Optimizing Tourniquet Pressure in Primary Total Knee Arthroplasty: Limb Occlusion Pressure vs Systolic Blood Pressure Method: A Randomised Controlled Study.

BACKGROUND: This study aims to systematically compare the efficacy of two distinct approaches that is limb occlusion pressure (LOP) and systolic blood pressure (SBP) in determining the optimal tourniquet pressure for primary total knee arthroplasty. The overarching goal is to identify the method that yields superior outcomes in minimizing post-operative thigh pain while simultaneously reducing complications in our patient population. METHODS: 311 patients scheduled for primary total knee replacement (TKR) were randomized in two groups. Group A (LOP) had 154 patients and group B had 157 patients. In group A, LOP was determined for all patients. After adding the safety margin, the tourniquet pressure was determined which was kept during the procedure. By adding 150 mm Hg to SBP in group B, the tourniquet inflation pressure was ascertained. Postoperatively, thigh pain was evaluated from day 1 to day 3 and at 6 weeks. RESULTS: The average tourniquet pressure in group A patients having thigh circumference between 40 and 50 cm was 223.8 mm + - 19.8 mm Hg and in group B it was 262.1 + - 15.9 mm Hg (P < .01). Patients having thigh circumference between 51 and 60 cm had average tourniquet pressure of 240.07 + - 20.1 mm Hg in group A and 264.5 + - 17.4 mm Hg in group B (P < .01). The average tourniquet pressure for patients with thigh circumference more than 60 cm was 296 + /15.3 mm Hg in group A and 267.3 + /19.2 mm Hg in group B (P < 0.01). CONCLUSION: Tourniquet pressure determination based on the limb occlusion pressure (LOP) method provide less postoperative thigh pain and better range of motion. GRAPHICAL ABSTRACT: Optimizing Tourniquet Pressure in Primary Total Knee Replacement: Limb Occlusion Pressure vs Systolic blood pressure method to minimize thigh pain.