Role of tourniquet release timing on blood loss and functional outcomes in total knee arthroplasty: Insights from a low- and middle-income country.

Abstract

To identify the effect of releasing a tourniquet before versus after wound closure in total knee arthroplasty (TKA) on blood loss, functional outcomeand postoperative complications. A prospective cohort study was conducted including 53 patients from May 2023 to September 2023. All patients underwent unilateral TKA and were divided into two groups based on surgeon preference of deflating tourniquet, Group A consisted of patients in whom the tourniquet was deflated before wound closure for haemostasis and Group B consisted of patients in which tourniquet was deflated after wound closure and compressive dressing. Blood loss was evaluated via intraoperative blood loss (the number of soaked sponges/gauzes, blood in a suction bottle, total output in a suction bottle-irrigation used)and on-field blood lossand calculated blood loss (Using Gross and Meunier's formula). The Functional outcome was evaluated using Knee injury and osteoarthritis score-42 questions. Early postoperative complications and differences in the requirement of blood transfusions were also assessed. There was a significant difference in intraoperative blood loss between the two groups. The median intraoperative blood loss was 135 mL(interquartile range [IQR]: 90-149) in Group A and 56.2 mL (IQR: 45-68) in Group B (p value: 0.001). However, no difference was found between the groups in calculated blood loss using Gross and Meunier's formula. The median calculated blood loss was 439 mL (IQR: 450-813) in Group A and 508 mL (IQR:226-671) in group B (pvalue: 0.981). There was no significant difference between the groups in blood transfusion requirements or functional outcomes. Based on our results, we conclude that the intraoperative blood loss in TKA is significantly different between the groups but only represents a fraction of true blood loss (23%). The timing of releasing the tourniquet does not affect functional outcomes, blood transfusionand postoperative morbidity; hence, any time can be opted as per surgeon preference. Level II,prospective comparative study.