Association of medial meniscal extrusion with medial tibial osteophyte distance detected by T2 mapping MRI in patients with early-stage knee osteoarthritis

Abstract

BackgroundMedial meniscal extrusion (MME) is associated with progression of medial knee osteoarthritis (OA), but no or little information is available for relationships between MME and osteophytes, which are found in cartilage and bone parts. Because of the limitation in detectability of the cartilage part of osteophytes by radiography or conventional magnetic resonance imaging (MRI), the rate of development and size of osteophytes appear to have been underestimated. Because T2 mapping MRI may enable us to evaluate the cartilage part of osteophytes, we aimed to examine the association between MME and OA-related changes, including osteophytes, by using conventional and T2 mapping MRI.MethodsPatients with early-stage knee OA (n = 50) were examined. MRI-detected OA-related changes, in addition to MME, were evaluated according to the Whole-Organ Magnetic Resonance Imaging Score. T2 values of the medial meniscus and osteophytes were measured on T2 mapping images. Osteophytes surgically removed from patients with end-stage knee OA were histologically analyzed and compared with findings derived by radiography and MRI.ResultsMedial side osteophytes were detected by T2 mapping MRI in 98% of patients with early-stage knee OA, although the detection rate was 48% by conventional MRI and 40% by radiography. Among the OA-related changes, medial tibial osteophyte distance was most closely associated with MME, as determined by multiple logistic regression analysis, in the patients with early-stage knee OA (β = 0.711, p < 0.001). T2 values of the medial meniscus were directly correlated with MME in patients with early-stage knee OA, who showed ≥ 3 mm of MME (r = 0.58, p = 0.003). The accuracy of osteophyte evaluation by T2 mapping MRI was confirmed by histological analysis of the osteophytes removed from patients with end-stage knee OA.ConclusionsOur study demonstrates that medial tibial osteophyte evaluated by T2 mapping MRI is frequently observed in the patients with early-stage knee OA, showing close association with MME, and that MME is positively correlated with the meniscal degeneration.

Medial Opening Wedge High Tibial Osteotomy Decreases Medial Meniscal Extrusion and Improves Clinical Outcomes and Return to Activity

“…8 MME was measured before HTO and at 6-week follow-up (study protocol) through use of magnetic resonance imaging (MRI) by 2 experienced radiologists, both of whom were blinded to patient information. The measurements were made on the MRI coronal view of the medial meniscus showing the best image of the tibial eminence, in accordance with the techniques proposed by Hada et al 14 and Roos et al 22 The intraclass correlation coefficient (ICC) was used for interrater and intrarater reliability analyses. 20 To assess intrarater reliability, 1 radiologist repeated all measurements 2 weeks later.…”

Role of Signal Transduction Pathways and Transcription Factors in Cartilage and Joint Diseases

“…As described above, there are many potential therapeutic targets for osteoarthritis. Recently, a clinical study demonstrated the presence of hypertrophic chondrocytes and osteophytes in articular cartilage of early stage of patients with knee osteoarthritis [116]. Importantly, this study also showed that these pathological changes cause medial meniscal extrusion and consequent dislocation of the meniscus [116].…”

“…Recently, a clinical study demonstrated the presence of hypertrophic chondrocytes and osteophytes in articular cartilage of early stage of patients with knee osteoarthritis [116]. Importantly, this study also showed that these pathological changes cause medial meniscal extrusion and consequent dislocation of the meniscus [116]. Presumably, this process is different from the normal regulation of endochondral ossification, and unidentified molecular mechanisms are involved in the underlying pathological events.…”

Associations of serum citrate levels with knee structural changes and cartilage enzymes in patients with knee osteoarthritis

“…Hada found that osteophytes in the medial tibial and/or femoral sites were present in 98% of patients with knee OA (49/50 cases). 30 Although the molecular mechanisms of osteophyte formation remain unknown, experimental studies using animal models have shown that osteophytes develop as a result of repeated mechanical stresses or soluble growth factors. 31,32 The causal relationship and the underlying mechanisms need to be examined by future longitudinal studies and experimental researches.…”