Fibrous Dysplasia

WHAT IS FIBROUS DYSPLASIA?

Fibrous dysplasia is a condition in which the bone does not form properly and a type of fibrous tissue forms instead. This causes the bone to be weaker than normal. It can occur in any bone throughout the body and sometimes occurs in more than one bone. The fibrous tissue can grow over time, causing the bone to become weaker. At Loma Linda University Health, we offer treatment for fibrous dysplasia.

WHAT ARE THE SYMPTOMS OF FIBROUS DYSPLASIA?

Symptoms of fibrous dysplasia vary from person to person, and some people do not know they have one until it is discovered on an X-ray or other image. Typically, someone is more likely to have symptoms if more than one bone is involved and in locations where more weight is placed on the bone, such as the pelvis and legs. Those symptoms may include:

• Pain
• Cosmetic deformity
• Deformity of the bone
• Limb length discrepancy
• Fracture

WHAT ARE THE SYMPTOMS OF FIBROUS DYSPLASIA THAT DO NOT INVOLVE THE BONE?

Other symptoms of fibrous dysplasia may involve hormones and the skin rather than the bone, but these are rare. They typically occur in people who have fibrous dysplasia in multiple bones. Skin changes, called café-au-lait spots, are common when multiple bones are involved. These are darkened areas of skin that are sometimes felt to be birthmarks. Hormonal disturbances can also rarely occur, and depend on the gland affected. Symptoms can include:

• Early puberty
• Sweating, weight loss, and anxiety
• Weight gain and developing diabetes
• High levels of calcium in the blood
• Excessive growth

WHAT IS THE CAUSE OF DEVELOPING FIBROUS DYSPLASIA?

The exact cause of fibrous dysplasia is not known, other than that it is due to a genetic defect. It is not hereditary/passed down from generation to generation. The genetic defect causes the bone to not form properly and the fibrous tissue to form instead. Sometimes this can occur in multiple organs and not just the bone, causing hormonal problems. No toxins or environmental factors are known to cause the genetic defect, and it can occur in anyone.

HOW IS FIBROUS DYSPLASIA DIAGNOSED?

Diagnosis is by an X-ray and physical exam. You will likely be asked if you have any birthmarks, and your skin may be checked for café-au-lait spots. Many times, a bone scan will be ordered to see if there are other bones involved. A CT scan or MRI may also be needed to evaluate the bone. A biopsy may be necessary for diagnosis, which can typically be performed using a needle or a small incision under anesthesia. Blood tests may be performed to determine if you have a hormonal disturbance.

WHAT IS THE CANCER RISK WITH FIBROUS DYSPLASIA?

There is a very small risk (less than 1%) that fibrous dysplasia can become cancerous. If there is any new growth, pain, or other symptoms that develop, it should be checked immediately. Treatment of cancerous fibrous dysplasia may include:

• Further imaging (new x-rays, MRI, CT scan, bone scan)
• Biopsy
• Surgery for removal

HOW IS FIBROUS DYSPLASIA TREATED?

Treatment of fibrous dysplasia depends on the location and the amount of bone involved. If there is a small area of bone involved that is unlikely to break and there is no associated pain, it can be monitored. Medications, called bisphosphonates, may be used to help treat pain. If hormonal disturbances are discovered, you may be referred to an endocrinologist for further treatment.

If there is a risk for fracture, or if a fracture has occurred, surgery may be necessary. Surgery may also be necessary to prevent deformities or limb-length discrepancies from occurring. The type of surgery depends on the problem and location. As bone production is abnormal, bone that is obtained from an organ donor (cadaveric, allograft bone) may be used to replace the abnormal bone. Bone substitutes made from a form of calcium may be considered as well. There is a risk that the bone or bone substitute can be reabsorbed and the fibrous dysplasia may come back. This risk has been shown to occur when the patient’s own bone (autologous bone) is used.

During surgery, you may need a blood transfusion. Fibrous dysplasia has a healthy blood supply, and this may be needed depending on the extent of the surgery. Surgical treatment may consist of:

• Resecting the abnormal bone, called a curettage, where the fibrous tissue is scooped out
• Placing allograft (donated) bone and/or a bone substitute
• Placing a plate or rod in the bone to prevent a fracture or a deformity, or to fix a fracture
• Cutting the bone and using plates or rods inside the body, or external fixation outside the body to correct the deformity or limb-length discrepancy

Regardless of the treatment prescribed, the area of fibrous dysplasia is typically monitored periodically with X-rays.

NEXT STEPS

If you believe you may have fibrous dysplasia, here are the next steps we recommend.

• Seek medical intervention. Taking proactive action is paramount to avoiding future complications, and a medical exam is the first step. To request an evaluation at Loma Linda University Health, contact the Limb Lengthening Center or schedule the appointment through MyChart.

• Pay attention to details. If symptoms worsen or expand, make a note of it and bring it up during the appointment. We have the most experienced limb lengthening and reconstruction surgeons in the western United States – but as the patient or parent, you have firsthand knowledge of the condition.

• Participate in the journey. The Loma Linda University Health Limb Lengthening Center is comprised of a team that works well with patients of all ages. We customize a treatment plan for every patient and design it to accomplish all appropriate goals. Trusting the expertise of our physicians, collaborating with our physical therapists, and strong family participation are all required to make this happen.

Loma Linda University Health has experts in the field of diagnosing and treating fibrous dysplasia. We provide a comprehensive treatment plan that caters to the individual. When you seek treatment for fibrous dysplasia, we can help you determine whether observation, surgery, medication, or a combination of treatments is right for you.