Arthroscopic femoral osteoplasty/chielectomy for cam-type femoroacetabular impingement in the athlete.

Femoroacetabular impingement (FAI) represents an underlying bony abnormality of either the femoral head-neck junction or acetabulum, or most commonly, both. This often is associated with damage to intra-articular structures, primarily the labrum and chondral surfaces. Like pincer impingement, cam impingement has been associated with pain, limited hip range of motion, pain affecting athletic performance, and has been linked to the development of osteoarthritis. Cam impingement is the loss of offset of the femoral head-neck junction associated with loss of sphericity of the femoral head. Isolated cam impingement, although more common than isolated pincer impingement, it is much less common than both cam and pincer coexisting in people with FAI. Classically, the patient with isolated cam impingement is a young athletic male near 20 years of age. The classic pathology associated with the cam lesion is an acetabular articular cartilage injury in the anterosuperior acetabulum that is fairly well defined and may be deep, 1 to 1.5 cm from the acetabular rim, initially sparing the labrum, but eventually leading to labral detachment from the underlying bone. Treatment generally focuses on restoring the femoral head-neck offset by removing the excess bone. This article will review the underlying pathology of cam-type FAI, the evaluation and diagnosis, arthroscopic treatment, and reported outcomes.