Knee Injections
Colorado Knee Pain Treatment
More than 50 million adults in the United States have doctor-diagnosed
arthritis. That’s one in five people over the age of 18 years. Osteoarthritis
is the most common type of arthritis, and it affects around 30 million
Americans.
Osteoarthritis often occurs in the knee. At Colorado Clinic, our knee pain
injection therapy can relieve this and other types of knee pain by repairing
the damaged cartilage and tissue.
What are the types of knee injections?
Medications, substances, and solutions injected into the knee include:
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Hyaluronic acid (HA) supplements – These substances injected into the knee joint are used to replace
lost synovial fluid. The HA works much like the synovial fluid, and acts
as a shock absorber and lubricant. By replenishing the fluid, the bones
move smoothly over each other, and pain resolves. In addition, HA injections
help the knee with inflammation. Injecting HA in the joint restores normal
viscoelastic properties of the synovial fluid and studies show it has
disease-modifying effects. Examples of the product include Orthovisc,
Synvisc, and Hyalgan.
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Corticosteroid – Triamcinolone, dexamethasone, betamethasone acetate, betamethasone
sodium phosphate, and methyl-prednisolone are examples of corticosteroid
agents used for knee joint inflammation. The injection lasts for up to
six months, offering pain relief from cartilage breakdown in the joint.
Corticosteroid injections work through an immunosuppressive and anti-inflammatory
effect. In addition, they reduce vascular permeability and inhibit the
accumulation of inflammatory substances.
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Platelet-rich plasma (PRP) – This involves drawing the patient’s own blood, processing
it by centrifugation in the laboratory, and injecting the concentrated
platelets back in the knee joint. PRP contains growth factors that stimulate the body.
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Arthrocentesis – Joint fluid aspiration is called arthrocentesis. This involves
removal of joint fluid that has accumulated inside the joint space of
the knee. The doctor often removes excessive fluid before injecting the
knee with a corticosteroid, HA, or PRP. Withdrawing fluid will ease swelling and pain.
How is the knee injected?
The pain management specialist can inject the knee in his office. After
cleaning the skin with an antiseptic, the doctor uses a fine needle to
numb the skin. Once numb, the doctor inserts the procedure needle. Real-time
x-ray or ultrasound technology is often used to assure correct needle
placement. Once the solution is instilled into the joint space, the needle
is removed, and the doctor applies a Band-Aid to the injection site.
Do knee injections work?
There is much evidence from randomized controlled clinical trials that
support knee injections. In a recent study, corticosteroid injections
were found to be superior to placebo for pain control, with results and
benefits lasting around 26 weeks.
Clinical studies show that HA injections are safe and offer pain reduction
for up to 24 weeks. PRP injections work by using insulin-like growth factor,
transforming growth factor b-I, cytokines, and chemokines to repair the
injured and damaged tissues. In a recent clinical study, PRP injections
were used for 115 arthritic knees, with patients having significant improvement
at the 6-month and 12-month follow-up visits.
What can I expect after the knee injection?
Your knee will be a little tender after the injection. The full effects
are usually not felt right away. Results depend on the type of injection
given. This includes:
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Corticosteroid – Pain relief may be immediate when an anesthetic is added, and
the steroid begins to work after 3-5 days.
-
Hyaluronic acid – Most patients notice ease of movement and decreased stiffness
immediately. Pain relief is effective after 1-2 days.
-
PRP – Immediately after the injection, the knee joint goes through the
inflammatory phase, so expect some tenderness and warmth. Results are
noticed after 2-3 weeks.