Femoroacetabular impingement (FAI) is a common source of discomfort in the hip and groin region.
Also referred to as hip impingement, FAI occurs when the top of the upper femur (thigh bone) has an abnormal shape, leading to misalignment and friction between the bones in the hip joint. Over time, this repetitive rubbing gradually damages your hip joint.
UPMC offers a range of FAI treatment options, including nonsurgical and minimally invasive surgical approaches. Your doctor will consider your pain level and the amount of cartilage damage when recommending treatment.
Related services include:
Femoroacetabular impingement (FAI), or hip impingement, is a condition where extra bone grows on the femoral head in the hip joint. As the misshapen femoral ball repeatedly moves, it erodes the cartilage in the hip socket, leading to discomfort and pain.
You'll usually feel discomfort when you bend at the hip or sit for long periods. Prolonged repetitive motion can also damage the cartilage that cushions the hip.
The hip joint consists of:
Two types of cartilage in the hip are:
Image of hip x-ray with FAI.
Around 15% of people with hip pain have FAI. Although precise data on its prevalence is lacking, FAI is a common cause of hip and groin pain, especially among men and women aged 20 to 45.
Some people may not have symptoms, making diagnosing FAI challenging. However, teenagers, active adults, and athletes often discover their condition earlier because they have hip pain during their activities, leading them to seek a diagnosis sooner.
There are three types of FAI:
The exact causes of FAI aren't fully understood. However, factors such as hip abnormalities that you're born with, family history, and alignment issues may contribute to its development.
The risk factors associated with FAI include:
If left untreated, FAI symptoms often get worse. Over time, FAI can lead to osteoarthritis (the breakdown of cartilage around the hip joint) or joint deterioration.
In most cases, you can't prevent FAI. But if you have persistent pain in your hip, you can prevent further damage by seeing your doctor.
You can also modify your activities and focus on strengthening your hip and abdominal muscles to reduce the potential for cartilage damage.
Symptoms of FAI occur because of damage to cartilage around the hip joint. Pain often begins in the groin area because of its location on the hip.
FAI symptoms might include:
FAI symptoms can vary from person to person, and not everyone with FAI will have all of these symptoms. But if you're experiencing any common FAI symptoms, make an appointment with your doctor.
To diagnose FAI, your doctor will ask about your medical history and do a physical exam. They'll gently raise your knee toward your chest and rotate it inward. If you have any discomfort or pain during this maneuver, it may indicate a hip impingement.
To confirm the diagnosis, your doctor may request imaging tests to assess for FAI and any potential bone abnormalities. These scans will also provide a clear view of any joint damage.
Tests may include:
FAI treatment depends on your pain severity and the extent of cartilage damage.
If you have an FAI diagnosis but don't have symptoms, you may not need treatment. But it's still important to understand your FAI diagnosis, including ways to minimize joint stress and recognize when treatment might be needed.
When you're first diagnosed with FAI, your doctor might recommend nonsurgical treatment options before considering surgery, including:
Orthopaedic surgeons often use minimally invasive surgical techniques called arthroscopic surgery to treat FAI.
During the procedure, your surgeon will:
Arthroscopic surgery usually takes about two hours and requires general anesthesia. Most people go home the same day. Following surgery, you'll use crutches for at least a week.
In some cases, arthroscopic FAI surgery isn't possible due to damage to your hip joint. In these cases, your orthopaedic surgeon may choose open surgery, which typically involves a longer hospital recovery, lasting several days.
While rare, as with any surgical procedure, there are potential risks associated with FAI surgery. These may include anesthesia reactions, infections, cartilage or bone injuries, incomplete pain relief, and nerve irritation.
Whichever surgical approach your orthopaedic surgeon chooses, physical therapy is an important part of the healing process. It typically takes a minimum of three to four months to fully heal and resume your normal activities after FAI surgery.
FAI surgery usually relieves pain and prevents further damage to your hip joint and cartilage. However, some damage can't be repaired — and further damage may still happen in the future.
In some cases, if FAI has caused severe joint damage and you don't improve significantly after arthroscopic surgery, you may consider a hip replacement.
