title: Quantitative assessment of rotator cuff muscle elasticity: Reliability and feasibility of shear wave elastography.
abstract: Ultrasound imaging has been used to evaluate various shoulder pathologies, whereas, quantification of the rotator cuff muscle stiffness using shear wave elastography (SWE) has not been verified. The purpose of this study was to investigate the reliability and feasibility of SWE measurements for the quantification of supraspinatus (SSP) muscle elasticity. Thirty cadaveric shoulders (18 intact and 12 with torn rotator cuff) were used. Intra- and inter-observer reliability was evaluated on an established SWE technique for measuring the SSP muscle elasticity. To assess the effect of overlying soft tissues above the SSP muscle, SWE values were measured with the transducer placed on the skin, on the subcutaneous fat after removing the skin, on the trapezius muscle after removing the subcutaneous fat, and directly on the SSP muscle. In addition, SWE measurements on 4 shoulder positions (0°, 30°, 60°, and 90° abduction) were compared in those with/without rotator cuff tears. Intra- and inter-observer reliability of SWE measurements were excellent for all regions in SSP muscle. Also, removing the overlying soft tissue showed no significant difference on SWE values measured in the SSP muscle. The SSP muscle with 0° abduction showed large SWE values, whereas, shoulders with large-massive tear showed smaller variation throughout the adduction-abduction positions. SWE is a reliable and feasible tool for quantitatively assessing the SSP muscle elasticity. This study also presented SWE measurements on the SSP muscle under various shoulder abduction positions which might help characterize patterns in accordance to the size of rotator cuff tears.
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN, United States.
authors.forename: Taku
authors.initials: T
authors.lastname: Hatta
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN, United States.
authors.forename: Hugo
authors.initials: H
authors.lastname: Giambini
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN, United States.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Uehara
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN, United States.
authors.forename: Seiji
authors.initials: S
authors.lastname: Okamoto
authors.affiliation: Department of Physiology and Biomedical Engineering, College of Medicine, Mayo Clinic, Rochester, MN, United States.
authors.forename: Shigao
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, United States.
authors.forename: John W
authors.initials: JW
authors.lastname: Sperling
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Itoi
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN, United States. Electronic address: an.kainan@mayo.edu.
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D004548:Elasticity; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009142:Musculoskeletal Physiological Phenomena; D015203:Reproducibility of Results; D017006:Rotator Cuff / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012421:Rupture / Q000503:physiopathology; D012782:Shoulder
keywords: Feasibility; Muscle elasticity; Reliability; Shear wave elastography; Supraspinatus muscle