Department of Medicine for Orthopaedics and Motor Organ, Juntendo University Graduate School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
Department of Pathophysiology for Locomotive and Neoplastic Diseases, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
Arthritis Res Ther. 2017 Sep 12;19(1):201. doi: 10.1186/s13075-017-1411-0.
Medial 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.
Patients 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.
Medial 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.
Our 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.
内侧半月板外突（MME）与内侧膝关节骨关节炎（OA）的进展有关，但对于在软骨和骨部分发现的骨赘与 MME 之间的关系，我们知之甚少。由于放射摄影或常规磁共振成像（MRI）对骨赘软骨部分的检测能力有限，骨赘的发展速度和大小似乎被低估了。由于 T2 映射 MRI 可使我们评估骨赘的软骨部分，因此我们旨在通过常规和 T2 映射 MRI 检查 MME 与 OA 相关变化（包括骨赘）之间的关联。
对 50 例早期膝关节 OA 患者进行检查。根据全器官磁共振成像评分评估 MRI 检测到的 OA 相关变化以及 MME。在 T2 映射图像上测量内侧半月板和骨赘的 T2 值。对终末期膝关节 OA 患者手术切除的骨赘进行组织学分析，并与放射摄影和 MRI 结果进行比较。
在患有早期膝关节 OA 的患者中，98%通过 T2 映射 MRI 检测到内侧侧骨赘，而通过常规 MRI 检测的骨赘的检出率为 48%，通过放射摄影检测的骨赘的检出率为 40%。在 OA 相关变化中，内侧胫骨骨赘距离通过多变量逻辑回归分析与 MME 最密切相关，在患有早期膝关节 OA 的患者中（β=0.711，p<0.001）。在患有早期膝关节 OA 且 MME≥3mm 的患者中，内侧半月板的 T2 值与 MME 直接相关（r=0.58，p=0.003）。通过对终末期膝关节 OA 患者切除的骨赘进行组织学分析，证实了 T2 映射 MRI 评估骨赘的准确性。
我们的研究表明，在患有早期膝关节 OA 的患者中，通过 T2 映射 MRI 评估的内侧胫骨骨赘经常观察到，与 MME 密切相关，并且 MME 与半月板退变呈正相关。
