Intermittent tourniquet compared to throughout tourniquet use during Total Knee Arthroplasty in patients with Body Mass Index of 30 or more: A retrospective cohort study

Background: Tourniquet use during total knee arthroplasty (TKA) reduces bleeding which optimises bone-cement interface for prosthesis stability and improves surgical field visualisation. However, prolonged usage can lead to complications and poorer outcomes. Some surgeons advocate for intermittent tourniquet application. Limited literature exists for patients with high body mass index (BMI). This study aims to compare the outcomes of intermittent tourniquet (IT) to throughout tourniquet (TT) use among obese patients undergoing primary TKA for knee osteoarthritis. Methods: This was a retrospective cohort study. In the TT group, tourniquet was inflated from the beginning and released once the bone cement has hardened. In the IT group, tourniquet was inflated at the beginning, released after initial incision and haemostasis, then inflated again during cementation. Tourniquet was released once the bone cement had set. Categorical outcome measures were analysed using Chi-squared or Fisher's exact test. T-test or Kruskal-Wallis test were used for continuous data. Results: When comparing IT to TT among patients with BMI >= 30 (IT n = 48, TT n = 47), the mean duration of surgery was shorter in the TT group (p < 0.05). The difference in haemoglobin drop between the two groups was not statistically significant from post-operative day three onwards. There was no difference in transfusion rate (p > 0.05). ROM was greater in the IT group up to three weeks post-operatively (p < 0.05). When comparing patients with BMI <30 (n = 71) and BMI >= 30 (n = 48) with IT use, there was no statistically significant difference in ROM and LOS. Conclusion: Patients with BMI >= 30 in the IT group had greater ROM in the initial post-operative period. Although operative time and blood loss were greater among the IT group, there was no difference in transfusion rate. Outcomes of TKA performed with IT were similar for patients with BMI >= 30 and BMI <30. The authors recommend intermittent tourniquet use during TKA for patients with BMI >= 30.