Table 4.

Association of Graf method and femoral head coverage with instability groups.

US method∗	Stable (100 hips)	Subluxatable (193 hips)	Dislocatable/dislocated (45 hips)
Graf type I	86 (86%)	37 (19.2%)	8 (17.8%)
Graf type IIa	13 (13%)	113 (58.5%)	6 (13.3%)
Graf type IIb	0	0	0
Graf type IIc	1 (1%)	13 (6.7%)	2 (4.4%)
Graf type D	0	11 (5.7%)	8 (17.8%)
Graf type III	0	17 (8.8%)	10 (22.2%)
Graf type IV	0	2 (1%)	11 (24.4%)
FHC ≥ 50%	84 (84%)	26 (13.5%)	2 (4.4%)
FHC < 50%	16 (16%)	167 (86.5%)	43 (95.6%)