Bipolar versus total hip modular prosthesis following proximal femoral resection for primary bone tumors: A comparative study

Objectives: The objective of the study is to compare the bipolar hemiarthroplasty (BHA) and total hip modular prosthesis total hip arthroplasty (THA) regarding functional outcomes, dislocation rate, and detection of the rate of acetabular erosion for the BHA. Methods: A comprehensive retrospective cohort comparative study was conducted on patients aged between 15 and 65 years, who underwent wide resection and reconstruction by proximal femoral modular prosthesis for a primary bone tumor, either with THA (21 patients) or BHA (33 patients), from January 2017 to October 2020, and with a minimum follow-up of 1 year. Results: The 1-year Musculoskeletal Tumor Society score was statistically significantly better in the THA group (26.32 points), compared to the BHA group (24.10 points) ( P : 0.007). The 1-year Harris Hip Score was 90.53 points in the THA group, and 87.55 points in the BHA ( P : 0.032). No statistically significant difference was found regarding dislocation incidence and infection between the two groups ( P : 1.000 and 0.386, respectively). The acetabular erosion rate for the BHA was 27.3% with a mean post-operative time of 81.50 months. Conclusion: The study suggests better functional outcomes in the THA group compared to the BHA group, with no significant difference in dislocation or infection rates. The higher acetabular erosion in the BHA group suggests that, for young patients with a primary bone tumor, a THA may provide better functional outcomes.