Saupe Classification

Saupe's Classification: Based on the position of the accessory ossification center

More about bipartite patella here

Type I (5%)	Accessory ossification center at the inferior pole
Type II (20%)	Accessory ossification center at the lateral margin
Type III (75%)	Accessory ossification center at the superolateral pole

Normal Variant: Bipartite Patella

Bipartite patella occurs due to presence of unfused ossification centre.
Other variants include

• Tripartite patella
• Multipartite patella

These normal variants can be classified using Saupe's classification.

Male : Female = 9 : 1

Occurs in 2% of population

Usually asymptomatic

Saupe type 3 Bipartite patella. About half of bipartite patellae are bilateral.

Ossification:

• Primary ossification begins at 5 - 6 years old
• 77% from one center
• 23% from two or three centers
• The ossification centers usually fuse mutually