A hyaluronan preparation (500-730 kDa) in the treatment of osteoarthritis: a review of clinical trials with Hyalgan

The purpose of this paper is to review the intra-articular treatment of osteoarthritis (OA) of the knee with the hyaluronan preparation 500-730 kDa (Hyalgan). Reviewing the results of 24 clinical trials, it can be concluded that 3-5 weekly injections of Hyalgan significantly improve the pain and functional status of patients with OA. Although the onset of improvement is delayed by 3-4 weeks, the effect can last at least six months and up to one year after treatment cessation. The benefits of Hyalgan compared with intra-articular corticosteroids are also addressed. The potential for Hyalgan to have a structure-modifying action by retarding stuctural progression in OA of the knee is considered. However, further studies of Hyalgan in OA in other joints, and in damaged joints in rheumatoid arthritis, are needed.