Table 3.

Compared the AA between the dislocated hips and unaffected hips in the group of grade II, III and IV according to the classification of Tönnis

Tönnis grade	Dislocated hips		Unaffected hips		P-value
	Mean±SD	Range	Mean±SD	Range
II	16.57 ± 3.08°	(12–22°)	12.65 ± 2.83°	(9–18°)	0.008
III	17.94 ± 3.20°	(13–23°)	12.61 ± 3.38°	(5–18°)	0.001
IV	18.03 ± 3.96°	(12–26°)	12.26 ± 1.55°	(10–15°)	0.001

AA acetabular anteversion, SD standard deviation