Structural Characteristics of Articular Cartilage in the Early Detection of Post-Traumatic Osteoarthritis by Microscopic Imaging Techniques

Cartilage is a specialized form of connective tissue that provides support and cushioning to adjacent tissues in the body. Cartilage is of three types: Hyaline, fibrocartilage, and elastic. The articular cartilage is a hyaline type and is the most found throughout the animal and human bodies. Articular cartilage is composed of a dense extracellular matrix (ECM) with specialized cells, and chondrocytes, which are sparsely distributed. The ECM is primarily made up of collagen, proteoglycan, water, non-collagenous proteins, and glycoproteins. The components of the ECM are subject to change in the disease state, especially in osteoarthritis. As a result of the complex and unique nature of the articular cartilage, early detection, treatment, and repair pose a challenge in clinic. Imaging techniques such as magnetic resonance imaging (MRI) has been used in the noninvasive evaluation of the cartilage structure, and polarized light microscopy (PLM) allows the examination of the molecular organization at optical resolution.The first project in this dissertation aimed to study the structural characteristics of the articular cartilage in the patella and the fibrocartilage of the suprapatella in the knee joint. This was achieved quantitatively using µMRI and PLM at both low and high resolutions. The second project in this dissertation aimed to compare the structures between the immature and mature articular cartilage of the femur and humerus qualitatively and quantitatively using µMRI and PLM. The third project in this dissertation was aimed at the structural characteristics of the articular cartilage in the disease state. Specifically qualitative and quantitative characteristics from traumatized joints (post-traumatic osteoarthritis) were studied using µMRI and PLM at high resolutions. These studies confirmed the ability of µMRI and PLM to examine the cartilage structure quantitatively and qualitatively in a healthy state and in a diseased state. The ability to study the microscopic anatomy of cartilage and pathology (osteoarthritis) in the early stage will contribute to the treatment and early diagnosis of arthritis.