The aim of this study was to measure the effect of hospital case-volume on the survival of revision total knee arthroplasty (RTKA).

A retrospective analysis of Scottish Arthroplasty Project data was performed. The primary outcome was RTKA survival at ten years. The primary explanatory variable was annual hospital case-volume. Kaplan-Meier survival curves were plotted with 95% confidence intervals (CI) to determine the lifespan of RTKA. Multivariable Cox proportional hazards were used to estimate relative revision risks over time.

From 1998 to 2019, 8894 patients underwent RTKA surgery in Scotland (median age 70 years, median follow-up 6.2 years, 4789 (53.5%) females; 718 (8.8%) for infection). Of these patients, 957 (10.8%) underwent a second revision procedure on their knee. Male sex, younger age at index revision, and positive infection status were associated with need for re-revision. The ten-year survival estimate for RTKA was 87.3% (95%CI 86.5–88.1). Adjusting for gender, age, surgeon volume and infection status, increasing hospital case-volume was significantly associated with lower risk of re-revision (Hazard Ratio 0.78 (0.64–0.94, p<0.001)). The risk of re-revision steadily declined in centres performing >20 cases per year: relative risk reduction 16% with >20 cases; 22% with >30 cases; and 28% with >40 cases.

The majority of RTKA in Scotland survive up to ten years. Increasing yearly hospital case-volume above 20 cases is independently associated with a significant risk reduction of re-revision. Development of high-volume tertiary centres may lead to an improvement in the overall survival of RTKA.

Debate surrounds the optimum operative treatment of periprosthetic distal femoral fractures (PDFFs) at the level of well fixed femoral components; lateral locking plate fixation (LLP-ORIF) or distal femoral replacement (DFR). To determine which attributed the least peri-operative morbidity and mortality we performed a retrospective cohort study of 60 consecutive unilateral PDFFs of Su types II (40/60) and III (20/60) in patients ≥60 years; 33 underwent LLP-ORIF and 27 underwent DFR. The primary outcome measure was reoperation. Secondary outcomes included perioperative complications and functional mobility status. Kaplan Meier survival analysis was performed. Cox multivariable regression analysis identified risk factors for reoperation after LLP-ORIF.

Mean length of follow-up was 3.8 years (range 1.0–10.4). One-year mortality was 13% (8/60). Reoperation rate was significantly higher following LLP-ORIF: 7/33 vs 0/27, p=0.008. For the endpoint reoperation, five-year survival was better following DFR: 100% compared to 70.8% (51.8 to 89.8 95%CI) (p=0.006). For the endpoint mechanical failure (including radiographic loosening) there was no difference at 5 years: ORIF 74.5% (56.3 to 92.7); DFR 78.2% (52.3 to 100), p=0.182). Reoperation following LLP-ORIF was independently associated with medial comminution: HR 10.7 (1.45 to 79.5, p=0.020). Anatomic reduction was protective against reoperation: HR 0.11(0.013 to 0.96, p=0.046). When inadequately fixed fractures were excluded differences in survival were no longer significant: reoperation (p=0.156); mechanical failure (p=0.453).

Reoperation rates are higher following LLP-ORIF of low PDFFs compared to DFR. Where adequate reduction, proximal fixation and augmentation of medial comminution is used there is no difference in survival between LLP-ORIF and DFR.