Femoroacetabular impingement, sometimes also known as femoral acetabular impingement or FAI, is a condition in which bones of the hip joint experience abnormal friction that leads to pain and skeletal damage. This medical condition is believed to have a congenital basis but is more common in athletes, laborers, and others with very physically active lifestyles. Typically affecting young or middle-aged individuals, it is frequently treated with arthroscopic surgery.
In femoroacetabular impingement, the bones and cartilage that form the ball and socket joint of the hip come in contact more than normal, causing friction or pinching adjoining tissue. This in turn damages the cartilage that lines the bone sockets, which might result in the development of hip arthritis at an abnormally young age. Femoroacetabular impingement can occur in three forms, usually called cam type, pincer type, and mixed type. Athletes in certain sports might be more likely to develop femoroacetabular impingement. These sports include contact sports such as rugby and American football, as well as ice hockey, ballet, golf, soccer, and martial arts.
Individuals with this condition could experience pain, stiffness, and loss of range of motion in the hip joint, particularly after sitting for prolonged periods of time. Individuals might also experience a locking or clicking sensation in the hip joint, difficulty putting on shoes or walking uphill, and pain in the lower back or buttocks. Some people with femoroacetabular impingement do not experience pain symptoms.
A number of other medical conditions might be confused with femoroacetabular impingement. Commonly confused conditions include a strain of the abdominal muscles commonly known as a sports hernia, hip dysplasia, hamstring tendinitis, and trochanteric bursitis. Femoroacetabular impingement is sometimes determined to be the cause of hip or back pain only after ruling out conditions with similar symptoms.
Diagnosis of femoroacetabular impingement begins with a physical exam to evaluate range of motion in the hip joint. Diagnostic X-rays might be taken in addition to an MRI scan or, on occasion, a special kind of MRI called magnetic resonance arthrography. Arthroscopic surgery, which can be done on an outpatient basis, is frequently recommended to treat severe symptoms. Full recovery from surgery often takes four to six months or longer. Less severe cases might be treated with nonsurgical means, such as changing to a less active lifestyle and undergoing physical therapy to strengthen the hip joint. Regular use of anti-inflammatory medications could also be prescribed.
