Purpose Tourniquet use during primary total knee arthroplasty (TKA) may negatively impact the early postoperative functional recovery due to molecular effects of ischaemia. The hypothesis of the present study was that primary TKA without a tourniquet positively influences the postoperative muscle strength, functional outcome, patient satisfaction and health status. Methods The monocentric, randomized, controlled trial included a total of 99 patients scheduled to undergo primary TKA (ClinicalTrials.gov NCT02475603). The patients were randomly assigned to the tourniquet (n = 50) or non‐tourniquet (n = 49) group after receiving a written informed consent. As primary outcome parameter, the functional outcome, patient expectation/satisfaction and the health status were assessed preoperatively, 6 weeks, 6 months postoperatively using Oxford knee score, WOMAC score, Mancuso score, EQ‐5D index, EQ‐VAS, anxiety score, depression score, hospital anxiety and depression scale, respectively. Additionally, a rope pulley isokinetic system (Moflex, Recotec/Bernina, Switzerland) was applied to quantify the muscle strength preoperatively, 1 week, 6 weeks and 6 months postoperatively. Results No difference in any of the outcome parameters could be observed between the groups at all time points after TKA (n.s.). Also the isokinetic muscle strength of the knee joint as quantified by concentric/eccentric peak force (N), workload (J), total workload (J) and power (W) did not reveal statistically significant differences between the groups and time points. However, in both groups improved results were found with respect to the functional outcome, patient satisfaction, health status and isokinetic muscle strength up to 6 months postoperatively. Conclusions The application of the tourniquet did not affect the isokinetic muscle strength, the functional outcome, the patient satisfaction and the health status following primary TKA. However, with and without tourniquet use, the level of the knee functionality, the patient satisfaction as well as the health status improved significantly. Level of evidence I.

Background The use of the tourniquet in total knee arthroplasty is still a subject of controversial discussion. Previous studies mainly focus on parameters like blood loss and operation time. The aim of this systematic review is to evaluate the postoperative outcome involving parameters such as pain intensity, analgesic consumption, knee function and complication rate with and without tourniquet use, to find a recommendation for future application in total knee arthroplasty. Material and Methods This review is based on the PRISMA Checklists. A systematic research was performed in PubMed using the key words “tourniquet”, “total knee arthroplasty”, “TKA” and “knee endoprosthesis” up to and including January 2018. The initial search revealed 686 Papers which were extracted by the parameters intensity of pain, analgesic consumption, function (range of motion, Hospital for Special Surgery Score, Knee Society Score) and complications (deep vein thrombosis, surgical side infection, pulmonary embolism). The program Review Manager Version 5.3 was used for statistical analysis. A significance level of p < 0,05 was defined. Results 18 studies were included in this review with 1279 total knee arthroplasties overall (646 with the use of tourniquet and 633 without). The analysis shows a significant lower pain intensity until the fifth postoperative day (p = 0,03) and also after one to three months (p = 0,04) without using the tourniquet. Range of motion is significantly higher in two to three days postoperatively (p < 0,00 001) when the surgery was performed without tourniquet. Knee Society Score shows no difference between the two groups. A deep vein thrombosis appears significantly more often when using a tourniquet (p = 0,04). There was no higher occurrence in pulmonary embolism and surgical side infections. Conclusion The use of a pneumatic tourniquet in total knee arthroplasty affects especially the early postoperative pain and functional recovery.