Femoral Acetabular Impingement (FAI) is caused by increased friction between the head of the femur bone and the acetabulum. This abnormal rubbing leads to damage of the hip joint, possibly including the articular and labral cartilages. FAI is associated with cartilage damage, labral tears, early hip arthritis, hyperlaxity, sports hernias, subspinous AIIS impingement, ischiofemoral impingement, and low back pain.
Types of FAI
There are three types of FAI: pincer, cam, and combined cam & pincer impingement.
Pincer Impingement occurs due to excess bone extending out over normal rim of the acetabulum. The labrum can be impinged between the prominent rim of the acetabulum and the neck of the femur.
Cam Impingement occurs when the femoral head is not round and cannot rotate smoothly inside the acetabulum. The abnormal "cam bump" causes increased tension force on the labrum, eventually tearing the labrum off the bone of the acetabulum.
Combined The most common form of FAI (86% of cases) is a combination of cam and pincer. http://www.nirschl.com/hip-arthrosocpy-FAI.asp
Treatment for FAI varies. Conservative treatment can include reducing levels of physical activity may optimize alignment and mobility of the joint, thereby decreasing excessive forces on irritable or weakened tissues. Physical Therapy movement patterns must be assessed and improper muscular length-tension relationships must be accurately addressed throughout the hips, knees and ankles, which can lead to an increase stress applied at the hip joint. A physical therapist can create a specialized program that is specific so that "active rest" can occur, while continuing to address muscular limitations. "Active Rest" refers to performing a well-balanced therapeutic program that addresses functional and structural limitations and progressively allows the athlete to lengthen restricted muscular and strengthen awareness during the rehabilitation process. This will minimize the severity and intensity of symptoms when & if they weak musculature, while introducing proper body mechanic and functional movement do return, while providing the athlete with the proper education to reduce symptoms prior to moderate functional/ movement impairments which will lead once again to limiting activity.