Patellar dysplasia means an abnormally-shaped patella.

Page updated May 2024 by Dr Sheila Strover (Clinical Editor)

wiberg type 4 patellar dysplasia

This illustration of a cross-section through a dysplastic patella shows how the facets may be distorted.

 

What is the cause of patellar dysplasia?

Patellar dysplasia is generally considered something one is simply born with, but other possible causes may exist.

 

  • Quote from peer-reviewed paper:

    "....there is no consensus as to whether patellofemoral dysplasia is genetic in origin, caused by imbalanced forces producing maltracking and remodelling of the trochlea during infancy and growth, or due to other unknown and unexplored factors...."

    Citation: Zaffagnini S, Grassi A, Zocco G, Rosa MA, Signorelli C, Marcheggiani Muccioli GM. The patellofemoral joint: from dysplasia to dislocation. EFORT Open Rev. 2017 May 11;2(5):204-214. doi: 10.1302/2058-5241.2.160081. PMID: 28630757; PMCID: PMC5467684.

Back to top

 

What symptoms can result from patellar dysplasia?

Patellar dysplasia may lead to subluxation or dislocation of the patella.

 

  • Quote from peer-reviewed paper:

    "....Patellar dysplasia "is a major predisposing factor for instability of the patellofemoral joint....[but] represents an extremely challenging condition to manage."

    Citation: Zaffagnini S, Grassi A, Zocco G, Rosa MA, Signorelli C, Marcheggiani Muccioli GM. The patellofemoral joint: from dysplasia to dislocation. EFORT Open Rev. 2017 May 11;2(5):204-214. doi: 10.1302/2058-5241.2.160081. PMID: 28630757; PMCID: PMC5467684.

Back to top

 

Classification of Patellar Dysplasia

The Wiberg classification of the shape of the patella - based upon the relative lengths of the facets - is widely used to describe different patellar shapes.

 

Wiberg Type 1 patella

Wiberg Type 1 patella

Wiberg Type 2 patella

Wiberg Type 2 patellar dysplasia

Wiberg Type 3 patella

Wiberg Type 3 patellar dysplasia

wiberg type 4 patellar dysplasia

Wiberg Type 4 patellar dysplasia

 

Back to top

 

Patellofemoral Dysplasia

Patellofemoral dysplasia is when the groove of the trochlea mirrors any abnormality in the shape of the patella.

Back to top

 

Forum discussions

  • Please help a newbie!

    A patient with a shallow trochlea tries to understand the issues of potential surgery.

Back to top

 

Synonyms: 
dysplastic patella
kneecap dysplasia
dysplastic kneecap
Baumgartl classification
Wiberg-Baumgartl classification
-

Dr Sheila Strover (Editor)
BSc (Hons), MB BCh, MBA

See biography...