When an individual’s leg is turned outward at or below the knee, he or she may be diagnosed with varus deformity. In the mid-1800s, “bowlegged” was the term for people with this condition, but there are references to “curved” legs in ancient Greece texts based on Hippocrates’ teachings. While varus deformity is considered normal in babies and young children, it can signify illness in older children and adults.

Early Bowlegs

Inside a mother’s womb, a baby’s body folds to fit in the cramped quarters. When the baby is born, his or her legs are bent, with the knees turning outward. Babies’ bones inside the womb are softer to allow for passage through the birth canal, and this also allows their body to adapt to living in a small space. In most cases, however, bowed legs disappear by age three. Up until age two, the medical term for bowed legs is physiologic genu varum. Bone development continues into the 30s, which means bone issues can continue to develop due to genetics or trauma, until this time.

Varus Deformity in Children

If the legs have not straightened by the time a child reaches three years old, the physician may check for other issues including Blount’s disease, or perform tests for vitamin deficiencies. A varus deformity is most evident when the child stands or walks. The toes may turn inward, and he or she may complain of hip, knee, or ankle pain due to added stress on joints in other parts of the leg. Excess weight can also play a role when bowed legs continue into adolescence.

Bone Alignment in the Legs

When the knees are in normal alignment, the knee joints receive equal distribution of body weight. The knees turning inward is colloquially called “knock-kneed,” and, medically, a valgus deformity. Both varus and valgus deformities cause misalignment of the knee. Trauma to the leg at an early age can cause the misalignment but tends to appear only on the injured leg. Genetic causes present in both legs.

Symptoms of Varus Deformity

In addition to the visual appearance of the knees pointing outwards, pain is a symptom of varus deformity and may occur in the knees or hips. The misalignment prevents the knees from touching when the feet and ankles are together, adding stress on the joints. Although it is rare for younger children with the condition to feel any pain, adolescents and adults may experience discomfort on the outsides of the knees. People who experience worsening pain, increased misalignment, or difficulty walking or running should seek medical attention.

Causes of Bowlegs

Any condition that prevents the bones from forming properly can cause a varus deformity. Blount’s disease is most frequently diagnosed in toddlers and adolescents. An abnormality of the growth plates in the upper shinbone causes it. This condition may be difficult to diagnose in children under two years of age, due to bowed legs being normal in toddlers. Rickets can also cause varus deformities and may develop due to a vitamin D, phosphorus, or calcium deficiency. An inherited form of rickets that prevents absorption of vitamin D can cause varus deformity as well.

Paget’s Disease

In normal bones, old bone tissue is slowly replaced with new bone tissue, continuously. Paget’s disease is a metabolic condition that prevents bones from rebuilding as they should. More commonly diagnosed in older adults, it affects the spine, pelvis, skull, and legs. The condition can cause bow legs and additional joint problems. A family history of Paget’s disease increases the likelihood of developing the condition, and men are more often affected than women. Paget’s disease is treatable and generally does not cause serious complications.

Achondroplasia

Individuals with achondroplasia are unable to convert cartilage to bone. The genetic condition results in insufficient or abnormal bone growth and short stature, or dwarfism. As infants, people with achondroplasia have less muscle strength, and the ligaments are more flexible than normal. The fibula or calf bone usually grows longer than the tibia or the shinbone which causes a form of varus deformity called genu varum.

Other Causes of a Varus Deformity

Improperly healed bone fractures can cause varus deformities, as can poor posture and strain. Varus deformities are common in dancers and athletes who may make the issue worse by failing to seek medical attention. Lead or fluoride poisoning can cause bowlegs as well. In adults, arthritis is both a symptom and a cause of a varus deformity and is more common in those with rheumatoid arthritis than osteoarthritis. People with osteoarthritis may develop valgus deformities.

Treatment for a Varus Deformity

Pain is the most common symptom for which people seek medical care for varus deformities. Some also grow concerned about physical appearance. A physician will perform an exam, observe the individual’s walk, and likely order imagining tests. Most cases do not require treatment unless the condition is severe. In some cases, the doctor may consult an orthopedist. Special shoes, a cast, or a brace may alleviate the issue, but some cases eventually require surgery. Healing takes time and generally requires several appointments.

Future Care for Varus Deformities

In most cases, the prognosis for people with varus deformities is positive. By avoiding activities that can cause additional strain or injury, an individual can lessen the impact of the condition. However, if genetics are at play or the deformity is causing walking or movement issues and is left untreated, it can become worse. Obesity can exacerbate varus deformities, as can overuse through strenuous activity.