Morphological analysis of acromion and its significance in rotator cuff pathologies and impingement syndrome

Background: Coracoacromial arch, the structure is an important protective factor for shoulder joint from above. Any congenital or acquired factor which reduces subacromial space may result into impingement syndrome. Moreover, the lateral end of coracoacromial ligament may get ossified due to repeated frictional force which can be a precipitating factor for shoulder impingement syndrome. Morphology of acromion is directly related to the shoulder impingement syndrome as recorded by previous authors. Aims and Objectives: Aims and objectives of the present study were to calculate the incidence of different morphological varieties of acromion process of scapula in relation to sex including presence of enthesophytes, which will definitely help radiologists for supraspinatus outlet space evaluation. Materials and Methods: Two hundred scapulae procured from department of anatomy of both sexes. At first, four important measurements were taken, maximum scapular height, maximum scapular breadth, glenoid cavity height, and glenoid cavity breadth. These parameters are used to determine the sex of the scapula. After preliminary separation, types of acromia were recorded following the previousliterature guideline as follows; flat, curved, hooked, and convex undersurface as Type I, II, III, and IV. Results: Type II, curved type acromion is the commonest variety recorded in 42% cases irrespective of sex followed by Type I, flat variety, least common being the Type IV variety. Enthesophytes were present in 17.5% scapulae, more precise finding is enthesophyte that is recorded maximally in male Type II scapulae. Conclusion: Acromion with curved under-surface is most common variety recorded in the present study type. Enthesophytes most commonly recorded in male Type II scapulae, which is a significant finding.