Subscapularis lengthening and tendon transfers for shoulder dysfunction in children with obstetrical brachial plexus injuries

Background: Obstetrical brachial plexus injuries are reported to occur at a rate of between 0.1 to three cases per 1000 live births. Fortunately, most infants with brachial plexus palsy recover spontaneously with those who recover anti-gravity strength in the first few months of life going on to a full recovery in the first one to two years of life. Those infants who do not go on to a full recovery of C5-C6-C7 will develop permanent limitations in terms of mobility and strength. The common clinical sequela of an upper trunk injury with incomplete recovery is an internally contracted shoulder due to muscle imbalances across the joint. We hypothesized that simultaneous subscapularis lengthening combined with latissimus dorsi and teres major tendon transfer to the rotator cuff would improve shoulder function. We further hypothesize that patients would show greater improvement if the procedure was performed at a young age (at or around two years of age). Materials & methods: Twenty-three patients with obstetrical brachial plexus palsies between the ages of fourteen and sixty-nine months were surgically treated at our institution. Sixteen and sixty-nine months were subscapularis lengthening combined with a latissimus dorsi and teres major transfer to the rotator cuff while two patients underwent isolated tendon transfers to the rotator cuff. One of the patients underwent subscapularis lengthening at twenty-three months of age, followed by the tendon transfers at sixty months of age. The mean age at surgery was thirty months while the median age was twenty-two months. Twelve patients were operated on while they were about two years of age. Six patients underwent the procedure when they were older than two years of age. Range of motion was documented before surgery as well as at the time of last follow-up: passive external rotation with the arm at the side, passive external rotation with the arm abducted 90 degrees, as well as active forward elevation and active abduction. Mean follow-up was 39.5 months. Results: External rotation with the arm adducted at the side improved by a mean of 40 degrees (p<0.0001). Passive external rotation with the shoulder abducted to 90 degrees averaged 70 degrees preoperatively (range, 30 TO 95 degrees). Postoperatively, average external rotation in abduction measured 110 degrees (range, 90 to 120 degrees) representing a 30 degree improvement (p<0.0001). Active forward elevation improved from an average preoperatively of 95 degrees (range, 20 to 150 degrees) to an average of 158 degrees postoperatively (p<0.0001). Active abduction similarly increased by an average of 62 degrees from 88 degrees preoperatively to 158 degrees postoperatively (p<0.0001). The patients in the younger group did better on average than in the older group. Forward elevation improved 63 degrees for the younger patients versus 38 degrees for the older patients (p<0.04). Conclusions: Subscapularis lengthening combined with teres major and latissimus dorsi tendon transfers in the pediatric patient with residual shoulder dysfunction secondary to obstetrical brachial plexus palsy is a safe and effective means of improving function. Patients treated around the age of two had a statistically significantly greater improvement in forward elevation compared to those patients treated over the age of two.