Hip Impingement (or FAI)
Your hip is a ball-and-socket joint that is formed by two bones: the acetabulum, which is part of the large pelvis bone, and the thighbone (femur).
Hip impingement, also known as femoroacetabular impingement (FAI), occurs when extra bone grows on your acetabulum, femoral head or both. These extra growths are called bone spurs. Spurs can cause your bones to rub and grind against each other when you move them. This can result in damage to the labrum, a type of fibrocartilage.
- Cam, in which extra bone on the femoral head keeps it from rotating smoothly inside the acetabulum.
- Pincer, where extra bone grows out over the rim of your acetabulum and can crush your labrum.
- Combined, where both pincer and cam FAI occur, causing problems with hip joint movement.
- Pain in the groin or outer hip
- Stiffness or difficulty flexing the hip further than 90 degrees
FAI is not a condition that can be prevented. It is a deformity that occurs when bones abnormally develop during childhood. However, FAI does not always cause symptoms, which means it may not always require treatment.
- Medical history and symptom review. The healthcare provider will ask about symptoms and general health.
- Physical examination. The healthcare provider will examine the hip and likely perform an impingement test. During the test, he or she will bring the patient’s knee up toward the chest and rotate it inward. If the patient feels hip pain, it’s likely that hip impingement is present.
- Imaging tests. X-rays, CT scans and MRI scans can help the healthcare provider determine the extent of the hip impingement and whether it’s damaging the labrum and or other cartilage.
- Anesthetic test. The healthcare provider may inject some numbing medication into the hip joint. If the anesthetic medication relieves pain, then the patient has FAI.
- Conservative management. Changing activity, using medication and undergoing physical therapy may be enough to relieve symptoms of hip impingement.
- Surgical treatment. If FAI causes joint damage and symptoms cannot be managed by conservative treatment, arthroscopic or open surgery may be necessary to reshape the bones and/or repair damage to the cartilage.
- Learn about FAI treatment
After surgery, an exercise conditioning program can be used to help strengthen the hip and restore range of motion.