Acromial impression fracture of the greater tuberosity with rotator cuff avulsion due to hyperabduction injury of the shoulder

Abstract

A heavy-set, muscular, 23-year-old, right hand–dominant male office worker who participates in basketball, weight lifting, and some throwing sports had a hyperabduction injury (without evidence of glenohumeral dislocation) of the right shoulder after falling down a cliff. As depicted in Figure 1, the fall was a sheer 15-foot free fall onto the hyperabducted arm, as he had placed his forearm over his head for protection. After this, there was a further 40-foot sloped descent whereupon the patient reports that he “tumbled like a rag doll through trees and rocks.” Upon landing the final time, his arm was out to the side (in abduction), feeling locked, with normal motor function in the hand. He also had multiple ligamentous injuries to the left knee. The radiographs depicted in Figure 2 demonstrate the lateral defect in the greater tuberosity. Subsequent ultrasound examination of the shoulder (not shown) suggested rotator cuff avulsion. Axial computed tomography (CT) (Figure 3, A) demonstrated the extensive lateral impression fracture of the superolateral greater tuberosity and anatomic neck, which left an extensive cavitary bony deficit. In Figure 3, B, the reconstructed sagittal CT section better demonstrates the bony defect and its extent, as well as defining the fragments of subacromial bone, which were presumed to represent avulsion of the supraspinatus tendon from the greater tuberosity. After the patient’s knee was reconstructed, operative treatment involved positioning the patient supine and semiupright in the beach-chair position. A longitudinal lateral incision was made from the acromion down the deltoid, followed by a deltoid split to explore the damage. After finding the crater of the humeral head defect, which appeared to key together with the acromion, the rotator cuff was explored and the deltoid dissected subperiosteally from the acromion for proper exposure. We did not enter the rotator interval anteriorly. The substance of the rotator cuff tendons appeared to be entirely intact, and they mobilized remarkably well, considering that the operation was at 18 days after injury. The rotator cuff could not be classified as a tear,2,3 as the substance of it was in full continuity. However, we did keep in mind the principle of regaining tension of the tendon, which has been noted in rotator cuff tears to be more Dr Kaspar holds research grants from McMaster University and from the Physicians’ Services Incorporated (PSI) Foundation of Ontario, neither of which had any bearing on this report. From McMaster University. Reprint requests: Scott Mandel, MD, FRCSC, 414 Victoria Ave N, Suite M8, Hamilton, Ontario, Canada, L8L 5G8. J Shoulder Elbow Surg 2004;13:112-14 Copyright © 2004 by Journal of Shoulder and Elbow Surgery Board of Trustees. 1058-2746/2004/$35.00 0 doi:10.1016/S0009-9236(03)00177-0 Figure 1 Diagrammatic representation of the mechanism of injury. The patient’s body weight landed onto his right upper extremity, which he had used to protect his head, hence yielding a hyperabducted right shoulder. After this 15-foot free fall, he continued tumbling for a further 40 feet.