Morphologic and Morphometric Study of Human Acetabulum and its Clinical Significance

Abstract

Introduction: The acetabulum is a cup shaped hemispherical depression which is present on the hip bone, contributed by ilium, ischium and pubis. It has a central depressed non-articular part called acetabular fossa, surrounded by a curved lunate articular surface which articulates with the head of femur to form hip joint. The knowledge of acetabular dimensions assists the radiologists in diagnosing acetabular dysplasia and aids the surgeon to determine the correct size of the acetabular cup during total hip arthroplasty and to realign the acetabulum back to normal position. Aim: To measure and analyse the relationship between the depth and diameter of acetabulum and also to study the variations in the morphology of anterior acetabular ridge. Materials and Methods: A cross-sectional study was done on 104 unpaired dry human adult hip bones from February 2017 to September 2019 after obtaining ethical clearance. The diameter and depth of acetabulum was measured using vernier calliper and a metallic strip and correlation between them were analysed using Pearson’s test. Student’s t-test was used to test the significance between the variables. The p-value <0.05 were considered as statistically significant. The different shapes of anterior acetabular ridge were noted. All the recorded data were analysed using Statistical Package for the Social Sciences (SPSS version 16.0). Results: The average measurements of acetabular diameter and depth were 48.98±2.91 mm and 24.12±2.54 mm, respectively. A positive and a significant correlation was found between diameter and depth of the acetabulum (r=0.388, p<0.001). The mean values of diameter and depth of acetabulum in right side were 48.76±2.94 mm and 23.6±2.48 mm, respectively. The average values of diameter and depth in left side were 49.2±2.92 mm and 24.6±2.59 mm, respectively. Though the measurements of acetabular dimensions on left side were slightly greater than right side, they were not statistically significant (p>0.05). Four different shapes of anterior acetabular ridges were noted: angular (23.08%), curved (63.46%), straight (2.88%) and irregular (10.58%). Conclusion: The present study showed weakly positive correlation between diameter and depth of the acetabulum and morphological variations in the shape of anterior acetabular ridge.