Spinal to accessory nerve transfer in traumatic brachial plexus palsy: is body mass index a predictor of outcome?

Several factors that affect functional recovery after surgery in severe brachial plexus lesions have been identified, i.e., time to surgery and presence of root avulsions. The body mass index (BMI) of the patient could be one of these possible factors. The objective of the present paper is to systematically study the relationship between BMI and the outcome of abduction following spinal accessory to suprascapular nerve transfer. We retrospectively studied 18 cases that followed these inclusion criteria: (1) Male patients with a spinal accessory to suprascapular nerve transfer as the only procedure for shoulder function reanimation; (2) at least C5-C6 root avulsion; (3) interval between trauma and surgery less than 12 months; (4) follow-up was at least 2 years; (5) no concomitant injury of the shoulder girdle. Pearson correlation analysis and linear regression was performed for BMI versus shoulder abduction. The mean range of post-operative abduction obtained across the entire series was 49.7A degrees (SD +/- A 30.2). Statistical evaluation revealed a significant, negative moderately strong correlation between BMI and post-operative range of shoulder abduction (r = -0.48, p = 0.04). Upon simple linear regression, time to surgery (p = 0.04) was the only statistically significant predictor of abduction range negatively correlated. Analysis of this series suggests that a high BMI of patients undergoing brachial plexus surgery is a negative predictor of outcome, albeit less important than others like time from trauma to surgery. Nevertheless, the BMI of patients should be taken into consideration when planning surgical strategies for reconstruction.