Hyaluronic Acid
Hyaluronic Acid (HA) is a mucopolysaccharide found naturally throughout the body including synovial fluid of the joints, vitreous fluid of the eyes, and the tendons and ligaments.
Although HA is approved for use in the treatment of pain due to osteoarthritis in a number of different joints, it is generally not covered by most insurance plans due to the lack of evidence of the cost-effectiveness of the therapy. The cosmetic uses as dermal fillers are paid privately.
There are other indications such as an injectable bulking agent for gastro-urology use (FDA product code: LMN)
Intraarticular hyaluronic acid is currently considered a class III medical device, most often used to alleviate symptoms of joint pain due to osteoarthritis and requires premarket approval to sell in the USA (FDA product code: MOZ)
Dermal implantation of hyaluronic acid for general and plastic surgery is a class III medical device that requires premarket approval to sell in the USA (FDA product code: LMH)
Botulinum Toxin A (BTx-A)
Botulinum toxin (BTx-A) is a pre-synaptic neuromuscular blocking agent that triggers chemical denervation by temporarily suppressing secretion of acetylcholine at motor nerve endings, thereby reducing muscle contractions. Skeletal muscle strength generally weakens 2-5 days after BTx-A injection, minimizes within 2 weeks and then recovers. This weakening effect continues from 6 weeks to 6 months (median 3-4 months), and the injection dose influences the degree and period of denervation.
The reduction of pain associated with muscle contraction is well known, but BTx-A appears to have alternate pathways to act on peripheral nerves to directly reduce pain. This has led to testing directly on osteoarthritic joints to help relieve pain.
