Eaton classification of volar plate avulsion injury

The Eaton classification can be used to classify volar plate avulsion injuries of the fingers.

Usage

Along with the Keifhaber-Stern classification, this classification is considered (c. 2016) one of the most useful classifications for the management of volar plate avulsion injuries ². 

Knowledge of the orthopedic Eaton classification is practical when reporting volar plate injury of the PIP joint as for Eaton types I, II and IIIa, conservative management is recommended with surgical management for Eaton types IIIb ².

Classification

• Eaton type I: hyperextension mechanism of injury with an avulsion of the volar plate and a longitudinal tear of the collateral ligaments; the opposing joint surface remain congruent

• Eaton type II: dorsal dislocation of the PIP joint with avulsion of the volar plate; there is complete tear of the collateral ligament

• Eaton type III

  • Eaton type IIIa

    • fracture dislocation with an avulsed small fragment <40% of the articular surface

    • dorsal aspect of the collateral ligament remains attached to the middle phalanx

  • Eaton type IIIb: fracture dislocation with fracture or impaction of the articular surface of >40%

History and etymology

This classification was proposed by Eaton and Malerich in 1980 ¹.