Femoroacetabular Impingement (FAI)

The human hip joint follows a very simple structure composed of two components, the femoral head (ball) and the pelvic acetabulum into which it fits (socket). When abnormal bone growth (bone spurs) arises between the two surfaces, friction can increase and lead to the development of a condition known as Femoroacetabular Impingement.

The increased intra-articular friction causes the tissues to fray, or tear, which causes significant discomfort and pain. Eventually, the tissue wears away completely, and the bone of the femur is left to grind directly against surface of the acetabulum.

Femoroacetabular Impingement can manifest in two distinct forms known as Cam Impingement and Pincer Impingement.

CAM Impingement: CAM Impingement is most commonly seen in the young male population. This type of impingement occurs when a bulge in the femoral head begins to rub against the edges of the acetabular ridge which invariably produces a significant lesion in the adjacent cartilage.

PINCER Impingement: PINCER Impingement occurs when the anterior lateral edge of the acetabulum socket begins to protrude outwards and over the femoral head. When this happens, hip function is severely compromised and the patient’s quality of life reduced.

However, the two most common types of impingement are not mutually exclusive. Many diagnostic tests will confirm a combination of both types of impingement occurring at the same time. This is known as combined impingement.

Symptoms of Femoroacetabular Impingement

The most common symptoms of Femoroacetabular impingement are:

• Hip pain (most patients describe the pain as a dull ache)
• Hip instability
• The hip socket may experience a sensation of locking or catching
• Reduced range of motion in the hip joint
• Lumbar pain
• Groin pain

Risk Factors

Femoroacetabular Impingement can happen to anyone. However, specific demographics are significantly more likely to develop it over their lifetime. The most at-risk groups are:

• Those who engage in high-impact sports such as wrestlers, and weightlifters
• Manual laborers who regularly perform heavy lifting
• Those who engage in activities where repeated hip rotation is common
• Patients suffering from any form of inflammatory arthritic disease

Diagnosis

As with all orthopedic conditions, the diagnosis will consist of a three-pronged approach:

• The patient’s complete medical history will be analyzed for the presence of congenital risk factors
• A thorough physical examination will determine the severity and extent of the symptoms
• Analysis of various diagnostic images such as a CT scan, MRI or X-ray

Treatment Options

Femoroacetabular Impingement may be treated with nonsurgical therapies. However, these conservative treatment methods will, at best, only provide relief from discomfort and pain. The only way to eliminate the underlying source of the patient’s discomfort (bone spurs), is through surgical means.

Non-surgical treatment options include:

• Reducing physical activities that exacerbate the condition
• Anti-inflammatory medications
• Physical rehabilitation
• Corticosteroid injections into the hip joint

Femoroacetabular Impingement Surgery

When non-surgical treatment options fail to provide the patient with significant pain relief and improved range of motion, hip arthroscopy can be used to repair damage to the acetabulum and the cartilaginous surface of the femoral head.

By scrapping away damaged tissue, surgeons encourage the regrowth of improved tissue. Implanted materials may be utilized in severe cases of hip joint deterioration, to provide stability and improve hip function.