What are the other Names for this Condition? (Also known as/Synonyms)

• Acetabular Rim Syndrome
• Cervicoacetabular Impingement
• Hip Impingement Syndrome

What is Femoroacetabular Impingement? (Definition/Background Information)

• The femur/thighbone ends in the femoral head, which forms part of the ball and socket joint at the hip. The cup-shaped socket at the pelvis is called the acetabulum, into which fits the ball-shaped femoral head
• Femoroacetabular Impingement (FAI) is a condition characterized by abnormally-shaped bones within the hip, which may cause bone friction resulting in a joint damage. There is a certain constrain to the free movement of the ball within the socket, limiting the movement range
• If left untreated, FAI may be a main cause for the onset of early hip osteoarthritis, particularly in young athletes, or physically active individuals

There are 3 types of Femoroacetabular Impingement, which include:

• Pincer Femoroacetabular Impingement: Pincer Femoroacetabular Impingement is characterized as an abnormal surface deformity of the femoral head. This type of impingement occurs when an additional bone grows along the acetabular socket rim or when the socket is angled abnormally
• Cam Femoroacetabular Impingement: Cam Femoroacetabular occurs, when the femoral head within the hip is abnormally rounded.  Certain specific movements associated with the bone may result in cartilage and labrum damage
• Combined Femoroacetabular Impingement: This type of FAI implies that both the Pincer and Cam type impingement exist

Who gets Femoroacetabular Impingement? (Age and Sex Distribution)

• Femoroacetabular Impingement may occur in individuals of all age, race, ethnic groups, or gender
• However, athletes with a high level of physical exertion, have the highest rate of occurrence
• Cam FAI chiefly occurs in young male athletes into their 20s
• Pincer FAI is observed to mostly occur in physically-active women, between the ages of 30-40 years

What are the Risk Factors for Femoroacetabular Impingement? (Predisposing Factors)

Common risk factors associated with Femoroacetabular Impingement include:

• Individuals, who participate in intense sports, such as ice hockey, ice skating, tennis, skiing, cycling, certain track and field events, etc.
• Individuals, who are physically active involving extreme hip movements, such as due to intense exercising, martial arts, dancing, etc.
• Any previous injury/fracture to the hip may increase an individual’s risk of developing FAI
• Some Femoroacetabular Impingement cases have a genetic prevalence. Individuals, who have an immediate family member or relative with a history of this condition, are at an increased risk

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Femoroacetabular Impingement? (Etiology)

A few causal factors of Femoroacetabular Impingement include:

• Participation in sports, physical activities
• Family history of the condition

What are the Signs and Symptoms of Femoroacetabular Impingement?

Signs and symptoms of Femoroacetabular Impingement include:

• ‘Vague’ aching sensation
• Sharp acute pain, which any physical activity/movement would induce 
• The joint may lock-up while walking. Occasionally, one may also hear a clicking sound, associated with walking
• Pain within the lower back
• Difficulty performing certain particular tasks, such as tying shoelaces

It has to be noted that in some cases, normal/regular activities may cause the impingement (abnormal contact between the femoral head and acetabulum). In some individuals, only intense physical/sports activities causing extreme movement of the hip or legs may bring about the discomfort and pain, due to FAI.

How is Femoroacetabular Impingement Diagnosed?

Diagnostic methods that a physician may use to help diagnose Femoroacetabular Impingement include:

• Impingement test: Impingement test is part of a physical examination process that requires the individual to lift their knees up to the chest and rotate it inwards
• X-ray: A physician may order an x-ray to see if the hip is abnormally-shaped. X-rays can also detect, if any arthritis has started to develop
• Computerized tomography (CT): A physician may order a CT scan that takes a more detailed image and help identify any abnormally in the hip
• Magnetic imaging (MRI): An MRI is a detailed scan that uses radio waves and a magnetic field to produce images that allow a physician to view any damage to the labrum and articular cartilage tissue that surrounds the hip

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Femoroacetabular Impingement?

Some complications due to a Femoroacetabular Impingement include:

• Damage to the hip cartilage
• Rupture of the ligaments that connect the ball to the hip joint
• Early-onset arthritis of the hip joint

How is Femoroacetabular Impingement Treated?

Nonsurgical treatment measures for Femoroacetabular Impingement:

• Any activity that aggravates the hip condition should be avoided. The physician may advise the individual to refrain from participating in any physical activities, till the pain or symptoms get better
• Non-steroidal anti-inflammatory oral medications, such as indomethacin and naproxen, may be used to treat FAI. These medications can help decrease the pain and swelling
• Individuals are likely to need physical therapy. The goal of these exercises is to strengthen the muscles within the hip, improve flexibility, and decrease joint stiffness. It may take several months for an individual to complete the physical therapy program

If diagnostic tests show damage to the hip and non-surgical treatments are not helpful in providing pain-relief, a physician may recommend surgery.

• Arthroscopy: Arthroscopic surgery is a moderately invasive intervention method used to repair the hip joint using small surgical instruments, which are inserted through small incisions in the hip

How can Femoroacetabular Impingement be Prevented?

There are no known preemptive methods to prevent Femoroacetabular Impingement. However, by following certain guidelines while exercising and participating in sports, or other intense physical activities, individuals can protect themselves against a future risk of FAI. These guidelines include:

• Regularly stretch before doing any exercises/work-out
• After each exercising session, let your body cool down gradually

What is the Prognosis of Femoroacetabular Impingement? (Outcomes/Resolutions)

• The signs and symptoms associated with Femoroacetabular Impingement usually improve after surgery. This may prevent further damage to the hip joint and premature arthritic development
• If individuals are not surgically treated early, some damage may be too severe to repair
• Even though a small percentage of surgical treatment may be unsuccessful, it is still the most effective method of treating Femoroacetabular Impingement

Additional and Relevant Useful Information for Femoroacetabular Impingement:

Perthes disease is a rare, but painful condition that develops in childhood, when blood supply to the ball portion of the hip joint (the femoral head) is temporarily disrupted. Perthes disease is thought to be associated with the development of Femoroacetabular Impingement.