Large Diameter Total Hip Replacement for Acute Displaced Femoral Neck Fracture

Total hip replacement for acute femoral neck fracture is the preferred treatment for younger, physically and socially active patients. The risks, particularly dislocation, are higher than for elective total hip replacement for arthritis. Larger diameter bearings provide increased stability and can be used in this higher risk setting.

In this study, 391 patients with acute femoral neck fractures were treated with total hip replacement using 40-mm and 44-mm femoral heads. These femoral heads were placed in thin, two-piece, highly cross-linked polyethylene-lined acetabular shells. The procedures were performed by community orthopedic surgeons using the posterior approach. Patients were mobilized immediately and with only routine postoperative precautions. Patients were followed for 5 years. Follow-up radiographs were measured to determine component position.

There were no dislocations in the first 3 years following surgery, but there were 3 late dislocations. There were 29 revisions performed for impingement (n = 8), infection (n = 12), periprosthetic fracture (n = 3), instability (n = 2), and component loosening (n = 4). No instances of polyethylene wear or trunnion corrosion were identified. Overall, 37% of acetabular components simultaneously met the safe zone targets for inclination and anteversion. The mean Harris hip score was 90.

The dislocation rate in this study was lower than in prior studies, as was the overall revision rate. Using a femoral head ≥ 40 mm is a simple measure that reduces the dislocation rate without adding additional cost or complexity to the procedure. This device is available to all surgeons and may be an advantage to the hip surgeon treating femoral neck fractures with total hip replacement.