Osteoarthritis, the most common type of arthritis, happens when the protective cartilage that surrounds your bones wears down over time. A “wear and tear” disease, osteoarthritis affects the entire joint in addition to the breakdown of cartilage. As the cartilage wears away, the protective space between the bones decreases, which can result in bone-on-bone rubbing.
All joints are at risk of osteoarthritis, but it typically damages the hands, spine, hips and knee. The knee is particularly high risk because it is under a lot of pressure, and knee osteoarthritis is one of the most common knee injuries patients have.
Knee osteoarthritis symptoms
Having knee osteoarthritis can make it difficult to perform everyday actions, like walking and climbing stairs. Symptoms of knee osteoarthritis include:
- Pain: Pain in your knee may be worse with prolonged activity, repetitive bending, climbing stairs, and inactivity, according to a book on knee osteoarthritis by Hunter Hsu and Ryan M. Siwiec.
- Stiffness: When you’re getting up after sitting or lying down for a while, you might have difficulty bending and straightening your knee.
- Swelling: Soft tissue inflammation in the knee can cause swelling and discomfort.
- Locking and sticking: Loose fragments of cartilage can interfere with smooth knee motion, causing snapping, creaking, grating, or grinding.
- Bone spurs: Extra bits of bone can form around the joint.
Some people with arthritic knees also notice increased pain with rainy weather, as well as tenderness around the joint.
The 5 stages of osteoarthritis
Stage 0
Description: In this stage, the knee is a normal, healthy knee with no signs of impairment or pain.
Treatment: No treatment is needed.
Stage 1
Description: This stage presents minor bone spur growth. Someone in this stage might not experience pain or discomfort.
Treatment: If you are vulnerable to osteoarthritis due to risk factors or predisposition, your doctor might recommend taking supplements or beginning an exercise routine to slow the progression.
Stage 2
Description: This is considered a mild stage of osteoarthritis. X-rays of the knee joint will reveal greater bone spur growth; however, cartilage is still usually at a healthy size, meaning the space between bones is normal and there is no bone-on-bone rubbing or scraping. Still, you may start to experience symptoms, such as greater stiffness, tenderness, or pain after a long day of exercise.
Treatment: As this stage of osteoarthritis is still minor, most therapies in this stage do not require medicine. Instead, your doctor may recommend getting a brace or wrap to stabilize your knee, and avoiding kneeling, jumping, or squatting. In addition, if you are overweight, you should lose weight through diet and exercise. General exercise will help regardless of weight.
Stage 3
Description: This stage is considered moderate osteoarthritis because the cartilage shows obvious damage and the space between the bones starts to get smaller. You are likely to experience frequent pain as well as joint stiffness and joint swelling.
Treatment: If the previous treatments did not work, your doctor might recommend cortisone injections or prescription pain medication. They may also recommend viscosupplementation injections.
Stage 4
Description: This stage is classified as severe, as many people in this stage have significant pain and discomfort when they move the joint or walk. The cartilage is almost completely gone, leaving the joint extremely stiff.
Treatment: If nonsurgical treatments were not effective, a doctor might recommend a knee arthroscopy or a total knee replacement.
What causes knee osteoarthritis?
While the most common cause of knee osteoarthritis is age, there are several risk factors that can lead someone to develop it at an earlier age. According to Dr. Vladimir Alexander, a founding partner of Alexander Orthopaedics, genetics is a significant factor:
"Most of the time, the arthritis comes from genetic predisposition, meaning it’s in your genes to have an arthritic knee. One of your family members who’s senior to you probably had an arthritic knee, and the cartilage in those people breaks down prematurely and, as the cartilage breaks down, you develop bone-on-bone contact, and that’s where the pain comes from."
Other risk factors include:
- Weight: Since weight adds extra pressure on your joints, especially the knees, being overweight can lead to osteoarthritis and other knee joint problems.
- Gender: Women over the age of 55 are at greater risk of developing osteoarthritis, although it isn’t clear why, according to the Mayo Clinic.
- Sports: Soccer, tennis, long-distance running, and other sports can put athletes at greater risk of developing osteoarthritis of the knee.
- Repetitive stress injuries: People with certain occupations may do certain activities on a daily basis that stress the knee, such as squatting, lifting heavy boxes, and kneeling, which can make them more likely to develop osteoarthritis due to consistent pressure on the joint.
- Other illnesses: Certain illnesses, such as rheumatoid arthritis and metabolic disorders, can cause higher risk of osteoarthritis.
How is knee osteoarthritis diagnosed?
When you see a knee physician about pain in the knee, there are many different tests they can perform depending on what issues are being presented, including active and passive range-of-motion (ROM) testing and a palpatory exam, according to Hsu and Siwiec.
After conducting these special knee tests, your physician may order X-rays to evaluate bone and cartilage damage. If the X-rays are ineffective or if they indicate that other types of joint tissue are damaged, MRI scans are sometimes ordered, as well. A blood test may also be ordered to rule out rheumatoid arthritis.
What is the treatment for knee osteoarthritis?
Nonsurgical treatment
There are many ways to treat and manage the symptoms of knee osteoarthritis before considering surgery. According to Dr. Alexander, knee osteoarthritis is “initially treated with anti-inflammatory medication and/or physical therapy. The anti-inflammatory medication can be oral or in the form of an injection of a material like cortisone into the knee, which is a strong anti-inflammatory.” Here are a few nonsurgical treatments for knee osteoarthritis:
Lifestyle changes
If you are overweight, losing weight can help reduce the strain on your knee joints, which can alleviate symptoms. Getting regular exercise can help you manage your weight as well as build up muscle strength to support your knee joint and reduce stress. Certain types of low-impact aerobic exercise are suitable for those with knee osteoarthritis, including swimming, cycling, walking, yoga and other stretching exercises.
While some people may wonder if walking on an arthritic knee is a good idea, Dr. Alexander recommends it for those with more moderate cases of knee osteoarthritis:
“Walking is generally very good because it keeps up exercise tolerance and nourishes the healthy cartilage that you have left in the joint. So, keeping a walking regimen is a good idea. However, in patients that have severe arthritic change, sometimes something as simple as walking is painful. In general, although it is good to keep walking and stay limber, it can have certain repercussions if the arthritis is severe.”
Assistive devices
Shoe inserts, braces, knee sleeves, and other assistive devices can help the knee’s stability and function in earlier stages of arthritis.
Physical therapy
A physical therapist can help you learn exercises that will strengthen the muscles surrounding the knee, as well as increase your flexibility.
Medications
There are several types of medications that can help treat osteoarthritis, which is why it’s important to consult with an experienced physician to determine what treatment is right for you. Some medications for treating knee osteoarthritis in more moderate to severe stages include over-the-counter pain relievers and anti-inflammatory medications, such as acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs) and COX-2 inhibitors.
Injections
There are many different types of injections that can be used to treat knee osteoarthritis, including:
- Cortisone injections: these injections can help relieve inflammation and pain, although this form of injection only works on a temporary basis.
- Viscosupplementation: another injection treatment in which hyaluronic acid is injected into the knee joint to help reduce pain and swelling, and improve the quality of the joint fluid.
- Amniotic tissue injections: these injections can also be used to reduce inflammation and swelling in the knee.
- Platelet rich plasma (PRP): this is a single, one-time injection that uses your blood to repair and regenerate the knee cartilage.
Surgical treatment
At Alexander Orthopaedics, only about 10% of patients with arthritic knees require surgery — most will improve without surgical treatment. However, when the arthritis is severe and becomes unresponsive to nonsurgical treatment, then we will consider knee surgery; either arthroscopy or knee replacement, depending on the severity of the condition.
Knee Arthroscopy
A common, minimally invasive procedure, knee arthroscopy typically involves small incisions to the knee that can help relieve symptoms. However, it is not a total cure for knee osteoarthritis.
Total knee replacement
According to Dr. Alexander, “knee replacement is a cure for osteoarthritis of the knee that is severe and unresponsive to nonsurgical treatment.” This procedure involves completely replacing the knee joint with an artificial knee prosthetic.
What is the knee osteoarthritis recovery process?
It can be hard to know what you can do when managing knee osteoarthritis. Dr. Alexander says it depends on the situation:
“You can do whatever you want to your own level of tolerance. If what you do does not bother you, you should do it. If what you do does bother you, then you should pull back to a certain degree. Everyone’s level of tolerance is different.”
If you are experiencing pain, stiffness and discomfort in your knee, we’re here to help. With personalized treatment plans, expert physicians and at-home recovery, we’re your partner in helping you get back to doing the things you love.