Morphometric Study on the Coracoacromial Arch, the Acromial Articular Surface, and the Glenoid Cavit of the Scapula in Koreans

The present study was performed to provide an anatomical basis of the coracoacromial (CA) arch and the articular surfaces of the scapula which can be applied to the diagnosis and treatment of some common shoulder problems. The standard dimensions and the range of variation of the CA arch, the acromial articular surface and the glenoid cavity were investigated in 114 dry scapulae obtained from 57 (male, 35 ; female, 22) Korean cadavers ranging in age from 18 to 97 years (average age of 67). The results were as follows : 1. The length (46.3mm), width(25.2mm), thickness (8.2mm) and height (4.5mm) of the acromion were measured. The length, width and thickness were significantly larger in the males. The slope of the acromion was 51.5°, and the slope of the scapular spine was 118.5°. 2. The height (13.5mm), slope of the root (138.4°) and the horizontal part (25.3°) of the coracoid process, and the angle between the root and the horizontal part (106.6°) were measured. There were no significant differences between sexes and sides in all morphometric values related to the coracoid process. 3. The length (67.6mm) and height (24.7mm) of the CA arch, the height of the CA ligament from the supraglenoid tubercle (13.1mm), and length of the CA ligament (27.6mm) were measured. Both the length and height of the CA arch and the length of the CA ligament were significantly larger in the males. The slope and anterior and posterior angles of the CA arch were 16.8°, 42.2°, and 34.7°, respectively. 4. The long (13.8mm) and short (8.0mm) diameters of the acromial articular surface were measured, and both diameters were significantly longer in the males. The acromial articular surface was 8.4mm away from the tip of the acromion and extended 1.4mm inferiorly below the inferior surface of the acromion. 5. The long (34.8mm) diameter, and superior (15.0mm), middle (19.5mm), and inferior (25.6mm) short diameters of the glenoid cavity were measured. The long and both superior and inferior short diameters were significantly longer in the males.