Size Does Matter: The Role of Patient's Body Surface Predicting Surgical Difficulty in Total Knee Replacement.

Abstract

Introduction: Total knee replacement (TKR) is a frequently performed surgery with reported very positive outcomes. However, the difficulty of TKR surgery can vary greatly between patients. Many factors have been related to higher surgical difficulty in TKR, but the role of patient anthropometry is still unclear. Although patient Body Mass Index (BMI) is known to affect the postoperative outcome after TKR, it has not proved to be a reliable predictor of surgical difficulty. The aim of this work was to state whether if the patient's overall size, measured with the patient's body surface, had a direct impact on surgical difficulty. Material and methods: We retrospectively reviewed 250 patients who underwent TKR surgery in our center from January 2014 to October2014. The following data were collected from the pre-anesthesia evaluation sheet: age (in years), weight (in kilograms), height (in centimeters),BMI (using the formula weight/height2), body surface (using Dubois' formula [20], x = 0.007184 x weight (kg)0.425 x height (cm)0.725) expressed in m2, and surgical times. Statistical analyses were performed. Results: After the analyses we found there wasn't association between high BMI and higher surgical times. However, there was a direct relation between surgical times and patient body surface values. These findings were statistically significant. Conclusion: In our experience, the patient's body surface is a reliable predictor of surgical difficulty