Baskey Stephen J, Andreana Marco, Lanteigne Eric, Ridsdale Andrew, Stolow Albert, Schweitzer Mark E
Faculty of MedicineUniversity of OttawaOttawaONK1H 8M5Canada.
Department of Mechanical EngineeringUniversity of OttawaOttawaONK1N 6N5Canada.
IEEE J Transl Eng Health Med. 2018 Dec 25;7:1800211. doi: 10.1109/JTEHM.2018.2889496. eCollection 2019.
Previous studies using nonlinear microscopy have demonstrated that osteoarthritis (OA) is characterized by the gradual replacement of Type II collagen with Type I collagen. The objective of this study was to develop a prototype nonlinear laser scanning microendoscope capable of resolving the structural differences of collagen in various orthopaedically relevant cartilaginous surfaces. The current prototype developed a miniaturized femtosecond laser scanning instrument, mounted on an articulated positioning system, capable of both conventional arthroscopy and second-harmonic laser-scanning microscopy. Its optical system includes a multi-resolution optical system using a gradient index objective lens and a customized multi-purpose fiber optic sheath to maximize the collection of backscattered photons or provide joint capsule illumination. The stability and suitability of the prototype arthroscope to approach and image cartilage were evaluated through preliminary testing on fresh, minimally processed, and partially intact porcine knee joints. Image quality was sufficient to distinguish between hyaline cartilage and fibrocartilage through unique Type I and Type II collagen-specific characteristics. Imaging the meniscus revealed that the system was able to visualize differences in the collagen arrangement between the superficial and lamellar layers. Such detailed imaging of the cartilage surfaces could obviate the need to perform biopsies for histological analysis in the future, and provide an alternative to conventional external imaging to characterize and diagnose progressive and degenerative cartilage diseases such as OA. Moreover, this system is readily customizable and may provide a suitable and modular platform for developing additional tools utilizing femtosecond lasers for tissue cutting within the familiar confines of two or three portal arthroscopy techniques.
以往使用非线性显微镜的研究表明，骨关节炎（OA）的特征是Ⅱ型胶原蛋白逐渐被Ⅰ型胶原蛋白取代。本研究的目的是开发一种原型非线性激光扫描微型内窥镜，能够分辨各种与骨科相关的软骨表面胶原蛋白的结构差异。当前的原型开发了一种小型化的飞秒激光扫描仪器，安装在关节定位系统上，能够进行传统关节镜检查和二次谐波激光扫描显微镜检查。其光学系统包括一个使用梯度折射率物镜的多分辨率光学系统和一个定制的多功能光纤护套，以最大限度地收集背向散射光子或提供关节囊照明。通过对新鲜、处理最少且部分完整的猪膝关节进行初步测试，评估了原型关节镜接近和成像软骨的稳定性和适用性。图像质量足以通过独特的Ⅰ型和Ⅱ型胶原蛋白特异性特征区分透明软骨和纤维软骨。对半月板成像显示，该系统能够观察到表层和板层之间胶原蛋白排列的差异。对软骨表面进行如此详细的成像，未来可能无需进行活检进行组织学分析，并为传统外部成像提供一种替代方法，以表征和诊断诸如OA等进行性和退行性软骨疾病。此外，该系统易于定制，可能为在熟悉的两孔或三孔关节镜技术范围内开发利用飞秒激光进行组织切割的其他工具提供一个合适的模块化平台。
