Association of acromial morphological parameters and rotator cuff tears, and evaluation of the influence of age and gender on the parameters and impact on cuff tears: A study on a Middle Eastern population

Abstract

Objective: The aim of this study is to evaluate the presence of significant differences regarding the lateral acromial angle, critical shoulder angle, and the acromial index between patients with and without rotator cuff tears.

Method: The MRIs (Magnetic Resonnance Imaging) of 82 patients were studied. The rotator cuff tear group (RCT group) included 41 patients while the control group also included 41 patients without rotator cuff tears. Acromial parameters and demographical data were extracted for statistical analysis.

Results: No statistical significant difference was found in terms of the studied acromial parameters between patients with and without rotator cuff tears. No correlation was found between age and any of the studied parameters. LAA (Lateral Acromial Angle) was found to be significantly different between males and females of the studied sample. However, no difference was found between patients with and without rotator cuff tears when both genders were studied separately. Moreover, no statistical significant difference was found in terms of the studied acromial parameters between males and females when the RCT group and the control group were studied separately. When gender was the covariate in the one-way MANCOVA test, gender was not significantly dependent on the type of groups (RCT group vs control group).

Conclusion: The results obtained from this study suggested that the studied acromial parameters in patients with rotator cuff tears were not different from the parameters found in patients without rotator cuff tears. Moreover, gender was not found to influence the acromial parameters, with no subsequent effect on the development of rotator cuff tears. Further studies may be required for better understanding on the biomechanics, taking into consideration age, gender, and the given population.

Keywords: Acromion; Biomechanics; Magnetic resonance images; Parameters; Rotator cuff; Shoulder.

Fig. 1

The acromion index (AI) represented by the distance from the glenoid plane to the lateral border of the acromion (GA) divided by the distance from the glenoid plane to the lateral aspect of the humeral head (GH).

Fig. 2

The lateral acromial angle (LAA) represented by the angle enclosed between the glenoid plane and the undersurface of the acromion.

Fig. 3

The critical shoulder angle represented by the line connecting the superior and inferior bony margins of the glenoid and an intersecting line drawn from the inferior bony margin of the glenoid to the most lateral border of the acromion.