Soong Classification/Grading

Soong classification/grading of plate prominence in ‘Volar plate fixation of distal radius fracture’

The grading is based on post-op lateral radiographs, where a line is drawn tangential to the most volar extent of volar rim, parallel to the volar cortical bone of the radial shaft.
Grade 0: The plate does not extend volar to the line.
Grade 1: The plate is volar to the line but proximal to the volar rim.
Grade 2: The plate is directly over the volar rim or distal to it.

see Figure from the article 2 below:

Please see this article for more details:
1. Volar locking plate implant prominence and flexor tendon rupture
by Soong M, Earp BE, Bishop G, Leung A, Blazar P

2. Relationship between plate removal and Soong grading following surgery for fractured distal radius
by Caroline A. Selles, Sam T.H. Reerds, Gert Roukema, Kees H. van der Vlies, Berry I. Cleffken & Niels W.L. Schep