Methods	A series of 40 patients undergoing primary unilateral total knee arthroplasty were entered into this randomised controlled trial to assess the safety and efficacy of post-operative autologous blood salvage and reinfusion. Method of randomisation and allocation concealment were not described
Participants	40 patients undergoing primary unilateral total knee arthroplasty were randomised to one of two groups: Group 1 (Autotransfusion groups): n=20; M//F=6//14; mean age = 71.3 years Group 2 (Control group): n=20; M//F=6//14; mean age = 70.3 years
Interventions	Group 1: Autotransfusion group (Solcotrans orthopaedic reinfusion system) had the two deep intra-articular drains connected to a Solcotrans reservoir and a suction pressure of 80mmHg applied for an initial period of 10 minutes, after which the wound was allowed to drain by gravity alone. Two Solcotrans reservoirs were attached sequentially to each patient regardless of the volume drained. Blood was re-infused if a sufficient volume had been collected. Drains were removed at 48 hours. Group 2: Control group had all drains attached to Redivac bottles. Autotransfusion was not used.
Outcomes	Outcomes reported: amount of blood collected by the cell saver, amount of blood retransfused from the cell saver, amount of allogeneic blood transfused, adverse events, haematological variables
Notes	Transfusion threshold: allogeneic blood was given to patients if the haemoglobin level fell below 9.5g/dL or if indicated haemodynamically
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method used to generate allocation sequences was not described
Allocation concealment (selection bias)	Unclear risk	Method used to conceal treatment allocation was unclear.
Blinding (performance bias and detection bias) All outcomes	High risk