Fibrous Dysplasia

Fibrous dysplasia is a rare bone condition that happens when abnormal fibrous (scar-like) tissue replaces healthy bone tissue. The condition weakens your bones and may increase your risk of bone fractures. Fibrous dysplasia (fI-bruhs-dis-play-zhee-uh) can affect any bone in your body. But it most commonly affects the:

• Thigh bone (femur)
• Shin bone (tibia)
• Ribs
• Skull (including your facial bones)
• Upper arm (humerus)

Fibrous dysplasia is a benign bone disorder. That means it won’t spread to other bones.

Types of fibrous dysplasia

Healthcare providers classify fibrous dysplasia by the number of bones it affects:

• Monostotic fibrous dysplasia affects one bone
• Polyostotic fibrous dysplasia affects several bones

You may have polyostotic fibrous dysplasia if you have McCune-Albright syndrome. This rare syndrome affects your bones, skin and endocrine system.

Symptoms of fibrous dysplasia

Fibrous dysplasia may cause the following conditions and symptoms:

• Broken bones
• Bone pain
• Changes in the shape of your bones
• Painless, swollen area on your ribs
• Curvature of the spine (scoliosis)
• Bulging eyes
• Jaw misalignment
• Misaligned or misshapen teeth
• Nasal congestion

You can have fibrous dysplasia without having symptoms. Some people find out they have the condition when they have X-rays for an unrelated issue. People with fibrous dysplasia in one bone have fewer issues than if the condition affects several bones.

Fibrous dysplasia causes

This condition happens when the GNAS1 gene changes after conception. This gene change affects osteoblasts. These cells help your bones develop and grow. Experts don’t know what triggers this change. Fibrous dysplasia isn’t hereditary. That means you can’t pass the change on to your biological children.

Complications of fibrous dysplasia

The most common complication is that fibrous dysplasia increases the chance that you’ll break a bone. You may have issues with hearing or vision if it affects bones around your eyes or ears.

How doctors diagnose this condition

A healthcare provider will do a physical exam. If you have pain, they’ll carefully examine the area of your body that hurts. They’ll ask when you first noticed symptoms. Your provider may do the following tests:

• Blood tests or urine tests to check for high enzyme levels that could mean you have fibrous tissue growing in your body
• Imaging tests like X-rays, CT scans or MRIs that may detect fibrous tissue on your bones, broken bones or changes in the shape of your bones
• Biopsy to remove a sample of the fibrous tissue or your healthy bone tissue for testing

How fibrous dysplasia is treated

Your treatment will depend on your symptoms and how the condition affects you. The most common fibrous dysplasia treatments are:

• Observation. You might not need any treatment other than follow-up appointments with your healthcare provider. They’ll watch for any changes in your bone health.
• Medication. Providers may prescribe drugs that strengthen your bones and help prevent fractures.
• Bracing. Wearing braces can support your bones and help them grow correctly.
• Surgery. You may have surgery to treat broken bones, including bone grafts.

When should I see my healthcare provider?

You should talk to a healthcare provider if you have bone pain that doesn’t go away. If you have fibrous dysplasia, talk to your provider if you feel like your symptoms are getting worse or if it seems that treatments aren’t making a difference.

Fibrous dysplasia weakens your bones, so you’re more likely to break a bone. If you fall, get hit on a bone or are in a vehicle accident, go to the emergency room right away.

What can I expect if I have fibrous dysplasia?

There’s no single answer to that question. Fibrous dysplasia affects people in different ways. But one thing is certain: fibrous dysplasia is a chronic condition. That means there’s no cure for it. There are treatments to reduce the ways the condition may affect you. If you have fibrous dysplasia, ask your healthcare provider what you may expect.