Orthopaedic Biomechanics Group, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
Department of Orthopaedics, Maastricht UMC+, Maastricht, The Netherlands.
Cartilage. 2021 Dec;13(2_suppl):1540S-1550S. doi: 10.1177/19476035211063861. Epub 2021 Dec 11.
This study aims to evaluate the applicability of the ultrasound roughness index (URI) for quantitative assessment of cartilage quality (post-mortem), after 6 months of articulation with a Focal Knee Resurfacing Implant (FKRI).
Goats received a metal FKRI () or sham surgery () in the medial femoral condyles. After 6 months animals were sacrificed, tibial plateaus were stained with Indian ink, and macroscopic scoring of the plateaus was performed based on the ink staining. The URI was calculated from high-frequency ultrasound images at several sections, covering both areas that articulated with the implant and non-articulating areas. Cartilage quality at the most damaged medial location was evaluated with a Modified Mankin Score (MMS).
The URI was significantly higher in the FKRI-articulating than in the sham plateaus at medial articulating sections, but not at sections that were not in direct contact with the implant, for example, under the meniscus. The mean macroscopic score and MMS were significantly higher in the FKRI-articulating group than in the sham group (, , respectively). Correlation coefficients between URI and macroscopic score were significant in medial areas that articulated with the implant. A significant correlation between URI and MMS was found at the most damaged medial location ().
This study demonstrates the potential of URI to evaluate cartilage roughness and altered surface morphology after articulation with a metal FKRI, rendering it a promising future tool for quantitative follow-up assessment of cartilage quality.
本研究旨在评估超声粗糙度指数（URI）在定量评估关节成形术后 6 个月软骨质量（死后）方面的适用性。
山羊的股骨内侧髁接受金属 FKRI（）或假手术（）。6 个月后，动物被处死，胫骨平台用印度墨水染色，并根据墨水染色对平台进行宏观评分。在几个节段从高频超声图像中计算 URI，这些节段覆盖与植入物关节和非关节区域。使用改良 Mankin 评分（MMS）评估最受损的内侧位置的软骨质量。
在与植入物关节的内侧关节段，FKRI 关节的 URI 明显高于假平台，但在与植入物没有直接接触的节段，例如半月板下，URI 没有明显差异。在与植入物关节的内侧区域，FKRI 关节组的平均宏观评分和 MMS 明显高于假组（，分别）。URI 与宏观评分之间的相关系数在与植入物关节的内侧区域具有统计学意义。在最受损的内侧位置发现 URI 与 MMS 之间存在显著相关性（）。
本研究表明，URI 具有评估金属 FKRI 关节成形术后软骨粗糙度和表面形态改变的潜力，有望成为软骨质量定量随访评估的一种有前途的新工具。
