RESUMO
Background: The purpose of this study was to determine if scapular anatomy differs between younger and older patients with atraumatic full-thickness supraspinatus tears. Methods: The critical shoulder angle, acromial index and lateral acromial angle were measured on standardized radiographs of two groups of patients who underwent arthroscopic repair of full-thickness degenerative supraspinatus tears. Group 1 included 61 patients under the age of 50 years while Group 2 included 45 patients over the age of 70 years. The mean critical shoulder angle, acromial index, and lateral acromial angle were then compared. Results: There was no significant difference between groups for the critical shoulder angle (p = .433), acromial index (p = .881) or lateral acromial angle (p = .263). Interobserver reliability for critical shoulder angle, acromial index, and lateral acromial angle was nearly perfect (interclass correlation coefficient 0.996, 0.996, 0.998, respectively). No significant correlation existed between age and critical shoulder angle (p = .309), acromial index (p = .484) or lateral acromial angle (p = .685). Discussion: While the critical shoulder angle and acromial index were found to be high and in the typical range for patients with rotator cuff tears in both groups, there were no significant differences in acromial morphology between Groups 1 and 2.
RESUMO
BACKGROUND: Rotator cuff tears that have flipped upon itself and adhered medially have been recently described as Fosbury flop tears (FFT). However, there are no reports on the cause and clinical outcomes of FFT. We investigated the preoperative anatomical factors and clinical outcomes related to the occurrence of FFT. METHODS: Among patients with more than two years of follow-up, 33 patients with FFT who underwent arthroscopic rotator cuff repair (ARCR) for a small-to-medium sized tear of the supraspinatus tendon alone (Group F: mean age, 63.4 ± 8.9 years) and 52 patients without FFT who underwent ARCR (Group C: mean age, 62.1 ± 7.0 years) were included. Presence of diabetes mellitus, critical shoulder angle (CSA), lateral acromial angle (LAA), acromiohumeral distance (AHD), sagittal and coronal morphologies of the acromion, JOA score, and rate of rotator cuff re-tear were evaluated. RESULTS: There were significantly more males in Group F (P = 0.017). There were no significant differences in age or rate of diabetic complications. The mean CSA, LAA, and AHD in the Groups F and C were respectively as follows: CSA, 33.7 ± 4.0° and 34.5 ± 3.4°; LAA, 82.1 ± 9.9° and 82.1 ± 6.9°; AHD, 10.2 ± 1.4 mm and 9.8 ± 1.4 mm. There were no significant differences between groups. The acromial morphology showed no significant difference in the sagittal plane; however, significantly more double-floor type acromia were found in the coronal plane (P < 0.001). Although the JOA score significantly improved in both groups, there was no significant difference between groups. The re-rupture rate was significantly higher in Group F than Group C (15.2% versus 1.9%; P = 0.02). CONCLUSIONS: Double-floor type acromia in the coronal plane was common in Group F. The location of osteophytes on the inferior surface of the acromion was believed to be associated with the occurrence of FFT. Furthermore, a high re-tear rate was observed in group F.
RESUMO
BACKGROUND: Various radiographic measurements that describe humeral head coverage by the acromion and the effect on rotator cuff pathology have been reported. This study aimed to describe and validate a new radiographic measurement, the acromiohumeral centre edge angle (ACEA). METHODS: We compared the ACEA on computed tomography (CT) and plain X-ray to determine whether X-ray is accurate for measuring this angle. We then compared the results from this control population with 107 patients with acute rotator cuff tears. We compared functional outcomes in rotator cuff tear patients to determine whether the ACEA has any effect on outcome after surgery. An intra- and inter-observer variability analysis was performed and we compared the ACEA to the acromial index (AI) on rotation X-rays. RESULTS: The ACEA was comparable on CT and plain X-ray and was most accurate when true anteroposterior glenohumeral X-rays were used (15.94° vs. 15.87° on CT, p = 0.476). The ACEA showed high intra- and inter-observer reproducibility and was unchanged on internal and external rotation X-rays (20.48 vs. 20.47, p = 0.842), whereas the AI was significantly different (0.74 vs. 0.70, p < 0.001). The ACEA was significantly higher in our rotator cuff tear patients than the control population (23.9° vs. 16.6°, p < 0.001), although a higher ACEA was not associated with poorer outcomes. CONCLUSION: The ACEA is a valid measurement for describing humeral head coverage by the acromion and can be accurately measured on plain radiographs with good reproducibility. It is unaffected by shoulder rotation and was significantly higher in patients with acute rotator cuff tears.
