The medial rotation contracture caused by weak external rotation secondary to obstetric brachial plexus injury leads to deformation of the bones of the shoulder. Scapular hypoplasia, elevation and rotation deformity are accompanied by progressive dislocation of the humeral head. Between February and August 2005, 44 children underwent a new surgical procedure called the ‘triangle tilt’ operation to correct this bony shoulder deformity. Surgical levelling of the distal acromioclavicular triangle combined with tightening of the posterior glenohumeral capsule (capsulorrhaphy) improved shoulder function and corrected the glenohumeral axis in these patients. The posture of the arm at rest was improved and active external rotation increased by a mean of 53° (0° to 115°) in the 40 children who were followed up for more than one year.

There was a mean improvement of 4.9 points (1.7 to 8.3) of the Mallet shoulder function score after surgical correction of the bony deformity.

Whereas a general trend in the management of obstetric brachial plexus injuries has been nerve reconstruction in patients without spontaneous recovery of biceps function by three to six months of age, many recent studies suggest this may be unnecessary. In this study, the severity of glenohumeral dysplasia and shoulder function and strength in two groups of matched patients with a C5-6 lesion at a mean age of seven years (2.7 to 13.3) were investigated. One group (23 patients) underwent nerve reconstruction and secondary operations, and the other (52 patients) underwent only secondary operations for similar initial clinical presentations. In the patients with nerve reconstruction shoulder function did not improve and they developed more severe shoulder deformities (posterior subluxation, glenoid version and scapular elevation) and required a mean of 2.4 times as many operations as patients without nerve reconstruction.

This study suggests that less invasive management, addressing the muscle and bone complications, is a more effective approach. Nerve reconstruction should be reserved for those less common cases where the C5 and C6 nerve roots will not recover.

We describe the long-term results in ten patients with obstetric brachial plexus palsy of anterior shoulder release combined with transfer of teres major and latissimus dorsi posteriorly and laterally to allow them to act as external rotators. Eight patients had a lesion of the superior trunk and two some involvement of the entire brachial plexus. The mean age at operation was six years, and the mean follow-up was 30 years.

Before operation, the patients were unable actively to rotate the arm externally beyond neutral, although this movement was passively normal. All showed decreased strength of the external rotator, but had normal strength of the internal rotator muscles. Radiologically, no severe bony changes were seen in the glenohumeral joint.

No clinically detectable improvement of active abduction was noted in any patient. The mean active external rotation after operation was 36.5°. This was maintained for a mean of ten years, and then deteriorated in eight patients. At the latest follow-up the mean active external rotation was 10.5°.

The early satisfactory results of the procedure were not maintained. In the long term there was loss of active external rotation, possibly because of gradual degeneration of the transferred muscles, contracture of the surrounding soft tissues and degenerative changes in the glenohumeral joint.