Blount’s disease is a growth disorder that affects the two parallel bones, the fibula and tibia which make up the lower leg and cause them to curve outward or bow.
There are two types of Blount’s disease:
Infantile: This type of Blount’s disease that affects toddlers, usually before the age of 4. 70 percent of infantile diagnoses are in both legs, or bilateral.
Adolescent: Adolescent Blount’s disease affects older children and teens. These types of Blount’s disease generally affect one leg.
Although the cause is not known, many doctors believe that the weight of the growth plate causes the curvature, or uneven bone growth, and the shin bone, or tibia, does not develop normally causing the bone to become angled. Blount’s disease is progressive and worsens with growth and should be treated aggressively. Blount’s disease is more prevalent among African-American children and is also associated with obesity and early walking.
Symptoms of Blount’s Disease
The symptoms of Blount’s disease are:
- One or both of the lower legs are turned inward or bowed
- This bowing or angle is visible just below the knee
- The symptoms quickly get worse
Diagnosing Blount’s Disease
If your child’s legs appear bowed, and complaining that their knee hurts and it seems to be worsening over time and cannot be linked to a back injury, your doctor may suspect Blount’s disease and refer you to a pediatric orthopedic doctor who will perform a complete physical examination of your child and have X-rays of their legs taken.
The doctor will look for abnormal bone growth in the X-rays and take various measurements of your child’s leg to determine the severity of the bowing or angling.
In children under 2, it is sometimes difficult to determine if they have Blount’s disease because sometimes there is age-appropriate bowing that occurs. For these cases it is important to have close follow-up. Usually when your child is 3, it is easier to determine a more definitive diagnosis.
Treatment of Blount’s disease can involve the following:
Bracing: Braces are used to treat children under three years of age who develop severe bowing.
Surgery: Surgery may be needed if the bowing is not diagnosed until your child is older, or, if braces do not work to correct the bowing. Surgical procedures can be done to place the shin in the proper position and in some cases, lengthen the shin. In other cases, the growth of the outer half of the shin bone can be restricted and surgery can correct this limitation, which allows the child’s natural growth to correct or reverse the bowing.