Shear wave ultrasound elastography of the shoulder joint tendons

Abstract

Background: The assessment of tissue elasticity in clinical practice has not been well established. Shear wave ultrasound elastography is a recent technique which quantitatively estimates tissue elasticity. This study, therefore, aimed to assess the biomechanics of the rotator cuff and biceps tendons of the shoulder joint in asymptomatic participants, in order to establish a reference range for use in clinical practice. The objectives of this study were to measure the elasticity of the rotator cuff and biceps tendons (in kilopascals), using shear wave ultrasound elastography and to establish a shear wave ultrasound elastographic reference range of the rotator cuff and biceps tendons for use in clinical practice. Methods: This quantitative study included 260 asymptomatic participants aged between 21 and 45 years (mean age 34.52±7.75 years). The demographic data incorporated participants’ age, gender, race, weight, height, daily lifestyle activities, body mass index and medical history. Data was collected using a demographic questionnaire, B-Mode ultrasound and shear wave ultrasound elastography, using the GE Logiq E 9 equipment. The proximal, middle and distal sites of the biceps, subscapularis, and supraspinatus and infraspinatus tendons were imaged in both longitudinal and axial planes. The teres minor tendon was imaged in a single sagittal and axial plane. Results: The reference ranges of the rotator cuff and biceps tendons have been evaluated by finding 95% confidence intervals for the mean elasticity for each of the tendons. A 95% confidence interval provides a lower and upper limit into which 95% of tendon measurements would be expected to fall. The reference ranges for the mean tendon elasticity for the tendons were as follows: For the biceps tendon in sagittal and axial planes, the reference ranges are 102.52-108.34 kPa and 96.44-101.08 kPa respectively. For the subscapularis tendon in sagittal and axial planes, the reference ranges are 102.84-110.60 kPa and 110.60 kPa-108.02 kPa respectively. The supraspinatus tendon in sagittal and axial planes have reference ranges 106.83-114.54 kPa and 102.29-109.59 kPa, respectively. The infraspinatus tendon in sagittal and axial planes have reference ranges 102.39-111.87 kPa and 99.61-107.77 kPa respectively. The reference ranges for teres minor tendon in sagittal and axial planes are 96.90-101.20 kPa and 96.68- 101.09 kPa respectively. There was a statistically significant difference in the reference values observed between males and females for the proximal, middle and distal sites of the biceps tendon in the sagittal plane (p<0.05). The reference values ranged from 101.93±18.84 kPa-104.09±16.86 kPa (in females) and 109.40±18.15 kPa-109.41±19.07 kPa (in males). A statistically significant difference was also noted in the teres minor tendon in the sagittal and axial planes (p<0.05). The reference values ranged from 96.71±16.49 kPa (in females)-102.74±18.76 kPa (in males) in the sagittal plane and 97.03±18.29kPa (in females)-101.79±17.39 kPa (in males) in the axial plane. Conclusion: This study provided a non-invasive estimate of the elasticity of the rotator cuff and biceps tendons in kPa, using shear wave ultrasound elastography (SWUE). The results of our study have the potential to complement B-Mode ultrasound in the diagnosis, treatment and follow up of rotator cuff and biceps tendon pathology.