Kong Min Ho, Hymanson Henry J, Song Kwan Young, Chin Dong Kyu, Cho Yong Eun, Yoon Do Heum, Wang Jeffrey C
Department of Orthopaedic Surgery, University of California at Los Angeles, California, USA.
J Neurosurg Spine. 2009 Apr;10(4):357-65. doi: 10.3171/2008.12.SPINE08321.
The authors conducted a retrospective observational study using kinetic MR imaging to investigate the relationship between instability, abnormal sagittal segmental motion, and radiographic variables consisting of intervertebral disc degeneration, facet joint osteoarthritis (FJO), degeneration of the interspinous ligaments, ligamentum flavum hypertrophy (LFH), and the status of the paraspinal muscles.
Abnormal segmental motion, defined as > 10 degrees angulation and > 3 mm of translation in the sagittal plane, was investigated in 1575 functional spine units (315 patients) in flexion, neutral, and extension postures using kinetic MR imaging. Each segment was assessed based on the extent of disc degeneration (Grades I-V), FJO (Grades 1-4), interspinous ligament degeneration (Grades 1-4), presence of LFH, and paraspinal muscle fatty infiltration observed on kinetic MR imaging. These factors are often noted in patients with degenerative disease, and there are grading systems to describe these changes. For the first time, the authors attempted to address the relationship between these radiographic observations and the effects on the motion and instability of the functional spine unit.
The prevalence of abnormal translational motion was significantly higher in patients with Grade IV degenerative discs and Grade 3 arthritic facet joints (p < 0.05). In patients with advanced disc degeneration and FJO, there was a lesser amount of motion in both segmental translation and angulation when compared with lower grades of degeneration, and this difference was statistically significant for angular motion (p < 0.05). Patients with advanced degenerative Grade 4 facet joint arthritis had a significantly lower percentage of abnormal angular motion compared to patients with normal facet joints (p < 0.001). The presence of LFH was strongly associated with abnormal translational and angular motion. Grade 4 interspinous ligament degeneration and the presence of paraspinal muscle fatty infiltration were both significantly associated with excessive abnormal angular motion (p < 0.05).
This kinetic MR imaging analysis showed that the lumbar functional unit with more disc degeneration, FJO, and LFH had abnormal sagittal plane translation and angulation. These findings suggest that abnormal segmental motion noted on kinetic MR images is closely associated with disc degeneration, FJO, and the pathological characteristics of interspinous ligaments, ligamentum flavum, and paraspinal muscles. Kinetic MR imaging in patients with mechanical back pain may prove a valuable source of information about the stability of the functional spine unit by measuring abnormal segmental motion and grading of radiographic parameters simultaneously.
作者进行了一项回顾性观察研究，使用动态磁共振成像来研究不稳定、矢状节段异常运动与包括椎间盘退变、小关节骨关节炎（FJO）、棘间韧带退变、黄韧带肥厚（LFH）以及椎旁肌状态在内的影像学变量之间的关系。
使用动态磁共振成像在1575个功能脊柱单元（315例患者）的前屈、中立和后伸姿势下研究矢状面内>10度成角和>3毫米平移定义的节段异常运动。根据动态磁共振成像观察到的椎间盘退变程度（I - V级）、FJO（1 - 4级）、棘间韧带退变（1 - 4级）、LFH的存在情况以及椎旁肌脂肪浸润情况对每个节段进行评估。这些因素在退行性疾病患者中经常被注意到，并且有分级系统来描述这些变化。作者首次试图探讨这些影像学观察结果与对功能脊柱单元运动和不稳定的影响之间的关系。
IV级退变椎间盘和3级关节炎性小关节患者的平移异常运动患病率显著更高（p < 0.05）。与较低退变等级相比，在椎间盘退变和FJO晚期的患者中，节段平移和成角的运动量均较小，并且这种差异在成角运动方面具有统计学意义（p < 0.05）。与正常小关节患者相比，4级退行性小关节骨关节炎患者的异常成角运动百分比显著更低（p < 0.001）。LFH的存在与平移和成角异常运动密切相关。4级棘间韧带退变和椎旁肌脂肪浸润的存在均与过度的异常成角运动显著相关（p < 0.05）。
这种动态磁共振成像分析表明，椎间盘退变、FJO和LFH更多的腰椎功能单元存在矢状面平移和成角异常。这些发现表明，动态磁共振图像上观察到的节段异常运动与椎间盘退变、FJO以及棘间韧带、黄韧带和椎旁肌的病理特征密切相关。通过同时测量节段异常运动和影像学参数分级，动态磁共振成像对于机械性背痛患者可能是关于功能脊柱单元稳定性的有价值信息来源。
