This document provides guidelines for classifying ligament injuries based on stress x-ray measurements. Partial tears of the posterior cruciate ligament are under 8mm, total tears are between 8-12mm, and combined injuries are over 12mm. Partial tears of the posterolateral corner are over 4mm. Partial medial collateral ligament tears are under 3.2mm and total tears are over 3.2mm. Partial fibular collateral ligament tears are over 2.7mm.

1. Stress X-ray
(Side to side difference)
STRESS X-RAY PARTIAL TOTAL COMBINED
PCL < 8 mm 8-12 mm > 12 mm
PLC > 4 mm
MCL < 3.2 mm > 3.2 mm
FCL > 2.7 mm