he influence of the acromial coverage index in rotator cuff ears

s everal intrinsic and extrinsic factors have been advoated in the pathogenesis of rotator cuff tears, but it is till unclear whether the origin of the tear is related to endon degeneration itself or induced by several morhologic changes. The purpose of this study is to deermine the relationship between the acromial coverge of the humeral head and the presence of a cuff ear. We evaluated 148 shoulders, including 45 that nderwent surgical rotator cuff repair (group I), 26 ith documented rotator cuff tears treated conservaively (group II), and 77 with no cuff pathology as a ontrol group (group III). The mean acromial coverage ndex was 0.68 in group I, 0.72 in group II, and 0.59 n group III, giving a highly significant difference (P 0001) between the control group and both cuff tear roups. Patients with a cuff tear have a significantly igher acromial coverage index than the control roup. (J Shoulder Elbow Surg 2007;16:347-351.)