Table 4.

Arthroscopic classification and treatment of intrinsic ligament instability.¹⁷

Grade	Diastasis	Average of three midcarpal stress shift tests: distraction, translation, rotation	Treatment
I	Volar opening of 2.3 mm, no dorsal opening	Less than 10% shift	Partial tear does not require pin stabilization
II	2.3 mm or greater diastasis, both dorsally and volarly	Shifts between 10% and 25%: A: radiocarpal view, ligament reduced to normal bed B: radiocarpal view, ligament free edge not reduced	A: arthroscopic repair with early mobilization B: limited open direct anchor repair of ligament edge
III	2.5 mm or greater diastasis	Shifts > 25%: A: radiocarpal view, ligament reduced to normal bed B: radiocarpal view, ligament free edge not reduced	A: arthroscopic repair, no early mobilization owing to damaged secondary stabilizing ligaments B: limited open direct repair of ligament edge