Simultaneous fracture of the acromion and coracoid process: Rare variant of double disruption of the superior shoulder suspensory complex

Abstract

Introduction: Simultaneous fracture of the acromion and coracoid process represents a double disruption of the superior shoulder suspensory complex (SSSC). To date, the two largest reported series have comprised five and eight cases. The aim of this study was to investigate the functional outcome in patients who sustained this rare injury and to provide a review of the relevant literature. Material and methods: In this retrospective study, patients who were surgically treated between 2009 and 2014 were identified from medical records and the patients were asked to attend a follow-up examination. Functional results, measured as the Constant score and Disabilities of the Arm, Shoulder and Hand (DASH) score, were the main outcomes of the study. Results: A total of six patients underwent surgery for this type of double disruption of the SSSC. All but one patient suffered a high-impact trauma with other associated injuries. The coracoid fracture was classified as type I according to Ogawa in all cases, and the acromion fracture was type III according to Kuhn in 5 out of 6 cases. At least one of the fracture sites was stabilized. Of the patients one showed a concurrent lateral clavicle fracture, representing a third disruption of the SSSC, and another had a fracture of the medial third of the clavicle, representing a strut fracture. In these cases, two fracture sites were operated on. At an average follow-up period of 47 months all but one fracture had healed. In one patient, asymptomatic non-union of the acromion was found. The average DASH score was 22 points and the average Constant score was 74 points. Conclusion: This rare injury pattern is usually caused by high-impact trauma, and concomitant injuries frequently occur. Nevertheless, surgical stabilization of at least one of the fracture sites showed satisfactory functional results.