Background: Shoulder joint stiffness commonly occurs in patients with rotator cuff tears. Rotator cuff tear morphology can be classified into articular side partial-thickess tears, bursal side partial-thickess tears and full-thickness tears. However, the relationship between rotator cuff tear morphology and shoulder joint stiffness is not well known. The aim of this study was to evaluate the correlation between rotator cuff tear patterns and shoulder joint stiffness.
Methods: We retrospectively evaluated 903 arthroscopically treated shoulders (506 male, 397 female), in which rotator cuff tears morphology were correctly recorded. Patients below 40 years of age and accompanied shoulder dislocation histories were excluded in this study. Concerning rotator cuff tear morphology, articular side partial-thickness tears were classified as group A, bursal side partial-thickness tears were classified as group B and full-thickness complete tears were classified as group C. Shoulder joint stiffness was diagnosed in the patients with less than 120 degrees in maximum rotational angles: total external and internal rotation angles at 90 degrees of abduction under general anesthesia. The ratio of shoulder joint stiffness in the three groups was statistically evaluated.
Results: The ratio of shoulder joint stiffness was 29.5% (70/237) in group A, 17.0% (24/141) in group B and 6.3% (33/525) in group C. Shoulder joint stiffness was observed more frequently in partial-thickness tears than in full-thickness tears. Articular side partial-thickness tears have the highest correlation between shoulder joint stiffness.
Conclusion: Our results showed that there is significant correlation between rotator cuff tear morphology and shoulder joint stiffness.
