Lee HJ, et al. - Stress radiography and arthrometer measurements were evaluated for their diagnostic value for anterior instability at different knee flexion angle positions. Forty-three patients with complete anterior cruciate ligament (ACL) rupture (group 1) and 37 normal subjects (group 2) underwent arthrometer (KT-1000) measurements and stress radiography by Telos to evaluate side-to-side differences. Findings revealed significant superiority of evaluation at the 30° knee position to that at other positions for both stress radiography and arthrometer measurements. However, researchers identified no significance of the 90° knee flexion position for any measurements. They recommend performing evaluation with a 3-mm cutoff value for stress radiography at the 30° knee position. Nevertheless, a higher diagnostic value could be gained via combining stress radiography and arthrometer measurements at the 30° knee flexion.