Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
Osteoarthritis Cartilage. 2012 Jul;20(7):719-26. doi: 10.1016/j.joca.2012.03.018. Epub 2012 Mar 30.
The aim of the study was to investigate whether high frequency ultrasound technique, originally designed for arthroscopic use can be utilized to detect traumatic cartilage injuries.
A total of four intact osteochondral plugs were prepared from eight patellas for parallel comparison (total of 32 plugs). The plugs were injured by dropping an impactor on them from heights of 2.5 cm, 5.0 cm, 10.0 cm and 15.0 cm (corresponding to impact energies of 0.12, 0.25 0.50 and 0.74 J, respectively), in a custom made dropping tower. The samples were imaged with a high frequency (40 MHz) ultrasound device before and after the injury. Reflection coefficient (R), integrated reflection coefficient (IRC), apparent integrated backscattering (AIB) and ultrasound roughness index (URI) were determined for each sample.
Injuries invisible to the naked eye could be sensitively detected via the decreased values of the ultrasound reflection parameters (P < 0.05). Furthermore, a decreasing trend was detected in the values of R and IRC as the momentum of the impactor increased. The values of AIB were significantly lower for samples injured by dropping the impactor on the cartilage from heights of 2.5 cm and 15 cm but the URI values were similar in intact and injured cartilage. Histological analysis of the cartilage samples revealed that the injured cartilage exhibited depletion of the cartilage surface proteoglycans but the structure of collagen network was almost normal.
Quantitative ultrasound imaging enables the detection of minor visually non-detectable cartilage injuries. As the present technique is feasible for arthroscopic use it might have clinical value in the evaluation of cartilage lesions during arthroscopy e.g., after tear of the anterior cruciate ligament.
本研究旨在探讨原本为关节镜设计的高频超声技术是否可用于检测外伤性软骨损伤。
共从 8 个髌骨中制备了 4 个完整的骨软骨栓用于平行比较（共 32 个栓）。将这些栓从 2.5cm、5.0cm、10.0cm 和 15.0cm 的高度用冲击器撞击，以模拟分别为 0.12、0.25、0.50 和 0.74J 的撞击能，在定制的落塔中进行。在损伤前后，使用高频（40MHz）超声设备对样本进行成像。确定每个样本的反射系数（R）、积分反射系数（IRC）、表观积分背散射（AIB）和超声粗糙度指数（URI）。
通过降低超声反射参数的值，可以敏感地检测到肉眼不可见的损伤（P<0.05）。此外，随着冲击器动量的增加，R 和 IRC 值呈下降趋势。当冲击器从 2.5cm 和 15cm 的高度撞击软骨时，AIB 值明显低于完整软骨的 AIB 值，但 URI 值在完整和损伤的软骨中相似。软骨样本的组织学分析显示，损伤的软骨表面蛋白聚糖耗竭，但胶原网络结构几乎正常。
定量超声成像可检测到肉眼不可见的微小软骨损伤。由于目前的技术可用于关节镜检查，因此它可能具有在关节镜检查中评估软骨病变的临床价值，例如在前交叉韧带撕裂后。
