Cartilage viscoelasticity changes as cartilage degenerates. Hence, a cartilage viscoelasticity measurement could be an alternative to traditional imaging methods for osteoarthritis diagnosis. In a previous study, we confirmed the feasibility of viscoelasticity measurement in ex vivo bovine cartilage using the Lamb wave method. However, the wave speed-frequency curve of Lamb wave is totally nonlinear and the cartilage thickness could significantly affect the Lamb wave speed, making wave speed measurements and viscoelasticity inversion difficult. The objective of this study was to measure the cartilage viscoelasticity using the Rayleigh wave method (RWM). Rayleigh wave speed in the ex vivo bovine cartilage was measured, and exists only in the near-source and far-field region. The estimated cartilage elasticity was 0.66 ± 0.05 and 0.59 ± 0.07 MPa for samples 1 and 2, respectively; the estimated cartilage viscosity was 24.2 ± 0.7 and 27.1 ± 1.8 Pa·s for samples 1 and 2, respectively. These results were found to be highly reproducible, validating the feasibility of viscoelasticity measurement in ex vivo cartilage using the RWM. Current method of cartilage viscoelasticity measurement might be translated into in vivo application.

软骨的粘弹性随着软骨退化而改变。因此，软骨粘弹性测量可以替代传统的骨关节炎诊断成像方法。在之前的一项研究中，我们证实了使用 Lamb 波法在体外牛软骨中测量粘弹性的可行性。然而，Lamb波的波速-频率曲线是完全非线性的，软骨厚度会对Lamb波速产生显着影响，给波速测量和粘弹性反演带来困难。本研究的目的是使用瑞利波法 (RWM) 测量软骨粘弹性。测量了离体牛软骨中的瑞利波速，并且仅存在于近源和远场区域。估计的软骨弹性为 0.66 ± 0.05 和 0.59 ± 0。样品 1 和 2 分别为 07 MPa；样品 1 和 2 的估计软骨粘度分别为 24.2 ± 0.7 和 27.1 ± 1.8 Pa·s。发现这些结果具有高度可重复性，验证了粘弹性测量的可行性使用 RWM 进行离体软骨。目前的软骨粘弹性测量方法可能会转化为体内应用。