A morphometric study of spinoglenoid notch, subcoracoacromial arch, and spinous process of the scapula on shoulder impingement

Introduction: Morphometric study of spinoglenoid notch, coracoacromial arch, and another measurement of the scapulae are required to understand the reason for spasms of common muscle due to supraspinatus tendinitis, nerve compression over the spinoglenoid notch. Therefore, the aim of this study was to discuss the subcoracoacromial arch, deviation of the spinous process, and measurement of the spinoglenoid notch. Materials and Methods: This study was conducted at the Department of Anatomy, Sri Venkateshwaraa Medical College Hospital & Research Centre, Chennai, Tamil Nadu, India on 70 scapulae that include 58 non-articulated scapulae and 12 articulated scapulae. All the measurements were performed with a vernier caliper and the alignment of the spinous process of the scapula was measured with a goniometer. All the measurements are compared on both sides. Results: All the measurements were performed and presented as mean with standard deviation. We found the variation of diameter between the left and right sides. Spinoglenoid notch diameters were noted as anterior to posterior right 2.97 ± 0.37 cm, left 3.06 ± 0.56 cm and medial to lateral right 1.36 ± 0.14 cm, left 1.4 ± 0.08 cm. Subcoracoacromial arch was observed as right 1.85 ± 0.23 cm and left 1.92 ± 0.4 cm. The direction of the spinous process of the scapula was noted as right 21.50º ± 8.50 and left 18.8º ± 7.89. Conclusion: The present morphometric study findings may give a different approach to supraspinatous tendinits, shoulder instability, and dislocation cases due to morphometric changes present in the spinous process, acromion process, glenoid cavity, and spinoglenoid notch of the scapula. These morphometric studies on scapula can help radiologists, orthopedicians, and physiotherapists to plan patient management.