Background OA is a disease with articular cartilage degeneration, synovial and subchondral bone changes, meniscus and ligament pathologies. Bone marrow edema -like lesions (BMLs), with histologically represented bone damage, are predictors of cartilage loss (chondropathy) and pain in KOA.
Objectives to assess the prevalence of different structural changes in knee OA.
Methods All pts with available baseline (BL) MRI and X-ray were included. MRI was performed on 1,5T extremity system, including sagittal and axial proton density fat-suppressed and coronal STIR sequences. MRI and X-ray were read by 2 musculkoskeletal radiologists. Plain knee radiographs have been performed by Buckland -Wright. The joint was divided in 5 subregions. Cartilage morphology was scored from 0 (normal cartilage) to IV (uncover subchondral bone). Additionally there were assessed bone cysts, synovitis, meniscal damage, cruciate and collateral ligaments.
Results 80 knee OA patients (1 knee per person, 5 regions per knee, 400 subregions) were included (women 90%; mean age 57,0; mean BMI - 27,7 kg/m2, K-L stage 0-6%; I-25%; II-43,75%; III-25% respectively). Healthy cartilage was noted in X-ray negative knee joints (KJ) in lateral femur and tibia condyles (60% of the whole surface), cartilage softness and edema were estimated in patella and medial femur compartments in 100%. Cartilage cracks and erosions (>50% of surface) were revealed, in patella, medial femur and tibia compartments in spite of X-ray stages. In the same subregions uncovered subchondral bone were seen in I (20%) and II (17%) K-L stages, and significantly more frequent in III stage (75%). Bone cysts were seen only at the III-d stage in the medial femur (41,25%) and tibia (36,25%) condyles; in patella - 13,75%. Bone marrow edema-like lesions was estimated only at the I-st X-ray stage in patella (12,5%), medial femur (18,75%) and tibial (16,25%) subregions under the most damaged cartilage. Synovitis was noted at all stages (0-III) in 60%. Meniscus and cruciated ligaments tears and lesions were found in 59% and 22,5% respectively at the III-d stage only.
Conclusions Prevalent cartilage damage, incident BMIs in the same subregion are strongly correlated with early KOA. If cartilage damage were targeted in management of knee OA, it might prevent the development of knee OA, the other joint's structure damages.
Disclosure of Interest None declared