Hyaluronan therapy has numerous medical applications, including the treatment of joint arthropathies, wound healing, prevention of postsurgical adhesions, treatment of urinary incontinence, ophthalmic surgery, and tissue augmentation and engineering. Studies have been conducted and are ongoing to evaluate the efficacy of intra-articular hyaluronans in disease modification in osteoarthritis of the knee; efficacy in disease states other than osteoarthritis; as adjunct therapy after joint surgery; and in joints other than the knee--namely the shoulder, hand, hip, temporomandibular joint, spine, foot, and ankle. Preliminary results have been promising and parallel what has been found in treatment of osteoarthritis of the knee. Research also continues into the development of chemically modified derivatized hyaluronan to optimize responses and enhance duration of action, as well as to expand the uses of this therapeutic modality.