The Risk of Postoperative Periprosthetic Femoral Fracture After Total Hip Arthroplasty Depends More on Stem Design Than Cement Use

BACKGROUND: In this study, we estimated the risk of surgically treated postoperative periprosthetic femoral fractures (POPFFs) associated with femoral implants frequently used for total hip arthroplasty (THA). METHODS: In this cohort study of patients who underwent primary THA in England between January 1, 2004, and December 31, 2020, POPFFs were identified from prospectively collected revision records and national hospital records. POPFF incidence rates, adjusting for potential confounders, were estimated for common stems. Subgroup analyses were performed for patients >70 years of age, with non-osteoarthritic indications, and with femoral neck fracture. RESULTS: POPFFs occurred in 0.6% (5,100) of 809,832 cases during a median follow-up of 6.5 years (interquartile range [IQR], 3.9 to 9.6 years). After cemented stem implantation, the majority of POPFFs were treated with fixation. Adjusted prosthesis time incidence rates (PTIRs) for POPFFs varied by stem design, regardless of cement fixation. Cemented composite beam (CB) stems demonstrated the lowest risk of POPFF. Collared cementless stems had an equivalent or lower rate of POPFF compared with the current gold standard of a polished taper slip cemented stem. CONCLUSIONS: Cemented CB stems were associated with the lowest POPFF risk, and some cementless stem designs outperformed modern cemented stem designs. Stem design was strongly associated with POPFF risk, regardless of the presence of cement. Surgeons, policymakers, and patients should consider these findings when considering femoral implants in those most at risk for POPFF. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.