Warfarinised patients frequently present for total knee arthroplasty (TKA). Current practice of heparin `bridging¿ is potentially cumbersome and hazardous. The research question is if cessation of warfarin is necessary for TKA.MethodsThe study design was a retrospective case¿control series of 61 warfarinised patients and 61 control patients undergoing TKA. TKA was performed by the senior author using a medial parapatellar approach without tourniquet. The target perioperative international normalised ratio (INR) for warfarinised patients was 2¿2.2. Primary outcomes were changes in haemoglobin, transfusion requirements and complication rates.ResultsThere was no statistically significant difference between control and warfarin group in mean perioperative Hb (g/L) (pre-op 140 vs 141, day 0 115 vs 115, day 1 108 vs 111, P¿=¿0.63), transfusion rates (14.75% vs 9.83%, P¿=¿0.58), total complication rate (9.8% vs 9.8%, P¿=¿0.75), demographics, range of motion or length of stay. There was a statistically significant higher use of the re-infusion drain in the warfarinised group (47.5% vs 24.6 %, P¿=¿0.014).ConclusionThis study supports the hypothesis that warfarin cessation is non-essential in patients undergoing TKA. This data is applicable to a patient group using re-infusion drains. Limitations of this study are typical of a small non-controlled observational study.