Abstract. Introduction. It is common practice for all patients to have postoperative bloods tests after total knee arthroplasty (TKA). However there have been significant improvement in perioperative care with arthroplasty surgery. As healthcare systems and providers strive towards a more efficient service we must re-consider whether such an intervention is necessary for all patients. Methodology. This retrospective study included all patients who underwent a primary unilateral TKA at a single tertiary arthroplasty centre during a 1 year period. Electronic medical records of 776 patients were reviewed for patient demographics, length of stay and American Society of Anaesthesiologists grade. Blood tests were examined to investigate the incidence of post operative anaemia requiring transfusion, electrolyte abnormalities that required treatment and the incidence of acute kidney injury. Results. Average length of stay in hospital was 4.3 days. Pre-operative (R=-0.22) & post-operative haemoglobin (R=0.2) levels were both negatively correlated with length of stay (p<0.01). There was 1 patient that required a blood transfusion post operatively due to symptomatic anaemia. This patient underwent a complex primary TKA. Significant abnormal post-operative electrolyte levels were found in 100 (12.9%) of patients. 87 of these patients either had abnormal electrolyte levels pre-operatively or were taking a medication that causes the electrolyte abnormality. Medical treatment for abnormal electrolyte levels was required in 32 (4.1%) of all patients. The incidence of acute kidney injury was 4.4%. Conclusion. Routine blood tests after primary total knee arthroplasty is unnecessary for most patients. Blood tests should only be performed in those with identifiable risk factors

Aims

The rate of day-case total knee arthroplasty (TKA) in the UK is currently approximately 0.5%. Reducing length of stay allows orthopaedic providers to improve efficiency, increase operative throughput, and tackle the rising demand for joint arthroplasty surgery and the COVID-19-related backlog. Here, we report safe delivery of day-case TKA in an NHS trust via inpatient wards with no additional resources.