Department of Orthopaedics, Naresuan University Hospital, Phitsanulok, Thailand.
Department of Neurosurgery, Nanoori Gangnam Hospital, Seoul, South Korea.
Neuroradiology. 2020 Aug;62(8):971-978. doi: 10.1007/s00234-020-02414-y. Epub 2020 Apr 15.
Ligamentum flavum is one of the structures that could compress the spinal canal. Few studies have reported atrophy of ligamentum flavum after spinal fusion. The purpose of this study was to demonstrate the reduction of ligamentum flavum size after oblique lumbar interbody fusion (OLIF) using magnetic resonance imaging (MRI).
Seventeen patients who underwent OLIF without direct decompression were included. The MRI was obtained at the preoperative period, immediate postoperative period, and the follow-up period. Disc height (DH) was measured in plain radiograph. MRI measurements were spinal canal cross-sectional area (SCSA), ligamentum flavum thickness (LFT), ligamentum flavum area (LFA), and foraminal area (FA).
Mean age of the patients was 68.5 ± 10.8. Mean times between postoperative MRI and follow-up MRI were 20.2 ± 11.9 months. Mean disc height increased from 7.6 ± 1.6 to 11.6 ± 1.7 mm at an immediate postoperative period but decreased to 10.1 ± 1.6 mm during follow-up (p < 0.001). SCSA increased from 96.9 ± 54.9 to 136.0 ± 72.7 mm and 171.4 ± 76.10 mm during follow-up (p < 0.001). LFT decreased from 3.9 ± 1.2 to 3.2 ± 0.8 mm (17.9%) and further decreased to 2.9 ± 0.7 mm during follow-up (9.4%) (p < 0.001). LFA decreased from 97.4 ± 36.9 to 86.1 ± 36.9 mm2 (11.6%) and further decreased to 77.2 ± 32.5 mm during follow-up (10.3%) (p = 0.001). FA increased from 69.2 ± 26.6 to 96.1 ± 23.0 mm and increased to 112.9 ± 23.0 mm during follow-up (p < 0.001).
OLIF could decompress the spinal canal and foraminal canal indirectly. Despite the diminishing disc height during the follow-up period, the spinal canal was further increased in size from the remodeling of the ligamentum flavum.
黄韧带是可能压迫椎管的结构之一。很少有研究报道脊柱融合术后黄韧带萎缩。本研究旨在通过磁共振成像（MRI）显示斜侧腰椎体间融合（OLIF）后黄韧带大小的减少。
纳入 17 例未行直接减压的 OLIF 患者。术前、术后即刻和随访时均行 MRI 检查。在普通 X 线片上测量椎间盘高度（DH）。MRI 测量包括椎管横截面积（SCSA）、黄韧带厚度（LFT）、黄韧带面积（LFA）和椎间孔面积（FA）。
患者平均年龄为 68.5±10.8 岁。术后 MRI 与随访 MRI 之间的平均时间为 20.2±11.9 个月。DH 从术后即刻的 7.6±1.6 毫米增加到 11.6±1.7 毫米，但在随访期间降至 10.1±1.6 毫米（p<0.001）。SCSA 从 96.9±54.9 毫米增加到 136.0±72.7 毫米和随访期间的 171.4±76.1 毫米（p<0.001）。LFT 从 3.9±1.2 毫米减少到 3.2±0.8 毫米（17.9%），并在随访期间进一步减少到 2.9±0.7 毫米（9.4%）（p<0.001）。LFA 从 97.4±36.9 毫米减少到 86.1±36.9 毫米（11.6%），并在随访期间进一步减少到 77.2±32.5 毫米（10.3%）（p=0.001）。FA 从 69.2±26.6 毫米增加到 96.1±23.0 毫米，并在随访期间增加到 112.9±23.0 毫米（p<0.001）。
OLIF 可以间接减压椎管和椎间孔。尽管随访期间椎间盘高度降低，但黄韧带的重塑使椎管进一步增大。
