Miyazaki Masashi, Morishita Yuichiro, Takita Chikahiro, Yoshiiwa Toyomi, Wang Jeffrey C, Tsumura Hiroshi
Department of Orthopaedic Surgery, Oita University, Oita, Japan.
J Spinal Disord Tech. 2010 Jun;23(4):242-8. doi: 10.1097/BSD.0b013e3181a8123e.
Retrospective cross-sectional study.
This study aimed to elucidate the relationship among facet orientation, kinematics of a spinal unit, and change in lumbar spine canal diameter by using kinetic magnetic resonance imaging.
Some studies have suggested an association between increased sagittally oriented facet angles and degenerative lumbar spondylolisthesis. However, no study has specifically addressed the association of facet orientation with the kinematics of a spinal unit and change in canal diameter.
Kinetic magnetic resonance imagings were performed with patients in flexion, neutral, and extension positions. Study subjects were classified into 6 groups-AA, BB, CC, AB (BA), BC (CB), and AC (CA)-on the basis of bilateral facet angles (A, narrow; B, normal; and C, wide) and disc and facet joint degeneration. A magnetic resonance imaging analyzer was used for anatomic measurements and for calculating changes in canal diameters and disc bulging as well as the lumbar spine kinematics.
Osseous canal diameters were significantly smaller in the group AA than in the group BB, whereas they were significantly larger in the group CC than in the group BB. Canal diameter at the disc level was significantly smaller in the group AA than in the group BB in all 3 positions, whereas it was significantly larger in the group CC than in the group BB. Translational motion was significantly more in the group AA than in the group BB, whereas it was significantly lesser in the group CC than in the group BB.
We demonstrated the relationship among facet orientation, osseous canal diameter, kinematics of a spinal unit, and change in lumbar spine canal diameter. Patients with sagittally oriented facets had narrow osseous canals with mobility, whereas those with coronally oriented facets had stable and wider osseous canals. This finding is helpful in understanding the mechanism underlying lumbar spinal canal stenosis and degenerative spondylolisthesis.
回顾性横断面研究。
本研究旨在通过动态磁共振成像阐明小关节方向、脊柱节段运动学与腰椎管直径变化之间的关系。
一些研究表明矢状面小关节角度增大与退变性腰椎滑脱之间存在关联。然而，尚无研究专门探讨小关节方向与脊柱节段运动学及椎管直径变化之间的关联。
对处于前屈、中立和后伸位的患者进行动态磁共振成像检查。根据双侧小关节角度（A，狭窄；B，正常；C，宽大）以及椎间盘和小关节退变情况，将研究对象分为6组——AA、BB、CC、AB（BA）、BC（CB）和AC（CA）。使用磁共振成像分析仪进行解剖测量，并计算椎管直径变化、椎间盘膨出情况以及腰椎运动学参数。
AA组的骨性椎管直径显著小于BB组，而CC组的骨性椎管直径显著大于BB组。在所有3个位置，AA组椎间盘水平的椎管直径均显著小于BB组，而CC组的则显著大于BB组。AA组的平移运动显著多于BB组，而CC组的则显著少于BB组。
我们证实了小关节方向、骨性椎管直径、脊柱节段运动学与腰椎管直径变化之间的关系。矢状面小关节的患者具有狭窄且可活动的骨性椎管，而冠状面小关节的患者具有稳定且宽大的骨性椎管。这一发现有助于理解腰椎管狭窄和退变性腰椎滑脱的潜在机制。
