Validation of a magnetic resonance imaging based method to study passive knee laxity: An in-situ study

Med Eng Phys. 2022 Jan:99:103733. doi: 10.1016/j.medengphy.2021.103733. Epub 2021 Nov 27.

Abstract

Knee laxity can be described as an increased anterior tibial translation (ATT) or decreased stiffness of the tibiofemoral joint under an applied force. Küpper et al. (2013, 2016) and Westover et al. (2016) previously developed and reported on a magnetic resonance (MR)-based in vivo measure of knee laxity. In this study, the application of an in situ knee loading apparatus (ISKLA) is presented as a step toward validating the MR-based methodology for measuring ATT and stiffness. The ISKLA is designed to measure these outcome variables using MR imaging and is validated against a gold-standard ElectroForce mechanical test instrument (TA Instruments 3550). Accuracy was assessed through an in situ experimental setup by testing four cadaveric specimens with both the MR-based methodology and in the ElectroForce system. The outcome of the current study showed that the MR-based ATTs and stiffness measurements using the ISKLA were within 1.44-2.10 mm and 0.16-6.14 N/mm, respectively, of the corresponding values measured by the gold standard system. An excellent ICC was observed for ATT (0.97) and good ICC for stiffness (0.87) between the MR and ElectroForce-based systems across all target force levels. These findings suggest that the MR-based approach can be used with satisfactory accuracy and correlation to the gold standard measure.

Keywords: Accuracy; Anterior tibial translation; Design; Knee; Magnetic resonance imaging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anterior Cruciate Ligament
  • Anterior Cruciate Ligament Injuries*
  • Biomechanical Phenomena
  • Cadaver
  • Humans
  • Joint Instability* / diagnostic imaging
  • Knee Joint / diagnostic imaging
  • Magnetic Resonance Imaging
  • Range of Motion, Articular
  • Tibia