Safety and Blood Loss Associated With Tourniquets in Total Knee Arthroplasty.

Objective To measure total blood loss and safety of tourniquets, tourniquets during cementation, or no tourniquets during total knee arthroplasty (TKA). Methods This retrospective cohort study included 75 patients from King Khalid University Hospital in Riyadh, Saudi Arabia. Patients were equally divided into three groups: tourniquets, no-tourniquets, and tourniquets during cementation. Recorded data included: baseline characteristics (age, sex, weight, height, body mass index (BMI), anesthesia type, and comorbidities), blood loss parameters (total blood loss, preoperative and postoperative hematocrit (Hct) and hemoglobin (Hgb), and blood transfusion units), duration of surgery, hospital stay, and thromboembolic events during 3-months postoperatively. Statistical significance was reported by using a P-value < 0.05, and 95% confidence intervals. Results The tourniquet group had significantly lower mean total blood loss (544.67 mL ± 418.86; P = 0.001), higher mean postoperative hemoglobin values (115.44 g/dL ± 10.97; P = 0.004) and hematocrit (34.25 % ± 3.35; P = 0.005), and lower median intra-operative loss (100 cc, 10-300; P < 0.001), than the other groups. Tourniquets during cementation required significantly more mean surgery time (131.84 minutes ± 22.12; P = 0.003), and longer median hospital stay (8 days, 5-13) than the other groups. Conclusion Tourniquet use during TKA significantly decreased total and intraoperative blood loss, but it did not have any significant effect on the transfusion rate or the incidence of thromboembolic events.