Case Control Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Apr 18, 2020; 11(4): 206-212
Published online Apr 18, 2020. doi: 10.5312/wjo.v11.i4.206
Role of shoulder gradient in the pathogenesis of rotator cuff tears
Amir Sobhani Eraghi, Mikaiel Hajializade, Ehsan Shekarchizadeh, Shadi Abdollahi Kordkandi
Amir Sobhani Eraghi, Mikaiel Hajializade, Ehsan Shekarchizadeh, Shadi Abdollahi Kordkandi, Department of Orthopedics, Rasul-e Akram Hospital, Iran University of Medical Sciences, Tehran 1445613131, Iran
Author contributions: Sobhani Eraghi A ‎designed research; Hajializade M and Abdollahi Kordkandi S and Shekarchizadeh E performed research; Shekarchizadeh E analyzed data; Hajializade‎ M and Sobhani Eraghi A wrote the paper.
Institutional review board statement: ‎This study was reviewed and approved by the Ethics Committee of Iran University of Medical Sciences under code of IR.IUMS.FMD.REC 1396.9423715006
Informed consent statement: The patients provided written consent before participation in the ‎study.‎
Conflict-of-interest statement: The authors of this article declare no conflict of interest to disclose.
Data sharing statement: All data requests should be submitted to the corresponding author for consideration. Access to anonymised data may be granted following review.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Mikaiel Hajializade, MD, Orthopedic Resident, Department of Orthopedics, Rasul-e Akram Hospital, Iran University of Medical Sciences, Satarkhan St., Tehran 1445613131, Iran. michaelalizadeh@gmail.com
Received: September 17, 2019
Peer-review started: September 17, 2019
First decision: December 23, 2019
Revised: January 15, 2020
Accepted: February 8, 2020
Article in press: February 8, 2020
Published online: April 18, 2020
ARTICLE HIGHLIGHTS
Research background

Rotator cuff tear (RCT) is referred to the injury of one or more of the tendons or muscles of the rotator cuff and is known as one of the most common causes of shoulder pain and disability among the adult population.‎ Identification of risk factors, which predisposes the incidence of RCT, is of considerable importance in the prevention of such ‎injuries.‎

Research motivation

Earlier investigations have revealed an association between shoulder gradient and shoulder pathologies, such as shoulder impingement syndrome. We hypothesized that the shoulder gradient might also predispose the occurrence of RCT.

Research objectives

In this study, we evaluated the association between the shoulder gradient and RCT incidence to find whether the shoulder gradient could be regarded as a risk factor for RCT or not.

Research methods

Sixty-one patients with a confirmed diagnosis of RCT were identified as eligible for the study. On the anteroposterior radiograph of the shoulder, we evaluated the gradient of both shoulders in ‎adduction and neutral rotation positions. The ‎gradient difference between affected and unaffected shoulders was also calculated.

Research results

The mean shoulder gradient was 14.11º ± 2.65º for the affected shoulder and 15.8º ± 2.2º for the ‎unaffected shoulders. Based on these results, a gradient difference of 1.15º ± 1.82º was found between the injured ‎and non-injured shoulders. This difference was not statistically significant (P = 0.41).‎ The shoulder gradient was not correlated with the pain level of the patients (r = 0.109, P = 0.071), as well as with ‎ other clinical and demographic characteristics of ‎the patients.‎

Research conclusions

Based on the results of this study, there is no association between the shoulder gradient and incidence of RCT. Moreover, the shoulder gradient is not associated with the pain level of RCT patients.

Research perspectives

Future large-scale studies allowing the elimination of confounding factors in a multivariate analysis will shed more light on the role of shoulder gradient in the incidence of RCT.