Table 3

Evaluation of varus and valgus instability using stress radiographs Side-to-side differences between the injured and the noninjured knee using stress radiograph to evaluate varus and valgus knee instability.

Varus stress testValgus stress test
<2.7 mm → Normal or partial tear<3.2 mm → Normal or partial tear
2.7 mm → Isolated FCL tear3.2 mm →Complete sMCL tear
≥4 mm: →Complete PLC injury≥9.8 mm → Complete tear of all medial structures
  • FCL, fibular collateral ligament; PLC, posterolateral corner; sMCL, superficial medial collateral ligament.