MRI Findings Predictive of Shoulder Stiffness in Patients With Full-Thickness Rotator Cuff Tears.

OBJECTIVE. The objective of our study was to evaluate the relationship between stiff shoulder in patients with a full-thickness rotator cuff tear and MRI findings, especially joint capsule abnormality. MATERIALS AND METHODS. This study included 106 patients with small to large (≤ 5 cm) full-thickness rotator cuff tears. Joint capsule edema and thickness in the axillary recess, obliteration of the subcoracoid fat triangle, fatty degeneration of the torn rotator cuff muscle, and degree of retraction were assessed by two radiologists. The size and location of tears were determined by MRI findings and operative report. Associations between MRI findings and preoperative passive range of motion (ROM) were assessed by simple and multiple linear regression analyses and proportional odds logistic regression analysis. RESULTS. 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 (p = 0.018), external rotation and joint capsule edema in the humeral portion of the axillary recess (p = 0.011), and internal rotation and joint capsule edema in the glenoid portion of the axillary recess (p = 0.007). Male sex (p = 0.041) and posterosuperior rotator cuff tear (p = 0.030) were independent predictors of shoulder ROM on external rotation. Degree of fatty degeneration (p = 0.003) was another independent predictor of shoulder ROM on internal rotation. CONCLUSION. MRI findings-especially joint capsule edema and thickness at the axillary recess-can be useful in predicting shoulder stiffness in patients with rotator cuff tear.