Bowleg, or genu varum, is a condition involving the misalignment of the knees that can affect individuals across all age groups. It has various causes—congenital, developmental, or post-traumatic—and, if untreated, may lead to knee pain and progressive joint degeneration. This condition places abnormal stress on the knee joint, often resulting in pain, increasing deformity, instability, and further damage. Correcting the alignment can improve knee function, alleviate pain, and prevent accelerated joint degeneration.

In adults with longstanding bowleg, the inner (medial) knee compartment is overloaded, while the outer (lateral collateral ligament) is overstretched, leading to pain, instability, and arthritis. To delay or prevent the need for knee replacement surgery, realignment using osteotomy is often recommended.

Bowleg is characterized by legs that curve outward, causing the knees to remain apart even when the ankles are together. While this is common in infants due to their fetal position, most children outgrow it as they begin standing and walking between 12 and 18 months. If bowing persists beyond age three, evaluation for underlying deformities may be required.