The acromial morphology and its implication in impingement syndrome: An anatomical study

Abstract Introduction Resection of acromion in case of impingement syndrome is a controversial issue. It is associated with the risk of instability of humeral head. The aim of our study was to determine the morphometry of acromion so that the decision for arthroscopic resection becomes easier in these cases. The morphometry of acromion was also correlated with other parameters of scapula. Material and methods The study was conducted in sixty one intact dry adult scapulae of unknown sex. Various parametric and nonparametric data from scapulae were taken. Result Type I (flat), Type II (curved) and Type III (hooked) were found in 24.59%, 49.18% and 26.22% scapulae respectively. The average scapular length and breadth were 135.96 ± 11.96 mm and 98.8 ± 7.56 mm respectively. Mean value of length, breath, and thickness of acromian were 41.23 mm, 22.12 mm and 7.01 mm respectively. The thickness of acromion was less than 8 mm in 86.67% of scapulae. In 13.33% cases the thickness was >8 mm. A statistically significant positive correlation was also found between the length of acromion and the length and breadth of scapula. Discussion Our study may suggest that in Indian population, 13.33% population is at risk of impingement syndrome according to the thickness of acromion. In addition, angles of acromion tilt and acromion slope are larger in Indian scapulae as compare to that of other countries. This knowledge would be useful for orthopaedic surgeons and radiologists.