Synvisc or Orthovisc are trade names for the generic compound: Hylan GF-20. Hylan is a thick substance like the synovial fluid that occurs naturally in the joints. Synovial fluid acts as a lubricant and shock absorber.
Hylan G-F 20 is injected into the knee joints for the treatment of pain in individuals with osteoarthritis. It has been used for other purposes besides arthritis. A recent study from Turkey used hylan in the Achilles tendons of rats. They found it had a positive healing effect on Achilles tendonitis.
Studies in humans using hylan for tendonitis haven’t been done yet. This first study may pave the way for future studies. Ask your doctor about trying this on an experimental basis.