Hip Preservation

About Hip Preservation

The focus of hip preservation is on the biological reconstruction of the hip for optimal movement and interaction of the hip joint, ball and socket. Abnormal hip joints can cause pain in your everyday life and have been shown to be the leading cause of osteoarthritis. Our center is the front runner in hip preservation research and development, which means better care for patients with abnormal hip conditions and extended life in patient’s hips. Our services treat the following conditions:

• Hip dysplasia
• Femoroacetabular impingement (FAI)
• Labral tear
• Perthes disease, SCFE

Hip Dysplasia

Hip dysplasia, sometimes called DDH (developmental dysplasia of the hip), is a relatively common abnormality in the shape of the hip joint. This abnormality originates at birth or in early childhood. DDH is the most common developmental hip deformity causing symptoms in adults and is also the most common single cause of osteoarthritis in the hip. Most frequently hip dysplasia is in a hip socket (acetabulum). The shallowness of the acetabulum causes the head of the femur to exert excessive pressure on the rim of the acetabulum.

Individuals with acetabular dysplasia often go through childhood and adolescence without symptoms or knowledge of their condition. However, when they reach young adulthood, they may experience hip pain. At that time an x-ray will reveal the acetabular dysplasia.

Classic Dysplasia vs. Retroversion

Classic dysplasia is demonstrated in figure A where the socket (acetabulum) is facing forward and the lines representing the front wall (anterior) of the socket and the back (posterior) wall of the socket are not overlapping. In classic dysplasia there is not enough coverage of the outside of the femoral head.

Retroversion, figure B, is when the opening of the socket is facing to the side or backwards causing the femur to contact the front of the socket when it rotates. This can cause “femoroacetabular impingement” and can damage the cartilage inside the socket (articular cartilage) and the rim of the socket (bone or labrum). The arrow shows the part of the anatomy (ischial spine) that should not usually be visible unless this whole region of the pelvis is twisted backwards. There is often enough or too much lateral coverage of the head, but there may not be enough coverage of the back of the head.

Femoroacetabular Impingement (FAI)

FAI is a process that can go on in the hip joint due to abnormal shape of the ball and socket. This condition can cause pain when the individual sits or stretches. It can be caused from retroversion of the acetabulum or an abnormal shape to the front of the femoral head and neck (top of the thigh bone), or, in about 80% of cases, a combination of both.

A hip with a bump or not enough offset between the head and the neck (as seen on the left) can force its way into the hip joint, moving the labrum out of the way and then cause damage to the cartilage lining the socket. It acts like a “cam” (seen on the left in diagram B). On the right, when the socket is too deep or it is facing backwards, the head gets pinched and the labrum often gets damaged and a ridge or divot can form on the neck (seen on the right in diagram B).

Acetabular Labral Tears

The labrum is the gristle-like lining around the rim of the hip socket (acetabulum). It helps to stabilize the joint and maintain proper hip joint mechanics. A tear of the labrum usually causes sharp pain in the front of the hip, sometimes shooting down the thigh. A catching or giving way sensation in the hip may also occur.

Symptoms usually occur when the hip is changing position. If the labrum tears, it is usually because of an underlying anatomic abnormality of the hip. Much less commonly, a twisting injury or injuries can tear the labrum. Since a torn labrum not only causes pain and instability but also disturbs function of the hip and predisposes to arthritis, a labral tear is an indication for treatment both to prevent arthritis and to improve symptoms.

MRI scans frequently diagnose labral tears. Labral tears may also be found on an MRI that are not giving a patient symptoms. There are also different kinds of tears. (See below.) Though hip arthroscopy usually can allow symptom-relieving trimming of the torn labrum in a minimally invasive way, if the torn labrum occurred because of an underlying anatomic abnormality in the hip, usually the underlying anatomic hip abnormality is corrected first.

Developmental hip abnormalities predisposing to labral tears include hip dysplasia, Legg-Calvé-Perthes disease, and Slipped Capital Femoral Epiphysis. Hip arthroscopy is highly successful in relieving symptoms of a labral tear and improving hip function, as long as the anatomic problem is corrected. It is more difficult to correct bony abnormalities through a scope and therefore more significant abnormalities may require an open surgery.

Types of Labral Tears

Labral degeneration is seen in hips where the labrum has seen too much stress over a long period of time (one to five years). The labrum frequently has damage that can include fraying, overall breakdown over a large area and/or a cyst forming inside it. In classic dysplasia the labrum frequently thickens and then breaks down. In retroversion the labrum frequently thins and gets frayed.

Labral detachment is very commonly seen with FAI as a result of the femur forcing its way into the socket. The labrum can also frequently be detached from the rim of the acetabulum and the underlying articular cartilage.

Labral tear, which is more uncommon for us to see within the substance of the labrum; this type of tear can do well with hip arthroscopy if there is no underlying bony abnormalities.