DISLOCATION RISK FOLLOWING CEMENTED HEMIARTHROPLASTY WITH THE LUBINUS SP-II ANATOMICAL FEMORAL STEM IN A DISTRICT GENERAL HOSPITAL

The Lubinus SP-II composite beam anatomical femoral stem has built-in anteversion. Thus, excessive anteversion, particularly in less experienced hands, may increase dislocation risk in hip hemiarthroplasty. This study assessed dislocation following cemented hemiarthroplasty for intracapsular neck of femur (NOF) fracture using the Lubinus SP-II stem in a district general hospital. From 2017 and 2020, 731 patients underwent cemented hemiarthroplasty for intracapsular NOF fracture at Victoria Hospital Kirkcaldy, using the Lubinus SP-II femoral stem. A substantial portion of these were performed by middle-grade registrars under consultant supervision. Demographics and perioperative data was collected prospectively in a hip fracture database. Patient records and national imaging records were reviewed at mean 5.5-year follow-up (SD 1.1) to identify dislocation episodes, revision surgeries, infection, and postoperative periprosthetic fracture. Mean age was 81.2 years (SD 8.8; range 50–100), with 501 females (69%). Eight patients sustained dislocation, giving a dislocation rate of 1.1% (8/731). There were ten dislocation episodes in total, with two patients dislocating twice. In the dislocation cohort, mean age was 76.4 years (range 52–94); six patients were female and two male. Four patients were ASA 2 and four were ASA 3. Two dislocation cases underwent revision while one underwent excision arthroplasty. Implant survivorship was 98.2% (95% CI 95.9–99.9%) at 7 years. The Lubinus SP-II anatomical stem demonstrated a low dislocation rate following cemented hemiarthroplasty despite the potential technical challenge of avoiding unnecessary additional anteversion when surgeons are more familiar with polished taper stems.