Department of Orthopaedic Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Medical Center for Translational and Clinical Research, Hiroshima University Hospital, Hiroshima Japan.
Foot Ankle Int. 2020 Jun;41(6):698-704. doi: 10.1177/1071100720910381. Epub 2020 Mar 8.
Magnetic resonance imaging (MRI) is useful for evaluating the stability of an osteochondral lesion of the talus (OLT). A T2 high-signal line between the fragment and its bed on MRI is known as a reliable indicator of an unstable lesion. However, the lesion exhibits various conditions even if a T2 high-signal line is observed. The purpose of this study was to evaluate the relationship between the T2 value of a high-signal line and the condition of the area between the fragment and its bed in OLT.
T2 values of the T2 high-signal line and those of joint fluid were measured from preoperative MRI images in 46 ankles with OLT and the T2 ratio (high-signal line / joint fluid) was calculated. The relationship between the T2 ratio and CT, arthroscopic, and histologic findings was examined.
The mean T2 ratio was 0.48. T2 ratios of cystic lesions (0.62) or bone absorption (0.67) in the bed were significantly higher than those without a cyst (0.40) or no absorption (0.40). The T2 ratio of an unstable lesion (0.51) was significantly lower than that of a stable lesion (0.29). In histologic findings, there were 2 separate patterns: chondral and subchondral bone separations. The T2 ratio of the chondral separation (0.60) was significantly higher than that of bone separation (0.48).
This study showed that the T2 ratio on a high-signal line was a predictor of stability, cyst, and bone absorption in OLT.
Level III, comparative series.
磁共振成像（MRI）可用于评估距骨骨软骨病变（OLT）的稳定性。MRI 上的骨碎片与其床之间的 T2 高信号线是不稳定病变的可靠指标。然而，即使观察到 T2 高信号线，病变也会表现出各种情况。本研究旨在评估 T2 高信号线的 T2 值与骨碎片与其床之间区域的状况之间的关系。
在 46 例 OLT 患者的术前 MRI 图像上测量 T2 高信号线和关节液的 T2 值，并计算 T2 比值（高信号线/关节液）。检查 T2 比值与 CT、关节镜和组织学发现之间的关系。
平均 T2 比值为 0.48。床内囊性病变（0.62）或骨吸收（0.67）的 T2 比值明显高于无囊肿（0.40）或无吸收（0.40）的 T2 比值。不稳定病变的 T2 比值（0.51）明显低于稳定病变的 T2 比值（0.29）。在组织学发现中，存在 2 种分离模式：软骨和软骨下骨分离。软骨分离的 T2 比值（0.60）明显高于骨分离的 T2 比值（0.48）。
本研究表明，T2 高信号线的 T2 比值是 OLT 稳定性、囊肿和骨吸收的预测指标。
III 级，比较系列。
