| Type | Alpha angle | Beta angle | Bony roof | Ossific rim | Cartilage roof | Interpretation |
| I a | >60 | <55 | good | sharp | covers femoral head | mature |
| I b | >60 | >55 | good | usually blunt | covers head | mature |
| II a | 50-59 | >55 | deficient | rounded | covers head | < 3 months of age (physiological ossification delay) |
| II b | 50-59 | >55 | deficient | rounded | covers head | > 3 months of age |
| II c | 43-49 | <77 | deficient | rounded/flat | covers head | |
| II d | 43-49 | >77 | severely deficient | rounded/flat | compressed | on point of dislocation |
| III a | <43 | >77 | poor | flat | displaced up echo poor | dislocated |
| III b | <43 | >77 | poor | flat | displaced up reflective | dislocated |
| IV | <43 | >77 | poor | flat | interposed | dislocated |