2026 AAHKS Annual Meeting: Isolating the Collar Effect on Periprosthetic Fracture Risk in Triple-Taper Cementless THA

6817 patients undergoing primary unilateral cementless total hip arthroplasty (THA) with triple-taper femoral stems were retrospectively evaluated to compare collared and collarless femoral stems. Two comparisons were performed: collared versus collarless versions of a single implant design (n=3346) and all collared triple-taper stems versus a single collarless stem (n=6794). The primary outcome was postoperative periprosthetic femoral fracture (PPF). Outcomes were assessed postoperatively, although the follow-up duration was not reported. Overall, the results revealed that collared stems were associated with significantly lower odds of PPF in both comparisons, although the weighted risk difference was statistically significant only in the broader comparison. These findings suggested that femoral stem collars may independently reduce PPF risk beyond the protective effects of triple-taper stem geometry.