What causes genu valgum (knock-knees)?
In most cases, the child will grow out of their knock-knees and there is little cause for concern. In instances where this does not happen, or where genu valgum develops later in life, formal treatment may be needed.
What is genu valgum?
Genu valgum, or knock-knees, is common in children and usually resolves itself before puberty.
Image credit: BioMed Central, (2007, August 10)
Genu valgum is more commonly referred to as knock-knees. When someone with genu valgum stands with their knees together, there is a sizeable gap between the ankles of about 2 to 3 inches. The knees will appear to push in towards each other.
This condition is fairly common, affecting more than 20 percent of 3-year-olds. In most young children, the condition will naturally correct itself. Only 1 percent of children age 7 years are still affected.
In rare cases, genu valgum may continue into adolescence. In other cases, older children may develop it as a result of an underlying disease or condition.
Most of the time, genu valgum cannot be prevented. However, there are various treatment options available that may help ease some of the symptoms.
Knock-knee that develops as a result of an underlying condition can be prevented if the cause is identified and treated.
There are several potential causes of genu valgum, including metabolic bone disorders and genetic disorders. Most cases of genu valgum, however, are harmless.
Other risk factors for genu valgum include:
- injury or illness affecting the leg or knee
- arthritis, particularly in the knee
- deficiency of vitamin D and calcium
Symptoms of genu valgum include an obvious visual separation of the ankles when the knees are together. The individual's gait is also likely to be affected as they compensate for the lack of gap between their knees.
The altered gait may cause additional symptoms, such as:
- knee pain
- a limp when walking
- pain in feet, hips, and ankles
- stiff joints
- lack of balance when standing
X-rays may be used to diagnose genu valgum.
Image credit: BioMed Central, (2007, August 10)
Genu valgum is not typically diagnosed in younger children, as the condition is common in early development. In older children and adults, a doctor will attempt to diagnose the cause of genu valgum. The cause will determine if any treatment is needed to correct the condition.
To formally diagnose genu valgum, a doctor would need to look at a person's medical history. Questions will include information about family history and any other known pre-existing conditions that might cause knock-knees.
If pain is present, a doctor will likely ask a person to identify where it is located, how severe it is, and when it occurs.
The doctor will also look at:
- knee alignment when standing
- how a person walks
- if the legs have different lengths
A doctor may look for uneven wear patterns on the soles of the person's shoe as well. In some cases, a doctor may order an MRI or X-ray to examine the bone structure.
Treatment for genu valgum will largely depend on the cause and severity of the condition. Typical treatment options may include some of the following:
Medications and supplements
If an underlying disease is causing genu valgum, the disease will need to be treated first in order to correct the leg alignment. This may be treated with medications and supplements.
A doctor may recommend some simple exercises and stretches or refer a person to a physical therapist. Exercises and stretching can help strengthen muscles of the legs and realign the knees.
A doctor or physical therapist will recommend exercises based on a person's gait. The exercise routine will likely include plans to add weights or switch the routine as the muscles develop.
If a person is carrying excessive body weight, it can be a contributing factor to genu valgum. Extra weight puts additional strain on the legs and knees, which can cause knock-knees to worsen.
A doctor will likely recommend that a person who is overweight lose weight through a combination of diet and exercise.
Orthotics are inserts placed in the shoes to help correct a person's gait or the way their foot strikes the ground when they walk or run. This may be especially helpful for people with genu valgum who have one leg that is longer than the other.
Braces or splints may be used for some children in addition to or instead of orthotics. The braces are designed to help the bones grow in the correct position.
If other treatment options do not relieve the symptoms of genu valgum, then surgery may be recommended.
Surgery is not typically the first treatment choice for a person with genu valgum. Surgery is usually reserved for the following cases:
- severe knock-knees
- where exercise, stretching, and weight loss do not relieve pain
For children, a procedure called guided growth surgery is often used. A surgeon inserts a small piece of metal into the knee. This metal plate helps the bone grow in the correct direction. Once the bone is aligned correctly, further surgery is done to remove the metal plate.
In adults and older teens, osteotomy may be used. Similar to guided growth surgery, osteotomy involves a surgeon inserting a small metal plate into the knee. The plate is used as a permanent brace to keep the knee correctly aligned and will not be removed.
In rare cases, a doctor may recommend a knee replacement. In this case, an artificial knee that has been correctly aligned will resolve the genu valgum.
In almost all cases of genu valgum, the condition will resolve itself before a child reaches adolescence.
For older children and adults, the most likely form of therapy involves stretches and exercises to realign the knees and relieve pain. Some people might find relief with orthotics or braces.
In some severe cases, surgery may be necessary, but it is usually a last resort as other therapies tend to be effective in treating genu valgum.
Treating genu valgum in adults and older children is important. When untreated, it can lead to further health problems with joints and muscles, including osteoporosis.