|
Class I
|
A completely normal hip joint
|
|
Class II
|
A spherical femoral head (same concentric circle on anteroposterior and frog-leg lateral radiographs), but with one or more of the following abnormal characteristics of the femoral head, neck, or acetabulum:
|
| |
(1) Larger than normal (although spherical) femoral head (coxa magna);
|
| |
(2) Shorter-than-normal femoral neck;
|
| |
(3) Abnormally steep acetabulum
|
|
Class III
|
A non-spherical (ovoid, mushroom-shaped, or umbrella-shaped) but not flat femoral head. Abnormal characteristics of the femoral head, neck, and acetabulum (as described for Class II) are present also.
|
|
Class IV
|
A flat femoral head and abnormalities of the femoral head, femoral neck, and acetabulum
|
|
Class V
|
A flat femoral head and a normal femoral neck and normal acetabulum
|
