Adhesive capsulitis of the shoulder: dimensions of the rotator interval measured with magnetic resonance arthrography.

Abstract

This study was performed to define the dimensions of the rotator interval (RI) in adhesive capsulitis using magnetic resonance (MR) arthrography preoperatively to clarify and evaluate pathology. We performed a retrospective review of a series of 73 shoulders that underwent MR arthrography. The shoulders were grouped according to their diagnosis: group I comprised 47 shoulders without adhesive capsulitis; group II comprised 26 shoulders with adhesive capsulitis. Using MR arthrography, we estimated the height, base, RI area, width, RI index, and RI ratio. The group II shoulders differed significantly in height, base, RI area, RI index, and RI ratio from the group I shoulders. There were statistically significant differences in RI dimensions between patients with and without adhesive capsulitis of the shoulder. Estimating the dimensions of the RI in adhesive capsulitis using MR arthrography may prove to be valuable for assessing patients preoperatively.