Thirty-three infants underwent surgery for obstetrical brachial plexus palsy at a mean age of 4.7 months of age. Thirteen had an upper palsy and 20 had a total palsy. Surgery consisted of nerve reconstruction in all and secondary tendon transfers in 16. Mean follow-up was almost five years. Multiple outcome measurements were used including the Toronto grading scale, hand movement score, Mallet score, sensibility, grip strength, and bimanual function score.
In the upper palsy group, a neuroma at the superior trunk was the most common finding. Root avulsion(s) were found in four cases. Intraplexal nerve grafting and extraplexal nerve transfers (usually spinal accessory nerve) were used to reconstruct the plexus. Five patients required secondary tendon transfers about the shoulder or elbow. In the total palsy group, more severe injuries were encountered, although a similar combination of intraplexal and extraplexal reconstruction was utilized. Ten patients required secondary tendon transfers about the shoulder, elbow, or hand. Ten upper plexus patients (70%) showed useful (movement > ½ range against gravity) shoulder function. Eleven (75%) had useful elbow flexion. Only four (20%) total plexus patients had useful shoulder function and seven (35%) possessed useful elbow flexion. Hand function correlated with motion, sensibility, and grip and was severely impaired in total palsy patients.
The authors highlight many of the difficulties in treating and comparing outcomes in children with brachial plexus palsies. Comparisons between cohorts that have different characteristics (i.e. upper versus global, rupture versus avulsion, grafting versus nerve transfer) are inappropriate. Furthermore, secondary surgery, such as a tendon transfer, adds an additional confounding factor. Nonetheless, surgery can clearly provide shoulder and elbow function in upper plexus lesions (70-75%). Secondary tendon transfers appear to augment the motion obtained by nerve reconstruction. Surgery for total lesions is much less successful and only 20% regained adequate shoulder motion and 35% elbow motion. Root avulsions are more common in total lesions, which create a dilemma at the time of nerve reconstruction. There is an insufficient supply of viable axons and an excessive amount of potential outflow options. Extraplexal sources of viable axons are commonly used, but an axonal deficiency still persists. Therefore, infants with total lesions unfortunately have a much worse prognosis compared to upper plexus injuries.