Hip dysplasia is the medical term for a hip socket that does not completely cover the ball portion of the upper thighbone. This causes the hip joint to become partially or completely dislocated.
Most people with hip dysplasia are born with the condition. Therefore, doctors check for symptoms of hip dysplasia in newborns. A hip dysplasia diagnosed in early infancy may be corrected with a soft brace. On the other hand, a hip dysplasia diagnosed after the age of 2, it may require surgery to move the bones into the right positions.
Mild cases of hip dysplasia may not show any symptoms until puberty and adolescence. Hip dysplasia can damage the cartilage lining the joint and it may also damage the soft cartilage (labrum) that rims the socket portion of the joint. This is known as a hip labral tear.
Symptoms
Symptoms of hip dysplasia vary by age group. In infants, a sign of hip dysplasia may be one leg longer than the other or during diaper changes, one hip may be more flexible than the other. Once a child begins to walk, a limp may develop.
Symptoms of hip dysplasia in teenagers and young adults include activity-related groin pain, a sensation of instability in the hip or pain that possibly indicates osteoarthritis or a hip labral tear.
Causes
In newborns, the hip joint consists of soft cartilage that gradually hardens into bone. The ball and socket should fit together as molds for each other. A ball that is not seated firmly into the socket obstructs the socket from fully forming around the ball leading to a shallow socket.
The final month before birth causes the space within the womb to decrease, which may result in the ball of the hip joint to move out of its right position leading to a shallower socket. Factors that may reduce the amount of space in the womb include:
- Large baby
- First pregnancy
- Breech presentation
Risk factors
Hip dysplasia is more common in girls and it may run in the family. Factors that increase the risk of hip dysplasia involve babies born in the breech position or with foot deformities.
Complications
A common complication of hip dysplasia is a hip labral tear (damage of the soft cartilage that rims the socket portion of the hip joint). Hip dysplasia may also increase the risk of developing osteoarthritis on the same joint. This can occur due to higher contact pressures over a smaller surface of the socket. Eventually, the smooth cartilage on the bones wears away.
