Fractures in patients with hip and knee prostheses

BACKGROUND: Fractures in patients with hip or knee prostheses (periprosthetic fractures, PPF) are rare but clinically significant complications whose absolute number is steadily increasing as implantation rates rise. In Germany, approximately 200 000 hip and 170 000 knee joints are primarily replaced each year: PPFs account for approximately 15% of all revisions of hip surgery and 3% of all revisions of knee surgery. METHODS: This review is based on publications retrieved by a selective search in the PubMed/MEDLINE and Google Scholar databases up to December 2025. Registry analyses, meta-analyses, systematic reviews, and clinical trials were included. RESULTS: Key risk factors for PPF are advanced age (OR 1.4-1.7), female sex (OR 1.6-2.1), and osteoporosis as the overarching risk modifier. The 1-year mortality rate of 11-24% is comparable to that after fractures around the hip joint. History-taking and physical examination serve not only to assess fracture morphology but also to rule out implant loosening and low-grade infection. Most of the available evidence on treatment is derived from retrospective cohort and registry studies. The choice of treatment is mainly determined by implant stability: if the implant is stable, angle-stable osteosynthesis is performed; if it is loose, it must be replaced. The goal of surgery is a reconstruction that is stable under full weight-bearing, so that early functional mobilization can ensue and secondary complications can thereby be avoided. CONCLUSION: Interdisciplinary treatment planning for the early resumption of function, along with low-threshold osteoporosis screening in the presence of risk factors, are key strategies for lowering mortality and preventing further fractures.