Initial pre-referral workup

Clinical history

Physiological knock knees is seen from three to five years of age; it resolves with growth by age eight

Knocked knees may be familial.

Physical examination

Determine the patient’s height and weight percentiles.

Measure intermalleolar distance in standing with knees together.

Investigations

X-ray of knees if:

• unilateral deformity
• progressive deformity
• lack of spontaneous resolution after age of eight

GP management

Reassure the parents that the majority of physiological knock knees will resolve with normal development by age eight, with no specific treatment required.

If concerned, serial measurement of intermalleolar 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 significant knock knees beyond age eight
• intermalleollar separation more than eight centimetres
• asymmetrical deformity
• progressive deformity or lack of spontaneous resolution
• pain after a traumatic event
• other associated skeletal deformity such as height below fifth centile for age