Failure of the femoral stem: A case series of intra-prosthetic fractures and proposed classification system.

Abstract

Femoral implant failure is an uncommon but significant complication in orthopaedic surgery associated with significant patient morbidity. This study presents a case series of femoral implant fractures treated at a single institution between 2007 and 2024, alongside a review of the relevant literature, to identify possible risk factors. A retrospective analysis of patients with femoral implant fractures was, over a 17-year period, conducted at a single academic institution. Data collected included patient demographics, implant type, time to failure, treatment approach and postoperative outcomes. A literature review was performed to contextualise findings within existing research. We also propose a pragmatic and reproducible classification system based on anatomical location of the fractures within the stem. A total of fourteen cases were identified across the defined study period with implant fractures occurring at a mean of 129 months postoperatively. The mean age of patients in this study was 71.76. Seven of the fourteen cases involved polished taper slip (PTS) stems, while twelve of the fourteen intra-prosthetic fractures occurred around cemented stems. The most frequent fracture sites were the middle third of the stem. Each of the cases were treated with revision arthroplasty. Postoperative complications and functional outcomes varied based on fracture type and patient factors. Four types of fracture are described based on the fracture location - Type A-D. Femoral implant fractures remain a challenging issue in orthopaedic surgery. Identifying risk factors and optimising implant selection and surgical technique are crucial for complication prevention. This case series highlights key patterns and management strategies, contributing to the growing body of evidence on implant longevity and failure mechanisms. Further research is needed to improve early detection and intervention strategies for at-risk patients. A simple, pragmatic, location-based classification system could improve communication and standardisation of revision strategies.