Abstract. Introduction. Inter-prosthetic femoral fractures (IPFF) are fractures occurring between ipsilateral hip and knee implants or fixation devices. In 2020, the National Hip Fracture Database (NHFD) was extended to capture data from patients with peri-prosthetic femoral fractures (PPFF), including those specifically with IPFF. This study aims to describe the epidemiology and treatment of IPFF in England and Wales. Methodology. This population-based observational cohort study utilised open-access data available from the NHFD. Patients aged over 60, admitted to an acute hospital in England or Wales with an IPFF, within the period 1st January 2020 to 31st December 2020 were included. The primary outcome of this study was the incidence of IPFF in England and Wales. The secondary outcome was the treatment received. Results. Of 2606 patients admitted with PPFF, a total of 133 fractures occurred between ipsilateral hip and knee implants. Internal fixation was performed most frequently, in 87 cases. Revision arthroplasty was performed in 15 cases (hip n=10, knee n=5). A total of 20 patients were managed non-operatively, and three underwent primary arthroplasty (hip n=2, knee n=1). Conclusion. As the proportion of patients living with hip and knee implants continues to increase, it is expected that so too will the incidence of IPFF. This study is the first to estimate the incidence of IPFF in England and Wales. This is likely an underestimate of the true incidence and so we support calls for the prioritisation of further research into the epidemiology, prevention, and management of IPFF

Abstract. Introduction. In 2020, the National Hip Fracture Database (NHFD) was extended to capture data from patients with periprosthetic femoral fractures (PPFF) with plans to include these patients in Best Practice Tarif. We aimed to describe the epidemiology of PPFF in England and Wales, with a particular focus on fractures occurring around the femoral component of knee prostheses. Methodology. This population-based observational cohort study utilised open-access data available from the NHFD. Patients aged over 60, admitted to an acute hospital in England or Wales with a PPFF, within the period 1st January 2020 to 31st December 2020 were included. The primary outcome was the incidence of PPFF in England and Wales. The secondary outcome was the treatment received. Results. We identified 2606 patients with PPFF from 135 hospitals. Of these, a total of 578 fractures occurred around the femoral component of a knee implant. These were classified as Vancouver A (epicondylar, n=77), B (involving implant/cement, n=166) and C (proximal to implant/cement, n=335). Internal fixation was the most employed treatment, used in 352 cases. Revision arthroplasty was performed in 80 cases, and 100 were managed non-operatively. Only 28% of operated PPFF went to theatre within 36 hours but nearly 90% had orthogeriatrician review within 72 hours. Conclusion. Eighty six percent of patients with PPFF were treated with non-revision surgery and would not be recorded in the National Joint Registry. In response, we support calls for the prioritisation of further research into the prevention and management of PPFF around the knee