femoral and acetabular offset, limb length discrepancy (LLD), and center of rotation (COR) is an important consideration. Achieving proper symmetry may improve gait, quality of life, and overall outcomes. This case series includes 10 patients with non-tumoral pathology treated with megaprostheses for complications after THA between 2014 and 2024. Megaprosthesis conversion was performed for sepsis (n = 2), aseptic loosening (n = 4), and periprosthetic fracture (n = 4). Dislocation occurred in 20%, with one case showing restored hip symmetry but dislocating due to trauma and noncompliance. Another case had an LLD of 3 cm, contributing to dislocation. Periprosthetic infection was observed in 20%, managed with a two-stage approach. Although hip symmetry was not fully restored in all patients, strict follow-up and rehabilitation were essential for improving functionality and quality of life. Megaprosthesis is an effective solution for MPFD in non-oncological patients when performed correctly. Restoring hip symmetry is challenging and depends on patient care and compliance, though it is an important factor influencing outcomes.