An outward angulation of the lower legs such that when the knees are touching the ankles are separated.
Causes, incidence, and risk factors
By the time the child is 2 or 3 years old most children develop a slight knock-kneed stance, often with significant separation at the ankles when the knees are touching. This is part of normal development and often persists through age 5 or 6, at which time the legs begin to straighten fully. By puberty, most children can stand with the knees and ankles touching (without forcing the position). Knock-knees can also develop as a result of disease processes. Most often the precipitating condition has already been diagnosed and the knock-knees are recognized as a symptom of the condition.
Signs and tests
If the history and a physical examination indicate a specific cause for the knock knees other than normal development, your health care provider will order the appropriate studies.
Treatment
The condition is usually not treated. Surgery may be considered for a condition that persists beyond late childhood and in which the separation between the ankles is severe.
Expectations (prognosis)
Physiological knock-knees normally resolves without intervention. For cases requiring surgery, the procedure provides excellent cosmetic results.
Calling your health care provider
Call your health care provider to schedule an evaluation if you suspect your child has knock-knees.
Prevention
There is no known prevention for normal knock-knees.