Factors Affecting Operative Duration in Isolated Open Carpal Tunnel Release.

 Open carpal tunnel release (CTR) is one of the most commonly performed operative procedures with operative duration being a primary metric of operating room efficiency. The purpose of this study was to identify factors associated with prolonged operative duration, in performing CTR.  CTR cases performed by a single surgeon from September 2013 to October 2015 were reviewed. Patient age at the time of surgery, sex, location of surgery (specialty orthopaedic hospital versus ambulatory surgery center), body mass index (BMI), American Society of Anesthesiologists classification, total operative duration (TOD), and procedure time (PT) were recorded. Obesity was defined as BMI > 30 and morbid obesity was defined as BMI > 35. Data were analyzed to identify factors associated with prolonged TOD or PT.  One hundred and nine consecutive patients underwent isolated CTR. Mean age at time of surgery was 62 years (range: 24-92 years). Nonobese patients were found to have significantly shorter TOD than obese patients (22.3 vs. 24.4 minutes). Similarly, patients who were not morbidly obese had significantly shorter TOD than morbidly obese patients (22.6 vs. 26 minutes). No other factors were associated with prolonged TOD. No difference in PT was found between normal weight, obese, and morbidly obese groups.  TOD, but not procedure time, is significantly affected by obesity. Our findings are relevant when scheduling and preparing obese patients for surgery, which may have a significant impact on health resource utilization.  This is a Level III, economic/decision analysis study.