MRI of the annular ligament of the elbow: review of anatomic considerations and pathologic findings in patients with posterolateral elbow instability.

Abstract

The annular ligament is one of the major stabilizers of the proximal radioulnar joint. However, it is one of the least studied structures in the lateral elbow because of imaging challenges and low pathologic incidence. This article will examine the anatomy of the annular ligament, its biomechanics, and its functional importance. Eight surgically proven cases of annular ligament abnormality in patients with posterolateral and nursemaid elbow, along with the associated findings, are presented. Adequate understanding of the anatomy and familiarity with the associated injuries that can be seen in annular ligament displacement or rupture will improve detection of annular ligament abnormality.