Osteoarthritis (OA) of the knee typically causes pain and stiffness that can interfere with even the simplest day-to-day activities. For some, over-the-counter and prescription pain medications provide enough relief, especially in early-stage OA. For others, it may be necessary to try other treatment options.
If you have tried medications with little to no relief and aren’t ready for surgery, then injectable treatments for OA may be able to provide the relief you’re looking for.
Here is an overview of each of the most common types of injectables for OA of the knee. Discuss these options with your doctor to see which one might be right for you.
Corticosteroid injections are the most commonly used injectables for OA of the knee. The injections often contain a combination of steroids and a local anesthetic.
Some doctors use two separate needles: one to inject the steroid and another to inject the anesthetic. The corticosteroids are injected directly into the knee joint for targeted relief from pain and inflammation.
These injections usually occur anywhere from every few days to months apart, depending on the patient and symptoms. A newer type of corticosteroid injection, triamcinolone acetonide (Zilretta), is only used for OA of the knee. It can be given just once.
Although these treatments are commonly used and known to provide relief with few side effects, most doctors will limit the number of injections you receive. Some evidence has suggested that repeated injections in the knee can break down cartilage. Pain and redness is common at the injection site. This can be relieved by applying ice to the area. Redness and warmth on the face or chest is also fairly common after receiving a corticosteroid injection. Infection and bleeding are very rare complications. People with diabetes should be aware that corticosteroid injections may temporarily increase blood sugar levels.
Viscosupplementation (hyaluronic acid injections)
Viscosupplementation isn’t as widely used as corticosteroid injections, but may be an option if other treatments have failed. It involves injecting a gel-like substance called hyaluronic acid (HA) into the knee joint. HA is naturally found in the joint fluid and works as a lubricant to help joints move smoothly. It also acts as a cushion during walking. People with OA have altered HA in the joints.
Your injection schedule will depend on which specific product is used. Some brands include Synvisc, Hyalgan, Euflexxa, and Orthovisc. Treatments range from weekly injections to every three to five weeks. If your knee is swollen, a small amount of joint fluid may first need to be removed in order to make room for the HA.
Viscosupplementation doesn’t provide relief for everyone. Results vary from person to person. Common side effects are similar to those mentioned above for corticosteroid injections, with most people experiencing only some discomfort at the injection site. Again, infection and bleeding are rare complications. Unlike with corticosteroids, you’re required to avoid putting pressure on the joint for the first 48 hours after treatment.
Arthrocentesis (joint fluid aspiration)
Although it doesn’t necessarily involve injecting anything into the body, arthrocentesis does use a needle to temporarily relieve pain associated with OA of the knee. A hollow needle is inserted into the joint to remove excess joint fluid. For many, some relief of pain and inflammation occurs almost immediately. Unfortunately, the fluid tends to accumulate within hours to days.
Along with the removal of excess fluid, arthrocentesis can be used to diagnose knee problems. For people with OA, it can be used before a corticosteroid or HA injection. Those who have excess fluid in the knee will need to have this procedure before receiving other treatments for their knee pain.
The right injectable treatment for you will depend on the severity of your OA and symptoms. Your doctor will also consider other factors, such as other medical conditions, when deciding which treatment option is best for you.