Challenges in the management of hip dislocation disease in Madagascar

Table 1 Severin classification

Group	Radiographic appearance	Vertical center edge angle
I	Normal
I-a	Normal	> 19° (ages 6-13)
I-b	Normal	> 25° (older than 13 years)
II	Mild deformity of the femoral head, neck, or acetabulum	Same as group I
III	Dysplasia without subluxation	< 15° (ages 6-13) < 20° (> 13 years)
IV
IV-a	Moderate subluxation	≥ 0°
IV-b	Severe subluxation with neo-hip joint formation at the upper margin of the acetabulum	< 0°
V	Recurrent dislocation