Wiberg classified the patella based on its anatomic features. These features correlate with its functional stability.
Size of Medial Facet |
Shape of Medical Facet |
Type |
equal to lateral facet |
slightly concave |
I |
small |
slightly concave |
II |
small |
flat |
II/III |
small |
slightly convex |
III |
very small |
steeply sloped |
IV |
absent, with no central ridge |
NA |
V |
where:
• Type V is also called a Jagerhut patella.
Type |
Stability |
I |
excellent |
II |
good |
II/III |
fair |
III |
fair |
IV |
suboptimal |
V |
poor |
Specialty: Surgery, orthopedic