Table V.

Radiographic characteristics before and after PAO

Parameter	Nonarthroscopy group (n = 69)	Arthroscopy group (n = 26)	P value
Before PAO
Center-edge angle
Median (interquartile range)	17° (13° to 20°)	20° (17° to 21°)	0.055
Range	−10° to 24°	11° to 24°
Acetabular index angle
Median (interquartile range)	15° (12° to 20°)	14° (12° to 18°)	0.222
Range	0° to 33°	8° to 21°
After PAO
Center-edge angle
Median (interquartile range)	34° (29° to 36°)	34° (32° to 37°)	0.317
Range	17° to 40°	25° to 46°
Acetabular index angle
Median (interquartile range)	3° (1° to 6°)	1o (−1° to 3°)	0.010
Range	−3° to 16°	−8° to 16°
Crossover sign before PAOa
Before PAO	9	9	0.036
At 2-year followup	4	0	0.572

^aCrossover sign before arthroscopy were not possible to evaluate, since postoperative radiographs after PAO were supine taken.