Osteoarthritis is common with radiographic features practically universal in at least some joints in people aged over 60 years. One of the main therapeutic interventions used in the management of osteoarthritis is the injection of corticosteroid and hyaluronan (Gossec 2006). However, there exist few studies that seek to explore possible factors that influence outcome following injection. This study examined the factors that may influence the outcomes following injection of either corticosteroid or hyaluronan in the management of osteoarthritis of the knee.