Biomechanics of Femoroacetabular Impingement

Femoroacetabular impingement (FAI) is a biomechanically complex condition, and understanding the kinematics and pathomechanics of this condition is crucial to treating it appropriately. There are many etiologies for the development of cam type, pincer type, and mixed type FAI, including genetics, physical activity, and dysplasia. The presence of FAI can lead to abnormal biomechanics both on the macro (e.g., altered gait and squat) and micro (e.g., repeated abutment of the acetabular rim) levels. Symptomatic FAI is also commonly associated with changes in spinopelvic alignment and kinematics. Careful surgical correction of cam and pincer lesions can help to minimize the negative effects of FAI postoperatively, and in some cases restore normal biomechanics. Untreated FAI can have numerous consequences, including osteoarthritis, labral tears, and chondral lesions.