Department of Large Animal Clinical Studies, College of Veterinary Medicine, Michigan State University, USA.
Equine Vet J. 2011 May;43(3):259-64. doi: 10.1111/j.2042-3306.2010.00291.x. Epub 2010 Sep 23.
By study of the translocation and deformation of equine menisci throughout the range of motion, it may be possible to identify potential mechanical factors in the pathogenesis of injury to the cranial horn of the medial meniscus.
To quantitatively document meniscal translocation and deformation using radiographic and MR imaging, and to evaluate for potential variation between the medial and lateral menisci.
Radiographic markers were embedded in the periphery of the menisci in 6 cadaver stifles. Proximal-distal radiographs were taken at 15° intervals ranging from full flexion (30°) to full extension (160°). Magnetic resonance imaging sequences of 3 additional cadaver stifles were obtained in axial and sagittal planes at the predetermined stifle angles.
A significantly greater overall mean cranial-caudal translocation (1.6 times) of the lateral meniscus relative to the medial was seen from full extension to full flexion (P = 0.002). The cranial horn of the medial meniscus was the least mobile of the 4 horns, yet a significant cranial displacement relative to the cranial horn of the lateral meniscus was seen in the terminal 10° of extension. MRI images revealed a significantly greater axial compressive strain in the cranial horn of the medial meniscus relative to the cranial horn of the lateral meniscus in the terminal 10° of extension (P = 0.017).
The equine menisci exhibit a cranial-caudal translocation over the tibia throughout the range of motion. While the cranial horn of the medial meniscus is the least mobile of the 4 horns, it undergoes significant cranial translocation and axial compression in the terminal 10° of extension.
Hyperextension of the stifle may place the cranial horn of the medial meniscus at risk of injury and thus explain the higher prevalence of meniscal tears at this location.
通过研究马膝关节半月板在运动范围内的移位和变形，可能确定内侧半月板头状突损伤发病机制中的潜在机械因素。
使用放射照相和磁共振成像定量记录半月板移位和变形，并评估内侧和外侧半月板之间的潜在差异。
在 6 个尸体膝关节的半月板周围嵌入放射照相标记物。在从完全屈曲（30°）到完全伸展（160°）的 15°间隔内拍摄近-远位射线照片。在预定的膝关节角度，在另外 3 个尸体膝关节的矢状面和轴向平面上获得磁共振成像序列。
从完全伸展到完全屈曲，外侧半月板相对于内侧半月板的整体平均头-尾向移位明显更大（1.6 倍）（P = 0.002）。内侧半月板的头状突是 4 个角中最不活动的，但在伸展的最后 10°，相对于外侧半月板的头状突，观察到明显的头状突移位。MRI 图像显示，在伸展的最后 10°，内侧半月板的头状突相对于外侧半月板的头状突具有更大的轴向压缩应变（P = 0.017）。
马膝关节半月板在整个运动范围内在胫骨上发生头-尾向移位。虽然内侧半月板的头状突是 4 个角中最不活动的，但在伸展的最后 10°，它经历了明显的头状突移位和轴向压缩。
膝关节过度伸展可能使内侧半月板的头状突容易受伤，从而解释了在该位置半月板撕裂的发生率更高。
