Dislocation of Total Hip Replacement in Femoral Neck Fracture: Do Surgical Approach and Dual Mobility Implant Matter?

Introduction: Total hip replacement (THR) in the neck of femur fracture in the elderly is associated with a higher risk of dislocation compared to hemiarthroplasty of hip or total hip replacement in the native hip. There is uncertainty regarding combining surgical approach, femoral head size, and the usage of single bearing or dual mobility to reduce the risk of dislocation. This study looks into the bearing of the prosthesis for posterior or lateral surgical hip approach as well as their head size to give a stable hip to these vulnerable groups of patients. Methods: Initial data were collected retrospectively from February 2017 till May 2019 from the electronic records database and clinical notes. Patients included in the study had a femoral neck fracture (age >60 years) who underwent a total hip replacement. Subsequent data were collected prospectively from June 2019 to July 2020. Results: High rate of dislocation was found with posterior approach and single bearing prosthesis. However, if dual mobility prosthesis was used while using the posterior approach the dislocation rate was very low. Also, with lateral approach and single bearing prosthesis using large femoral head size, the dislocation rate was negligible. Conclusions: We recommend a dual mobility prosthesis for posterior approach THR and lateral approach with single-bearing hip replacement with large size femoral head. The dislocation rate is low using this principle irrespective of the surgical approach.