The Prevalence of Radiographic Findings of Structural Hip Deformities for Femoroacetabular Impingement in Patients With Hip Pain

Background: Radiography is the initial imaging modality used to evaluate femoroacetabular impingement (FAI), and diagnostic radiographic findings are well-established. However, the prevalence of these radiographic findings in patients with hip pain is unknown. Purpose: The purpose was 3-fold: (1) to determine the overall prevalence of radiographic FAI deformities in young patients presenting with hip pain, (2) to identify the most common radiographic findings in patients with cam-type FAI, and (3) to identify the most common radiographic findings in patients with pincer-type FAI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A geographic database was used to identify patients aged 14 to 50 years with hip pain between the years 2000 to 2016. The following were evaluated on radiographs: cam type: typical pistol grip deformity, alpha angle >55°; pincer type: crossover sign (COS), coxa profunda or protrusio acetabuli, lateral center edge angle (LCEA) ≥40°, Tönnis angle 55° was 577 (42.1%) and 1069 (78.0%), respectively. The mean alpha angle was 66.9°± 10.5°. The prevalence of pincer-type radiographic findings was the following: COS, 1062 (77.5%); coxa profunda, 844 (61.6%); ISS, 765 (55.8%); PWS, 764 (55.7%); Tönnis angle 55°. The most common radiographic finding for pincer-type FAI was the COS.