Femoral-Acetabular Impingement

Femoral-Acetabular Impingement

Femoral-Acetabular Impingement involves a deformity of the hip joint that limits normal range of motion. Though it can be caused by trauma to the hip or by the repetitive movements of certain athletic activities, FAI is typically caused by improper bone growth in either the femoral head or the socket in the hip joint. Since not all bodies are alike, slight variations in anatomy can leave some people predisposed to the condition. There are two types of FAI, Cam Impingement and Pincer Impingement. In many cases FAI is caused by a combination of both types.

Cam Impingement

FAI caused by an improperly shaped femur (thigh bone) is called a Cam Impingement. It occurs when the femur’s head grows into a shape that is unevenly rounded. Certain movements can cause the extra bone to catch against the edge of the socket, damaging the cartilage and labrum (a ring of cartilage that surrounds the socket of the hip joint).

Pincer Impingement

FAI caused by an improperly shaped socket is called a Pincer Impingement. It occurs when extra bone grows along the socket’s rim or when the socket is not angled properly, allowing the socket and the femur to impact abnormally.

Symptoms can include sensation ranging from a dull ache to a sharp pain, often in the front of the hip but also in the buttocks or side of the thigh. The hip may pop or catch and the pain may increase during physical activity or after periods of prolonged sitting or walking.


The symptoms of hip impingement may include the inability to move freely without pain, joint stiffness, pain in the hip or groin, inability to put weight on your leg on the side of your injured hip, stiffness and swelling in and around the hip area.


Dr. LaReau, a top Chicago hip surgeon, performs a thorough examination to evaluate and determine the extent of your condition and conducts a complete review of your medical history. He may also choose to utilize diagnostic tools, such as an MRI, X-ray or CT scan to confirm the extent of your condition


The main goal of treating hip impingement is to relieve pain, improve hip mobility and overall quality of life.  Reaching this goal includes improving the function of the hip through controlling pain.  Dr. LaReau’s treatment plans can involve rest, use of a cane to take weight off the affected hip, nondrug pain relieve techniques to control pain, loss of excess weight, exercise, over-the-counter medications to control pain, surgical intervention and rehabilitation.