Device for Assessing Knee Joint Dynamics During Magnetic Resonance Imaging.

Area of Science:

• Orthopedics
• Radiology
• Biomedical Engineering

Background:

• Knee assessment with and without load using magnetic resonance imaging (MRI) aids in diagnosing knee joint diseases by providing insights into knee joint dynamics.
• Routine MRI studies require a loading device for in-scanner knee loading, highlighting a need for such devices and their clinical evaluation.

Purpose of the Study:

• To design and develop a portable, user-friendly axial loading device for evaluating knee joint dynamics during MRI studies.

Main Methods:

• A prospective study involving nine healthy subjects was conducted.
• A portable axial loading device was designed, developed, and tested for MR safety, ease of use, and image artifact generation.
• The device's loading capacity was calibrated, and its effect on knee MR parameters, including tibiofemoral bone gap (TFBG), femoral cartilage thickness (FCT), tibial cartilage thickness (TCT), and cartilage T2 values (FCT2, TCT2), was evaluated.

Main Results:

• The developed device is conditionally MR safe, portable (<3kg), and easy to use (4.9/5 score), with no visible image artifacts (SSIM 0.9889).
• The device accurately replicated loads similar to standing on both legs (r > 0.9).
• Loading induced relative percentage changes (RPC) in TFBG (1.5%-11.0%), FCT (7.9%-8.5%), and TCT (-1.5% to 13.0%), and reduced FCT2 (1.5-2.7 msec) and TCT2 (0.5-2.3 msec).

Conclusions:

• The developed knee loading device is conditionally MR safe, cost-effective (
• This device shows potential for enhancing knee joint dynamic assessment during MRI, aiding in the diagnosis of knee joint diseases.