Initial pre-referral workup

Clinical history

Physiologic bowing is the most common cause of bow legs and is seen from birth until two or three years of age.

Be aware of pathological causes such as rickets and Blount’s disease.

Physical examination

• determine the patient’s height and weight percentiles
• assess in-toeing
• measure intercondylar distance in standing with feet together
  

Investigations

X-ray of knees if:

• unilateral deformity
• progressive deformity
• lack of spontaneous resolution
• aged over three years old
• consider checking Vitamin D in at risk groups

GP management

Reassure the parents that physiological bow legs will resolve by age three with normal development. No specific treatment is required.

If concerned, serial measurement of intercondylar distance every six months to document progression or resolution may be useful.

Refer parents to Bow legs and knock knees in children (fact sheet).

Indications for specialist referral

Routine

• persistence of bow legs after three years of age
• intercondylar separation is more than six centimetres
• asymmetrical deformity
• excessive deformity
• progressive deformity or lack of resolution
• pain after a traumatic event
• other associated skeletal deformity such as height below fifth centile for age