Humeral avulsion of the posterior band of the inferior glenohumeral ligament: MR arthrography and clinical correlation in 17 patients.

Abstract

The purpose of this article is to describe the MR arthrography findings of humeral avulsion of the posterior band of the inferior glenohumeral ligament in 17 patients. To elucidate the clinical importance of this abnormality, we also correlate our imaging findings with the presence of coexisting structural abnormalities; clinical presentation; and, when available, arthroscopic evaluation (n = 8). Humeral avulsion or insufficiency of the posterior band of the inferior glenohumeral ligament can be easily detected using MR arthrography. This ligamentous abnormality may be seen in isolation, or it may occur in conjunction with posterior or, less often, anteroinferior capsulolabral abnormalities. The presence of this lesion in a subgroup of patients with the clinical diagnosis of multidirectional instability may offer insight into the causes and pathogenesis of this complex entity.