Table 1.

The Geissler classification of interacarpal ligament injury

Arthroscopic classification of the tears of the intracarpal ligaments
Grade	Description
I	Attenuation or hemorrhage of the interosseous ligament as seen from the radiocarpal space. No incongruency of carpal alignment in the midcarpal space.
II	Attenuation or hemorrhage of interosseous ligament as seen from the radiocarpal space. Incongruency or step-off of midcarpal space. There may be slight gap (less than width of probe) between carpal bones.
III	Incongruency or step-off of carpal alignment as seen from both radiocarpal and midcarpal space. Probe may be passed through gap between carpal bones.
IV	Incongruency or step-off of carpal alignment as seen from both radiocarpal and midcarpal spaces. There is gross instability with manipulation. A 2.7-mm arthroscope may be passed through the gap between carpal bones.

This classification system depicts injury severity based upon arthroscopic findings. Grade 1 injuries are the least severe while grade 4 injuries have the highest level of damage. Reprinted with permission from Geissler WB, Freeland AE, Savoie FH, McIntyre LW, Whipple TL. Intracarpal soft-tissue lesions associated with an intra-articular fracture of the distal end of the radius. J Bone Joint Surg Am. 1996;78(3):357-65