Factors influencing length of stay following primary total knee replacement in a UK specialist orthopaedic centre

AimTo identify factors significant in influencing LOS following primary TKA in a UK specialist arthroplasty centre.MethodWe retrospectively reviewed factors affecting LOS of 514 patients who underwent primary TKA in a single specialist arthroplasty centre in the UK over a one-year period. Surgical and patient factors that may influence LOS were recorded.ResultsThe median LOS was 5 days. 85% were discharged within 10 days. Those staying longer were classified as long stay (up to 3 months). The only surgical factor that influenced length of stay was postoperative blood transfusion (p < 0.0001). Females stayed longer as did those who lived in more deprived areas. These factors did not remain significant in multivariate analysis. The other most significant predictors at multivariate analysis were pre-operative patient factors such as poor anaesthetic fitness (ASA3 and ASA4) (p = 0.001), BMI = 30–35 (p = 0.04), BMI > 35 (p = 0.009) and age > 80 (p = 0.01).ConclusionLength of stay is largely due to case mix and this should be considered when planning a local arthroplasty service.Level of evidence2-II.