Osteoarthritis (OA) is a progressively disabling musculoskeletal disease characterized by degeneration of the articular cartilage. The current understanding within the field of orthopedics is that the progression of OA is accompanied by structural and compositional changes within the tissue due to collagen damage at the articular surface and loss of proteoglycans (PG) through the articular surface. This leads to a loss of the articular cartilage, followed by sclerosis of the subchondral bone and the formation of subchondral bone cysts and osteophytes.

Currently, a significant complication in the treatment of osteoarthritis is the inability to diagnose the disease process at an early stage. While macroscopic, end-stage cartilage damage can be recognized by radiographic methods, early stages of OA that involve disruption of the cartilage but without any obvious surface damage are much more difficult to identify.

FT-IR spectroscopy is currently emerging as a technique that is being increasingly utilized for the analysis of proteins in biological tissues. In this thesis, a new alternative for IR sampling utilizes an infrared fiber optic probe (IFOP) in the investigation of spectral changes related to early articular cartilage degradation. Here we show that molecular changes associated with the degradation of the superficial zone type Q collagen network can be monitored by FTIR spectroscopy. Specifically in the 1800-1000 cm^-1 wavenumber region, we have demonstrated that there are spectral changes associated with the degradation of type n collagen. These changes are consistent between normal and arthritic cartilage, both in human and animal studies. This evidence is also further corroborated when collagenase treated articular cartilage is compared to normal cartilage.

We envision the use of the IFOP as a diagnostic tool that can be used in conjunction with arthroscopy for the evaluation of cartilage integrity and also for assessing the integration of tissue engineered cartilage.