Retrospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Apr 18, 2021; 12(4): 223-233
Published online Apr 18, 2021. doi: 10.5312/wjo.v12.i4.223
Predictors of clinical outcomes after non-operative management of symptomatic full-thickness rotator cuff tears
Christopher Bush, Joel J Gagnier, James Carpenter, Asheesh Bedi, Bruce Miller
Christopher Bush, Joel J Gagnier, James Carpenter, Asheesh Bedi, Bruce Miller, Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI 48106, United States
Author contributions: All authors designed the research study; Carpenter J, Bedi A and Miller B recruited and treated the study patients; Bush C and Gagnier JJ performed the data analysis, Bush C wrote the manuscript; all authors have read, extensively edited and approved the final manuscript.
Institutional review board statement: The study was reviewed and approved by the University of Michigan Institutional Review Board (study No. HUM0024612).
Informed consent statement: Consent was not obtained but the presented data are anonymized and risk of identification is low.
Conflict-of-interest statement: All authors have nothing to disclose.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at
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:
Corresponding author: Christopher Bush, MD, Lecturer, Department of Orthopaedic Surgery, University of Michigan, 24 Frank Lloyd Wright Drive, Lobby A, P.O. Box 391, Ann Arbor, MI 48106, United States.
Received: December 15, 2020
Peer-review started: December 15, 2020
First decision: December 31, 2020
Revised: January 17, 2021
Accepted: March 10, 2021
Article in press: March 10, 2021
Published online: April 18, 2021

Previous studies have shown that non-surgical management can be an effective treatment strategy for many patients with rotator cuff tears. Despite the prevalence of rotator cuff disease, few studies have examined the patient and tear related factors that predict outcomes of nonsurgical management in this cohort of patients.


To identify factors that are associated with changes in patient reported outcomes over time in individuals with full-thickness rotator cuff tears treated without surgery.


A cohort of 59 patients who underwent non-surgical management of full thickness rotator cuff tears with a minimum of 1-year follow-up were identified from our institutional registry. Patient demographics, comorbidities and tear characteristics were collected at initial presentation. Outcome measures were collected at baseline and at each clinical follow-up, which included Western Ontario Rotator Cuff (WORC) index, American Shoulder and Elbow Surgeons score, Visual Analog Scale for pain and Single Assessment Numerical Evaluation. Multi- and univariate regression analyses were used to determine the impact of each patient and tear related variable on final WORC scores and change in WORC scores throughout the study.


In this non-surgical cohort, all patient-reported outcome measures significantly improved compared to baseline at 1 and 2-year follow-up. There was no significant difference in outcomes between 1 and 2 years. The average improvement surpassed the published minimal clinically important differences values for WORC, American Shoulder and Elbow Surgeons, Visual Analog Scale pain and Single Assessment Numerical Evaluation scores. Regression analysis identified female gender (β = - 19.88, P = 0.003), smoking (β = -29.98, P = 0.014) and significant subscapularis fatty infiltration (β = -15.35, P = 0.024) as predictors of less favorable WORC scores at 1 year, and female gender (β = -19.09, P = 0.015) alone as a predictor of lower WORC scores at 2 years. Patients with symptom duration greater than 1 year at presentation reported less improvement in WORC scores at 1-year follow-up (β = -14.63, P = 0.052) and patients with traumatic tears reported greater improvements in WORC scores at 2-year follow-up (β = 17.37, P = 0.031).


Patients with full thickness rotator cuff tears can achieve and maintain clinically meaningful benefit from non-surgical management through 2-year follow-up. Female patients, smokers, and those with significant subscapularis fatty infiltration tend to have lower overall WORC scores at 1-year follow-up, and females also have lower WORC scores at 2-year follow-up. Patients presenting with symptoms greater than 1 year had less clinical improvement at 1-year follow-up, and those with traumatic tears had greater clinical improvement at 2-year follow-up.

Keywords: Rotator cuff tear, Conservative treatment, Patient reported outcome measures, Shoulder injuries, Shoulder pain

Core Tip: This clinical study examines the factors, both patient and tear-related, that predict patient reported outcome measures in a cohort of 59 patients with symptomatic, full-thickness rotator cuff tears who are treated non-surgically. All patients included in this study presented with magnetic resonance imaging scans which were used to measure several important characteristics including tear size, associated fatty infiltration and the supraspinatus tangent sign. Linear regression analyses were performed to determine which factors independently predicted patient reported outcome measures.