The anterior tilt of the acromion: radiographic evaluation and correlation with shoulder diseases

Abstract

The aim of this study was to test whether the anterior tilt of the acromion can be objectively evaluated on lateral radiographs, and whether there is a relation between this anatomical feature and the most common shoulder diseases. Lateral radiographs of 15 dried scapulas were performed in neutral position and with 5 degrees of caudal, cranial, anterior and posterior angulations. Two hundred and forty-three shoulders, both asymptomatic and affected by chronic and post-traumatic impingement, calcific tendinitis and instability, were examined by conventional radiography. The presence of rotator-cuff tears was investigated by sonography. A method was elaborated to obtain reproducible lateral radiographs and to determine the acromial tilt angle. Inter- and intraobserver and inter- and intraoperator variations in measurements were evaluated. Variations in tube angulation produced changes in tilt-angle values on dried scapulas. The average tilt angle for the chronic impingement and the instability groups were significantly different from the post-traumatic, calcific tendinitis and control groups. Rotator-cuff tears were significantly more frequent in the chronic impingement group and related to a more acute tilt angle. The inter- and intraobserver variability coefficients were 0.95 and 0.98, whereas the inter- and intraoperator variability coefficients were 0.94 and 0.96, respectively. Conventional radiography using fluoroscopy for positioning is a well-reproducible method for the evaluation of acromial tilt. There is a significant difference in tilt-angle values between some groups of subjects examined, but the lack of specificity limits the clinical importance of such measurement.

Glenoid version and rotator cuff tears

“…Aoki et al [3] found that patients with impingement had a significantly flatter slope of the acromion as viewed on lateral radiograph compared to those of asymptomatic patients. Other studies have also described morphologic features of the acromion, the coracoid and coracoacromial arch as risk factors for impingement syndrome leading to cuff disease [ 1,4,9, 1 1,13,17, 22,23,25,30,32]. However, further criteria are still needed to better identify individuals at risk for RC tears or to predict which part of the cuff is likely to fail.…”

A Study of the Clinical Utility of the BPI-12 and 23 in Predicting Shoulder Pain in Stroke Patients

“…Regardless of the direction of the upper extremity, the humeral head needs minimal subacromial space lest it should impinge against the glenoid fossa. The humeral head has stability and mobility due to shoulder external rotation (infraspinatus and teres minor) 32) . Shoulder external rotation is certainly needed for the supraspinatus and tendon to freely be moved as patients raise or stretch out their arms.…”

“…As patients with an unstable shoulder elevate their upper limbs, shoulder impingement occurs 32) . Regarding this issue, Rajaratnam et al 12) argued the necessity of a dynamic test for the shoulder joint to test stroke patients as they elevate their upper limbs.…”

Acromion Morphology in Coronal and Sagittal Plane; Correlation with Rotator Cuff Syndrome

“…갈고리형태의 견봉이 충돌증후군 및 회전근개 파열과 상관성이 있다는 예 1,2,6,8, 16,17,[25][26][27]29) 와 연관성을 부정하는 연구결과 4,10,14,20,22,28) 가 있다. 더욱이 견봉의 단순 방사선 영상은 관찰자간 오차가 보고되었다 11,12,24) . 하지만 아직 견봉의 회전근개 자극은 충돌증후군의 중요한 발생원인 으로 고려된다 17,21,26) .…”