Outcome of trapezius transfer to improve shoulder abductionin children with birth brachial plexus palsy

Abstract

Background: Addition of a trapezius to deltoid transfer has been recommended by various authors in overcomingthe deficit in shoulder abduction while correcting the deficit in external rotation of the shoulder in patients withbirth brachial plexus palsy (BBPP). Literature analyzing the effect of trapezius transfer in patients with paralyzeddeltoid stands limited. The purpose of our study is to report the outcome of trapezius transfer for improvement inshoulder abduction in patients with BBPP with weak deltoid function (motor power<grade 3) and to analyze thevarious preoperative factors that could potentially influence the outcome of the surgery. Methods: 25 patients with a mean age of 11 years with limited shoulder abduction and deltoid power<grade 3, underwent trapezius transfer between 2013 and 2023. Pre-operative assessments included age, rangeof shoulder abduction, extent of involvement, Mallet score, and power of elbow flexion. Post-operative rangeof shoulder abduction and Mallet score were noted. These patients were followed up for a minimum of 1 year(range, 12–60 months). Results: Average shoulder abduction improved from 48◦to 100◦(range: 40◦−147◦). The mean improvementin shoulder abduction noted was 52±12 degrees (p-value,<0.05). No statistically significant correlation wasfound between the improvement in shoulder abduction and the extent of neurological involvement, power ofelbow flexion, and previous nerve surgery. However, a weak-to-moderate negative correlation was noted betweenthe age at surgery and the improvement in shoulder abduction (Pearson’s r =−0.4138). A moderate positivecorrelation between the outcome of trapezius transfer and the pre-operative abduction was also noted (Pearsoncoefficient of 0.5175). Conclusion: Trapezius transfer is an effective method to improve shoulder abduction in patients with deltoidpower less than grade 3. Younger children with better preoperative abduction tend to get superior results oftrapezius transfer.