Blounts disease

What is Blount’s disease?

Blount’s disease is a growth disorder of the shin bone (tibia) in which the growth plate just below the inner side of the knee does not grow normally. This causes the lower leg to bow inwards (bow legs, or tibia vara). Unlike the bowing that is normal in toddlers and corrects by itself, Blount’s disease is progressive and does not resolve without treatment. It can appear in early childhood (infantile) or in older children and adolescents (late-onset), and is more common in children who walk early and in those carrying excess weight.

Signs and symptoms

• Bowing of one or both lower legs that is not improving with age

• Bowing that is getting worse

• A prominence on the inner side of the knee

• In some children, an in-turning of the foot

• Usually painless in younger children; older children may have knee discomfort

How is it diagnosed?

Diagnosis is made through clinical examination and standing X-rays of the legs, which show the characteristic changes at the growth plate and allow the angle of the deformity to be measured. The pattern helps distinguish Blount’s disease from normal physiological bowing.

Treatment options

In young children with mild changes, bracing may be tried. When the condition is progressive or presents in older children, surgery is usually required. 

Options include 

Guided growth (a small procedure that steers the remaining growth to straighten the leg) using an 8-plate, and 

Corrective osteotomy (cutting and realigning the bone). The choice depends on the child’s age, the severity, and how much growth remains.

Outlook

When identified and treated at the right time, the alignment of the leg can be substantially corrected. Early diagnosis improves the outcome and may allow simpler treatment.

When to seek advice

If your child’s leg bowing is not improving with age, is only on one side, appears to be worsening, or is associated with a limp.

This information is for general guidance only and is not a substitute for a consultation with Mr Wadia. If you are worried about your child, please seek medical advice.