Periprosthetic femoral fracture type and location are influenced by the presence of an ipsilateral knee arthroplasty implant: A case-control study of 84 interprosthetic femoral fractures. Issue 2 (February 2022)

• Record Type: Journal Article
• Authors: Townsend, Oliver; Jain, Sameer; Lamb, Jonathan N; Scott, Chloe E H; Dunlop, Douglas G; Pandit, Hemant G
• Is Part Of: Injury. Volume 53:Issue 2(2022)
• Page Start: 645
• Page End: 652
• Publication Date: 2022-02
• Subjects: Interprosthetic -- Periprosthetic -- Femoral fracture -- Total hip arthroplasty -- Total knee arthroplasty; Wounds and injuries -- Surgery -- Periodicals; Accidents -- Periodicals; Wounds and Injuries -- surgery -- Periodicals; Lésions et blessures -- Chirurgie -- Périodiques; Electronic journals; Electronic journals; 617.1
• DOI: 10.1016/j.injury.2021.11.047
• Languages: English
• ISSNs: 0020-1383

Abstract

Highlights: This is the largest cohort of interprosthetic fractures analysed in the literature and has important clinical findings. The presence of a total knee arthroplasty distal to a total hip arthroplasty stem increases the probability of a vancouver type c fracture. Ipsilateral total hip and knee arthroplasties may increase the likelihood of a fracture between the implants being an unstable bending-type fracture. Abstract: Background: This multicentre case-control study compares Vancouver Classification System (VCS) grade and Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) fracture type in interprosthetic femoral fractures (IPFFs) between primary total hip arthroplasty (THA) and ipsilateral total knee arthroplasty (TKA) to periprosthetic femoral fracture (PFF) without ipsilateral TKA. Methods: Data were collected following institutional approval. Eighty-four IPFFs were assessed for VCS grade and AO/OTA type. Each IPFF case (84) was matched to five PFF controls (360) by age, gender and stem fixation philosophy (SMD<0.1). VCS grade and AO/OTA type were compared between the IPFF and PFF groups using weighted proportions and medians. Results: Median (IQR) age of IPFF patients was 81.75 (76.57–85.33) years and 61 (72.6%) were female. The commonest VCS grade was B1 (34, 40.5%). The commonest AO/OTA type was spiral (51.8% of VCS B fractures; 50.0% of VCS C fractures). A greater proportion of fractures occurred distal to the stem in IPFF patients versus PFF patients (33.3% versus 18.2%, p = 0.003). VCS grade was significantly different between groups ( p = 0.015). For VCS C fractures, twice as many AO/OTA transverse and wedge fractures occurred in the IPFF group compared to the PFF group (25.0% versus 12.6% and 7.1% versus 3.3%, respectively) although the overall difference was not statistically significant ( p = 0.407). Conclusion: The presence of an ipsilateral TKA affects the location of PFF with more fractures occurring distal to the stem. A greater proportion of bending type fractures occurred when an ipsilateral TKA was present. These unstable fractures often require more complex surgery.