Dimensional Analysis of Intertubercular Sulcus in Adult Dry Humeri: A Cross-sectional Study

Introduction: Intertubercular Sulcus (ITS) is a depression in the superior end of humerus, located between the greater tubercle and lesser tubercle. It lodges the Long Head of Biceps Brachii Tendon (LHBT) and ascending branch of circumflex humeral artery. The dimensions of the ITS play a key role in the biomechanics of LHBT and are associated with complications of the shoulder region. Aim: To analyse the dimensions and associated parameters of ITS of humerus. Materials and Methods: This cross-sectional study was conducted in the Department of Anatomy at Dr. Chandramma Dayananda Sagar Institute of Medical Education and Research (CDSIMER), Dayananda Sagar University, Harohalli, Karnataka, India. A total of 80 humeri (47 right-sided and 33 left-sided) were included in the study. Morphometric parameters such as length, width, depth, medial wall length, lateral wall length, and incidence of supratubercular ridge of Meyer were noted. The mean and standard deviation for each independent variable were calculated, and t-test was used to compare the same for right and left-sides. A p-value of <0.05 was considered statistically significant. Results: The mean±SD for length, width, depth, medial wall length, and lateral wall length (in mm) were observed to be 68.5±7.6, 6.4±1.1, 4.8±0.9, 61.4±6.9, and 73.3±7.3 on the right- side, and 65.1±7.6, 6.02±1.2, 4.7±0.9, 57.9±7.3, and 69.7±8.3 on the left-side, respectively. The mean±SD for the medial and opening angles on the right and left-sides were found as 46.7°±5.9, 64.7°±8.31 and 47.4°±5.6, 62.1°±6.1, respectively. The incidence of the supratubercular ridge of Meyer was observed to be 25% on the right-side and 9% on the left-side. Conclusion: The ITS serves as an important anatomical landmark for aligning prostheses in shoulder arthroplasty. Understanding the dimensional variations is crucial for comprehending the functional nature of the shoulder region.