Femoral-acetabular impingement (FAI), also known as hip impingement, is a deformity of the hip joint that limits the joint’s normal range of motion. Though it can be caused by trauma to the hip or by the repetitive movements of certain athletic or work-related activities, FAI is typically characterized by bone growth in the femoral head and/or the socket in the hip joint.
The ball and socket of the hip joint can conflict with each other, pinching the tissue in between and causing damage to the hip joint (cartilage and labrum). Often these symptoms arise in athletic young adults, as early as age 15 and up, and in adults up to age 50.
Some people are more at risk for hip impingement because of certain anatomical differences. There are two types of FAI — cam impingement and pincer impingement. FAI caused by an improperly shaped socket is considered a pincer impingement. It occurs when extra bone grows along the socket’s rim or when the socket is not angled properly, allowing the socket and the femur to impact abnormally. FAI caused by an improperly shaped femur (thigh bone) is called a cam impingement, occurring when the femur's head grows into a shape that is unevenly rounded.
While some people experience no pain or discomfort with FAI, the following symptoms can occur:
- A locking, clicking or catching sensation within the joint
- Difficulty putting on socks or shoes
- Difficulty walking uphill
- Lower back pain
- Pain in the back of the pelvis, the buttocks or side of hip pain or aching (usually in the groin area), often after walking or prolonged sitting (such as in a car)
FAI symptoms are often confused with other sources of pain, such as hip flexor tendinitis, back pain, testicular pain or sports hernias.
People most at risk for developing FAI include:
- High-level athletes or active individuals
- Individuals with a history of trauma or sports injury to the hip
- Young male athletes (20s) or active females (30s and 40s)
Diagnosis is made based on the individual’s history, symptoms and a physical examination by their physician. Typically, an X-ray will confirm the diagnosis. Additionally, an MRI can evaluate the extent of soft tissue injury in the hip joint. Diagnostic injections with local anesthetic can be helpful in determining the source of a patient’s pain. These are sometimes done in the physician’s office or with X-ray guidance. A computerized tomography (CT) scan is used in select cases to illustrate 3-D bony anatomy and guide precise surgical decisions.
Nonsurgical Treatment Options
Oftentimes, the first course of treatment is to modify the patient’s activity and prescribe anti-inflammatory medications. Once the diagnosis is confirmed, patients may elect to have a cortisone shot in the hip, physical therapy for significant tendonitis (inflammation of a tendon, the tough cords of tissue that connect muscles to bones) or surgery.
Surgical Treatment Options
When there is established damage to the cartilage or labrum of the hip, patients are less likely to respond to nonsurgical treatment. Surgical options can range from minimally invasive surgery, known as arthroscopy, to total hip replacement. Limited open approaches combined with arthroscopy and surgical dislocation of the hip are also options in select patients.
Benefits of Hip Arthroscopy
Hip arthroscopy is a minimally invasive surgical option for patients with hip pain, hip injuries and early arthritis of the hip resulting in minimal pain and risk. These procedures often performed in an outpatient surgery setting, allow athletes to return to their sport, workers to return to their job and often prevent or delay the need for a joint replacement.
Arthroscopic surgery of the hip is performed through tiny incisions using a camera inside the joint to visualize the damaged structures. Using a variety of small instruments, the surgeon can repair torn tissue, remove bone spurs, reshape abnormal bones and treat injured cartilage. The goal of surgery is to repair damaged tissues and restore more normal mechanics to the hip.
Hip arthroscopy is typically performed as an outpatient procedure, meaning patients can return home the same day as their surgery. Patients often begin physical therapy and exercise on a stationary bicycle the day after their surgery. Most patients will take pain medicine only for a few days after surgery and will return to normal walking within two weeks. Athletes may return to competitive sports in as soon as three months following surgery.
Read a Patient Story
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||For six agonizing years, Sheela Houston had constant pains in her back and abdomen. After seeing several doctors,Sheela learned that she had femoral-acetabular impingement. Find out how minimally invasive hip surgery helped her become pain free. Read Sheela's femoral-acetabular impingement surgery story.
Sharp offers hip impingement surgery at the following Sharp hospital in San Diego:
Find a San Diego Orthopedic Surgeon
To find a Sharp-affiliated surgeon who specializes in FAI, send us an email, search for a San Diego orthopedic surgeon online or call 1-800-82-SHARP (1-800-827-4277), Monday through Friday, 8 am to 6 pm.