Ultrasound Shear Wave Elastography of the Elbow Ulnar Collateral Ligament: Reliability Test and a Preliminary Case Study in a Baseball Pitcher

Abstract

Overhead throwing athletes are at high risk of the elbow ulnar collateral ligament (UCL) injury, and there is a need for clinical tools to objectively diagnose severity of injury and monitor recovery. Mechanical properties of ligaments can potentially be used as biomarkers of UCL health. The objectives of this study are to evaluate the reliability of shear wave ultrasound elastography (SWE) for quantifying UCL shear modulus in 16 healthy nonthrowing individuals and use this technique to evaluate the difference in UCL shear modulus between the injured and uninjured elbows in a baseball pitcher with UCL tear. In the reliability test, the UCL shear modulus of both elbows of each participant was evaluated by SWE for five trials. The same procedures were repeated on two different days. The intra-day and day-to-day reliabilities were determined by the five measurements on the first day and two averages on the two days, respectively. In the case study, each elbow of the baseball pitcher with UCL tear was tested for five trials, and the average was calculated. The intra-day (intraclass correlation coefficient (ICC) = 0.715, Cronbach's alpha = 0.926) and day-to-day (ICC = 0.948, Cronbach's alpha = 0.955) reliabilities were found to be good. There was no difference between both sides. In the case study, the UCL shear modulus of the injured elbow (186.45 kPa) was much lower than that of the uninjured elbow (879.59 kPa). This study shows that SWE could be a reliable tool for quantifying the mechanical properties and health status of the UCL.

Elasticity assessment of flexor pronator muscles using shear wave elastography

“… 2 SWE has been reported to be a more accurate diagnostic tool than conventional strain elastography due to its improved reproducibility and quantification of muscle elasticity. 23 Previous studies have reported the use of SWE in assessing the tissue elasticity of the UCL of the elbow 13 , 21 ; however, this modality has rarely been applied to the assessment of FPMs. Therefore, our new method for evaluating the muscle stiffness of FPMs using SWE might contribute to the assessment of baseball players with a UCL injury.…”

“…Shear wave elastography (SWE) has been used as a quantitative ultrasound (US) technique to assess muscle stiffness by evaluating shear wave propagation speed. 10 , 20 , 32 Although SWE has been frequently used for quantitative evaluations of the UCL, 13 , 21 no studies have used this technique to assess the mechanical stiffness of FPMs.…”

Identifying Differences in Elastographic Properties of Calf Muscles and Tendons Across Subsets of Tennis Players

“…A customized supersonic shear wave elastography (SWE) method was used to measure shear modulus within lower leg muscles (11). The technique was validated using calibrated homogeneous elasticity phantom having various shear modulus values (Model 040GSE, CIRS, Norfolk, Virginia, USA) as well as other musculoskeletal tissues with the intraday and day-to-day reliability of 0.72 (95% Confidence Interval (CI) = 0.59-0.83) and (0.95 with 95% CI = 0.88-0.98), respectively (12). The ROI size of 7.39 mm × 7.39 mm was selected for the measurement of lower leg shear modulus in the gastrocnemius and soleus muscles, while the ROI height for the Achilles tendon measurements was adjusted to include just the tendon (ROI size = Tendon thickness × 7.39 mm) (13).…”

Shear wave elastography of the ulnar collateral ligament in division IA pitchers across a competitive collegiate season

“… 17 Only one prior report exists to our knowledge where SWE was used to assess the UCL in elite throwing athletes. 22 That report included 1 collegiate baseball pitcher with a ruptured UCL and found the SWV was 79% lower in the injured UCL compared to the contralateral UCL. The present study further investigates the utility of SWE in assessing the UCL of elite overhead throwing athletes.…”