Coxa valga (KAHKS-uh VAL-guh) is a deformity of the femur, the upper thighbone that sits in the socket of the hip.
The femur is the long bone in the thigh. At the top of the femur, a knob of bone sticks out at an angle. This knob is called the femoral head. It’s the part of the bone that sits in the socket of the hip. In most people, the femoral head sticks out from the shaft of the femur at an angle of 120–130 degrees. If the angle is greater than 130 degrees, the condition is called coxa valga, or a valgus hip.
The hip is a ball-and-socket joint, which means that the rounded end of one bone (in this case, the "ball" of the thighbone) fits into the hollow of another bone (the acetabulum, or cup-shaped "socket" of the pelvis). Ball-and-socket joints offer the greatest range of movement of all types of joints, which explains why we can move our legs forward, backward, and all around.
Kids can be born with coxa valga, or people can develop coxa valga due to an injury to the hip, cerebral palsy, knock-knees, rickets, or a number of other medical conditions. Coxa valga usually isn’t a problem in infants, whose hips have a naturally larger angle. But in older kids and adults, it can cause pain, limit mobility in the hip, and make one leg shorter than the other. In time, if it goes untreated, coxa valga can make walking difficult.
Some cases of coxa valga cause no symptoms and don’t need treatment. Moderate to severe cases are generally treated with physical therapy and the use of canes, walkers, or crutches to make walking easier. If conservative treatment isn’t enough to stop pain, surgery may be done to cut into the femur and decrease the angle of the femoral head.
In many cases, coxa valga is a symptom of another medical condition. Treating coxa valga should be part of treating the underlying cause. In kids who were born with coxa valga, surgery may correct the condition, but can lead to problems and is typically only done as a last resort.
All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.
