Morphometric Analysis of Ulnar Variance and Its Demographic Dynamics Using High Resolution MRI: A Retrospective Study in Indian Population and Review of Literature.

Abstract

Ulnar variance (UV) is the variation of the level of the distal articulating surface of the radius with respect to the distal articulating surface of the ulna. These variations either positive or negative can predispose to pathologies involving the wrist joint. The aim of this study was to measure the ulnar variance in a subset of Indian population using high-resolution MRI and compare our results with the existing literature. Retrospective analysis of 100 normal wrist MRIs were done performed during November 2020 to November 2021 and the ulnar variance was calculated using the Method of Perpendiculars. All the MRI sequences were performed by an experienced radiologist with prior fixed protocol for the study. The measurements were done on the mid-coronal section based on the Method of Perpendiculars using Meddiff Rispacs software. The average age of the participants was 42years, with Male to female ratio of 0.9:1. 47 MRIs were of the left wrist, while 53 MRIs were of the right wrist. The mean UV was -0.7mm (SD-0.175), ranging from -4.5mm to 3.5mm. There was a significant relationship between ulnar-variance and age, as ulnar-variance increases with the age (p value = 0.039). There was no statistically significant correlation of ulnar-variance with gender distribution and handedness. This study utilized high-resolution MRI for measuring ulnar-variance in a subset of Indian population and disclosed that the ulnar-variance affirms a positive correlation with age, while no specific pattern between the ulnar-variance and gender or handedness could be established.