What are Knee Joint Injections?
Your knee is a complicated joint designed to bear weight and enable movement, making it both strong and vulnerable to injury at the same time.
The knee is made up of bones, muscles, and connective tissues. There is fluid in the joint which helps with lubrication and ease of movement.
Any injury to these structures can impair the ability to perform daily activities. Knee injections are used to treat certain types of knee pain and inflammation involving ligaments, tendons, and cartilage.
Why are Knee Joint Injections performed?
The type of knee joint injection you receive depends upon the nature of your knee injury.
Common knee injections include:
- Corticosteroid injections: help reduce pain and inflammation
- Hyaluronic injections: help lubricate the joint and control osteoarthritis pain
- Nerve blocks: for patients who have had a knee replacement and is still experiencing pain
The most common conditions that knee joint injections help treat are chronic arthritis and acute injury in the joint.
Knee joint injections are minimally-invasive and performed in an outpatient setting, providing an alternative to surgery.
They can help decrease pain, promote healing, improve quality of life, treat inflammation, and lubricate the joint.
Pain relief from knee injections can allow you to be more mobile and engage in an active, healthy lifestyle. They’re best done with other treatments like physical therapy.
Knee pain occurs most often due to the simple wear and tear of the knee as we age. Osteoarthritis is the most common form of arthritis, causing inflammation and degradation of the cartilage in the knee.
Tendinitis, an inflammation of the knee joint, often causes knee pain due to a tendon injury that occurs after a twisting motion.
How are Knee Joint Injections performed?
Knee injections are a minimally-invasive procedure performed as an outpatient procedure.
The injection site is cleaned with antiseptic, and your doctor will use a local anesthetic to numb the area.
Once the area is comfortably numb, the doctor will insert a needle into the joint to check for and drain excess fluid, often resulting in immediate pain relief since it reduces pressure within the joint.
Next, another needle will be inserted into the knee joint and you’ll be injected with the medication. During the procedure, your doctor may opt to use digital imaging to guide the needle to the proper location.
What should I expect after Knee Joint Injections?
While generally safe, knee joint injections can have risks and/or side effects such as:
- Bleeding
- Infection
- Damage to tissues or nerves
Each type of knee injection has its own set of specific risks. Some osteoarthritis injections may include processed chicken or rooster combs, and patients with an allergy to eggs or poultry are at risk for an allergic reaction. Sometimes, hyaluronic injections may cause a pseudo-septic reaction in the knee joint that shows up as pain, swelling, and redness.
Corticosteroids have a serious risk for both local and systemic side effects. Repeated, long-term use of steroid injections poses a risk of cartilage or ligament damage. There is also the possibility that the corticosteroid will crystallize in the joint and worsen inflammation.
Systemic side effects of steroids include:
- Osteoporosis (bone loss)
- Increased blood pressure
- Elevated blood sugar levels
- Degenerative eye disease, such as cataracts and glaucoma
- Weight gain
- Depressed immune function, which increases risk of infection
- Ulcers and bleeding in the gastrointestinal tract
Make sure you discuss all of the risks and benefits of knee joint injections with your doctor. Because of risks with long-term use, most doctors will suggest a course of only a few injections per year, at most.
Recovery is usually simple and quick. You are able to go home after this outpatient procedure, and most people resume normal activity after just one day of rest. Pain relief may be gradual or it may be profound and nearly instant, depending on the condition being treated and the injection you receive.
For minor pain and swelling at the injection site, ice and over-the-counter medications can help. Call your doctor if you have any signs of infection, such as:
- Pain and swelling increases
- You experience fever
- There is blood or other discharge at the injection site
Success of knee injections depends on the severity of damage. You may require only a single injection, or a series of injections to find pain relief.
In osteoarthritis, patients usually report decreased pain after four to 12 weeks of treatment. Pain relief may last for months, and repeat treatments may be given as needed.
These injections are best when combined with physical therapy for muscle strengthening or helping with tightness or imbalances in the body, and to help resolve the underlying causes of your pain.
