Early Post-operative Periprosthetic Femur Fracture in the Presence of a Non-cemented Tapered Wedge Femoral Stem.

Non-cemented femoral fixation in hip arthroplasty has become the standard of practice in the USA. However, recent literature has brought attention to an increasing incidence of periprosthetic femur fractures with certain stem designs. This study examines reasons for early periprosthetic femur fractures in patients with a hip arthroplasty performed using a non-cemented tapered wedge stem design. A multivariate analysis using a matched-cohort design was performed to assess any potential risk factors that may predispose to such fractures. Six of 2,220 hips (0.3%) suffered a periprosthetic femur fracture within the first year after surgery; five of six were Vancouver Type B2. The average time to fracture was 9 weeks. This group of patients had a significantly higher canal-flare index and lower canal-calcar ratio. This complication may be preventable by having a better appreciation of the fit between the implant and the bone during pre-operative planning, with the goal of avoiding a proximal-distal mismatch.