Table V.
Definition of hip dysplasia across continents
| North America | South America | Europe | Asia | Australia | |
|---|---|---|---|---|---|
| Definition of hip dysplasia | |||||
| Number of studies defining hip dysplasia (number of hips) | 16 (1,048) (21%) | 0 | 5 (473) (14%) | 0 | 0 |
| Via LCEA < 25° | 4 (176) | 3 (276) | |||
| Via LCEA < 20° | 7 (457) | 1 (111) | |||
| Via ACEA < 20° | 2 (61) | ||||
| Via Tönnis angle > 10° | 2 (110) | ||||
| Via acetabular index < 20° | 1 (36) | ||||
| Via “dysplasia” | 2 (251) | ||||
| Via femoral head coverage (CT/MRI) | 1 (1) | ||||
| Via hypertrophic labrum (MR, arthroscopy) | 1 (1) | ||||
| Via anterior or posterior femoral head surface area <10% | 1 (36) | 1 (86) | |||
| Via Type I (incongruent) or II (short arc) | 13 (320) | 8 (366) | 1 (7) | 1 (1) | |
| Not defined, but reported the number of subjects with dysplasia | |||||
| Number of studies defining borderline hip dysplasia (number of hips) | 0 | 0 | 0 | ||
| Via LCEA 20°–25° | 4 (252) | 1 (111) | |||
| Via LCEA 18°–25° | 1 (22) | 0 | |||
| Via ACEA 20°–25° | 1 (106) | 0 | |||
| Via Sharp’s angle > 40° | 1 (106) | 0 | |||
| Number of subjects with hip dysplasia | 82 | nr | 63 | 7 | 0 |
| Number of subjects with borderline hip dysplasia | 78 | nr | 10 | 0 | 1 |
| Number of studies that excluded dysplastic hips from investigation (proportion) | 10 (13%) | nr | 5 (14%) | 0 | 1 (20%) |
ACEA, anterior center edge angle; LCEA, lateral center edge angle; CT, computed tomography; nr, not recorded.