Supraspinatus tendon micromorphology in individuals with subacromial pain syndrome

Authors

Federico Pozzi, Division of Biokinesiology and Physical Therapy, University of Southern CaliforniaFollow
Amee L. Seitz, Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine Northwestern University
Hillary A. Plummer, Division of Biokinesiology and Physical Therapy, University of Southern California
Kira Chow, Department of Radiology, West Los Angeles Veterans Administration Medical Center & Department of Radiology, David Geffen UCLA School of Medicine
Gregory R. Bashford, Department of Biological Systems Engineering, University of NebraskaFollow
Lori A. Michener, Division of Biokinesiology and Physical Therapy, University of Southern California

Date of this Version

5-11-2017

Citation

2017 Hanley & Belfus, an imprint of Elsevier Inc. All rights reserved.

Comments

Biological Systems Engineering

Abstract

Study Design: Cross-sectional cohort. Introduction: Tendon collagen organization can be estimated by peak spatial frequency radius (PSFR) on ultrasound images. Characterizing PSFR can define the contribution of collagen disruption to shoulder symptoms.

Purpose of the Study: The purpose of this was to characterize the (1) supraspinatus tendon PSFR in participants with sub acromial pain syndrome (SPS) and healthy controls; (2) PSFR between participants grouped on a tendon visual quality score; and (3) relationship between PSFR with patient-reported pain, function, and shoulder strength.

Methods: Participants with SPS (n ¼ 20) and age, sex, and arm-dominance matched healthy controls (n ¼ 20) completed strength testing in scaption and external rotation, and patient-reported pain, and functional outcomes. Supraspinatus tendon ultrasound images were acquired, and PSFR was calculated for a region of interest 15 mm medial to the supraspinatus footprint. PSFR was compared between groups using an independent t-test and an analysis of variance to compare between 3 groups for visually qualitatively rated tendon abnormalities. Relationships between PSFR with pain, function, and strength were assessed using Pearson correlation coefficient.

Results: Supraspinatus tendon PSFR was not different between groups (P ¼ .190) or tendon qualitative ratings (P ¼ .556). No relationship was found between PSFR and pain, functional loss, and strength (P > .05).

Conclusions: Collagen disruption (PSFR) measured via ultrasound images of the supraspinatus tendon was not different between participants with SPS or in those with visually rated tendon defects. PSFR is not related to shoulder pain, function, and strength, suggesting that supraspinatus tendon collagen disorganization may not be a contributing factor to shoulder SPS. However, collagen disruption may not be isolated to a single region of interest.

Level of Evidence: 3b: case-control study.