Hip Dysplasia

What is hip dysplasia?

The hip is a ball-and-socket joint. Normally, the ball at the top of the thigh bone fits into the hip socket. Hip dysplasia occurs when the hip joint has not developed properly and the socket (acetabulum) is too shallow. This allows the ball (femoral head) to slip partially or completely out of the joint. Hip dysplasia ranges from a mild abnormality to a complete dislocation of the hip.


Severe cases of hip dysplasia are usually diagnosed during a routine screening within the first few months of a baby’s life. Other times, the problem may only become noticeable as a child grows and becomes more active.

Hip dysplasia is a treatable condition. However, if left untreated, it can cause irreversible damage that will cause pain and loss of function later in life. It is the leading cause of early arthritis of the hip before the age of 60. The severity of the condition and catching it late increase the risk of arthritis. Therefore, monitoring and early intervention are both important to reduce a child’s risk of pain and disability in adulthood.

Who is affected?

Hip dysplasia can affect anyone at any age. Although it is believed to develop around birth, a child with mild dysplasia may not have symptoms for years, or even decades.

The age at which older kids and young adults with hip dysplasia begin to notice symptoms depend on the severity of the condition and their activity level. Athletes who place a lot of load on their hips by participating in dance, hockey, football, soccer, or track and field may experience symptoms sooner.

Meet Louise

Undiagnosed hip dysplasia caused such severe knee pain, this former track star sometimes had trouble walking after competitions. With surgery behind her, and a degree in medicine in the works, she has returned to the sport she loves.

Read her story

Meet Louise Atadja. With surgery behind her, and a degree in medicine in the works, she has returned to the sport she loves.

Girls and women are two to four times more likely than boys to have hip dysplasia. It also tends to affect first-born children and those who have a close family member with hip problems. Some people with hip dysplasia are affected in only one hip while others have it in both hips.

In boys, the condition tends to be accompanied by other hip problems. These include acetabular retroversion (when the hip socket grows too far over the head of the femur) or CAM lesions (extra bone growth on the surface of the bone that causes extra friction and joint damage).

Hip dysplasia is sometimes confused with hip impingement, which occurs when extra bone grow on the acetabulum or femoral head. The irregular shape creates friction within the joint and wears down cartilage. Some patients have both conditions, both of which cause hip pain and are easy to confuse. However, they are different issues that require different treatments.

In a healthy hip joint, the head the femur fits comfortably inside the hip socket. With hip dysplasia, children’s hips are prone to partially or fully dislocate. Partial dislocation is also known as subluxation.

Generally speaking, treating hip dysplasia as early as possible can minimize joint damage and reduce the chance of early onset arthritis.

How we care for hip dysplasia

The Child and Young Adult Hip Preservation Program at Boston Children’s Hospital is at the forefront of research and innovation. We combine specialized expertise in non-surgical and surgical treatments with structured physical therapy to help children, adolescents, and young adults live healthy, active lives.

Our team has treated thousands of children with every level of complexity and severity of hip deformity. Our hip specialists have pioneered minimally invasive procedures as well as open surgical techniques to help treat patients of all ages. We perform more periacetabular osteotomy (PAO) procedures every year than any other hospital in the country and have helped hundreds of athletes return to the activities they love.

We have the experience to treat you or your child. Our goal is the same as yours: to help you get better so you can return to being healthy and pain-free.

Patient resources

Download these fact sheets to learn more about hip dysplasia and treatment options.