Does Tourniquet Use Impact Early Patient Outcomes in Total Knee Arthroplasty?

Introduction Tourniquets are commonly used when performing total knee arthroplasty (TKA) to reduce intra-operative blood loss, improve surgical field visibility, and potentially improve cement penetration during prosthesis implantation. However, they may be associated with increased thigh pain, postoperative opiate use, and longer lengths of hospital stay. Methods Retrospectively collected data was obtained from our institution's electronic patient records and database. We compared data between those patients receiving a TKA with or without tourniquet use. Our primary outcome measure was cement penetration on immediate postoperative X-rays. Secondary outcome measures included the need for opiate analgesia, blood loss, need for transfusion, and length of hospital stay. Results There were 285 patients in this study, with 170 patients undergoing TKA with a tourniquet and 115 patients without a tourniquet. There was a significantly better median total cement penetration as measured on combined anteroposterior (AP) and lateral radiographs in the tourniquet group (39.14 vs 33.3mm, U=6991, z=-4.08, p<0.01). There was a statistically lower drop in hemoglobin levels when tourniquets were used (-13.4 (SD=8.6) vs -15.5 (SD=8.8), p=0.03). However, there were no cases in our series where patients required a transfusion. There was no significant difference in opiate analgesia requirements between tourniquet and non-tourniquet groups following surgery, 115 (68%) vs 69 (60%); X² (1,285)=1.75, p=0.19. The median length of stay following surgery was slightly longer in the tourniquet group (2.5 vs 2.8 days); however, the Mann-Whitney U test indicated that this difference was not significant (U=9076, z=-0.70, p=0.31). Conclusion The use of a tourniquet was associated with significantly improved bone cement penetration as measured on postoperative AP and lateral radiographs. However, the clinical relevance of this in terms of implant survival remains controversial. Tourniquet use was also significantly associated with lower blood loss, but this did not translate into a lower need for transfusions. The use of a tourniquet was not associated with increased analgesia requirements following surgery or significantly longer lengths of stay.