Distal femoral replacement – Does length matter? Mid-term results for distal femoral replacements

Abstract

BackgroundReview of mid-term results (five years) for tumour and revision arthroplasty surgery using the Stanmore METS® distal femoral replacement. MethodsData were collected retrospectively for 90 patients for procedures performed between 2002 and 2019. Kaplan-Meier survivorship for implant was estimated at five years post-op. Endpoints for survivorship analysis included revision for any cause and as per Henderson classification. Log rank test was used to compare implant survival for different categorical variables. Musculo-Skeletal Tumour Society (MSTS) score was used to estimate function. ResultsOverall implant survival at five years was 76% (95% CI 66–86). Implants with a short body (<= 45 mm) had significantly better implant survival [87% (95% CI 78–99)] compared to those with larger bodies [63% (95% CI 48–82)] (logrank test, p = 0.031). There was no significant difference in implant survival for tumour and revision arthroplasty patients (logrank test, p = 0.61). Mean MSTS scores (median follow-up = 3.5 years) for tumour and revision arthroplasty patient were 71% and 63% respectively (Wilcoxon rank test, p < 0.05). Higher total number of surgeries was a significant predictor of patient mortality [HR = 0.7 (95% CI 0.49–0.99)]. Longer bodies were a significant predictor of implant failure [HR = 3.2 (95% CI 1.05–10.53), p < 0.05]. ConclusionOverall outcome of Stanmore METS® distal femoral replacement at five years following tumour and revision arthroplasty reconstruction is comparable to the other implants.