The limited use of a tourniquet during total knee arthroplasty under a contemporary enhanced recovery protocol has no meaningful benefit: a prospective randomized controlled trial

PURPOSE: This prospective randomized controlled trial aimed to determine whether the limited use of tourniquets during total knee arthroplasty (TKA) would be more beneficial under the contemporary enhanced recovery after surgery (ERAS) protocol than the conventional use of tourniquets. METHODS: One hundred patients with knee osteoarthritis who underwent primary TKA were randomly assigned to the limited tourniquet (LT, n = 51) and conventional tourniquet (CT, n = 49) groups. Operation time, serial hemoglobin drops, calculated blood loss, transfusion rate, D-dimer levels, and the presence of deep vein thrombosis (DVT) were assessed. In addition, visual analog scale (VAS) scores for pain around the knee and thigh were measured while resting during the day, at night, and during ambulation. Opioid consumption, range of motion, knee circumference, and postoperative complications were also analyzed. Isokinetic muscle strength, knee injury and osteoarthritis outcome scores, and Euro-QoL-5D scores were also assessed before and 3 months after TKA. For statistical analysis, Chi-square and Fisher's exact tests were performed to compare the differences in categorical variables. Continuous variables were compared using an independent t test or Mann‒Whitney U test. RESULTS: The average tourniquet time was 46.7 min in the CT group and 5.4 min in the LT group. Knee pain on the first night after surgery was significantly higher in the CT group (3.2 vs. 4.6, p = 0.033). However, daytime pain in the thigh at 2 weeks and in the knee at 3 months after TKA were higher in the LT group than in the CT group (p = 0.048 and p = 0.036, respectively). The D-dimer level 3 months after TKA was also higher in the LT group than in the CT group (p = 0.028), but there was no difference in DVT incidence between the two groups (n.s.). Additionally, there were no significant differences in the other variables between the groups. CONCLUSIONS: Although the limited use of tourniquets did not increase the operation time, blood loss, or transfusion rate, this study found that the limited use of tourniquets would not provide additional meaningful benefit in reducing pain and early functional restoration after TKA when applying the ERAS protocol. LEVEL OF EVIDENCE: I.