Background: Scapulothoracic dissociation is an infrequent injury that is often accompanied by neurovascular injuries with a potentially devastating outcome. The aim of this study was to evaluate the functional outcome following scapulothoracic dissociation.

Methods: During a twenty-four-year period, we treated twenty-five patients with a scapulothoracic dissociation. The average age was 32.5 years. The average Injury Severity Score was 22 points. Nine patients had a complete brachial plexus avulsion, and ten had an incomplete brachial plexus avulsion. Three patients died from their associated injuries, and six patients required an above-the-elbow amputation. The outcome was assessed with use of the Short-Form 36-Item Health Survey, and the shoulder function of the patients who had not had an amputation was evaluated with use of the Subjective Shoulder Rating System. The degree of initial scapular lateralization was quantified with the scapula index.

Results: The average duration of follow-up was 12.6 years. The physical and mental component summary scores and the scores on the role-physical, general health, vitality, and mental health subscales of the Short-Form 36-Item Health Survey were significantly lower for patients with a complete brachial plexus avulsion (p < 0.05). The Subjective Shoulder Rating System score was also significantly lower in patients with a complete brachial plexus avulsion (33.8 points compared with 72.5 points for the patients with no or an incomplete avulsion, p = 0.046). The average scapula index was 1.29 ± 0.19. The scores on the Short-Form 36-Item Health Survey scales and the Subjective Shoulder Rating System score did not correlate with the initial scapula index (p > 0.05).

Conclusions: The presence of a complete brachial plexus avulsion is predictive of a poor functional outcome in a patient with a scapulothoracic dissociation. Therefore, we suggest a modification of the classification of the severity of this injury, with complete brachial plexus avulsion considered to be the most severe injury type.

Level of Evidence: Prognostic study, Level II-1 (retrospective cohort study). See Instructions to Authors for a complete description of levels of evidence.