Hospital for Special Surgery, 535 East 70th St., New York, NY, 10021, USA.
Eur Spine J. 2021 Sep;30(9):2480-2485. doi: 10.1007/s00586-021-06759-7. Epub 2021 Feb 20.
To investigate associations between muscle size, fat infiltration (FI), and global sagittal alignment in patients with adult spinal deformity (ASD).
Retrospective cohort study was conducted on a single-institution database of ASD patients with preoperative radiographs and CTs. Following multiplanar reconstructions of CTs, images in the plane of each vertebra were generated. The posterior vertebral musculature (PVM) was contoured on axial images at three vertebral levels (T2, T10, L3). FI was calculated by comparing Hounsfield units within muscles to the normative values of fat. Correlation analyses were conducted between demographics, alignment, and muscle characteristics.
107 patients underwent preoperative spine CT (58yo, 79%F, BMI 27 kg/m). Muscle data were available for 49 pts at T2, 39 pts at T10, and 81 pts at L3. Mean FI was T2 = 33% ± 18, T10 = 28% ± 19, L3_Erector = 39% ± 19, and L3_Psoas = 19% ± 9. FI correlated across levels (T2 vs. T10 r = 0.698; T10 vs L3_Erector r = 0.506; L3_Erector vs Psoas r = 0.419) and with demographics; older pts had greater fat percentages (r = 0.31-0.45) and BMIs (r = 0.24-0.51). Increased FI at T2, T10, and L3 was associated with increased pelvic retroversion (PT: r = 0.25-0.43), global deformity (TPA: r = 0.27-0.45), and anterior malalignment (SVA: r = 0.23-0.41). The degree of FI in the PVM increased with the severity of SRS-Schwab PT and SVA modifiers.
In ASD patients, global sagittal malalignment is related to FI of the PVM throughout the lumbar and thoracic spine, as identified through CT. Future research should investigate how FI relates to ASD pathogenesis.
研究成人脊柱畸形（ASD）患者的肌肉大小、脂肪浸润（FI）与整体矢状面平衡之间的关系。
对单中心 ASD 患者的术前影像学资料进行回顾性队列研究，包括 X 线片和 CT。对 CT 进行多平面重建后，生成每个椎体层面的图像。在 T2、T10 和 L3 三个椎体水平的轴位图像上描绘椎旁肌肉（PVM）。通过比较肌肉内的体素 Hounsfield 单位与脂肪的正常值来计算 FI。对患者的一般情况、矢状面参数和肌肉特征进行相关性分析。
107 例患者接受了术前脊柱 CT 检查（58 岁，79%女性，BMI 27kg/m2）。49 例患者在 T2 水平、39 例患者在 T10 水平和 81 例患者在 L3 水平有肌肉数据。T2 的平均 FI 为 33%±18，T10 为 28%±19，L3 竖脊肌为 39%±19，L3 腰大肌为 19%±9。FI 在不同水平之间存在相关性（T2 与 T10 之间 r=0.698；T10 与 L3 竖脊肌 r=0.506；L3 竖脊肌与腰大肌 r=0.419），并与患者的一般情况相关；年龄较大的患者脂肪百分比（r=0.31-0.45）和 BMI（r=0.24-0.51）更高。T2、T10 和 L3 的 FI 增加与骨盆后倾（PT：r=0.25-0.43）、整体畸形（TPA：r=0.27-0.45）和前凸失衡（SVA：r=0.23-0.41）有关。PVM 的 FI 程度随 SRS-Schwab PT 和 SVA 修正值的严重程度而增加。
在 ASD 患者中，通过 CT 发现，整个胸腰段的 PVM 全局矢状面失衡与 FI 有关。未来的研究应探讨 FI 与 ASD 发病机制的关系。
