Özcan-Ekşi Emel Ece, Börekci Ali, Ekşi Murat Şakir
Bahçeşehir University, School of Medicine, Department of Physical Medicine and Rehabilitation, Istanbul, Turkey.
FSM Training and Research Hospital, Neurosurgery Clinic, Istanbul, Turkey.
World Neurosurg. 2023 May;173:e606-e615. doi: 10.1016/j.wneu.2023.02.111. Epub 2023 Mar 1.
Facet joint orientation (FJO) and facet joint tropism (FJT) are associated with intervertebral disc degeneration and paraspinal muscle atrophy. However, none of the previous studies has evaluated the association of FJO/FJT with fatty infiltration in the multifidus, erector spinae, and psoas muscles at all lumbar levels. In the present study, we aimed to analyze whether FJO and FJT were associated with fatty infiltration in the paraspinal muscles at any lumbar level.
Paraspinal muscles and FJO/FJT were evaluated from L1-L2 to L5-S1 intervertebral disc levels on T2-weighted axial lumbar spine magnetic resonance imaging.
Facet joints were more sagittally and coronally oriented at the upper and lower lumbar levels, respectively. FJT was more obvious at lower lumbar levels. The FJT/FJO ratio was higher at upper lumbar levels. Patients with sagittally oriented facet joints at the L3-L4 and L4-L5 levels had fattier erector spinae and psoas muscles at the L4-L5 level. Patients with increased FJT at upper lumbar levels had fattier erector spinae and multifidus at lower lumbar levels. Patients with increased FJT at the L4-L5 level had less fatty infiltration in the erector spinae and psoas at the L2-L3 and L5-S1 levels, respectively.
Sagittally oriented facet joints at lower lumbar levels could be associated with fattier erector spinae and psoas muscles at lower lumbar levels. The erector spinae at upper lumbar levels and psoas at lower lumbar levels might have become more active to compensate the FJT-induced instability at lower lumbar levels.
小关节方向（FJO）和小关节不对称（FJT）与椎间盘退变及椎旁肌萎缩相关。然而，既往研究均未评估FJO/FJT与所有腰椎节段多裂肌、竖脊肌和腰大肌脂肪浸润之间的关联。在本研究中，我们旨在分析FJO和FJT是否与任一腰椎节段椎旁肌的脂肪浸润相关。
在T2加权腰椎轴位磁共振成像上，从L1-L2至L5-S1椎间盘节段评估椎旁肌及FJO/FJT。
腰椎上下节段的小关节分别在矢状面和冠状面方向上更为明显。FJT在腰椎下段更为明显。FJT/FJO比值在腰椎上段更高。L3-L4和L4-L5节段小关节矢状位方向的患者，其L4-L5节段的竖脊肌和腰大肌脂肪含量更高。腰椎上段FJT增加的患者，其腰椎下段的竖脊肌和多裂肌脂肪含量更高。L4-L5节段FJT增加的患者，其L2-L3和L5-S1节段的竖脊肌和腰大肌脂肪浸润分别减少。
腰椎下段矢状位方向的小关节可能与腰椎下段竖脊肌和腰大肌脂肪含量增加有关。腰椎上段的竖脊肌和腰椎下段的腰大肌可能变得更加活跃，以代偿腰椎下段FJT引起的不稳定。
