Radial head volume measurements using quantitative three-dimensional computed tomography images for radial head deformation following missed Monteggia lesions

Abstract

<h2>Abstract</h2><h3>Introduction</h3> In chronic radial head dislocation, the radial head may enlarge and become dome-shaped. To date there is no validated tool to quantify radial head deformation and predict its influence on surgical outcome. This study assesses the potential value of volume and surface calculations obtained by quantitative three dimensional CT scanning (Q3DCT) in the workup for corrective surgery in pediatric patients with missed Monteggia lesions. <h3>Material and methods</h3> Ten consecutive pediatric patients with a missed Monteggia lesion were included (2012-2020). The volume and the articular surface size of the radial head were calculated using Q3DCT and a three dimensional reconstruction of the articular surface relief was depicted in a heat map. The head/neck ratio was calculated and compared to Q3DCT data of missed Monteggia patients and their age/sex matched controls. <h3>Results</h3> The radial head volume and radial articular surface size did not differ significantly between patients with missed Monteggia lesions and age/sex matched controls (volume 1487 mm³ versus 1163 mm³, p=0,32; articular surface size 282 mm³ versus 236 mm³ ,p=0,33). Optically, heat maps of the articular surface of missed Monteggia patients did not differ notably from control heat maps.. A higher head/neck ratio correlated to a larger radial head volume (Pearson r=0,73; p=0,02). <h3>Discussion and conclusion</h3> Q3DCT may be an interesting tool in the preoperative workup of pediatric missed Monteggia lesions. Prospective research with larger cohort sizes and data that compares the affected side to the contralateral elbow is needed to assess its true clinical potential.