RESUMEN
BACKGROUND:Acromion morphology is the most important external factor of degenerative rotator cuff tear,and studies on acromion morphology and acromion coverage have been continuing. OBJECTIVE:To investigate the coverage of acromion on rotator cuff tissue in three-dimensional space,measure coronal and sagittal parameters,and explore the relationship of acromial overhang,acromioglenoid angle and acromial coverage angle with degenerative full-thickness rotator cuff tears. METHODS:A total of 56 patients diagnosed with full-thickness rotator cuff tears by shoulder arthroscopic surgery or MRI in the Affiliated Hospital of Xuzhou Medical University from January 2022 to June 2023 were retrospectively collected as the tear group,while 48 patients with non-rotator cuff tear were included as the control group.Clinical data and chest CT data of the patients of the two groups were collected,and the shoulder blades of the patients were reconstructed using Mimics software.Acromial overhang,acromioglenoid angle and acromial coverage angle were measured in 3-matic software.The differences between the measurement parameters were compared between the two groups.Binary Logistic regression analysis and receiver operating characteristic curve analysis were performed to evaluate the ability of the measurement parameters to predict rotator cuff tear.It is generally believed that the parameter had good diagnostic value when the area under the receiver operating characteristic curve was greater than 0.8. RESULTS AND CONCLUSION:(1)The mean acromial overhang in patients with rotator cuff tears was greater than that in controls(P<0.001).The mean acromial coverage angle was also greater in patients with rotator cuff tears than in controls(P<0.001).There was no significant difference in the acromioglenoid angle between the two groups(P>0.05).(2)Binary Logistic regression analysis showed that acromial overhang and acromial coverage angle were both risk factors for rotator cuff tear(P<0.05).(3)Receiver operating characteristic curve analysis indicated that the areas under the curve of acromial overhang and acromial coverage angle were 0.725 and 0.865,respectively,and the optimal cutoff values were 36.15 mm and 60.65°.(4)The results showed that the acromial overhang and acromial coverage angle were greater in patients with rotator cuff tears than in patients without rotator cuff tears.Both were associated with degenerative full-thickness rotator cuff tears,and they could be used to predict rotator cuff tears,and the acromial coverage angle was more effective in predicting rotator cuff tears.