Background
Tendon disease is often the first presentation of rheumatoid arthritis (RA). Tenosynovial proliferation results in scarring and adhesion formation. Synovial invasion into tendons occurs in 50% of cases and is associated with multiple tendon ruptures and a poorer prognosis. Recent work on diseased joints suggests that hypoxia may play a key role in synovial invasion. We hypothesised that hypoxia promotes and maintains the inflammatory response in RA tenosynovium via neovascularisation.