The Effect of Cementless Stem Design on Late Periprosthetic Fractures After Total Hip Arthroplasty. Does the Design of Cementless Stems Affects the Rate of Periprosthetic Femoral Fractures?

Background Periprosthetic femoral fractures (PFFs) are a leading cause of revision after total hip arthroplasty (THA). Cementless stems have been associated with higher rates of early and late PFFs than cemented fixation. This study evaluated whether cementless stem design is associated with the risk of late PFF following primary THA. Methods We performed a retrospective review of all primary cementless THAs implanted at a tertiary teaching hospital between January 2000 and December 2023 (n = 3772). Early fractures (<3 months) were excluded. PFFs were classified according to Vancouver classification. Stem designs were analyzed individually and grouped according to the Khanuja classification. Kaplan–Meier survival analysis was performed with PFF as the endpoint, and survival distributions were compared using log-rank tests. Cox regression was used to assess the association of age and sex with PFF risk. Results At a mean follow-up of 14.5 years, the incidence of late PFF was 1.4% (53 of 3772). No difference in overall survival was observed among stem designs ( P = .108). Exploratory pairwise comparisons showed higher PFF-free survival for 1 type 2 stem design than for two other type 2 designs ( P = .002 and P = .003, respectively). No differences were found between type 2 (double wedge) and type 3 (tapered) stems ( P = .510). Increased age was independently associated with PFF ( P = .02). Conclusions Late PFF after cementless THA was uncommon. Although survivorship did not differ between broad stem categories, variability among individual designs warrants further evaluation in larger multicenter or registry-based studies.