valgum

Valgum is a descriptive term for a deformity in which the distal part of a limb deviates away from the midline in the coronal plane. The term is used for several joints, with genu valgum (knock-knee) being the most common in the lower extremity. Other examples include cubitus valgus at the elbow and hindfoot ankle valgus. Valgum is typically contrasted with varus, where the distal segment deviates toward the midline.

In children, valgus deformities are often physiological. Genu valgum commonly appears around ages 3 to 5 and usually self-corrects by around 7 to 8 years of age. Persistent or progressive deformity, or valgus associated with symptoms or a known underlying condition, warrants further evaluation. Causes beyond normal development can include nutritional deficiencies such as rickets, congenital or metabolic bone disorders, past physeal injuries, trauma, obesity, or neuromuscular or developmental conditions. Hip disorders that affect growth can also contribute indirectly to knee valgus.

Diagnosis is based on physical examination and imaging. Clinicians assess alignment, gait, and the distance between the ankles when the knees touch (intermalleolar distance). Weight-bearing radiographs of the lower limbs evaluate the tibiofemoral and mechanical axis angles and help quantify deformity and plan management.

Management ranges from observation to intervention. Mild, asymptomatic, or physiologic valgum often requires no treatment beyond monitoring. Physical therapy may improve strength and alignment concepts. Bracing or guided growth using temporary physeal modulation (such as eight-plate hemiepiphysiodesis) can correct deformity over time in growing children. Severe, disabling, or progressive valgus in adolescents or adults may necessitate surgical procedures, including osteotomies to realign the limb. Prognosis is generally favorable with appropriate management, particularly when the underlying cause is addressed.