Retrospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. May 18, 2021; 12(5): 301-309
Published online May 18, 2021. doi: 10.5312/wjo.v12.i5.301
Usefulness of computed tomography based three-dimensional reconstructions to assess the critical shoulder angle
Dominic Mah, Uphar Chamoli, Geoffrey CS Smith
Dominic Mah, Faculty of Medicine, University of New South Wales, Sydney 2052, New South Wales, Australia
Uphar Chamoli, Spine Service Research Group, St. George and Sutherland Clinical School, University of New South Wales, Sydney 2052, New South Wales, Australia
Uphar Chamoli, School of Biomedical Engineering, University of Technology Sydney, Sydney 2007, New South Wales, Australia
Geoffrey CS Smith, St. George and Sutherland Clinical School, Faculty of Medicine, University of New South Wales, Sydney 2217, New South Wales, Australia
Geoffrey CS Smith, Department of Orthopaedics, St. George Hospital, Sydney 2217, New South Wales, Australia
Author contributions: Mah D designed and performed the research, and wrote the paper; Chamoli U designed the research, and contributed to the analysis; Smith GCS designed and performed the research, and supervised the report.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the University of New South Wales.
Informed consent statement: The private patients of Dr Geoffrey Smith sign a consent form for their deidentified radiographic imaging data and intra-operative images to be used for teaching, medical education and research purposes (including computer modelling).
Conflict-of-interest statement: We have no financial relationships to disclose.
Data sharing statement: No additional data are available.
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: Geoffrey CS Smith, FRCS, MBChB, Surgeon, St. George and Sutherland Clinical School, Faculty of Medicine, University of New South Wales, Sydney 2217, New South Wales, Australia. gcssmith@icloud.com
Received: January 9, 2021
Peer-review started: January 9, 2021
First decision: January 18, 2021
Revised: January 28, 2021
Accepted: March 8, 2021
Article in press: March 8, 2021
Published online: May 18, 2021
ARTICLE HIGHLIGHTS
Research background

The critical shoulder angle (CSA) is a radiological measure that assesses both glenoid inclination and acromial length, with higher values being associated with rotator cuff (RC) tears.

Research motivation

It is difficult to obtain a high-quality true anteroposterior (AP) radiograph of the shoulder, with any excess scapular version or flexion/extension resulting in deviation from the true CSA value. This may be overcome by using three-dimensional (3D) bony reconstructions from computed tomography (CT) shoulder scans, which can be rotated to replicate an ideal true AP view.

Research objectives

This study aimed to evaluate CSA measurements performed on 3D bony reconstructions of shoulder CT scans.

Research methods

CSA measurements were performed on 3D bony reconstructions of shoulder CT scans and corresponding true AP radiographs. Measurements were performed by two observers, on two separate occasions.

Research results

There was a strong positive correlation between the two methods. Better intra-observer and inter-observer reliability was seen when using the 3D bony CT reconstructions to measure the CSA.

Research conclusions

The use of 3D bony reconstructions from CT shoulder scans may offer a viable alternative to plain radiographs in the measurement of the CSA.

Research perspectives

Future research should consider the use of 3D CT bony reconstructions in the preoperative evaluation of RC tears, particularly in the consideration of lateral acromioplasty as an adjunct to RC repair.