Fig. 2

Association between medial meniscal extrusion (MME) and medial tibial osteophyte distance in patients with early-stage knee osteoarthritis. a Representative images of proton density-weighted magnetic resonance imaging (MRI) with fat suppression and T2 mapping MRI of the medial tibiofemoral joint. The patients were classified into four subgroups with MME grade 0, 1, 2, or 3. b Correlation between medial tibial osteophyte distance and MME. The medial tibial osteophyte distance was compared among the subgroups with MME grade 0 (n = 13), 1 (n = 13), 2 (n = 18), or 3 (n = 6). c Comparison of T2 values of medial meniscus among the subgroups with MME grade 0 (n = 13), 1 (n = 13), 2 (n = 18), or 3 (n = 6). d Correlation between T2 values of medial meniscus and MME. Closed circles represent the patient subgroup with MME grade 0 or 1 (n = 26); open circles represent the patients with MME grade 2 or 3 (n = 24). Bp Bone part of osteophyte, Cp Cartilage part of osteophyte, M Medial meniscus