Adults

Understanding Hip Dysplasia


Adults

If you have hip dysplasia, you are not alone!

Its the most common cause of hip arthritis before the age of 50. Nine out of ten cases of hip dysplasia are diagnosed during adolescence or adulthood. Doctors are more and more aware of this common condition that often escapes detection during childhood. In fact, this silent form of hip dysplasia is the reason for 5% to 10% of all total hip replacements in the USA.

What is Adolescent and Adult Hip Dysplasia?

Adults with hip dysplasia have a hip socket that is too shallow to support the ball of the hip. The ball is called the femoral head and the socket is called the acetabulum. Some adults have leftover problems from childhood hip dysplasia but most adults never knew they had a problem until their hip started hurting.

A joint that is the wrong shape or shallow will wear out faster than one that has a more normal shape. The smooth surface of the joint has a thin layer of cartilage that can’t be repaired or re-grown by the body. This cartilage surface needs to last a lifetime, or stiffness and pain occurs as the joint wears out.

How do I know if I have hip dysplasia?

The first sign of hip dysplasia in an adolescent or young adult is typically hip pain and/or a limp. This is usually in the groin area and/or lateral aspect of the hip. Pain is usually increased by activity and diminished by rest. Often there is a sensation of catching, snapping or popping in addition to pain with activities. Adult patients with hip dysplasia may see more than three healthcare providers and have symptoms for five years before a correct diagnosis is made, so you may want to consider getting a second opinion if your hip pain is getting worse for no apparent reason. To learn more about adult symptoms and diagnosis, click here.

Is there a cure for hip dysplasia?

Sooner or later, most people with hip dysplasia need surgery to build better support for the hip. In the early stages of arthritis from hip dysplasia, some of the cartilage surface may be intact and hip preservation surgery is possible to re-align the joint. Re-aligning the joint allows the remaining joint surface to be in a better position for weight-bearing. Doctors often compare the joint surface to the tread on a tire that wears down with use. When the tire is out of balance, the tread will wear out faster. Sometimes the tire tread has uneven wear with large areas intact. If the tires are rotated before the tire wears out completely, then the remaining tread is in a better position to last longer. To learn more about hip preservation surgery, click here.

After the joint surface is completely worn out, then total hip replacement is the only answer and special techniques are needed to replace a dysplastic hip. To learn more about total hip replacement, click here.

Sometimes the abnormal shape of the joint leads to tears in the soft rim of the socket because of instability. This rim is called the labrum and a torn labrum can sometimes be repaired by arthroscopic surgery. Athletes with trauma causing a torn labrum often benefit from arthroscopic surgery. However, arthroscopic surgery is rarely a long-term solution for hip dysplasia unless the underlying bone deformity is corrected at the same time as labral repair. To learn more about arthroscopic surgery, click here.

Are there non-surgical treatments available for adult hip dysplasia?

Unfortunately, non-surgical methods rarely provide a lasting solution for hip dysplasia because the joint itself is not properly formed. To learn more about non-surgical treatments, click here. Some lifestyle changes can be made to preserve the life of the hip joint. Using a cane or losing weight are the best ways to decrease the pressure on your hip joint, and a little weight loss can make a big difference.

Hip Anatomy and Terminology

The hip is the largest “ball-and-socket” joint in the body. It is held together by ligaments, tendons, and a joint capsule.

The ball is called the “femoral [fem-er-uhl] head,” which is the top of the femur or thigh bone.

The socket is called the “acetabulum” [as-i-tab-yuh-luhm] and is a part of the pelvis.

The femoral head fits into the acetabulum forming the hip joint. They fit together so the ball can rotate freely in the socket.

Articular cartilage is a very smooth surface that covers the femoral head and the acetabulum so that the hip joint glides easily during motion.

The labrum is a soft rim that lines the edge of the acetabulum. The labrum creates a seal of the hip joint. This seal helps keep an oily fluid called synovial fluid inside the hip joint. The labrum also helps stabilize the hip. The hip is also stabilized by the surrounding muscles, ligaments, tendons and joint capsule.

Doctors use a number of different terms for hip dysplasia depending on severity and time of occurrence. These names include:

  • Hip Dysplasia
  • Developmental Dislocation of the Hip (DDH)
  • Hip Dislocation
  • Developmental Dysplasia of the Hip (DDH)
  • Acetabular Dysplasia
  • Congenital Dislocation of the Hip (CDH)

Abductor muscles lift the leg to the side and keep the pelvis level when walking. If the hip socket is shallow, then these muscles must work harder.

Psoas muscle also called the Iliopsoas muscle. This is a flexor of the hip and must work harder when the hip socket is shallow. The section that runs across the front of the pelvis and hip joint may cause a snapping feeling or noise as the hip moves underneath this muscle.   

Adductor muscles are the inner thigh muscles that bring the thighs together. These are rarely painful in people with hip dysplasia.