Diseases & Conditions

Bandy Leg - Bowleg

Overview, Causes, & Risk Factors

Bowleg refers to an outward curving, or bowing, of the legs. It is due to a deformity of the knees.

What is going on in the body?

During infancy, bowleg is normal. The condition usually corrects itself over the first few years of life. In an adult with bowleg, the knee alignment is not normal. The lower leg curves outward from the thigh, moving the knees farther apart.

What are the causes and risks of the condition?

The deformity can result from arthritis that affects the inside of the knee more than the outside. This causes wearing of the inner joint cartilage and bone. The problem can also come about when a fractured leg bone heals with an outward curvature. An injury to the growth plate of a child's knee joint, particularly on the inside, can lead to unbalanced growth of the bone. This can also cause the legs to bow. Bowlegs are associated with rickets as well. Rickets is a childhood bone disease that stems from a lack of vitamin D in the diet.

Symptoms & Signs

What are the signs and symptoms of the condition?

Children generally have no symptoms. Adults may have discomfort on the inside of the knee from excess pressure on the joint. There may also be discomfort on the outside of the knee from tension on the ligament.

Diagnosis & Tests

How is the condition diagnosed?

The first step in diagnosis is for the doctor to examine the legs. When standing or lying down, the affected person's knees are bowed outward. They appear farther apart than normal. An instrument to measure angles, called a goniometer, can be used to determine the abnormal bowing. Joint X-rays can also confirm this condition.

Prevention & Expectations

What can be done to prevent the condition?

Prevention involves avoiding the causes of the problem such as:

  • angled healing of fractures, which can be prevented with proper bone fracture repair
  • arthritis, which can occasionally be prevented by avoiding repeated overuse or injury to the joints
  • childhood rickets, which is often caused by a lack of sunlight and low vitamin D intake
  • injury to the growth plates of the knee
  • What are the long-term effects of the condition?

    There may be progressive deformity and arthritis on the inside of the knee.

    What are the risks to others?

    There are no risks to others.

    Treatment & Monitoring

    What are the treatments for the condition?

    No treatment is necessary for most infants, since bowlegs usually correct themselves. During childhood, assure the proper intake of vitamin D to prevent rickets. Corrective operations can also be performed, if necessary. The person would need to wear casts or braces following the operation.

    What are the side effects of the treatments?

    Surgery carries the risk of fracture to the knee, injury to nerves, or damage to blood vessels. It can also cause compartment syndrome, which is increased pressure within the muscle compartment caused by bleeding. After surgery, the knee may not realign, or the bone could fail to heal. In addition, the deformity may not adequately correct after bracing or casting.

    What happens after treatment for the condition?

    After surgery, a cast or brace is used until the bone heals. Physical therapy can also help restore knee motion and strength.

    How is the condition monitored?

    The knees should be observed for proper alignment during growth. Any new or worsening symptoms should be reported to the doctor.


    Author:John A.K. Davies, MD
    Date Written:
    Editor:Crist, Gayle P., MS, BA
    Edit Date:09/27/02
    Reviewer:Eileen McLaughlin, RN, BSN
    Date Reviewed:10/01/01