Genu valgum

Associate Editor-In-Chief:

Genu valgum, commonly called "knock-knees", is a condition where the knees angle in and touch one another when the legs are straightened. Individuals with severe valgus deformities are typically unable to touch their feet together while simultaneously straightening the legs. The term originates from the Latin genu, "knee", and valgum, "bowlegged".

Mild genu valgum is relatively common in children up to two years of age, and is often corrected naturally as children grow and develop. However, the condition may continue or worsen with age, particularly when it is the result of a disease, such as rickets or obesity. Idiopathic is the term used to describe genu valgum that is congenital or has no known cause.

Other systemic conditions may be associated, such as Schnyder Central Corneal Dystrophy, an autosomal dominant condition frequently reported with hyperlipidemia.

Treatment
Generally, there is no known cure for knock knees post-childhood. Contrary to common belief, no amount of orthotic treatment or bodybuilding exercise will straighten knock knees for adults. If the condition persists or worsens into late childhood and adulthood, a corrective osteotomy may be recommended to straighten the legs. This however is more of a cosmetic remedy, and may hamper athletic performance in the future.

Adults with uncorrected genu valgum are typically prone to injury and chronic knee problems such as chondromalacia and osteoarthritis. In some cases, total knee replacement (TKR) surgery may be required later in life to relieve pain and complications resulting from severe genu valgum.

Diagnostic test
The Q angle which is formed by a line drawn from the anterosuperior iliac spine through the center of the patella and a line drawn from the center of the patella to the center of the tibial tubercle, should be measured next. In women, the Q angle should be less than 22 degrees with the knee in extension and less than 9 degrees with the knee in 90 degrees of flexion. In men, the Q angle should be less than 18 degrees with the knee in extension and less than 8 degrees with the knee in 90 degrees of flexion.