A rotator cuff tear is a shoulder injury that can be caused by a single event such as lifting a heavy weight or having a fall, or just through general wear and tear. You may feel constant or recurring pain, particularly when your arm is above your head, and the joint may feel stiff.
New research has found that joint capsule abnormality seen on MRI scans can be used to help predict which patients with rotator cuff tear will suffer shoulder stiffness, the American Roentgen Ray Society reports.
In a study due to be published in the May issue of the American Journal of Roentgenology (AJR), researchers in South Korea analysed MRI scans of 106 patients with full-thickness rotator cuff tears. They looked at joint capsule oedema and thickness at the axillary recess, as well as obliteration of the subcoracoid fat triangle, fatty degeneration of the torn rotator cuff muscle, and degree of retraction.
Tear size and location were determined by MRI findings and operative report, while associations between MRI findings and preoperative passive range of motion (ROM) were evaluated with simple and multiple linear regression analyses and proportional odds logistic regression analysis.
In particular, joint capsule oedema and thickness at the axillary recess were useful in predicting stiff shoulder in this patient group.
There was a significant, negative linear correlation between limited ROM at forward elevation and thickness of the joint capsule in the glenoid portion of the axillary recess, external rotation and joint capsule oedema in the humeral portion of the axillary recess, and internal rotation and joint capsule oedema in the glenoid portion of the axillary recess. Male sex and posterosuperior rotator cuff tear were independent predictors of shoulder ROM on external rotation. Degree of fatty degeneration was another independent predictor of shoulder ROM on internal rotation.
“This study is important,” wrote Yoon Yi Kim and colleagues at Korea’s Veterans Health Service Medical Center, “because it is the first to highlight joint capsule abnormality on MRI as a factor associated with stiff shoulder in patients with full-thickness rotator cuff tears.”