Numerous studies have shown the Lachman test at 20 1/2 flexion to have a higher diagnostic accuracy in the clinical evaluation of anterior cruciate ligament (ACL) insufficiencies than does the anterior drawer test of the knee at 90 1/2 flexion [1, 7, 12, 13, 15, 16]. Several new clinical tests improve our diagnosis of sagittal instability, but these clinical methods are unsuccessful in determining accurately the degree of laxity [2, 4, 14]. The most reliable and reproducible assessments of sagittal laxity to date have been by radiographic methods [3, 5, 8–11]. The objectives of this study are to document the effectiveness of several stress-radiographic techniques in assessing sagittal laxity of the knee and to compare this with the results obtained with the KT 1000 arthrometer.
