Physiological genu varum is a very common condition among young children, characterized by an angular deformity of the knee curving laterally. It generally affects children younger than 2 years and is the most common cause of leg bowing in children. The condition generally does not cause pain or functional impairments and, in most cases, resolves spontaneously.

Causes / typical injury mechanism: Physiological genu varum is a result of the typical progression of lower extremity alignment over the first 7 years of life. At birth, lower limb alignment is varus (mild bowing), which generally increases with the introduction of ambulation. A more accentuated varus angle is referred to as physiological genu varum, which is defined as having a varus deformity with a tibiofemoral angle that is within 2 standard deviations from the mean for the age of the patient. This measurement is a very important tool in distinguishing physiological and pathologic genu varum.

Classic history and presentation: Parents usually come in with concerns about the appearance of the child's legs, excessive falling, and sometimes in-toeing. More specifically, the condition presents with bilateral and symmetric bowing of both femur and tibia bones, as well as a normal stature overall.

Prevalence:

• Age – Children younger than 2 years.

Risk factors: There are no well-established risk factors for the condition.