[Arthrodesis of the shoulder for post-traumatic palsy of the brachial plexus. Analysis of a series of 18 cases].

PURPOSE OF THE STUDY: In case of severe traction injuries of the supraclavicular brachial plexus in adult, the functional results of direct shoulder nerve repair are less predictable than those of the elbow. Furthermore, the surgical management of the remaining flail shoulder is still controversial. The post-operative results and the indication for shoulder arthrodesis are evaluated in this study.

MATERIAL AND METHODS: Between October 1978 and January 1994, 18 gleno-humeral arthrodesis were performed on 18 patients for paralytic shoulder following brachial plexus injury. The average age at the time of operation was 25 years. A C5C6 lesion was present in 2 patients, a C5C6C7 lesion in 8 patients and a C5 to T1 lesion in the remaining 8 patients. Seven patients had a suprascapular nerve reinnervation failure. All these 18 patients recovered an active elbow flexion spontaneously or following direct nerve repair, tendon or free muscle transfer. The average delay between nerve repair and arthrodesis was 2 years and 4 months. For fixation, we always used internal fixation by screws, combined to an external fixator device in 10 cases.

RESULTS: 16 patients were reviewed with an average follow-up of 6 years and 10 months (min. 6 months, max. 15 years and 8 months). Two types of complications occurred: 2 cases of gleno-humeral non-union requiring revision with bone-grafting, and 3 humeral fractures in the first 6 months after arthrodesis. The study of the arthrodesis position showed an average abduction of 25 degrees, an average flexion of 18 degrees, an average internal rotation of 22 degrees. The average motion values are 60 degrees of abduction and flexion, 14 degrees of extension, 0 degree of external rotation and 48 degrees of internal rotation. The range of motion depends closely on scapulo-thoracic muscles strength, especially the serratus anterior muscle. A flail hand primarily influences the subjective result. 14 of the 16 patients could easily reach their mouth. The average muscle shoulder strength, evaluated with the Isobex device, is 11 kg for flexion and abduction, 9 kg for adduction, 8 kg for internal rotation and 4 kg for external rotation.

DISCUSSION AND CONCLUSION: Gleno-humeral arthrodesis is a reliable method for restoring shoulder function in case of brachial plexus sequellae lesion, giving more strength, but less external rotation than shoulder nerve repair.