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Femoroacetabular Impingement or FAI

    Femoroacetabular Impingement or FAI


    Femoroacetabular Impingement or FAI is now recognized as a reason for disabling hip pain in adolescents and adults and a possible etiology of early hip arthritis. It is estimated that 10% of our population has some degree of FAI. There are two types of FAI, namely the Cam type and the Pincer type. Cam type FAI describes impingement originating from the femoral side of the joint. Typically in this situation the femoral head neck junction is more oval shaped than round. With continued rotation and use of the hip joint with activity, this mismatch or conflict between the oval shaped head and the round cup eventually can tear the acetabular labrum and can damage the acetabular cartilage. The acetabular labrum is a fibrocartilagenous extension of the acetabular rim, and is believed to be important for both hip stability and as a seal for the hip joint. Pincer type of FAI originates on the acetabular side. In this type, the cup can be retroverted which causes anterior over coverage or the cup can simply be too deep for the head. This creates impingement between the two sides of the joint by over covering or constraining the femoral head. This conflict also can result in tearing of the acetabular labrum and cartilage.

    The treatment for FAI can be either an open procedure with surgical dislocation of the hip or an arthroscopic procedure. With either technique, the goal is to remove bone from both the acetabular and femoral sides of the joint to remove the impingement conflict and improve the biomechanics of the joint. In addition, the acetabular labrum is repaired and cartilage injuries are addressed. Not surprisingly, hip arthroscopy performed by those with appropriate training can result in improved outcomes and a quicker recovery compared to the open approach