Morphological Analysis of Glenoid Cavity of Scapula in Bihar Population

Background: The glenoid cavity of the scapula forms the socket component of the shoulder joint and is a critical anatomical structure for maintaining shoulder stability and function. Variations in its shape, size, and orientation are of immense clinical importance, particularly in shoulder dislocation, arthroplasty, and rotator cuff injuries. Precise morphometric data on the glenoid cavity can assist orthopedic surgeons and anatomists in better understanding joint biomechanics and designing prosthetic components. However, population-based variations are known to exist, and limited data is available for the Bihar region. Objectives: • To determine the shape of the glenoid cavity in dry human scapulae from Bihar. • To record morphometric parameters such as superoinferior diameter, anteroposterior diameters (at upper and lower halves), and glenoid cavity index. • To classify the shapes based on standard anatomical classification and correlate findings with similar Indian and international studies. Materials and Methods: This cross-sectional osteological study was conducted in the Department of Anatomy, Anugrah Narayan Magadh Medical College, Gaya, Bihar. A total of 100 adult human dry scapulae (50 right and 50 left) were included. Damaged or deformed specimens were excluded. Parameters measured included superoinferior diameter (SI), anteroposterior diameter at upper and lower halves (AP1 and AP2), and glenoid cavity index (GCI). The shape of the glenoid cavity was classified into pear-shaped, oval, or inverted commashaped based on anatomical landmarks. Data were statistically analyzed for side-wise comparison and variation patterns. Results: The most common shape observed was the pear shape (45%), followed by oval (33%) and inverted comma (22%). The mean superoinferior diameter was 36.8 mm on the right and 37.2 mm on the left. The mean AP diameters were 24.6 mm (upper) and 26.8 mm (lower). The mean glenoid cavity index was 67.1% on the right and 68.5% on the left. No statistically significant difference was found between the sides. Conclusion: This study confirms that glenoid cavity morphology in the Bihar population is predominantly pearshaped, with measurements aligning closely with other Indian populations. The data provide a valuable reference for orthopedic and reconstructive shoulder surgeries and emphasize the need for population-specific anatomical databases to guide clinical decision-making.