Hip dysplasia, also known as congenital hip dysplasia or developmental dysplasia of the hip (DDH), is a condition in which the hip joint does not develop properly, leading to misalignment between the ball (femoral head) and the socket (acetabulum) of the hip. It is typically present at birth and can vary from mild to severe. In mild cases, the ball of the femur may be loose in the socket, while in more severe cases, the ball may be completely out of the socket. Hip dysplasia in infants often goes unnoticed because babies do not experience significant pain. Healthcare providers use physical exams and imaging tests, such as ultrasound or X-rays, to diagnose the condition.
The hip joint is where the thigh bone (femur) meets the pelvis (hip bone). In a healthy hip, the rounded top of the femur, known as the femoral head, fits snugly into a socket in the pelvis called the acetabulum. However, in hip dysplasia, the femoral head doesn’t fit correctly into the acetabulum, often due to a shallow socket or an abnormal femoral head shape, leading to a poor fit. This misalignment can cause the cartilage in the joint to become damaged, leading to pain, stiffness, and a higher risk of hip dislocations.
All new-borns are tested for hip dysplasia during their first few days after birth, as part of routine screenings. These checks are repeated at 6 weeks of age. If diagnosed early, particularly before 6 months of age, the condition can be treated successfully with non-invasive methods like the Pavlik harness, a soft brace which keeps the hip in the correct position to allow the joint to develop properly. By maintaining this position, the harness allows the hip socket to gradually mold around the ball, promoting proper alignment and development. Most babies diagnosed and treated early experience no long-term effects or complications.
The most common symptoms of hip dysplasia include hip pain, typically felt in the groin, instability, or a sensation that the hip is loose. Individuals may also notice limping or leg length discrepancies. For babies, symptoms include differences in leg positioning, such as one leg turning out more than the other, limited movement of one leg, or uneven skin folds around the thighs and buttocks.
Though less common, hip dysplasia can develop in older children. In these cases, it may be caused by delayed diagnosis in infancy or may develop later in life due to other factors, such as joint instability, trauma, or wear and tear over time. The condition can lead to pain, stiffness, and difficulty walking. Treatment for older children may include physical therapy, lifestyle adjustments, or surgery, such as hip replacement, depending on the severity of the condition and its impact on daily activities. Early diagnosis and treatment, especially for infants, can prevent future complications and ensure proper hip joint development.