In vivo strain analysis of the intact supraspinatus tendon by ultrasound speckles tracking imaging

Abstract

Limited data exist regarding why delaminated tears occur within the rotator cuff tendon, and no general agreement exists on how to handle this complicated tear. To analyze in vivo intratendinous strain of the supraspinatus tendon, the superficial, middle, and deep regions were marked with speckles using 2D speckle tracking echocardiography (2D STE) of 15 shoulders. The displacement and the strain of each speckle during isotonic and isometric shoulder motion were evaluated. Significantly different displacement and strains in the tendon were found between isometric and isotonic shoulder motions. In isometric motion, the average longitudinal displacement of the speckle at the superficial region (1.66 mm) was larger than at the deep region (0.61 mm), and the average peak strain at the superficial region (17.03%) was also higher than that at the deep region (3.42%). Conversely, in isotonic motion, the average longitudinal displacement of the speckle at the superficial region (0.70 mm) was less than that at the deep region (1.61 mm), and the average peak strain at the superficial region (4.73%) was also lower than that at the deep region (15.69%). A different strain was found between the superficial and deep regions within the intact live supraspinatus tendon. The strain and displacement patterns vary according to isometric versus isotonic shoulder motions. On the basis of our observations, we suggest that the delaminated tear of the rotator cuff tendon must be repaired separately layer by layer to resist the inhomogeneous strain after the repair. Keywords: rotator cuff tendon; in vivo; strain; 2D speckle tracking echocardiography; isotonic; isometric Rotator cuff tendon tears represent one of the most common causes of shoulder pain and disability. The tear configuration is variable and includes partialthickness tears, which originate on the articular side, the bursal side, or within the tendon substance, and full-thickness tears. Previous studies suggested that intratendinous delaminated tears occur often, accounting for almost half of all partial-thickness tears. 1,2 Furthermore, many full thickness tears have a delaminated component. However, limited data exist regarding why delaminated tears occur, and no general agreement exists on how to handle this complicated tear.Several studies demonstrated that the biomechanical behavior of the nonlinear response to loading the tendon is related to the tear pattern. 3-7 Different material properties and strain patterns exist between the articular and bursal sides of the supraspinatus tendon. 2,3,[8][9][10][11] showed that the rotator cuff tendon has different histological features in the joint and bursal layers, and the joint side has lower ultimate strain than the bursal side does. Reilly et al. 10 noted, in a cadaver study, a significant difference in strain between the joint and bursal sides of the supraspinatus tendon during glenohumeral abduction. They suggested that the difference may contribute to the propagation of intratendinous delaminated defects. 10 Be...

Which shoulder motions cause subacromial impingement? Evaluating the vertical displacement and peak strain of the coracoacromial ligament by ultrasound speckle tracking imaging

“…1,9,19 Although earlier studies focused on tracking the cardiac organs or blood flow, speckle tracking studies have become widely used to estimate the displacement and strain of tendons or muscles. 12,13,20,22 Stegman et al demonstrated the efficacy and accuracy of 2D STE in estimating the displacement of the flexor digitorum superficialis (FDS) tendon. 22 They assessed the displacement of the FDS tendon using 2D STE at wrist level while a video microscope simultaneously imaged the exposed FDS tendon as a reference for validation during open carpal tunnel surgeries.…”

“…Kim et al assessed not only the displacement but also the strain of the supraspinatus tendon using 2D STE. 12 They evaluated the in vivo strain of the intact supraspinatus tendon during isotonic and isometric shoulder motion. They demonstrated that interobserver and intraobserver reliability for isotonic strain measurement (r ¼ 0.78 and 0.81) was relatively lower than that for isometric strain measurement (r ¼ 0.88 and 0.90).…”

“…1,9,19 This ultrasonographic technique to analyze strain was used in other studies to evaluate strain on the supraspinatus tendon or myocardium. 2,12 We acquired 3 image loops and then analyzed each image 3 times.…”

Ultrasound strain mapping of Achilles tendon compressive strain patterns during dorsiflexion

“…Ultrasound elastography has been primarily utilized to quantify motion along the longitudinal axis of the tendon (Brown, Alsousou, Cooper, Thompson, & Noble, 2013; Farris et al, 2012; Farron, Varghese, & Thelen, 2009; Franz, Slane, Rasske, & Thelen, 2015; Kim, Kim, Bigliani, Kim, & Jung, 2011; Korstanje et al, 2012; Lichtwark & Wilson, 2006; Slane & Thelen, 2015; Yoshii et al, 2011). There is a lack of information on motion along the short axis of the tendon, which may have clinical implications for the treatment of insertional tendinopathies.…”

Ultrasound Elasticity Imaging for Determining the Mechanical Properties of Human Posterior Tibial Tendon: A Cadaveric Study

“…Other clinical applications include assessing contractility and strain deficiencies in the myocardium and quantifying mechanical properties of tissue-engineered implants [26]–[31]. Several recent studies have implemented UEI to quantify the mechanical properties of human skeletal muscle and tendon (electrically stimulated or under load) [4], [32]–[40]. However, none of these studies employed elasticity imaging to quantify differences in tendon mechanical properties associated with degeneration or rehabilitation.…”