Evaluating the risk factors for Lubinus SP II femoral stem fractures: A case series of 5 primary total hip arthroplasty patients with a mean follow-up of 7.5 years.

The reported rate of femoral stem fracture after total hip arthroplasty (THA) varies between less than 0.1 and 3.4%. The study aimed to evaluate the incidence of Lubinus SP II femoral stem fracture in our population and associated risk factors, and to examine clinical outcomes following revision THA for SP II stem fracture. 4244 primary THAs incorporating the anatomic femoral stem were identified within our institution from a prospectively compiled arthroplasty patient database. 5 patients presented with a broken Lubinus SP II anatomical hip stem. Immediately postoperatively, the operating consultant submitted intraoperative data detailing surgical approach, head size, and components used. Patients were reviewed 6 weeks postoperatively in an orthopedic clinic, then followed up at a dedicated orthopedic audit clinic at 6 months, 1, 3, and 5 years postoperatively, and data were collected prospectively. Postoperative complications were recorded at each follow-up visit. The incidence of stem fracture was 0.1% (5/4240) at a mean follow-up of 7.5 years. 3 were male, and 2 were female. The mean age was 63.8 years (range, 53-72, SD = 7.4). The mean weight was 109 kg (range, 88-128; SD = 14.2). The mean BMI was 36.5 kg m