Extensibility of Rotator Cuff Muscle with Tendon Rupture Determined Using SWE

  • An, Kai-Nan (PI)

Project: Research project

Project Details


Rotator cuff tears are the most common cause of shoulder pain and related disability. Likelihood of
injury increases dramatically with advancing age. Over time following injury, the tendon retracts,
leaving a large defect. However, not only is the tissue gap a problem, but also the nature of the
muscle changes, with an end result of decreased compliance and increased stiffness. Though it is
clear that the tension required for repair increases with time after injury, there is much individual
variation. Thus, it is critical to have an individualized pre-surgical prediction of extensibility of rotator
cuff muscles assist in pre-surgical planning and monitoring of recovery throughout the rehabilitation
process. Our long-term goal is to develop a non-invasive tool for acquiring such information to
improve the planning, and thus, the outcome of treatment. The purpose of this study is to initiate the
development by adopting a novel technology, namely, Shear Wave Elastography (SWE). The SWE
provides quantitative in vivo measurements of tissue stiffness and viscosity by evaluating shear wave
propagation speed, which is inherently related to tissue mechanical properties. We propose this
unique and innovative approach which combines b-mode ultrasound imaging (to assess muscle
geometric and morphological properties) with SWE (to assess muscle material properties) to quantify
muscle structural properties which will then be used to predict the extensibility of rotator cuff muscles
(typically supraspinatus muscle). The objective of this study will be accomplished in the following
three specific aims using cadaver shoulder specimens in vitro: Specific Aim 1: To obtain the material
and geometric properties of the supraspinatus muscles using SWE and b-mode ultrasound imaging,
respectively. Specific Aim 2: To measure muscle extensibility and structural properties of the
supraspinatus muscles through mechanical testing. Specific Aim 3: To establish the relationship
between structural stiffness of in vitro supraspinatus muscles (measured in Specific Aim 2) with
muscle modulus measured with SWE and geometric/morphological properties based on b-mode
imaging (measurements in aim 1) via regression analyses. The contribution will be significant
because it will provide a necessary, non-invasive assessment of whole-tissue extensibility that will
directly aid in prognosis, pre-surgical planning, and post-surgical evaluation of rotator cuff repair, one
of the most common and challenging procedures in orthopedics.
Effective start/end date7/1/146/30/16


  • National Institutes of Health: $174,900.00
  • National Institutes of Health: $209,880.00


  • Medicine(all)


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