Reliability of Continuous Shear Wave Elastography in the Pathological Patellar Tendon

Abstract
Objectives Patellar tendon injuries occur via various mechanisms such as overuse, or due to surgical graft harvest for anterior cruciate ligament reconstruction (ACLR). Quantified patellar tendon stiffness after injury may help guide clinical care. Continuous shear wave elastography (cSWE) allows for the assessment of viscosity and shear modulus in tendons. The reliability of the measure, however, has not been established in the patellar tendon. The purpose of this study was to investigate the interrater reliability, intrarater reliability, and between-day stability of cSWE in both healthy and pathological patellar tendons. Methods Participants with patellar tendinopathy (n = 13), history of ACLR using bone-patellar tendon-bone autograft (n = 9), and with no history of patellar tendon injury (n = 13) were recruited. cSWE was performed 4 times by multiple raters over 2 days. Intraclass correlations (ICC) and minimum detectable change (MDC95%) were calculated. Results Good to excellent between-day stability were found for viscosity (ICC = 0.905, MDC95% = 8.3 Pa seconds) and shear modulus (ICC = 0.805, MDC95% = 27.4 kPa). The interrater reliability measures, however, were not as reliable (ICC = 0.591 and 0.532). Conclusions cSWE is a reliable assessment tool for quantifying patellar tendon viscoelastic properties over time. It is recommended, however, that a single rater performs the measure as the interrater reliability was less than ideal.
Description
This is the peer reviewed version of the following article: Ito, N., Sigurðsson, H.B., Pohlig, R.T., Cortes, D.H., Grävare Silbernagel, K. and Sprague, A.L. (2022), Reliability of Continuous Shear Wave Elastography in the Pathological Patellar Tendon. J Ultrasound Med. https://doi.org/10.1002/jum.16115, which has been published in final form at https://doi.org/10.1002/jum.16115. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited. This article will be embargoed until 10/27/2023.
Keywords
anterior cruciate ligament, bone-patellar tendon-bone graft, continuous shear wave elastography, patellar tendon, tendinopathy, viscoelastic properties
Citation
Ito, N., Sigurðsson, H.B., Pohlig, R.T., Cortes, D.H., Grävare Silbernagel, K. and Sprague, A.L. (2022), Reliability of Continuous Shear Wave Elastography in the Pathological Patellar Tendon. J Ultrasound Med. https://doi.org/10.1002/jum.16115