Femoroacetabular Impingement (FAI)

What is Femoroacetabular Impingement (FAI)

Femoroacetabular impingement, also called hip impingement, is a painful condition that occurs when the bones of the hip joint do not fit together as they should. FAI is marked by extra bone that develops either on the ball (femoral head) and / or socket (acetabulum) bones of the hip joint. The extra bone results in an irregular shape of the ball and / or socket leading to premature contact between the bones with hip motion. Over time, the bones begin to rub or pinch against each other causing friction, joint damage, pain and limited activity.

The labrum is a cartilaginous ring that sits circumferentially around the rim of the acetabular socket.  It plays an important role in protecting the articular cartilage and contributes to hip stability. Either in an acute traumatic setting or more slowly over time, impingement of the hip joint can lead to damage and tears of the labrum.  Additionally, hip impingement can damage the articular cartilage that covers the ball and the socket, which results in early arthritis.

Dr. Leslie Vidal, hip arthroscopist and orthopedic hip specialist successfully treats patients from Vail, Eagle and Summit County, and those in the surrounding Denver area with FAI or femoroacetabular impingement.

What are the types of femoroacetabular impingement (FAI)?

There are two main types of femoroacetabular impingement. Patients may be diagnosed with one type or with a combination of these conditions:

• Cam Impingement – This type of hip impingement occurs when the femoral head is misshapen. Because it is more oval than round, it does not rotate concentrically inside the acetabulum (socket). This causes excessive pinching against the edge of the acetabular rim, damaging the cartilage inside the joint and tearing of the labrum.
• Pincer Impingement – This type of hip impingement occurs when extra bone on the acetabulum (socket) extends further than normal over the edge of the femoral head (ball at the end of the thigh bone), or when the acetabulum is too deep. This may cause damage to the articular cartilage and a tear or crushing of the labrum.
• Combined Cam and Pincer Impingement – This type of hip impingement has both elements of cam impingement and pincer impingement present. The combination can cause an even quicker deterioration of the articular cartilage and the labrum.

What are the symptoms of femoroacetabular impingement?

Patients in Vail, Frisco, and the greater Denver, Colorado communities typically report the following symptoms of FAI:

• Groin pain, especially when the hip is flexed, and the leg is turned inward
• Pain that radiates to the outside of the hip
• Pain that is stabbing and intense
• Catching or locking sensation
• Dull ache
• Stiffness
• Limp or change in gait
• Decrease in range of motion

How is FAI diagnosed?

Dr. Vidal will obtain a thorough patient history and will conduct a physical exam to determine if femoroacetabular impingement is the cause of their hip pain. She will perform several tests, including an impingement test where she will move the knee close to the chest and then carefully rotate it toward the shoulder. If the impingement test causes groin pain, FAI may be the cause. Dr. Vidal will also use imaging tests to properly evaluate the hip joint. X-rays will help her visualize any bone abnormalities and an MRI will help her “see” the soft tissues of the hip and diagnose a torn labrum or articular cartilage damage.

What is the treatment for hip impingement?

Non-Surgical Treatment:

Dr. Vidal may recommend the following non-surgical treatments to help alleviate hip pain caused by FAI:

• NSAIDs – Nonsteroidal anti-inflammatory drugs to reduce pain and inflammation.
• Activity modification – Stopping or changing the activities that cause pain or more severe symptoms
• Physical therapy – Strengthens the surrounding muscle of the hip joint and can relieve stress on the injured labrum or cartilage while restoring range of motion
• Injections – cortisone and / or biologic injections can help reduce the symptoms of FAI

Surgical Treatment:

Dr. Vidal will recommend surgical treatment for femoroacetabular impingement only when non-surgical treatments have failed to alleviate pain and associated symptoms. If surgery is indicated, she will use a minimally invasive approach called hip arthroscopy. This type of procedure is done using small surgical incisions and long, narrow, specialized surgical instruments. Dr. Vidal will use a small camera, called an arthroscope, to view the inside of the hip where she will repair damage to the labrum and articular cartilage. The different types of hip impingement will dictate the type of surgery required. In cases of predominantly cam impingement, the excess bone on the ball of the femoral head will be shaved and smoothed down. For pincer impingement, she will trim down the excess bone on the rim of the acetabulum.

It is important to note that patients with FAI are potentially at risk for future joint damage if not diagnosed and treated appropriately. Therefore, it is important to seek treatment and from a qualified and skilled FAI surgeon.  Dr. Leslie Vidal has extensive training and experience in performing this specialized type of surgery.

What happens after femoroacetabular impingement surgery?

It is often said that a patient’s best recovery comes from their willingness to follow post-operative protocol. After FAI surgery, it is extremely important for patients to follow the protocol for post-op recovery as set forth by Dr. Vidal. She will provide a well-supervised physical therapy program following arthroscopic hip surgery which focuses on reducing pain and restoring range of motion, strength and function.  Patients will be paired with a highly skilled physical therapists immediately following surgery and rehabilitation will begin immediately.

What is the recovery time after hip impingement surgery?

In general, healthy patients without underlying medical conditions can return to full activities in about 4 to 6 months. It is possible that not all of the damage from femoroacetabular hip impingement is able to be corrected. Some patients may need long-term activity modification to better protect the long-range health of the hip.

For more information on femoroacetabular impingement (FAI), or to learn more about arthroscopic hip surgery for hip impingement, please contact the office of Dr. Leslie Vidal, orthopedic hip specialist serving Vail, Frisco, and the greater Denver, Colorado area.