In Vivo Validation of Automated Knee Arthrometry: What Do These Measurements Really Represent?

Background

Objective assessment of anterior knee laxity (AKL) is important for evaluating graft integrity after anterior cruciate ligament (ACL) reconstruction. Automated arthrometers, such as the GNRB, provide reproducible measurements; however, the in vivo biomechanical meaning and validity of these measurements remain unclear. Hypothesis/Purpose: The primary purpose was to validate GNRB-derived AKL measurements against biplanar videoradiography (BVR)–derived metrics under in vivo postoperative conditions. It was hypothesized that GNRB measurements would differ significantly from BVR-derived measures of tibiofemoral translation and ACL graft elongation. A secondary, exploratory purpose was to examine the relationships between GNRB- and BVR-derived laxity measures. Study Design: Cohort study (Diagnosis); Level of evidence, 2.