Intraarticular fracture of distal radius - types by Melone

The Melone classification was first published in 1986. It divides distal radius fractures in four types. This classification is based on a concept of four major fragments including the shaft, the radial styloid process, a dorsal-medial fragment, and a palmar-medial fragment. The latter two fragments form the lunate fossa.

Type Description
I - undisplaced fractures Undisplaced or minimally displaced fracture with minimal comminution.
II - die-punch fractures "Die-punch" fracture with moderate to severe dorsal or palmar displacement of the medial complex.
III - spike fractures Presence of a spike fragment from the shaft that projects into flexor compartment and can injure the flexor tendons and the median nerve. Medial complex is displaced as a unit. Displaced radial shaft fragments.
IV - split fractures Wide separation or rotation of the intraarticular fragments, extensive soft tissue and periarticular damage.

References:

1. Melone CP Jr. Open treatment for displaced articular fractures of the distal radius. Clin. Orthop. Relat. Res. 1986 Jan;(202):103–11.
2. Andersen DJ, Blair WF, Steyers CM Jr, Adams BD, el-Khouri GY, Brandser EA. Classification of distal radius fractures: an analysis of interobserver reliability and intraobserver reproducibility. J Hand Surg Am. 1996 Jul;21(4):574–82.