Acromion Shape and Degenerative Changes of the Acromioclavicular Joint as Risk Factors for Sub-Acromial Impingement Syndrome.

The widespread condition Subacromial impingement syndrome (SAIS) appears among the leading causes of shoulder pain, which restrict people in their daily routine activities and diminish their quality of life. The condition specifically relates to subacromial space reduction that leads to rotator cuff damage. # Objective The study aims to determine whether particular acromion shapes and different stages of AC joint degeneration significantly contribute to the risk of developing SAIS. # Methods The retrospective study was conducted on 608 patients who underwent shoulder MRI between the period of 2017 to 2020. The Acromion type and AC joint degeneration severity were evaluated by using T1- or T2/PD-weighted MRI sequences obtained from sagittal and coronal oblique planes. # Results Type III acromion and mild AC joint degeneration were more frequently observed in SAIS patients, but these findings were not statistically significant (P-value =0.38). Results showed that supraspinatus and infraspinatus tendon pathologies together with reduced acromiohumeral distance were strongly linked to SAIS development. # Conclusion Acromion shape together with AC joint degeneration did not produce significant effects on increasing the risk of developing SAIS. However, the rotator cuff pathologies combined with reduced subacromial space act as primary causes of SAIS, additional studies are needed further for better diagnostics and treatment strategies.