Morphology and Morphometry of the Acromion Process in Dried Adult Vietnamese Human Scapulae

Introduction The shape and thickness of the acromion process are associated with the shoulder impingement syndrome (SIS), which is characterized by chronic pain and limited shoulder joint movement range. Specific morphological features of the acromion, including Bigliani type (hooked shape), increased thickness, and a reduced acromion-glenoid distance, are clinically associated with an increased risk of SIS. Thus, orthopaedic doctors and researchers need to understand the morphometry of the acromion process. Aims and objectives This study aims to investigate the morphology (shape and type classifications) and morphometry (length, breadth, thickness, and acromioglenoid distances) of the acromion process in dried adult Vietnamese human scapulae. Materials and methods This was a cross-sectional study. The study analyzed the morphology of the acromion process. The study measured the maximum length, breadth, thickness, acromio-coracoid distance, and acromio-glenoid distance. Results In the study, the most common shape of the acromion was the tubular shape. The thickness of the acromion process on the left and right sides was found not to be of significance (p > 0.05). The maximum length of the left and right acromion processes had an average value of 42.40 ± 6.50 mm and 43.62 ± 6.83 mm, respectively. In acromion breadth, the left side was 26.04 ± 6.44 mm, and 26.15 ± 6.75 was the average value of the right side. The acromio-coracoid distance was 37.77 ± 6.33 mm on the left and 35.60 ± 7.26 mm on the right side. The left and right acromio-glenoid distance was measured at 41.58 ± 7.12 mm and 40.43 ± 6.69 mm, respectively, with no statistically significant differences between the left and right sides for any parameters (p > 0.05) Conclusions The morphometric data provided - specifically, the dominance of the tubular shape and the mean acromial thickness of 6 mm - serve as a baseline for Vietnamese patients to prevent over-resection during acromioplasty, which can compromise the deltoid origin. Furthermore, the acromio-coracoid and acromio-glenoid distances provide surgeons with precise landmarks to identify pathological narrowing (<15 mm) of the subacromial space, facilitating more accurate decompression.