What it means?
Bow legs mean both knees won’t touch each other but both feet will touch together. Knocked knees means both knees will touch each other but both feet are apart
What causes it?
Normally babies will have bowing of both lower limbs up to the age of 2 years and gradually grow out of it and reach normal alignment that means straight limbs by 3 years of age
After that limbs will be in knocked position up to 6 years of age then gradually they grow out of it and reach normal adult straight limbs.
If the bowing or knocked knees persist beyond these ages which could be abnormal and need to be further evaluated.
Persistence of bowing or knocked knees may be due to metabolic causes like vitamin D deficiency, bony abnormalities like blounts disease, skeletal dysplasia, growth plate damage due to injury or infection
How child will present like?
- Deformity of lower limbs for example bowed legs, knocked knees
- Difficulty in running, walking, climbing stairs
- Some child may complaints of pain around the knee joint
What are the tests required?
- Child need to assessed clinically as a whole and entire lower limb – hip, knee and ankle joints
- Blood test like vitamin D3, Serum calcium, serum Phosphorus, Serum alkaline phosphatase to detect metabolic causes
- Full length standing x-ray of lower limb to assess alignment and magnitude of the deformity
What are the treatment options?
- Most toddlers with bow legs and older kids with knock knees grow out of it will not require any special braces or shoes
- If the kids fail to grow out of bow leg or knock knees with progressive or persistent deformity need further evaluation and management
- If deformity due to metabolic causes like vitamin D deficiency can be treated by medicines
- If deformity fails to improve with medicines or due to bony abnormalities like blounts disease need surgical correction
- Younger child by growth modulation surgery which means temporarily stop the growth of one side of growth plate and allow abnormal side to catch up growth and make limb straight
- Older child by corrective osteotomy which means cut the bone and realign it straight
What will be outcome?
- Toddler with typical bow legs or knock knees develop normally will not have any long term problems
- Abnormal bow legs or knock knees need to be detected early and treated accordingly and keep under regular follow up until the growth completes