Junie Lecours MD, Abstract Co-Author: Nothing to Disclose

Thomas Moser MD, Presenter: Nothing to Disclose

Etienne Cardinal MD, Abstract Co-Author: Nothing to Disclose

Our aim was to determine the incidence and appearance of proximal deltoid tears using MRI in patients with shoulder pain.

We retrospectively reviewed 420 consecutive shoulder MRI exams performed at a single hospital center during year 2009. Among them, 40 were excluded of further analysis for incompleteness or poor quality (n=18) or because of prior shoulder surgery (n=22). The proximal deltoid was assessed by two senior musculoskeletal radiologists and one fellow. Deltoid muscle tears were graded in consensus as type I = undersurface fraying, type II = shallow ulceration or thinning, type III = deep ulceration or thinning, type IV = full-thickness tear, altogether with their location and extent. Associated tears of the rotator cuff were recorded as well.

Among 380 exams, we identified thirty-five (9.2 %) of the 380 shoulder MRI studies had proximal deltoid muscle tears : 7 type I, 17 type II, 10 type III and 1 type IV (full-thickness tear). The tears were at the attachment on the acromion (n=10) or slightly more lateral (n=25). Large or massive rotator cuff tears coexisted in 21 cases (60 %).

Shoulder MRI frequently demonstrates partial-thickness tears of the deltoid muscle most of which are associated with rotator cuff tear.

Deltoid muscle tears on shoulder MRI in patients with shoulder pain and rotator cuff tears are more frequent than initially reported and may have therapeutic implications.

Lecours, J, Moser, T, Cardinal, E, Incidence of Proximal Deltoid Tears with MR Imaging in Shoulder Pain Patients.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9004658.html