The Relationship between Body Mass Index and Duration of Total Knee Replacement Surgery: A prospective cross sectional study

Introduction: These days, obesity is considered an important factor for many medical problems such as diabetes mellitus, cardiovascular diseases and joint degeneration. Obesity is one of the leading causes of osteoarthritis and the need for arthroplasty. We aim to study the effect of obesity and the duration of knee replacement surgery. Method: A cross-sectional study was conducted at the orthopedic department between February 2023 and July 2023. We had 68 patients who underwent total knee replacement surgery. Variables like age, gender, smoking history, ASA grade, BMI, and side of injury (unilateral or bilateral) were studied. Results: Out of 68 patients, we had 37 (54.4 %) of patients were female. The most common age group was 44- 54 years. 60.3 % of patients were non-smokers. We had 50 patients with unilateral injury and the rest were bilateral. ASA grade II (51 patients) were more than ASA grade I (17 patients). In this study, 41 patients were obese and the duration for total knee replacement was 90 - 120 minutes, in contrast to overweight patients (75 – 90 minutes) and normal patients (60-75 minutes). Conclusion: We found a significant correlation between BMI and the duration of total knee replacement surgery. The time could be doubled if the arthroplasty was bilateral.