Rotator Cuff Tear-induced Changes in Tendon Structure and Mechanics Measured by Quantitative Magnetic Resonance...

Area of Science:

• Biomedical Engineering
• Orthopedic Surgery
• Radiology

Background:

• Rotator cuff (RC) tears are common, leading to shoulder dysfunction.
• Magnetic Resonance Imaging (MRI) is used for diagnosis, but its link to tendon mechanics is unclear.
• This study explores quantitative MRI (qMRI) T2 relaxation time as a biomarker for RC tears.

Purpose of the Study:

• To investigate if qMRI T2 relaxation time correlates with structural and mechanical changes in supraspinatus tendons with RC tears.
• To assess the relationship between T2 relaxation time and tendon mechanical properties and collagen integrity.

Main Methods:

• Analysis of 24 human cadaveric supraspinatus tendons (10 intact, 14 torn).
• Mechanical testing for stiffness and failure force.
• T2 mapping using 9.4T MRI, Raman spectroscopy, and multiphoton imaging for biochemical and collagen analysis.

Main Results:

• Torn tendons exhibited significantly lower stiffness and failure force than intact tendons.
• Elevated T2 relaxation times, increased heterogeneity, and higher 90th percentile values were observed in torn tendons.
• T2 metrics strongly correlated with reduced mechanical properties and increased tear area; biochemical analysis revealed collagen degradation.

Conclusions:

• T2 relaxation time serves as a sensitive, non-invasive biomarker for tendon mechanical health and collagen structure in RC tears.
• qMRI, specifically T2 mapping, shows clinical potential for evaluating tendon pathology and guiding treatment decisions.