What Does It Mean to Have Subchondral Sclerosis?

Subchondral sclerosis is a thickening of the bone under the cartilage in joints. It is also called marginal sclerosis. 

Subchondral sclerosis is often seen in joints of the knee, hip, spine, sacroiliac (SI) joint, and foot.

The goal of treatment for subchondral sclerosis is managing symptoms and may include exercise, physical therapy, and anti-inflammatory medications. For severe cases, surgery might be needed.

This article looks at the symptoms and causes of subchondral sclerosis. It also covers how the condition is diagnosed and treated.

Causes and Risk Factors

Osteoarthritis is a key player in the development of subchondral sclerosis. Osteoarthritis wears down the cartilage in a joint and wears away at the subchondral bone under the cartilage.

The body tries to repair the damaged bone. As the bone is remodeled, it comes back thicker than it was before, which leads to subchondral sclerosis.

Subchondral sclerosis is most commonly found in the later stages of osteoarthritis and can be associated with painful joint symptoms and bone spurs. 

However, having subchondral sclerosis does not necessarily mean your osteoarthritis is severe or will get worse.

Risk factors for subchondral sclerosis include:

• Genetic predisposition
• Female sex
• Older age
• Obesity
• Previous joint injury
• Joint malalignment or abnormal joint shape

Symptoms

Subchondral sclerosis can cause painful bone spurs, which can reduce the range of motion of the affected joint. 

It can also happen when there's a deterioration of joint cartilage. If the knee, hip, or spine is involved, these changes can actually make a person shorter. When subchondral sclerosis occurs in the knee, the joint can also sometimes lock and cause trouble walking.

Subchondral sclerosis can also cause cysts to form under the cartilage. They do not always cause symptoms but can cause symptoms like bone spurs do (e.g., pain and trouble with joint flexibility). 

Diagnosis

On an X-ray of the joint, subchondral sclerosis looks like a dense area of bone just under the cartilage. It will look abnormally white along the joint line.

Magnetic resonance imaging (MRI) can also be used to look at the soft tissues in the body.

Treatment

There is no cure for subchondral sclerosis but there are steps you can take to slow the progression of osteoarthritis and reduce pain and other symptoms.

Low-impact physical exercises such as biking on a stationary bike, yoga, and swimming keep your joints active. 

If you are not at the most supportive weight for your body, losing weight will reduce the stress on your joints.

Your healthcare provider may recommend other treatments like:

• Physical therapy
• Hydrotherapy
• Holistic medical treatments, such as acupuncture
• Over-the-counter (OTC) anti-inflammatory medications such as ibuprofen or prescription medications for pain 
• Joint replacement surgery in severe cases that have not responded to other treatments

Outlook

Having subchondral sclerosis is not predictive of the progression or severity of osteoarthritis. It does not mean that your osteoarthritis is getting worse or that it will get worse. 

A study found that subchondral sclerosis may prevent cartilage loss in people with varus knee osteoarthritis. According to the researchers, the overgrowth of bone might help realign bowed knee joints and prevent excessive abrading.

Another study published in 2014 also found no significant association between baseline subchondral sclerosis and the risk of cartilage loss in the knee.

Summary

Subchondral sclerosis is common in people with osteoarthritis but it doesn’t mean your arthritis is progressing. It does mean that there are changes in your bones that may cause pain and problems with your joints.

You can treat the symptoms of subchondral sclerosis in a few ways, mostly with exercise and other lifestyle strategies. In severe cases, you might need surgery to replace a joint that is too badly damaged.