Comparative measurements of anterior tibial translation using the KT-1000 knee arthrometer with the leg in neutral, internal rotation, and external rotation

Position of the leg while using the KT-1000 knee arthrometer may be an important variable in attaining accurate and reliable measurements. The purpose of this study was to compare the anterior translation of the tibia on the femur with the tibia in neutral, internal rotation (IR), and external rotation (ER). Additionally, data were analyzed to determine the intratester and intertester reliability of the KT-1000 knee arthrometer with the leg in neutral. Data were collected from 50 subjects by two testers and one recorder, according to MEDmetric protocol. Tester 1 performed three pulls or one sequence in neutral, IR, and ER. A second sequence was performed in neutral. Tester 2 performed two sequences in the neutral position. Data in each sequence were averaged and evaluated. Intertester reliability was calculated at r = .64 (poor), while intratester reliability for tester 1 was r = .90 (high) and for tester 2 was r = .86 (good). A repeated measure, one- way ANOVA was used, and results demonstrated a statistical difference of p < .0001, with the difference found between IR when compared with ER and neutral. In conclusion, differences in tibial translation occurred between neutral, IR, and ER of the lower extremity. This may prove valuable for clinicians using the KT-1000.