Femoroacetabular Impingement

Orthopaedic & Spine Center
Dr. Burrow demonstrating the knee to a patient

John D. Burrow, DO

Hip Impingement or Femoroacetabular Impingement (FAI) happens when the bones that comprise the hip joint are shaped abnormally.  A person can be born with this defect, it can develop as a teenager or show up later in life.  Either the ball of the femur or the socket of the pelvis (acetabulum) can be malformed and during movement, cause friction and wear on the cartilage of the hip joint.  FAI is not the same as osteoarthritis, but it can be a precursor to the disease.

There are three classifications of FAI:

Pincer – Usually develops childhood, this type manifests with extra bone growth in the hip socket

Cam – This type can occur from increased physical activity, and manifests with boney growth at the head of the femur

Combination – both types of FAI are present in the hip

FAI may not have symptoms, especially at first.  As the damage to the hip joint increases, the patient will experience hip stiffness and pain that may worsen after long periods of sitting or activity. Some limping may occur, and the patient’s range of motion may become limited.  If left untreated, the cartilage of the hip joint may completely degenerate, leaving the patient with bone-on-bone osteoarthritis.

I diagnose FAI by ordering x-rays to look for damage and/or abnormalities in the hip joint. I will also do a physical exam to assess how the patient walks and if their hip joint is moving normally.  I can also do an impingement test where I ask the patient to bring their knee of the painful hip to their chest and rotate it to the opposite shoulder, which should produce a painful response. 

At this point, if all signs are pointing to an FAI, I’m going to go ahead an order an MR scan to get a better visual of what is happening inside the hip joint. If the labrum is severely torn, physical therapy or a steroid injection will be a cause of aggravation for the patient and a waste of time and money, as arthroscopic surgery will be required to repair the tear.

If the MRI comes back with only signs of a femoroacetabular impingement, nonsurgical treatments can be quite helpful.  Our treatment course will be corticosteroids that can be administered orally or by injection, but most often by injection. NSAIDS (naproxen sodium or ibuprofen) will also help with inflammation and pain.  Physical Therapy can help increase strength and range of motion.  Relative rest and activity modification are also important to allow the inflammation and irritation in the joint time to heal.  Heat and/or ice therapy may also be helpful in controlling pain, as may massage.

If these conservative methods do not work, surgery may be a consideration if all other measures fail to fix the boney abnormalities in the joint.  All but the most extensive hip surgeries can now be done arthroscopically to remove or smooth boney growths or repair torn cartilage.