Biomechanical influence of femoral stem design on periprosthetic femoral fractures in dorr type C femurs with normal bone quality

Periprosthetic femoral fracture (PFF) is a major complication following total hip arthroplasty (THA), particularly in patients with Dorr type C femurs, which have normal bone quality. Implant selection plays a critical role in early postoperative stability, but the biomechanical influence of different femoral stem designs in this high-risk population remains unclear. In this study, CT data from a Dorr type C femur with normal bone quality, obtained from a patient with hip osteoarthritis, were used to reconstruct a three-dimensional femoral model. Six femoral stems representing different designs were implanted to construct corresponding THA finite element models. The models were subjected to a simulated stumbling condition, with progressively applied axial displacement until PFF occurred. The maximum fracture load was recorded and compared among the stem designs. The maximum fracture load, ranked from highest to lowest, was as follow: Corail (6079.26 N), Omnifit (5605.11 N), Synergy (5165.03 N), Taperloc (5030.77 N), Excia (4192.37 N), and Profemur (4034.64 N). The Excia and Profemur stems showing lower fracture loads than the peak stumbling load of approximately 8.7 times body weight (4785 N). These results suggest that, for THA in patients with Dorr type C femurs with normal bone quality, the use of Corail, Omnifit, Synergy, or Taperloc stems may be preferable for minimizing the risk of postoperative PFF. • Six femoral stem designs were compared in Dorr type C femurs with normal bone quality. • Corail and Omnifit stems exhibited superior resistance to periprosthetic femoral fracture. • Excia and Profemur stems fractured below the stumbling peak load threshold. • Stem geometry strongly determined fracture onset, pattern, and mechanical stability. • Results provide guidance for stem selection to reduce postoperative PFF risk in THA.