Femoral-Acetabular Impingement

Why does it occur?

The hip joint is a ball-and-socket joint with the “ball” being the femoral head (thigh bone) and the “socket” being the acetabulum (pelvis).  Femoral-Acetabular Impingement (FAI) refers to bony overgrowth or bone spur from either the femoral head or the acetabulum, which can cause a painful rubbing of the bones in the joint.  It is not entirely understood why this bony overgrowth occurs.  Abnormal rubbing of the bone can eventually cause damage to the Labrum (ligaments surrounding the acetabulum) or premature wearing of the cartilage, leading to arthritis.


Different types of bony overgrowth occurs.  Cam Lesions refer to an overgrowth of the femoral head, and are more common in younger males. Pincer Lesions are bony overgrowth of the Acetabulum, and are more common in adult females, although a combination of both Cam and Pincer lesions also occur commonly.


Symptoms of FAI include pain ranging from a dull ache to severe pain with activity.  Patients may also have varying amounts of loss of range of motion (stiffness) in the hips, and difficulty sitting for prolonged periods of time.  Because of the stiffness, abnormal forces can also be transmitted to the lower back, causing pain in this area as well. On examination, Dr. Lee will flex and rotate the hip to test for signs of impingement, as well as rule out other potential causes of pain.

Diagnostic Testing:

An X-ray is important to evaluate the hip joint’s bony anatomy. It may reveal a Cam lesion, Pincer lesion, or both.  If a bony lesion is found, a CT scan may be considered to further assess.  An MRI is usually also obtained to assess the area including any damage to the soft tissue, such as the labrum and cartilage.

Treatment Options:

Treatment recommendations will vary depending on the patient’s severity and length of time of symptoms.  If your pain and imaging is not severe, Dr. Steven Lee will likely recommend rest, ice, NSAIDs such as Advil or Aleve with food (if not contraindicated) and a course of physical therapy. If your pain is severe and/or your imaging reveals joint damage, surgery may be advised to not only correct the problem(s) but to also prevent further joint damage.

Surgical Treatment:

Surgery is advised if the impingement is severe, significantly painful, leading to further joint damage, causing a labral tear, or if the patient has failed non-operative treatment.  It is important to try and address significant FAI prior to irreparable damage being done to the hip.  Dr. Lee will refer you to an orthopedic hip specialist for consultation if surgery is advised.

Recovery Expectations:

After surgery, patients will typically be able to bear weight fully, although with the help of crutches especially for the first few weeks.  Physical therapy is started within a few weeks after surgery, and full recovery can take approximately 3 months.





*It is important to note that all of the information above is not specific to anyone and is subject to change based on many different factors including but not limited to individual patient, diagnosis, and treatment specific variables. It is provided as an educational service and is not intended to serve as medical advice.  Anyone seeking specific orthopedic advice or assistance should consult Dr. Steven Lee or an orthopedic specialist of your choice.


*Dr. Steven Lee is a board certified orthopedic surgeon and is double fellowship trained in the areas of Hand and Upper Extremity Surgery, and Sports Medicine. He has offices in New York City, Scarsdale, and Westbury Long Island.  

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