A prospective, longitudinal outcome study of patients with carpal tunnel surgery and the relationship of body mass index.

This study investigated whether body mass index (BMI) was associated with effectiveness of carpal tunnel release as measured by physical and self-assessment tests. This prospective, longitudinal study was conducted from March 2001 to March 2003 using 598 cases (hands) diagnosed with carpal tunnel syndrome and scheduled for surgery at The Curtis National Hand Center, Baltimore, Maryland, and at the Pulvertaft Hand Centre, Derby, England. Body mass index was calculated, and demographic, clinical, and functional data were collected preoperatively and at 6-month follow-up. Grip, pinch, and Semmes-Weinstein scores were measured preoperatively and at 6-month follow-up. Levine-Katz self-assessment scores for symptom severity and functional status were measured preoperatively and at 6-month follow-up. Grip and pinch increased, whereas Semmes-Weinstein, symptom severity, and functional scores decreased by 6-month follow-up. Cases with BMI >35 had lower grip strength and higher symptom severity in males and higher functional status in both sexes pre- and postoperatively compared to normal-weight BMI cases. BMI had no relationship to patient satisfaction. Although morbidly obese cases did worse on some physical and self-assessment tests compared to normal BMI cases preoperatively, all improved to the same extent postoperatively regardless of BMI.