Strategies for fixation of periprosthetic fragility fractures of the neck of femur below a well-functioning hip resurfacing arthroplasty: A case-series.

Introduction: Metal-on-metal Hip Resurfacing (HR) was performed in many young individuals as it conserved bone stock and had low wear rates, before it became less popular due to the detection of Adverse Reactions to Metal Debris. As such, many patients in the community have well-functioning HRs and as they age, the incidence of fragility fractures of the neck of femur around the existing implant is expected to increase. These fractures are amenable to surgical fixation as adequate bone stock remains in the head of the femur and the implants are well fixed. Case-series: We present a series of six cases which were treated by fixation using locked plates (3), dynamic hip screws (2) and cephalo-medullary nail (1). Four cases achieved clinical and radiographic union with good function. One case had a delayed union, though union was finally achieved at 23 months. One case had an early failure necessitating revision to a Total Hip Replacement after 6 weeks. Discussion: We highlight the geometrical principles of placing fixation devices under an HR femoral component. We have also conducted a literature search and present details of all case reports to date. Conclusion: Fragility per-trochanteric fractures under a well-fixed HR with good baseline function are amenable to fixation using a variety of methods including large screw devices that are commonly used in this location. Locked plates including variable angle locking designs should be kept available if needed.