A quantitative study of the three dimensional microstructure of articular cartilage to assess its physical integrity

[Truncated abstract] The PhD research described within this thesis involved a quantitative study of the morphological features of the articular cartilage related to its physiological status and the stage of osteoarthritis (OA). A unique method of three dimensional (3D) quantitative image analyses was developed and applied to study the microstructure of articular cartilage with varying biological states assessed in the International Cartilage Repair Society (ICRS) from grade 0 to grade 2. Degeneration of articular cartilage, the precursor of OA, has a close relationship with structural changes within two important components, the collagen matrix and the distribution of chondrocytes. By using confocal microscopy, the characteristics of the 3D collagen network and chondrocyte distribution pattern within articular cartilage (AC) samples of different physiological states were assessed. Quantitative image analysis techniques were developed and applied to numerically describe the morphological features of the 3D collagen network and the 3D arrangement of the chondrocytes depicted in the images acquired using confocal microscopy. The orientation of the fibre bundles presented in the lamina splendens and the structure of the subjacent collagen network were studied in detail and numerically described using parameters. An objective assessment was concluded using parameters extracted from 3D confocal images. It was found that characteristic matrix features associated with the development of OA can be assessed efficiently and effectively using the developed parameters. The distribution of chondrocytes within cartilage was studied in detail.