Haley E. Ennis, MD, Hip & Knee Arthroplasty Specialist  Appointments:
Broomfield  (303) 544-3820
Longmont (720) 718-8288

Femoroacetabular Impingement

Femoroacetabular Impingement

The hip joint is also known as the ball and socket joint, where the ball (femoral head) of the thigh bone fits into the socket (acetabulum) of the pelvis bone.

Femoroacetabular impingement (FAI) is a condition in which the bones of the hip joint grow abnormally and do not fit together properly. This leads to restricted hip movement and increased friction between the ball and socket of the hip joint resulting in damage to the joint.

FAI can be associated with labral tears, cartilage damage and hip arthritis. The condition is also known as hip impingement.

Femoroacetabular impingement is commonly classified into three forms, based on the affected region of the hip joint:

  • CAM impingement deformity: A condition where the head of the femur is not smooth and rubs against the socket bone.
  • Pincer impingement deformity: In this condition, the socket has excessive coverage over the femoral ball.
  • Combined impingement deformity: This is a special condition in which both CAM and pincer impingement deformities occur together.


Femoroacetabular impingement occurs due to abnormal growth of the hip bones during a child’s growing years. People with the condition who are physically active and involved in certain sports such as cycling, ballet, martial arts, golf, soccer, baseball and deep squatting activities may experience symptoms earlier than those who are less active.

Signs and Symptoms

Symptoms of FAI include groin pain, hip pain or low back pain. You may have severe pain while turning, twisting and squatting. You may experience a locking or clicking sensation within the joint, and pain after sitting for extended periods.


Your doctor diagnoses femoroacetabular impingement by examining your hip, conducting an impingement test and performing imaging studies such as X-ray, CT (computed tomography) scan and MRI (magnetic resonance imaging).


Non surgical therapy.

Initial treatment involves resting, avoiding activities that increase pain, taking pain medications, and performing specific exercises to improve hip movement and strengthen the hip joint.

Surgical therapy.

Your physician may recommend arthroscopic hip surgery if nonsurgical therapy fails to improve the pain.

Hip Arthroscopy is a minimally invasive surgery performed through tiny incisions using a special viewing instrument called an arthroscope and special surgical tools.

During arthroscopy, your surgeon can repair any labrum or cartilage tears, remove bony bumps or trim off damaged or abnormal parts of the hip bones, facilitating free movement of the hip.

Arthroscopy is much less traumatic to the muscles, ligaments, and tissues than the traditional method of surgically opening the hip with long incisions.

Risks and Complications

As with any surgery, there are risks involved. Although rare, complications from hip arthroscopy can include:

  • Infection
  • Blood Clots
  • Nerve injury
  • Failure to relieve pain

Femoroacetabular impingement is a condition that occurs from abnormal growth of the hip bones leading to restricted movement and damage to the hip joint. Groin or hip pain caused by the impingement can be treated with conservative options such as rest and pain meds or may require hip surgery. Early correction can prevent further damage to the hip.

CMS Login