Distal Femoral Replacement Versus Open Reduction and Internal Fixation for Periprosthetic Distal Femur Fractures in Older Populations: A Systematic Review and Meta-Analysis of Failure, Revision, and Functional Outcomes

Background Periprosthetic distal femur fractures (PDFFs) following total knee arthroplasty (TKA) in patients aged ≥70 years are increasingly common and challenging to manage. Distal femoral replacement (DFR) and open reduction internal fixation (ORIF) are the two principal treatment options, but the optimal approach remains unclear. The aim of the study was to compare DFR and ORIF in elderly patients (≥70 years) with PDFFs following TKA, focusing on failure rates, revision rates, and patient-reported outcome measures (PROMs). Methodology A systematic review and meta-analysis was conducted in accordance with PRISMA guidelines. PubMed, Embase, Cochrane Library, and Scopus were searched up to December 2025. Eligible studies directly compared DFR and ORIF in studies as reported mean aged ≥70 years and reported at least one relevant outcome (failure, revision, PROMs, complications, or mortality). Risk ratios (RR) with 95% confidence intervals (CI) were used for pooled analysis. Results Five retrospective cohort studies including elderly patients with PDFFs were included. There was no statistically significant difference in failure rates between DFR and ORIF (RR 0.77, 95% CI 0.44–1.33). Infection rates, revision rates, complications, and mortality also showed no significant differences between groups. PROMs (OKS, KSS, Parker score) were broadly comparable. DFR showed a trend toward earlier mobilisation, while ORIF was associated with more mechanical complications such as nonunion and fixation failure. DFR demonstrated a trend toward higher infection and mortality rates, although these were not statistically significant. Conclusion In patients aged ≥70 years with PDFFs following TKA, DFR and ORIF demonstrate comparable outcomes in terms of failure, revision, and functional results. DFR may offer earlier weight-bearing but may carry higher infection risk, while ORIF is more prone to mechanical failure. Treatment should therefore be individualised based on patient factors, fracture pattern, and implant stability.