Clinical Outcomes Following Distal Femur Replacement for Periprosthetic Distal Femur Fractures: A Systematic Review and Meta-Analysis

Abstract

Background: Management of periprosthetic distal femur fractures (PDFFs) is often complicated by poor bone quality and limited bone stock making fixation attempts challenging and prone to failure. Distal femoral replacement (DFR) is being used to treat such injuries although outcome data are mostly from small case series. We sought to systematically review the literature on DFR for PDFF to summarize their outcomes.

Methods: PubMed, MEDLINE (EBSCO), and Cochrane Central Database were searched to identify reports of PDFFs treated with DFR. Articles reporting on 5 or more knees were systematically reviewed for clinical function, complications, and mortality. Random effects meta-analysis was used to create summary estimates and publication bias also assessed.

Results: Of 287 identified and screened articles, 15 were included, 14 retrospective, reporting on 352 knees. Following DFR, 87% (95% confidence interval [CI] 71-95) of patients were able to ambulate. The mean postoperative Knee Society Score was 80 (95% CI 77-84). The risk of periprosthetic joint infection was 4.3% (95% CI 2.2-8.2). One-year postoperative mortality rate was 10% (95% CI 6-18). There was some evidence of publication bias with a trend toward smaller studies reporting lower infection risk and mortality.

Conclusion: DFR for PDFFs is associated with high functional outcomes and a relatively modest risk of infection. The periprosthetic joint infection and 1-year mortality rates reported here should be considered lower bounds estimates due to publication bias and loss to follow-up. Further investigation of long-term outcomes following DFR for PDFFs is warranted though short-term functional outcomes are promising.

Keywords: ambulation; distal femoral replacement; knee society score; mortality; periprosthetic fracture; periprosthetic joint infection.