Blood loss and knee function after unicompartment knee arthroplasty(UKA) without tourniquet

Abstract BackgroundThe characteristics of blood loss and knee function after unicompartment knee arthroplasty(UKA) remains unclear. Utilization of tourniquet is considered to compromise the outcome of knee arthroplasty. This study aims to evaluate the hidden blood loss and function restoration of UKA without tourniquet by comparing with total knee arthroplasty(TKA).MethodsIn this retrospective study, a total of 112 patients were included from August 2017 to October 2018. Both the UKA group (n = 56) and the TKA group (n = 56) underwent procedure without utilization of tourniquet during the whole process. The gender, age, body mass index, American Society of Anesthesiologists score, Kellgren-Lawrence grade, preioperative Hb, and volume of hidden blood loss (HBL) were recorded and analysed. Knee function was assessed at 3 month and 12 month after procedure by using HSS score.ResultThe mean volume of HBL was significant lower in UKA group (324.23ml ± 147.05, 864.82ml ± 206.37, P = 0.001). The HSS score was higher in UKA group 3 month after procedure (88.16 ± 5.57, 83.04 ± 4.88, P = 0.033). No HBL difference was observed in either groups in terms of gender nor age. Hb level dropped to the bottom at the 4th day postoperatively. No correlation was observed between HBL and knee function.ConclusionWithout utilization of tourniquet, the HBL could not be ignored in UKA though it is much less than TKA, and the knee function was not compromised by it.Trial registrationCurrent trial ISRCTN85133278 (Retrospectively registered on 06 April 2020).