Most of the fluid in a healthy knee is hyaluronic acid, Altman says. But when you have knee OA, the hyaluronic acid in your knee thins. Your doctor can inject more hyaluronic acid into your knee to boost the supply.
Studies have shown that hyaluronic acid injections may help more than pain-relief medications for some people with OA. Other studies have shown they may improve symptoms as well as corticosteroid injections do. If you're considering hyaluronic acid injections, keep these in mind:
It’s often not the first approach. Your doctor may suggest hyaluronic acid if:
- Your symptoms aren't improved by pain-relief medications or non-drug treatments such as heat or ice.
- You can't take pain relievers such as Advil or Motrin (ibuprofen), Aleve (naproxen sodium), or Tylenol (acetaminophen).
- A steroid shot doesn’t help enough, or you or your doctor are concerned about its side-effects.
It may work in different ways. After an injection, hyaluronic acid helps cushion and lubricate the moving parts within your knee, Altman says. This effect is fairly short-lived. But the treatment seems to also provide more long-term benefit by relieving pain and inflammation.
You may need more than one injection. Five versions of hyaluronic acid injections are available in the U.S. Some types require only one injection. Others require up to five injections, usually within a five-week period. If needed, you can get another shot after six months, Altman says.
Platelet-Rich Plasma: Can It Help OA?
Another treatment getting attention is platelet-rich plasma (PRP). This requires drawing a sample of your blood and processing it to create a fluid that contains a higher-than-normal amount of platelets, tiny disks that help clot the blood. The doctor then injects the fluid back into your injured area.
The platelets in your blood contain natural chemicals that help heal injuries. Doctors have been treating other problems – like tendon damage – for more than a decade with PRP.
However, experts still know little about whether it works for knee osteoarthritis.