Bow Legs

Bow Legs (Genu Varum) in Children

Many children are born with bowed legs. In most cases, the legs gradually straighten naturally by about 2½–3 years of age.

Types of Bow Legs

Physiological Bow Legs

• Common and normal up to around 2 years of age
• Symmetrical and painless
• Improves spontaneously with growth

Pathological Bow Legs

Persistence beyond 3 years of age is abnormal and may be due to:

• Early walking in an overweight child
• Vitamin D deficiency (rickets)

Growth plate disorders affecting one side of the knee (e.g. Blount’s disease)

Assessment And Investigations

• Blood test to check vitamin D levels
  • Ideal level: >75 nmol/L
• Plain knee X-rays to assess growth plates
• Long-leg alignment X-rays to determine the site and severity of deformity

Treatment

Physiological Bow Legs

• Observation and monitoring until around 2½–3 years
• Vitamin D supplementation is advisable

Pathological Bow Legs

• Correct vitamin D deficiency if present
• Reassess alignment after levels normalise
• Consider surgery if deformity persists and is clinically significant

Surgery is usually considered about one year after vitamin D levels have been corrected, if required.

Surgical Options

The choice depends on age and remaining growth.

Hemiepiphysiodesis (growth modulation)

Temporary plates and screws slow growth on one side of the bone, allowing the opposite side to straighten the leg naturally.

• Child can usually walk soon after surgery as comfort allows
• Metalwork must be removed once correction is achieved

Corrective Osteotomy

Used in older children nearing skeletal maturity.

• Bone is cut and realigned to correct deformity
• Provides immediate correction but requires a longer recovery period

Early assessment ensures correct identification of pathological causes and helps prevent long-term knee problems.