Between March 1994 and June 2003, 80 patients with brachial plexus palsy underwent a trapezius transfer. There were 11 women and 69 men with a mean age of 31 years (18 to 69). Before operation a full evaluation of muscle function in the affected arm was carried out. A completely flail arm was found in 37 patients (46%). Some peripheral function in the elbow and hand was seen in 43 (54%). No patient had full active movement of the elbow in combination with adequate function of the hand. Patients were followed up for a mean of 2.4 years (0.8 to 8). We performed the operations according to Saha’s technique, with a modification in the last 22 cases. We demonstrated a difference in the results according to the pre-operative status of the muscles and the operative technique.

The transfer resulted in an increase of function in all patients and in 74 (95%) a decrease in multidirectional instability of the shoulder. The mean increase in active abduction was from 6° (0 to 45) to 34° (5 to 90) at the last review. The mean forward flexion increased from 12° (0 to 85) to 30° (5 to 90).

Abduction (41°) and especially forward flexion (43°) were greater when some residual function of the pectoralis major remained (n = 32). The best results were achieved in those patients with most pre-operative power of the biceps, coracobrachialis and triceps muscles (n = 7), with a mean of 42° of abduction and 56° of forward flexion. Active abduction (28°) and forward flexion (19°) were much less in completely flail shoulders (n = 34).

Comparison of the 19 patients with the Saha technique and the 15 with the modified procedure, all with complete paralysis, showed the latter operation to be superior in improving shoulder stability. In all cases a decrease in instability was achieved and inferior subluxation was abolished.

The results after trapezius transfer depend on the pre-operative pattern of paralysis and the operative technique. Better results can be achieved in patients who have some function of the biceps, coracobrachialis, pectoralis major and triceps muscles compared with those who have a complete palsy. A simple modification of the operation ensures a decrease in joint instability and an increase in function.

Most brachial plexus palsies are due to trauma, often resulting from motorcycle accidents. When nerve repair and physiotherapy are unsuccessful, muscle transfer may be considered. Paralysis of the deltoid and supraspinatus muscles can be addressed by transfer of the trapezius.

Between March 1994 and June 1997 we treated 38 patients with brachial plexus palsy by trapezius transfer and reviewed 31 of these (7 women, 24 men) after a mean follow-up of 23.8 months (12 to 39), reporting the clinical and radiological results and subjective assessment. The mean age of the patients was 29 years (18 to 46).

The operations had been performed according to the method of Saha described in 1967, involving transfer of the acromion with the insertion of the trapezius to the proximal humerus, and immobilisation in an abduction support for six weeks. Rehabilitation started on the first postoperative day with active exercises for the elbow, hand and fingers, and electrical stimulation of the transferred trapezius.

All 31 patients had improved function with a decrease in multidirectional instability of the shoulder. The average increase in active abduction was from 7.3° (0 to 45) to 39° (25 to 80) at the latest review. The mean forward flexion increased from 20° (0 to 85) to 44° (20 to 90). Twenty-nine of the 31 were satisfied with the improvement in stability and function.

Trapezius transfer for brachial plexus palsy involving the shoulder improves function and stability with clear subjective benefits.