AO/OTA classification of proximal humeral fractures

Last revised by Khalid Alhusseiny on 27 Aug 2023

Citation, DOI, disclosures and article data

Citation:

Gaillard F, Alhusseiny K, Feger J, et al. AO/OTA classification of proximal humeral fractures. Reference article, Radiopaedia.org (Accessed on 04 Dec 2023) https://doi.org/10.53347/rID-18312

DOI:

https://doi.org/10.53347/rID-18312

Permalink:

https://radiopaedia.org/articles/18312

rID:

18312

Article created:

28 Jun 2012, Frank Gaillard ◈

Disclosures:

At the time the article was created Frank Gaillard had no recorded disclosures.

View Frank Gaillard's current disclosures

Last revised:

27 Aug 2023, Khalid Alhusseiny ◉

Disclosures:

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

View Khalid Alhusseiny's current disclosures

Revisions:

10 times, by 9 contributors - see full revision history and disclosures

Systems:

Musculoskeletal

Sections:

Classifications

Tags:

humerus, shoulder, cases

Synonyms:

Proximal humeral fractures (AO classification)
Proximal humeral fractures (OTA classification)

The Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma Association (AO/OTA) classification together with the Neer classification is one of the most frequently used systems for classifying proximal humeral fractures. Like fractures in other bone segments, proximal humeral fractures are divided into three groups subject to the severity and complexity of the respective injury ¹.

In accordance with the Neer classification, the proximal humerus is divided into different parts and both the surgical neck and the anatomical neck form essential landmarks in the classification:

humeral head with the articular surface
metaphysis with greater tuberosity and lesser tuberosity
humeral shaft or proximal diaphysis

The new AO/OTA 2018 classification compendium has replaced the old classification from 2007 ^2,3:

type A: extraarticular unifocal or 2-part proximal humeral end segment fracture
- A1: unifocal tuberosity fracture
  - A1.1 greater tuberosity fracture
  - A1.2 lesser tuberosity fracture
- A2: surgical neck fracture
  - A2.1 simple surgical neck fracture
  - A2.2 wedge fracture of the surgical neck
  - A2.3 multifragmentary surgical neck fracture
- A3: unifocal vertical metaphyseal extraarticular fracture
type B: extraarticular bifocal or 3-part proximal humeral end segment fracture
- B1: extraarticular bifocal 3-part fracture surgical neck fracture *
  - B1.1 surgical neck with greater tuberosity fracture
  - B1.2 surgical neck with lesser tuberosity fracture
type C: multifocal, 4-part or articular proximal humeral end segment fracture
- C1: anatomical neck fracture
  - C1.1 valgus impacted anatomical neck fracture**
  - C1.3 isolated anatomical wedge fracture
- C3: anatomical neck with metaphyseal fracture
  - C3.1 multifragmentary metaphyseal segment but with an intact articular surface
  - C3.2 multifragmentary metaphyseal segment and fractured articular surface ***
  - C3.3 multifragmentary metaphyseal segment, articular fracture and diaphyseal extension ***

* applies for an intact or fragmentary wedge but this should be specified

** applies for the greater tuberosity, the lesser tuberosity or both tuberosities

*** applies for simple or multifragmentary articular fractures

The AO/OTA classification seems to be slightly less reliable and reproducible than the Neer classification but is ascribed a substantial descriptive power. It also seems to simplify the coding process ².