Changes in elbow joint contact area in symptomatic valgus instability of the elbow in baseball players

Kyosuke Numaguchi,Daisuke Momma,Norimasa Iwasaki,Nozomu Inoue,Yuki Matsui,Takayoshi Yamaguchi,Jun Oohinata,Eiji Kondo

doi:10.1038/s41598-021-99193-0

Kyosuke Numaguchi, Daisuke Momma + Show 6 more

Open Access

https://doi.org/10.1038/s41598-021-99193-0

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Abstract

The aim of this study was to evaluate the joint contact area of the dominant side and that of the non-dominant side without valgus instability in symptomatic pitchers. Ten symptomatic elbow medial ulnar collateral ligament (UCL) deficient baseball pitchers participated in this study. Computed tomography (CT) data from the dominant and non-dominant elbows were obtained with and without elbow valgus stress. The CT imaging data of each elbow joint were reconstructed using a 3D reconstruction software package, and the radiocapitellar and ulnohumeral joint contact areas were calculated. The center of the contact area and the translation from the position without stress to the position with valgus stress were also calculated. With elbow valgus stress, the contact area changed, and the center of the radiocapitellar joint contact area translated significantly more laterally in the dominant elbow than in the non-dominant elbow (p = 0.0361). In addition, the center of the ulnohumeral joint contact area translated significantly more posteriorly in the dominant elbow than in the non-dominant elbow (p = 0.0413). These changes in contact areas could be the reason for cartilage injury at the posterior trochlea in pitchers with UCL deficiency.

Highlights

The aim of this study was to evaluate the joint contact area of the dominant side and that of the non-dominant side without valgus instability in symptomatic pitchers
There was a trend towards increased contact area of the radiocapitellar joint with elbow valgus stress (263.1 ± 40.2 mm2) compared to without valgus stress (230.3 ± 32.7 mm2) on the non-dominant side (p = 0.0735), but, no difference was found on the dominant side between with valgus stress (240.6 ± 35.0 mm2) and without valgus stress (227.9 ± 60.0 mm[2], p = 0.5901) (Table 2, Fig. 1)
There were no significant differences in the mean contact area of the radiocapitellar joint between the dominant and non-dominant sides with and without valgus stress (p = 0.2201 and p = 0.9152, respectively)

Summary

Introduction

The aim of this study was to evaluate the joint contact area of the dominant side and that of the non-dominant side without valgus instability in symptomatic pitchers. The contact area changed, and the center of the radiocapitellar joint contact area translated significantly more laterally in the dominant elbow than in the non-dominant elbow (p = 0.0361). The center of the ulnohumeral joint contact area translated significantly more posteriorly in the dominant elbow than in the non-dominant elbow (p = 0.0413). These changes in contact areas could be the reason for cartilage injury at the posterior trochlea in pitchers with UCL deficiency. The aims of this study were (1) to evaluate the contact area across the elbow joint in symptomatic pitchers with UCL deficiency and (2) to clarify the changes in the contact area with and without elbow valgus stress

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