Evaluation of bilateral acromiohumeral distance on magnetic resonance imaging and radiography in patients with unilateral rotator cuff tears

Introduction The aim of this study was to evaluate the difference in the acromiohumeral distance (AHD) between the shoulders with full-thickness rotator cuff tear and contralateral healthy shoulders of the same patients on magnetic resonance imaging (MRI) and radiograph. Materials and methods We included 49 patients with unilateral full-thickness rotator cuff tears. The mean age of the patients (29 women and 20 men) was 54.57 +/- 7.10 years. The shoulders were divided into those with a full-thickness rotator cuff tear and healthy shoulders. The mean AHDs on radiograph and MRI were calculated by two radiologists experienced in the musculoskeletal system. Shoulders with rotator cuff tears on coronal plane and sagittal MRI were divided into 3 (Patte I, II, III) and 4 subgroups (S: superior, AS: anterosuperior, PS: posterosuperior, APS: anteroposterosuperior), respectively. The relationship between the groups and the subgroups was statistically investigated. Results The mean AHDs on radiograph were 6.93 and 9.11 mm and on MRI were 5.94 and 7.46 mm in the patient and control groups, respectively. The mean AHDs were 6.47, 6.03, and 4.95 mm in Patte I, II, and III, respectively. The difference between the subgroups was statistically significant. According to the sagittal plane topography, the mean AHDs (mm) were 6.39, 6.44, 5.8, and 4.6 mm in the superiorly, anterosuperiorly, posterosuperiorly, and anteroposterosuperiorly localized lesions, respectively. The relationship between S and AS was not statistically significant, and those between S and PS, AS and PS, S and APS, and PS and APS were significant. Conclusions In patients with unilateral full-thickness rotator cuff tear, AHD narrowing was observed on the tornekler side after evaluating the bilateral acromiohumeral distance on MRI and radiograph. AHD was significantly reduced by increasing the degree of supraspinatus tendon retraction in the coronal plane MRI and by the posterosuperior and anteroposterosuperior location of the rotator cuff tear in the sagittal plane MRI.