Skip to main content

Femoroacetabular Impingement (FAI)


Hip Anatomy

The hip is a ball and socket joint. The ball is the head of the upper leg bone called the femur. The ball fits securely in its socket in the acetabulum, a cup shaped socket on the pelvic bone. Articular cartilage lines the head of the femur and the socket for smooth movements. The socket is rimmed with a strong band of cartilage, called the labrum, which surrounds the ball and holds it in place, absorbs shock, and stabilizes and protects the hip joint; and allows for a wide range of motion.

What is FAI?

FAI is a disorder that results from abnormal contact between the head of the femur and/or the acetabulum and can lead to labral tears and cartilage damage. Abnormally shaped hip joint bones rub together during normal hip movements and lead to impingement (pinching) of the hip labrum. Repetitive impingement can cause pain and discomfort, accelerates joint deterioration, and causes tears of hip joint cartilage and hip labrum. FAI leads to hip instability and is a predominant cause of hip arthritis.

FAI is a common cause of joint pain in young and active people. It is important to note that many people may have abnormally shaped hip joints but have no problems, have FAI without symptoms or develop problems only with overuse.

What causes FAI?

The abnormal shape of the bones can be a developmental defect or acquired as a result of injury and repetitive motions. Typically this repetitive trauma is due to hip positioning during sports at a young age. The location of the impingement is determined by which bones are abnormally shaped.

What are the symptoms of FAI?

Symptoms of FAI are the same as those for a labrum tear. In fact, most labrum tears are caused by FAI. Symptoms include:

  • sporadic groin pain
  • pain at the outside of the hip
  • pain down the front of the thigh or in the buttocks
  • sharp stabbing pain with twisting, turning, squatting and getting into and out of a chair or the car
  • a dull ache after prolonged sitting or walking
  • a clicking sound in the hip with movement
  • hip instability
  • decreased range of motion
  • stiffness and limping

Once symptoms occur it is highly likely that there is damage to the labrum that will progressively worsen with overuse. FAI causes repeated incidences of microtrauma which produces bone spurs, hip joint degeneration and osteoarthritis.

How is FAI diagnosed?

Dr. Cooper will review your medical history including past hip injuries, inquire about your symptoms and what causes them to occur. He will conduct a physical exam including testing hip range of motion to diagnose impingement.

Because the symptoms of FAI may be confused with hip bursitis, a dislocated hip or muscle strain, Dr. Cooper will conduct specific hip impingement tests and order x-rays to evaluate the hip joint and to the show existence of abnormally shaped bones. Other imaging tests may be recommended to evaluate damage to the soft tissues in the hip joint. Dr. Cooper may recommend a steroid injection into the hip joint to see if it eliminates the pain, if so, it confirms the diagnosis of FAI.

How is FAI treated?

Generally, the first line treatment is conservative measures including activity modifications, time off from play, over the counter anti-inflammatory medications, and physical therapy. Steroid injections for pain may be offered. Symptoms should resolve within a few weeks on conservative measures.

Hip preservation surgery will be recommended when conservative measure fail to relieve pain.
Hip preservation surgery is a minimally invasive arthroscopic hip procedure designed to address the hip disorder that caused FAI, to treat bone abnormalities and soft tissue damage.

The goal is to preserve hip function, prevent further hip damage and to relieve pain. Hip preservation surgery is customized to address each patient’s anatomical needs. The goal is to prevent or delay development of osteoarthritis, and the potential future need for a hip replacement. It is valuable particularly for young and active patients with severe hip pain.

Dr. Cooper will recommend an individualized physical therapy plan after arthroscopic hip surgery. Full recovery and return to play can take 4 – 6 months.

Patients with hip pain should contact Dr. Joe Cooper to schedule a consultation. Dr. Cooper specializes in sports medicine with a focus on shoulders, knees, hips and elbows.

Our Locations

Choose your preferred location