Bone marrow lesions in the knee are associated with increased local bone density

Area of Science:

• Orthopedics
• Radiology
• Rheumatology

Background:

• Bone marrow lesions (BMLs) in knee osteoarthritis (OA) are linked to pain and joint space narrowing progression.
• BMLs are found in areas of increased joint loading, which also correlates with increased bone mineral density (BMD).
• The medial-to-lateral (M:L) BMD ratio of the tibial plateau serves as an indicator of knee loading patterns.

Purpose of the Study:

• To investigate the association between the M:L BMD ratio and the presence of medial and lateral BMLs in knee OA.
• To test the hypothesis that higher M:L BMD ratios are associated with medial BMLs and lower ratios with lateral BMLs.

Main Methods:

• Utilized magnetic resonance imaging (MRI) and bone mineral density (BMD) measurements from the Framingham Osteoarthritis Study.
• Defined medial and lateral BMLs using MRI in the medial and lateral tibiofemoral compartments.
• Employed logistic regression analysis, adjusting for covariates, to assess the relationship between M:L BMD ratio quartiles and prevalent BMLs.

Main Results:

• A significantly strong association was found between high M:L BMD ratios and medial BMLs (P for trend < 0.0001).
• Conversely, low M:L BMD ratios were strongly associated with lateral BMLs (P for trend < 0.0001).
• Odds ratios for medial BMLs increased substantially with higher M:L BMD ratio quartiles, while odds ratios for lateral BMLs increased with lower M:L BMD ratio quartiles.

Conclusions:

• Medial BMLs are associated with higher relative medial tibial bone density, and lateral BMLs with higher relative lateral tibial bone density.
• These findings support the hypothesis that local BMD reflects knee joint loading.
• The results underscore the critical role of biomechanical loading in the pathophysiology of knee osteoarthritis.