National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Blount disease



Other Names:
Tibia vara; Osteochondrosis deformans tibiae; Blount's disease; Tibia vara; Osteochondrosis deformans tibiae; Blount's disease; Blount-Barber syndrome; Erlacher-Blount syndrome; Osteochondrosis deformans tibiae, familial infantile type See More
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Blount disease is a growth disorder of the shin bone (tibia) characterized by inward turning of the lower leg (bowing) that slowly worsens over time. While it is not uncommon for young children to have bowed legs, typically the bowing improves with age.[1][2] There are two types of Blount disease (early-onset and late-onset), based on whether symptoms begin before or after four years of age.[3] Blount disease may occur in one or both legs and can lead to shortening of the affected leg and other changes within bones of the legs. The cause of Blount disease is not well understood; however,  a variety of hereditary and genetic factors are likely involved. The condition is more common among certain populations and is associated with obesity and early walking.[1][4] Treatment may involve bracing and/or surgery.[1]
Last updated: 7/27/2016

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Tibial bowing
Bowed shankbone
Bowed shinbone
[ more ]
0002982
30%-79% of people have these symptoms
Abnormality of the knee 0002815
Abnormality of the proximal tibial epiphysis
Abnormality of the end part of innermost shankbone
Abnormality of the end part of innermost shinbone
[ more ]
0010591
Abnormality of the tibial metaphysis 0006491
Osteochondrosis 0040188
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance 0000006
Genu varum
Outward bow-leggedness
Outward bowing at knees
[ more ]
0002970
Osteochondritis Dissecans 0010886
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Last updated: 7/1/2020

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources


Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • Orphanet lists European clinical trials, research studies, and patient registries enrolling people with this condition. 

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

Social Networking Websites


These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • The American Academy of Orthopaedic Surgeons has information on Blount disease. Click on the link above to view this information page.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Blount disease. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.


  1. Neil K. Kaneshiro. Blount disease. In: David Zieve. MedlinePlus. 11/20/2014; https://medlineplus.gov/ency/article/001584.htm.
  2. Bowed legs. American Academy of Orthopaedic Surgeon. http://orthoinfo.aaos.org/topic.cfm?topic=A00230. Accessed 3/19/2009.
  3. Sanjeev Sabharwal. Blount disease. J Bone Joint Surg Am. Jul 01 2009; 91 (7):1758-1776. http://www.ncbi.nlm.nih.gov/pubmed/19571101.
  4. Lauren LaMont, MD. Blount disease. Medscape. Dec 17, 2015; http://emedicine.medscape.com/article/1250420.