Hyalurionidase or hyaluronic acid (HA) occurs naturally in our bodies, both within joint fluid and between myofascial layers. It acts as a kind of lubricant, with protective qualities for joint cartilage, but seems to decrease in quantity as we get older. For the last 20 years or so medical companies have been commercially producing it from other sources such as rooster coombs, as well as synthetically. Doctors then use it as an injection into the joint in knee arthritis (as well as hips) and more recently in and around tendons and in bursae (which act as anti friction and buffering grease bags between tissue layers). It is also used as a filler for wrinkles and creases in the cosmetic medicine industry!
Dr Carter has been utilizing HA injections for 20 years, longer than any other practitioner in Bermuda. The benefits in reduced pain, swelling and improved function have been demonstrated in many patients during this time (including the doctor’s husband). Patients who respond well can usually expect at least 6 months of improvement, often considerably longer, before they feel compelled to return for a further injection. Courses are typically either one small injection weekly for about 3 weeks, or one larger injection once. Anaesthetic is used routinely prior to injection to maximise comfort, and in most people there is little to no downtime, although all patients are advised to avoid unduly stressing the joint for 2 days or so post procedure. Very occasionally a patient will react with a sore and swollen knee, which usually settles spontaneously, although sometimes requires medical intervention with anti-inflammatory treatment. Anyone who is sensitive in any way to bird products should only use the synthetically produced HA.
It has been noted that HA injections for arthritis of the knee work generally better in mild to moderate arthritis, and not as well once the arthritis is more advanced – in which case there is little joint cartilage left to protect.
Recent studies have now suggested that PRP (which is a well recognized treatment at this clinic) works better in the long term than HA to protect a joint. Advantages of HA include less expense, and no blood draw, and some clinics will also use it in conjunction with orthobiologics (PRP, stem cells etc). Each patient is assessed for their individual needs to determine what treatment pathway is likely to suit best.