A novel multipurpose device for guided knee motion and loading during dynamic magnetic resonance imaging

Area of Science:

• Biomechanics
• Medical Imaging
• Rehabilitation Engineering

Background:

• Developing advanced imaging techniques for joint motion is crucial for understanding biomechanics.
• Dynamic Magnetic Resonance Imaging (MRI) offers insights into physiological joint function.
• Current methods may lack the ability to capture complex knee movements under realistic loading conditions.

Purpose of the Study:

• To develop and evaluate a novel multipurpose device for guided knee flexion-extension during dynamic MRI.
• To assess participant experience, including pain and exertion, during device use.
• To obtain preliminary dynamic MRI data showcasing the device's capabilities in passive and active motion, with and without loading.

Main Methods:

• A novel device was used for guided passive (motorized pneumatic) and active (muscle-driven) knee motion.
• Ten healthy male participants underwent protocols to assess pain, exertion, and discomfort.
• Knee range of motion was recorded, and dynamic MRI was acquired using various sequences (2D Cartesian TSE, 2D radial GRE, 3D UTE) for passive and active motion under different loading conditions.

Main Results:

• Participants reported mild pain, discomfort, and varying exertion levels.
• An average knee flexion of approximately 40° was achieved, with loaded conditions generating knee moments up to 27Nm.
• High-quality dynamic MRI data were obtained, enabling retrospective slice extraction and demonstrating motion and loading effects.

Conclusions:

• A novel device for guided knee motion and loading during dynamic MRI was successfully developed.
• The device was well-tolerated and facilitated the acquisition of high-quality images under various physiological conditions.
• This technology holds potential for advancing the study of joint mechanics in both healthy and pathological states.