Femoroacetabular Impingement (FAI): Current Clinical Approaches

Abstract

The purpose of this paper is to review the history of femoroacetabular impingement (FAI), discuss its pathophysiology and clinical presentation, identify radiographic parameters used to characterize FAI, and provide an updated summary of outcome-based non-operative and surgical treatments for FAI syndrome based on recent trends and developments. Recent literature has shed further light onto the detailed pathophysiologic mechanisms of FAI syndrome, particularly in its relation to both osteoarthritis and hip dysplasia. This and recent outcome data have led to the development of improved diagnostic and treatment algorithms that incorporate specific radiologic studies and parameters, allowing for better patient selection for non-operative and operative treatment strategies. Along with a detailed history and physical examination, specific radiographic parameters allow for more precise identification FAI. These include, but are not limited to, the alpha angle, head-neck offset (HNO), lateral center edge angle (CEA), femoral version, and acetabular version. The clinician should also evaluate for concomitant cartilage degradation, labral pathology, and the presence of dysplastic features or instability, which have been shown to significantly affect treatment outcomes. This is reflected in recent best practice guidelines.