Bilateral comparison of intramuscular rotator cuff fat and atrophy in rotator cuff tears

• Grant number: 18/24019-6
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: April 01, 2019
• End date: July 25, 2019
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Paula Rezende Camargo
• Grantee: Gustavo Ricci Noés
• Supervisor: Amee Seitz
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Institution abroad: Northwestern University, Chicago, United States
• Associated to the scholarship: 18/07104-0 - Description of the painful arc and the lesions of the muscles supraspinatus and infraspinatus in individuals with the clinical picture of subacromial impingement syndrome, BP.IC

Abstract

Objective. Intramuscular fat infiltration is the greatest predictor of surgical outcomes in patients with a rotator cuff tear. Individual factors, such as age, BMI, have been shown to confound quantitative assessment of intramuscular fat infiltration. Yet rarely are these factors considered when evaluating patients with rotator cuff tears. Therefore, the true effect of small-medium rotator cuff tears on intramuscular fat infiltration and atrophy remain unknown. The purpose of this study is to evaluate the effects of rotator cuff pathology on intramuscular fat and atrophy controlling for individual confounders by normalizing to the same muscle in the uninvolved shoulder.Methods. Bilateral magnetic resonance images (MRI) including a specialized Dixon multi-echo fat-water sequence, were captured in 3 groups of subjects: healthy controls (n=11), individuals with unilateral RC tendinopathy (n=10), and individuals with unilateral rotator cuff tear (n=6 to date; enrolling 10 total). The Dixon fat-water sequences will be used to quantify rotator cuff intramuscular fat (%fat) and muscle volume of both shoulders in all subjects. A ratio of the %fat and muscle volume of the involved/ non-dominant shoulder to uninvolved /dominant shoulder will be calculated and used for group comparison. An ANOVA will be used to determine differences in fat infiltration and atrophy ratios in the rotator cuff between groups with significance set at a ±<0.05. (AU)