Bowed Legs (genu varum)

What are bowed legs?

Bowed legs are characterised by a distinct space between the knees and lower legs. This may result from one or both legs curving outward. This condition is common in toddlers, and generally the legs will straighten as the child grows. However, if it persists there may be an underlying cause and require treatment.

Diagram of lower limb alignment – Bowed legs (left) vs. Normal alignment (right)

Symptoms

  • Most often this condition is asymptomatic
  • Unusual walking pattern – this can be in combination with inward rotation of the feet (in-toeing).
  • Knee instability or giving way
  • Hip, knee and ankle discomfort or pain.
  • Difficulty running

Causes

  • Physiologic – normal part of growth and development (most common), seen from birth until 2-3 years of age.
  • Blount’s disease – an abnormality in the growth plate of the tibia.
  • Rickets
  • Trauma
  • Skeletal dysplasia
  • Infection
  • Benign tumours or tumour conditions

When should parents be concerned?

Bowed legs in toddlers usually isn’t cause for concern and should improve as your child gets older. Most commonly it will resolve by 3 years of age with normal development. However, it may be abnormal if there is:

  • A limp or pain
  • Difficulty in walking
  • Only one leg is affected, or one leg is significantly worse than the other
  • Severe
  • Deformity beyond 3 years old
  • Progressive deformity
  • Short statured
  • A traumatic event
  • A known underlying condition

Diagnosis

Dr Graff will take a history and examine the legs and likely organise x-ray imaging for further assessment.

Management and treatment

Treatment is rarely needed and most commonly as your child grows their legs will straighten. Majority will grow out of the condition by 3 years of age. Depending on the underlying cause and extent of deformity, bracing, surgery, or a combination of both may be used.

Surgery is only required if a severe deformity is present or persisting, the deformity is asymmetric, there is significant difficulty with pain or mobility which could be improved.

While your child is still growing (before the age of 13 - 14 for girls and 16 - 17 for boys), using guided growth (small metal plates or screws over the growth plate) is a small, usually day case procedure, to help correct over time. After growth has stopped, larger surgery may be required to correct the deformity.

Case imaging: Unknown Cause of Bowed Leg in 5 Year Old Boy, preoperative, with circular frame and post procedure by Dr Christy Graff

Case imaging: Blount's Disease in 17 Year Old Girl, preoperative, with circular frame and post procedure by Dr Christy Graff

Useful Website

Women's and Children's Health Network

https://cdn.wchn.sa.gov.au/downloads/WCH/children/orthopaedics/Bow-Leg-Fact-Sheet.pdf