Blount Disease: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Blount Disease?
A pediatric orthopedic surgeon (a children's bone doctor) treats Blount disease. A pediatrician or family doctor often notices the problem first and makes the referral. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is Blount disease?
Blount disease, also called tibia vara, is a bone growth problem in children. The shin bone (tibia) grows in a way that makes the lower leg bend inward, toward the other leg. Doctors call this inward bend a varus deformity. It happens when extra pressure on the growth plate, the cartilage area where bone grows, damages the inside part of the top of the shin bone. That side then grows more slowly than the rest of the bone. It is not common: less than 1 percent of children in the United States have it.
Symptoms
The main sign is legs that look bowlegged, and this does not go away as the child grows. Blount disease can cause severe bowing of one or both legs. Other signs include:
- Knee pain, mostly in the older child type.
- Lateral thrust, a sideways shift of the knee when the child walks.
- One leg shorter than the other.
- Trouble walking as the bend gets worse.
Some bowing is normal in toddlers under about age 2. Bowing that continues past that age, or gets worse, is a warning sign.
Causes and who gets it
The exact cause is not clear. Extra compressive force on the top of the shin bone plays a big part. Genetic susceptibility may also add to the risk. Known risk factors include obesity, walking at a very early age, and African-American heritage. The disease comes in two forms. The infantile type is diagnosed between ages 1 and 3. It usually affects both legs, and it is more common in boys. The adolescent type starts in late childhood or early teenage years. It usually affects one leg, often causes knee pain, and is linked to being overweight.
How doctors diagnose it
Doctors use the medical history, a physical exam, and X-rays. Long-leg X-rays, taken from hip to ankle on both sides, let the doctor measure the angle of the bend. Certain X-ray signs, such as a beak-shaped bump on the top of the shin bone, point to Blount disease. An MRI scan can show the cartilage in detail. Doctors also use the X-rays to sort the disease into six stages, from mild to severe.
Treatment
Treatment depends on the child's age and how severe the bend is:
- Bracing: a full-leg brace (a knee-ankle-foot orthosis) pushes the knee outward. It works best when started before age 3 in children who are not obese, worn mainly at night for about a year.
- Guided growth surgery (hemiepiphysiodesis): the surgeon places small implants on one side of the growth plate. That side slows down, so the other side catches up and the bone straightens over time.
- Osteotomy: the surgeon cuts and reshapes the bone to straighten the leg right away, or slowly with an external frame.
Surgery has risks. An osteotomy done all at once can injure the peroneal nerve, a nerve near the knee, or cause compartment syndrome, a painful buildup of pressure in the leg muscles.
When to see a doctor
See a doctor if your child's legs appear to be bowing, or if bowed legs appear to be getting worse. Bowed legs are a normal finding in most children until about age 2, so bowing that goes on past that age should be checked. Also see a doctor for knee pain on the inside of the knee in an older child, or for a sideways shift of the knee when walking. Early care gives the best chance of a straight leg.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either one can check your child's growth at regular visits, spot bowing that is not going away, and arrange the X-rays and specialist referral.
Common questions
Is bowlegged appearance ever normal?
Yes. Toddlers under about age 2 often have bowed legs. This is a normal stage of growth. Bowing that continues past age 2, or gets worse, should be checked by a doctor.
Can Blount disease be prevented?
There is no sure way to prevent it, because the exact cause is still unclear. Weight loss may be helpful for overweight children.
When is surgery needed?
Surgery is most often needed if braces do not work, or if the problem is not diagnosed until the child is older. Options include guided growth, which uses implants to straighten the bone slowly, and osteotomy, which reshapes the bone.
Does Blount disease affect both legs?
The infantile type usually affects both legs. About 80 percent of infantile cases are on both sides. The adolescent type more often affects just one leg.
Sources
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
