RESEARCH ARTICLE Prevalence of radiographi

Full list of author information is available at the end of the articleBackground Femoroacetabular impingement (FAI) is one factor known to cause pain and osteoarthritis (OA) of the hips. First described by Ganz et al. in 2003 [1,2], FAI was identified in cases previously considered ‘primary hip OA’, in which initial radiography assessment suggested no hip joint abnormalities [3]. Generally, in the diagnosis of FAI, disor-ders such as hip dysplasia, rheumatoid arthritis, avascular necrosis of the femoral head, and fractures around the hip joint must be excluded. FAI may be divided into two subcategories based on the pathogenic mechanism: pincer type (impingement due to acetabular retroversion or acetabular overcoverage) or cam type (impingement due to an aspherical femoral head) [4]. Currently, several radiographic indicators have been described for th