Swiss Registry Links Femoral Stem Design to Periprosthetic Fracture Risk

A commentary in The Journal of Bone and Joint Surgery discusses a nationwide registry study by Bouché et al. examining femoral stem design and periprosthetic femoral fracture risk across 182,118 total hip arthroplasties. The Swiss National Joint Registry analysis included cemented and cementless stems, using the Kheir classification to distinguish cementless designs.

Compared with cementless double-wedge stems (Kheir type 3), cementless anatomic stems (type 7) were associated with higher fracture risk. Cementless short, calcar-loading stems (type 1B) and cemented composite-beam stems were associated with lower risk. Collared stems, both cemented and cementless, were associated with fewer fractures requiring surgery than collarless designs. The commentary does not provide absolute event rates, effect estimates, or confidence intervals.

The findings support considering stem design alongside patient-specific risk factors when planning hip arthroplasty. The commentary suggests particular consideration of collared stems in older, frail patients with poor bone quality or fall risk. However, the observational analysis remains susceptible to residual confounding from incompletely captured patient characteristics. It also did not assess overall revision risk across designs, including revision for infection, dislocation, loosening, or wear; lower fracture risk therefore does not establish superior overall implant performance.