|
Blounts Disease is a cause of progressive lower extremity bowing. It is seen in too distinct age groups, toddlers and adolescents
Blounts Disease arises from a growth abnormality of the growth plate just below the knee, located in the proximal tibia. For reasons not fully understood, in the condition the inside part of the growth plate slows or stops its growth, while the outside part of the growth plate continues to grow normally. This results in the developing of a deformity called tibia vara. The foot becomes twisted in relative to the knee. The leg also is directed inward from the knee.
This is a image of a three year old male with bilateral Blounts Disease. Notice how acute the bowing is just below his knees especially on his left side.
This is an image of a fourteen year old male with left Blounts Disease.
Toddlers and adolescents with Blounts Disease are generally overweight, suggesting weight may play some role in the etiology of Blounts Disease.
For the young children with Blounts Disease, we can treat them with a special Blounts brace. Bracing is effective for children under three years old. After three years of age, there is usually not enough growth remaining in the tibia to allow the brace to work. For these kids, a surgical osteotomy of the tibia is performed to correct their leg alignment.
This is a picture of a Blounts brace. The brace has to correct both the angular and rotational deformity of the tibia. During the day, the brace is unlocked at the knee for walking. The rotational deformity is best corrected with the knee bent. At night, the brace is locked at the knee to better correct the angular deformity. Every few months the bar of the brace is bent to help correct the deformity.
Surgery to correct the deformity of Blounts Disease involves cutting the tibia and correcting the deformity. Cutting a bone is termed an osteotomy. An osteotomy is also the treatment of choice for the adolescents with Blounts.
The osteotomy must correct the rotational and angular deformities of the tibia. The correction can be done all at once or it can be done gradually with the use of an external fixator.
|