Table II.

Prognosis of femoroacetabular impingement (FAI)

Author/s	Population		Number of cases		Imaging used		Level of evidence		Major finding
Allen et al67	Patients < 55 yrs with symptomatic cam FAI (Canada)		113 (82M, 31F)		AP pelvis and lateral x-ray		Prognostic, III		88 patients with bilateral cam, but only 23 of these with bilateral symptoms
Audenaert et al68	Patients < 65 yrs undergoing THR (Belgium)		121		AP pelvis and cross-table lateral x-ray		Prognostic, IV		Low correlation of radiological and activity variables with age at THR. Patients with primarily cam impingement were younger at THR than patients with primarily pincer impingement
Bardakos and Villar69	Patients < 55 yrs with idiopathic OA with 10 years of radiological follow-up (UK)		43 hips (43 patients) (35M, 8F)		Supine AP pelvis x-ray		Prognostic, III		28 of 43 showed radiological progression of OA
Clohisy et al70	Patients < 50 yrs undergoing THR (US)		604 (710 hips), (314M, 290F), 118 with FAI		AP pelvis and cross-table lateral x-ray		Prognostic, IV		High prevalence of FAI in patients previously diagnosed with “unknown causes of OA” (118 of 121), 70 FAI patients with radiographs at more than one timpoint all with bilateral findings, 73% progression of disease over time
Hartofilakidis71	Contralateral hip of patients < 65 yrs treated for unilateral hip disease (Greece)		96 with FAI (31M, 65F)		AP pelvis x-ray		Prognostic, IV		17.7% progression of OA over 10 years, presence of “idiopathic OA” on contralateral side was the only predictor of progression