Application of Tourniquet Does Not Influence Early Clinical Outcomes After Total Knee Arthroplasty

Abstract

Introduction The use of a tourniquet during total knee arthroplasty (TKA) is still a topic of debate, given the conflicting results in the literature with respect to complications, pain, functional outcome, and blood loss. However, due to a lack of convincing data on early patient-reported outcomes (PROMS), this study aims to compare pain and functional outcomes in total knee arthroplasty patients with and without a tourniquet. Methods A randomized controlled trial was set up at a tertiary care hospital that spanned from 1st February 2015 to 31st July 2018. We included all primary total knee arthroplasties performed for patients aged between 50 and 80 years. Oxford Knee Score (OKS), Numerical Pain Rating Score (NPRS), Visual Analogue Scale (VAS) for satisfaction, active range of knee motion, and Short Form-12 Survey (SF-12) scores were collected pre-surgery and then at six-weeks and six-months interval with a p-value of 0.05 considered to be significant. Results Two hundred and forty patients participated in the study; 117 patients were randomized to surgery with the tourniquet inflated and 123 to surgery with the tourniquet deflated. There were 43.4% males, and 56.6% females in the tourniquet inflated group with an average age of 62.29±9.63 years while in tourniquet deflated group, there were 46.7% males and 53.3% females with a mean age of 65.41±9.042 years (p-value for age is 0.404; the p-value for gender is 0.086). Despite the increase in intraoperative blood loss in both the groups, there was no significant increase in blood transfusions as both groups recorded the need for postoperative blood transfusion - 12 patients in the tourniquet group and 19 in the non-tourniquet group, but this difference was statistically insignificant (p=0.231). The perioperative blood loss was significantly lower (p<0.001) in the tourniquet group (490.29±47.752) compared to in the non-tourniquet group (526.18±12.796), while the duration of surgery was comparable in both groups (p=0.156). The length of stay for the two groups did not statistically differ (p=0.976) - the mean length of stay for the tourniquet group was 6.16±2.38 days and for the non-tourniquet group it was 6.18±2.34 days. There were no significant differences between the two groups regarding patient-reported outcomes (PROMS) at six-weeks and six-months. However, during the in-hospital stay, only the NPRS score for knee pain showed that the non-tourniquet patients had a lower NPRS compared to the tourniquet group and this difference was statistically significant (p=0.02). During the postoperative hospital stay, there was no significant difference among the two treatment groups for VAS, OKS, SF-12, and range of motion (flexion/extension). At the six weeks follow-up, both groups had similar outcomes for the range of movements and pain scores. Besides, no difference was noted among the tourniquet and non-tourniquet groups even after a follow-up of six months. Regarding complications, 27 patients in the tourniquet group did complain of numbness during the study period compared to 10 in the non-tourniquet group (p=0.001). Conclusion In conclusion, a tourniquet application helps minimize intraoperative blood loss and results in a faster procedure. Furthermore, the application of the tourniquet is safe and effective and does not affect the functional outcomes and pain scale in total knee arthroplasty.