Meniscal pathology on MRI increases the risk for both incident and enlarging subchondral bone marrow lesions of the knee: the MOST Study

Abstract

Objectives: To investigate the association between meniscal pathology and incident or enlarging bone marrow lesions (BML) in knee osteoarthritis.

Methods: The authors studied subjects from the Multicenter Osteoarthritis Study aged 50-79 years either with knee osteoarthritis or at high risk of the disease. Baseline and 30-months magnetic resonance images of knees (n=1344) were scored for subchondral BML. Outcome was defined as an increase in BML score in either the tibial or femoral condyle in medial and lateral compartments, respectively. The authors defined meniscal pathology at baseline as the presence of either meniscal lesions or meniscal extrusion. The risk of an increase in BML score in relation to meniscal status in the same compartment was estimated using a log linear regression model adjusted for age, sex, body mass index, physical activity level and mechanical axis. In secondary analyses the investigators stratified by ipsilateral tibiofemoral cartilage status at baseline and compartments with pre-existing BML.

Results: The adjusted relative risk of incident or enlarging BML ranged from 1.8; 95% CI 1.3 to 2.3 for mild medial meniscal pathology to 5.0; 95% CI 3.2 to 7.7 for major lateral meniscal pathology (using no meniscal pathology in the same compartment as reference). Stratification by cartilage or BML status at baseline had essentially no effect on these estimates.

Conclusions: Knee compartments with meniscal pathology have a substantially increased risk of incident or enlarging subchondral BML over 30 months. Higher relative risks were seen in those with more severe and with lateral meniscal pathology.

Figure 1

Baseline: Mid coronal STIR MRI shows extrusion of the body of the medial meniscus (arrow) without bone marrow lesion (BML). 30-month follow-up: Coronal STIR MRI at the same level 30 months later shows stable extruded medial meniscus and new BMLs (WORMS grade 1) of the central medial femur (arrow) and tibia (arrowhead). There are also new small marginal osteophytes of the medial femur (WORMS grade 1) and tibia (WORMS grade 2).

Figure 1

Baseline: Mid coronal STIR MRI shows extrusion of the body of the medial meniscus (arrow) without bone marrow lesion (BML). 30-month follow-up: Coronal STIR MRI at the same level 30 months later shows stable extruded medial meniscus and new BMLs (WORMS grade 1) of the central medial femur (arrow) and tibia (arrowhead). There are also new small marginal osteophytes of the medial femur (WORMS grade 1) and tibia (WORMS grade 2).

Figure 2

Baseline: Sagittal fat-suppressed proton density-weighted MRI shows partial maceration of the posterior horn of the medial meniscus (arrow) without bone marrow lesions (BMLs). 30-month follow-up: Sagittal fat-suppressed proton density-weighted MRI at the same level 30 months later shows stable partially macerated medial meniscus and new large BMLs (WORMS grade 3) of the posterior medial femur (arrows) and anterior, central and posterior medial tibia (arrowheads). There is also new small joint effusion (WORMS grade 1).

Figure 2

Baseline: Sagittal fat-suppressed proton density-weighted MRI shows partial maceration of the posterior horn of the medial meniscus (arrow) without bone marrow lesions (BMLs). 30-month follow-up: Sagittal fat-suppressed proton density-weighted MRI at the same level 30 months later shows stable partially macerated medial meniscus and new large BMLs (WORMS grade 3) of the posterior medial femur (arrows) and anterior, central and posterior medial tibia (arrowheads). There is also new small joint effusion (WORMS grade 1).

Figure 3

Baseline: Mid coronal STIR MRI shows extrusion of the partially macerated body of the medial meniscus (small arrow) with small (WORMS grade 1) bone marrow lesions (BMLs) of the central medial femur (arrow) and tibia (arrowhead). 30-month follow-up: Coronal STIR MRI at the same level 30 months later shows enlarging BMLs (WORMS grade 2) of the central medial femur (arrow) and tibia (arrowhead).

Figure 3

Baseline: Mid coronal STIR MRI shows extrusion of the partially macerated body of the medial meniscus (small arrow) with small (WORMS grade 1) bone marrow lesions (BMLs) of the central medial femur (arrow) and tibia (arrowhead). 30-month follow-up: Coronal STIR MRI at the same level 30 months later shows enlarging BMLs (WORMS grade 2) of the central medial femur (arrow) and tibia (arrowhead).