What Are Bowed Legs?
Bowed legs, also known as genu varum, is a childhood condition in which there is a large gap between the knees when a child stands with the feet together. It is often a normal part of development and usually resolves on its own. Bowed legs usually happens due to the fetal position of the legs in his or her mother’s womb. If the bowed legs have not corrected themselves by about age 3, the child may have an underlying cause such as Blount’s disease or rickets.
The most common symptom of bowed legs is a noticeable gait abnormality. Most children with genu varum can walk with little issue; their walking just appears different. Bowed legs are often accompanied by the toes turning inward.
Bowed legs is not usually painful. However, if the condition is not corrected by adolescence, hip and knee problems can develop due to the extra stresses the condition places on these joints. Bowed legs can lead to development of knee arthritis in adults.
Causes and Risk Factors
For children under age 2, bowed legs is a normal variation of leg positioning. This is sometimes known as physiologic genu varum. It starts improving at about 18 months of age, and by age 3 or 4 the condition should be fully corrected.
If the bowed legs have not corrected themselves, they may be caused by an underlying condition. The two most common underlying causes of genu varum are Blount’s disease and rickets.
Blount’s disease is a problem with the growth plate of the tibia (shin bone). Growth plates are areas of cartilage in children’s bone that are responsible for the growth of the bone. During the teenage years the growth plates will mature into normal bone and growth of the bone will be completed. In Blount’s disease, the tibia’s growth plate near the knee grows abnormally, creating space between the knees. Sometimes Blount’s disease may not develop until adolescence.
Rickets is a micronutrient deficiency where a child does not get enough calcium, phosphorus or vitamin D in his or her diet, all of which are important for bone development. It can be developed due to malnutrition or due to genetic factors.
Diagnosing bowed legs is usually accomplished through a physical examination. The doctor will observe the child’s leg position when the child is standing and walking. If the child is under age 2, no further tests are usually necessary. If the child is a bit older, the doctor may call for an X-ray to check the growth plates around the knees for the presence of Blount’s disease or rickets.
For physiologic genu varum, treatment is not necessary as the condition is almost always self-correcting. Some adults may have mild bowed legs, which is considered normal, A pediatric orthopedic specialist will usually want to see the child occasionally to monitor the progression of bowed legs and watch for signs of one of the possible underlying conditions.
If Blount’s disease is causing the bowed legs, a brace may be able to correct the condition if it is caught early enough, before about age 4.
Rickets, too, can often be controlled or corrected nonsurgically. A metabolic specialist may be necessary to treat the child’s rickets. Treatment may include vitamin D orcCalcium supplementation. This medical treatment may lead to correction of the bowed legs
Uncorrected bowed legs of any cause may need surgery if the condition progresses beyond about age 4. Surgery for genu varum usually comes in two types.
- Guided growth: This type of bowed legs treatment stops growth on the abnormal side of the growth plate so that the other side can “catch up” and even out the legs.
- Tibial osteotomy: In this surgery, the tibia is cut below the knee and reshaped to correct the legs’ alignment.
After either surgery, the child may need to have his or her leg in a cast or brace to immobilize and protect it while it heals. Crutches may be necessary for a number of weeks after the surgery. An orthopedic surgeon may recommend physical therapy as part of the recovery to strengthen the legs and restore range of motion.
If you are concerned about your child’s bowed legs, request an appointment with our pediatric orthopedics division. Our experts will be able to examine your child and determine what’s causing the bowed legs, as well as recommend the best course of treatment for your child.