In Vivo MRI Analysis of Knee Cartilage and Meniscus Contact Areas Under Load
Overview
This study utilized MRI with prospective motion correction to evaluate tibiofemoral cartilage and meniscus contact areas under axial loading in healthy knees. Findings demonstrated an increase in cartilage-to-cartilage contact area and a decrease in cartilage-to-meniscus contact area when the knee was loaded with 400 N.
Background
The knee joint's articular cartilage and menisci play critical roles in load transmission, shock absorption, and joint stabilization. Meniscal roots and the meniscotibial ligament maintain meniscal positioning and prevent extrusion during axial loading. Traditional imaging methods have limitations in capturing dynamic cartilage and meniscal behavior under load. MRI with prospective motion correction offers enhanced visualization of these structures during mechanical loading, providing insights into their biomechanical responses.
Data Highlights
Nine healthy male participants (age 26-31, mean BMI 23.5 kg/m²) underwent 3T MRI scans of the knee with and without 400 N axial load. Imaging used a T1-weighted 3D gradient-echo sequence with 0.4 × 0.4 × 0.5 mm resolution and prospective motion correction via moiré phase tracking. Load was applied colinear to the limb axis with the knee in full extension.
Key Findings
Cartilage-to-cartilage contact area in the tibiofemoral joint significantly increased under 400 N axial load compared to the unloaded state.
Cartilage-to-meniscus contact area decreased during loading, indicating a shift in load distribution.
Prospective motion correction effectively minimized motion artifacts, allowing reliable in vivo assessment of cartilage and meniscal biomechanics under load.
The menisci maintained position on the tibial plateau during loading, consistent with their stabilizing function.
Findings support the dynamic nature of knee joint contact mechanics and the role of meniscal structures in load adaptation.
Clinical Implications
MRI with prospective motion correction enables direct visualization of cartilage and meniscal contact dynamics under physiological load, improving understanding of knee biomechanics. This technique may aid in early detection of meniscal or cartilage dysfunction and guide interventions to prevent osteoarthritis progression. Maintaining meniscal integrity is crucial for normal load distribution and joint health.
Conclusion
The study confirms that axial loading increases cartilage contact area while reducing cartilage-meniscus contact in healthy knees, highlighting the dynamic biomechanical interplay within the tibiofemoral joint. Advanced MRI techniques provide valuable insights into joint function under load, with potential clinical applications in diagnosis and management.
References
Various Authors 1-8 -- Meniscal function and osteoarthritis progression
Various Authors 9-12 -- In vivo tibiofemoral contact area studies
Various Authors 13-19 -- MRI studies of cartilage and meniscus under load
Various Authors 20-22 -- Prospective motion correction in MRI
Various Authors 23-26 -- Knee joint biomechanics and motion tracking
In a UK cohort, patients with osteoarthritis who initiated centrally acting analgesics had a higher hazard of knee or hip replacement than those who initiated SSRIs, though residual confounding by pain severity remains a key limitation.
