Knee Injection vs. Knee Replacement Surgery: Which is Right for You?

Knee pain treatments depend on severity of pain and damage

A woman bends over and grabs her knee in pain after running outside.

Knee pain treatments depend on severity of pain and damage

Knee pain can take many forms. It may be a sharp pain, achiness, a dull burning sensation, or uncomfortable swelling or stiffness. The pain may be worse at night, and the knee may feel unstable.

About one in four Americans lives with chronic knee pain that limits their function and mobility and interferes with their quality of life.

The most common cause of chronic knee pain in adults is osteoarthritis. It is a progressive form of arthritis where the cartilage that cushions the ends of the bones in the knee joint wears away over time. Osteoarthritis of the knee is usually associated with older adults, but it can also affect young people, especially if they suffered a previous knee injury.

Knee pain treatments depend on the severity of the pain and how advanced the damage is. Mild pain may be managed with over-the-counter, non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil) or naproxen (Aleve), along with physical therapy or a supportive knee brace. More significant pain may require medical treatment, especially if it affects your work, exercise or everyday activities.

Types of knee injections for pain

If conservative treatments aren’t effective, your doctor may recommend injections to relieve discomfort and restore your normal function.

“There are several types of injections to reduce inflammation in the knee joint, which can help with pain and mobility for several months or more,” says Jeffrey Wilde, MD, an orthopedic surgeon at Scripps Clinic Torrey Pines and Scripps Clinic Mission Valley. “The right choice is determined by your symptoms and your individual medical profile.”

Generally, the risk of side effects from knee injections is rare, but may include infection and pain at the injection site.


Also known as cortisone, corticosteroid injections are usually the first line of treatment to reduce joint inflammation. Cortisone may be injected alone or mixed with an anesthetic; pain relief usually begins in a few days and lasts for several months.

Most doctors recommend limiting cortisone injections for the knee to four times a year (every three months) in arthritic knees. Cortisone injections should be used more sparingly in knees with less arthritis since repeated doses may damage the cartilage.

Though rare, some people experience thinning of the skin around the injection site several months later that may last for up to a year. Cortisone injections are usually covered by insurance.

Hyaluronic acid injections

Hyaluronic acid (HA) is a gel-like substance found naturally in the synovial fluid that lubricates your joints and helps them move smoothly. Osteoarthritis tends to decrease synovial fluid production. Hyaluronic acid knee injections, also known as gel injections or viscosupplementation, help replace it.

You may need just one injection, or several spaced a week apart, to resolve pain and stiffness. The results usually last about six months. Although HA injections may not help in every case, they carry little overall risk to the patient. Insurance may cover HA injections.

Platelet-rich plasma (PRP) injections

PRP is a type of regenerative medicine, which means it uses your body’s natural abilities to heal. PRP injections use parts of your own blood to help treat joint inflammation and pain.

Platelets are blood cells that promote healing and tissue growth, and plasma is the liquid portion of your blood. In PRP therapy, your doctor will draw several tubes of blood from your arm, spin them in a centrifuge machine to separate out the platelets and plasma, and inject the platelet-rich plasma into the affected joint.

The platelets release growth factors that help repair damaged tissues naturally. Its effectiveness in the knee is still unknown as PRP is a relatively new treatment and is still considered experimental. Most insurance companies will not cover its use in the knee.

Knee replacement surgery

If injections and other treatments do not provide relief, or if knee osteoarthritis is severe, knee replacement surgery may be the best option.

During this procedure, the surgeon removes the damaged parts of the thigh and shin bones that make up the knee joint and replaces them with a combination of metal and plastic implants.

If only one part of the knee is damaged, a partial knee replacement may be appropriate. Typically, patients with limited osteoarthritis damage are younger. Patients who have extensive joint damage may need total knee replacement surgery. Both procedures can be done using minimally invasive surgical techniques that require fewer and smaller incisions than conventional “open” surgery.

Minimally invasive knee replacement surgery offers advantages that may include less pain and bleeding, a shorter hospital stay and a faster recovery,” says Dr. Wilde.

Knee replacement surgery typically takes 1-2 hours, and patients typically spend one night in the hospital. After surgery, patients work with a physical therapist to regain strength and range of motion in their knee. Most patients can return to their usual activities within three to six months and will obtain full recovery at around a year.

Scripps is a recognized national leader in knee replacement surgery. U.S. News & World Report consistently ranks Scripps as one of the nation’s best programs for orthopedics and orthopedic surgery.

Watch the video on treatments for knee pain

Watch the San Diego Health video with host Susan Taylor and Dr. Wilde discussing treatments for knee pain.

Related tags: