Wiberg classification of patella shape

Last revised by Jeremy Jones ◉ on 7 Jan 2025

Citation, DOI, disclosures and article data

Citation:

Luijkx T, Jones J, Ismail M, et al. Wiberg classification of patella shape. Reference article, Radiopaedia.org (Accessed on 02 Mar 2025) https://doi.org/10.53347/rID-30354

DOI:

https://doi.org/10.53347/rID-30354

Permalink:

https://radiopaedia.org/articles/30354

rID:

30354

Article created:

4 Aug 2014, Tim Luijkx

Disclosures:

At the time the article was created Tim Luijkx had no recorded disclosures.

View Tim Luijkx's current disclosures

Last revised:

7 Jan 2025, Jeremy Jones ◉

Disclosures:

At the time the article was last revised Jeremy Jones had no financial relationships to ineligible companies to disclose.

View Jeremy Jones's current disclosures

Revisions:

17 times, by 12 contributors - see full revision history and disclosures

Systems:

Musculoskeletal

Sections:

Classifications

Tags:

refs, cases, knee

Synonyms:

Patella shape
Patella shape (Wiberg classification)
Wiberg classification for patellar shape

Wiberg classification is a system used to describe the shape of the patella based mainly on the asymmetry between the patellar medial and lateral facets on axial views of the patella. Increasing number type indicates a larger degree of asymmetry. It is used as a predictor for risk of developing articular cartilage defects in the patellofemoral region⁴.

Classification

type I (or type A)
- roughly symmetrical, equal-sized facets
- concave facets
- although presumably the ideal shape of the patella, it is in fact rather uncommon, occurring in only 10% of the general population
type II (or type B)
- slightly smaller size of the medial facet
- flattening of the medial facet
type III (or type C)
- markedly smaller size of the medial facet
- more vertical orientation of the medial facet
- convex aspect of the medial facet