A rare condition, Blount's disease affects the growth of the shin bone (tibia) in children and adolescents. It results in bending the lower leg inward, giving the appearance of bowlegged. As well as causing pain and instability, Blount's disease can also damage nerves and cause arthritis in the knee. This blog post discusses the causes, symptoms, diagnosis, treatment, and prevention of Blount's disease.
The exact cause of Blount’s disease is not well understood, but it is likely related to a combination of genetic and environmental factors. In Blount’s disease, the bone growth plate near the inside of the knee is affected, which produces new bone tissue. It normally grows at the same rate as the rest of the bone, resulting in a straight leg. As a result of Blount's disease, the growth plate slows or stops growing, while the rest of the bone continues to grow normally, causing the lower leg to curve inward.
Some of the risk factors that may contribute to Blount’s disease are:
Obesity or rapid weight gain
Early walking (before 12 months of age)
Family history of the condition
African American race
A bowlegged appearance is the main symptom of Blount's disease, which occurs when the child stands or walks. This inward bend may be mild or severe, and it may affect one or both legs.
Knee pain or instability
Difficulty walking or running
Shorter stature than expected
Uneven leg lengths
By examining the leg and taking an X-ray, a doctor can diagnose Blount's disease. The doctor will look for signs of deformity, such as sharp angles or bumps on the inside of the knee. It is possible to observe abnormalities such as irregularity, fragmentation, or flattening of the growth plate on the X-ray, which will provide information about the shape and size of the bone and growth plate.
Blount’s disease is classified into two types based on the age of onset:
Infantile Blount’s disease: This type occurs in children between the ages of 1 and 3 years old. It usually affects both legs and only the tibia. It is more common and more responsive to treatment than the adolescent type.
Adolescent Blount’s disease: This type occurs in children over 10 years old. It is more likely to affect one leg and both the tibia and the femur (thigh bone). It is less common and less responsive to treatment than the infantile type.
The goal of treatment for Blount’s disease is to correct the deformity and improve the alignment of the leg. The treatment options depend on the age, severity, and type of Blount’s disease. The main options are:
In this non-surgical option, a special device is worn to apply pressure to the outside of the knee and straighten the leg without surgery. It may take several months or years for bracing to be effective in young children with infantile Blount's disease with mild to moderate deformity.
A surgical procedure involves cutting and reshaping the bone in order to correct the deformity. Surgery is usually reserved for older children with adolescent Blount's disease who suffer from severe deformity or who are unable to be braced. Depending on the location and extent of the deformity, different types of surgery are available, including osteotomy, hemiepiphysiodesis, and external fixation. Multiple procedures may be required and a lengthy recovery period may be required.
There is no sure way to prevent Blount’s disease, but some of the possible measures that may reduce the risk are:
Maintaining a healthy weight and avoiding obesity
Delaying walking until the child is ready (usually around 12 months of age)
Seeking medical attention if the child has persistent or worsening bowing of the legs
In children and adolescents, Blount's disease affects the development of the shin bones. As a result, the lower leg bends inward, giving the appearance of a bowlegged leg. Depending on the age, severity, and type of Blount's disease, treatment options include bracing or surgery. In addition to pain, instability, nerve damage, and arthritis in the knee, Blount's disease can cause pain, instability, and nerve damage. The prevention strategies include maintaining a healthy weight, delaying walking, and seeking medical attention if the child's legs continue to bow. Most children can achieve a good outcome and a normal quality of life with proper diagnosis and treatment of Blount’s disease.
