Some recent clinical approaches to osteoarthritis research.

Clinical investigation of osteoarthritis (OA) is the starting point of the "research triangle," leading to appropriate animal and in vitro studies. This article discusses the historical perspective of clinical investigation, definition of OA, case studies taking place in Bristol, assessment and measurement of OA, including imaging of various types and possible biochemical "markers" of the OA process. The different aspects of the process of OA need to be related to outcome, and the future for clinical research in OA is postulated.