Hip Anatomy

The hip joint is a ball and socket joint. As opposed to the shoulder, it is a large ball and a deep socket; which has inherent stability.  During development, the ball helps the socket to form and the socket helps the ball to form. The socket is surrounded by a piece of cartilage called the labrum. The labrums function is to provide a seal to the hip joint which keep normal fluid within the joint and allows for nourishment of cartilage.

Hip Pathology

Femoroacetabular impingment (FAI) is a disorder of the hip and can be a source of hip pain in active individuals. FAI is caused by abutment of the femoral head (ball) against the acetabulum (socket). This abutment can result from the femoral head (CAM lesion) and/or from the acetabulum (pincer lesion). Impingment can damage the hip joint by injuring the labrum and/or the articular cartilage.


Often femoracetabular impingement can improve with physical therapy.  In those patients who do not improve with physical therapy, surgery reliably improves patients symptoms.  Surgery often involves repair of the labrum with reshaping of the ball and/or the socket to improve congruity of the two closely interposed structures.

Cam Impingement

Pincer Impingement

Femoroacetabular Impingement FAQs

What is a labral tear?

  • Repeated impingment as a result of a pincer lesion or a cam lesion can lead to an injury of the acetabular labrum.  Pincer impingement often leads to a crush injury of the labrum. Cam impingement often leads to separation of the labrum from the cartilage of the socket.

Does having surgery for hip impingement decrease the chances of developing hip arthritis?

  • This is an excellent question and one that current researchers are trying to definitely answer. No study to date has proven that surgery will prevent the need for a hip replacement or the development of hip arthritis.  Hip impingement leads to cartilage damage and damage to the labrum. It seems to make sense that if we can prevent futher damage of the cartilage or labrum by recontouring the socket or the ball and repairing the labrum, then we can either slow or halt the development of hip osteoarthritis.


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