Research into the causes of osteoarthritis (OA) of the knee has traditionally followed a biomedical approach whereby the disease development and progression is regarded as an internal physiological process. As a result, treatment has focused on symptom reduction with limited modification of psychosocial variables. In fact, psychosocial factors such as environment and employment play a substantial role in the disease process and are important determinants of the overall level of disability of affected individuals. Thus, by placing greater importance on the biomedical aspects of knee OA, a complete representation of the health condition cannot be achieved thereby limiting treatment effectiveness. The purpose of this clinical commentary is to provide a rationale for the implementation of a biopsychosocial model of knee OA that can aid in more effective research and treatment for the disorder.