Abstract：
BACKGROUND: Using three-dimensional image analysis, we previously reported suppression of ossification progression following posterior fusion surgery for cervical ossification of the posterior longitudinal ligament (OPLL). Here, we aimed to evaluate the morphological changes in thoracic OPLL using three-dimensional analysis.
METHODS: Seventeen patients (eight males and nine females; mean age, 56.9 years) who underwent posterior decompression and fusion (PDF) for thoracic OPLL were included. We evaluated the OPLL volume using a novel analysis involving creating a three-dimensional model from computed tomography images to measure the volume accurately. Additionally, OPLL thickness, width, and length were measured on sagittal and axial computed tomography planes. We investigated the morphological changes in OPLL after PDF. Furthermore, patients were classified into reduced volume and increased volume groups and associated factors were compared.
RESULTS: The mean OPLL volume was 1,677 mm3 preoperatively and 1,705 mm3 at the final examination and did not significantly differ. Volume reduction was observed in 7 of 17 cases (41 %). Although OPLL width and length significantly increased postoperatively, OPLL thickness significantly reduced from 7.1 mm preoperatively to 6.5 mm postoperatively (all, p < 0.05). The annual thickness changes significantly differed (p <0.05) in the reduced volume group (-0.36 mm/year) compared to that in the increased volume group (-0.06 mm/year).
CONCLUSIONS: Thoracic OPLL after PDF becomes thinner in the anteroposterior direction but increases horizontally and craniocaudally. The reduction in OPLL thickness was related to a reduction in ossification volume. We believe that volume reduction in thoracic OPLL is influenced by pulsation of the dural sac.
METHODS: Seventeen patients (eight males and nine females; mean age, 56.9 years) who underwent posterior decompression and fusion (PDF) for thoracic OPLL were included. We evaluated the OPLL volume using a novel analysis involving creating a three-dimensional model from computed tomography images to measure the volume accurately. Additionally, OPLL thickness, width, and length were measured on sagittal and axial computed tomography planes. We investigated the morphological changes in OPLL after PDF. Furthermore, patients were classified into reduced volume and increased volume groups and associated factors were compared.
RESULTS: The mean OPLL volume was 1,677 mm3 preoperatively and 1,705 mm3 at the final examination and did not significantly differ. Volume reduction was observed in 7 of 17 cases (41 %). Although OPLL width and length significantly increased postoperatively, OPLL thickness significantly reduced from 7.1 mm preoperatively to 6.5 mm postoperatively (all, p < 0.05). The annual thickness changes significantly differed (p <0.05) in the reduced volume group (-0.36 mm/year) compared to that in the increased volume group (-0.06 mm/year).
CONCLUSIONS: Thoracic OPLL after PDF becomes thinner in the anteroposterior direction but increases horizontally and craniocaudally. The reduction in OPLL thickness was related to a reduction in ossification volume. We believe that volume reduction in thoracic OPLL is influenced by pulsation of the dural sac.
摘要：
背景：使用三维图像分析，我们以前报道过颈椎后纵韧带骨化(OPLL)后路融合手术后骨化进展受到抑制.这里,我们旨在使用三维分析评估胸部OPLL的形态变化.
方法：17例患者（男8例，女9例；平均年龄，56.9年）的患者接受了胸OPLL的后路减压和融合（PDF）。我们使用一种新颖的分析来评估OPLL体积，该分析涉及从计算机断层扫描图像创建三维模型以精确测量体积。此外,OPLL厚度,宽度,在矢状和轴向计算机断层扫描平面上测量长度。我们研究了PDF后OPLL的形态变化。此外，将患者分为体积减少组和体积增加组,并比较相关因素.
结果：术前平均OPLL体积为1,677mm3，最终检查为1,705mm3，没有显着差异。在17例中的7例中观察到体积减少（41％）。尽管OPLL宽度和长度在术后显著增加，OPLL厚度从术前7.1mm明显减少到术后6.5mm（所有，p<0.05)。与体积增加组（-0.06mm/年）相比，体积减少组（-0.36mm/年）的年厚度变化显着差异（p<0.05）。
结论：PDF后胸部OPLL在前后方向变薄，但在水平方向和颅尾方向增加。OPLL厚度的减少与骨化体积的减少有关。我们认为胸部OPLL的体积减少受硬膜囊脉动的影响。
方法：17例患者（男8例，女9例；平均年龄，56.9年）的患者接受了胸OPLL的后路减压和融合（PDF）。我们使用一种新颖的分析来评估OPLL体积，该分析涉及从计算机断层扫描图像创建三维模型以精确测量体积。此外,OPLL厚度,宽度,在矢状和轴向计算机断层扫描平面上测量长度。我们研究了PDF后OPLL的形态变化。此外，将患者分为体积减少组和体积增加组,并比较相关因素.
结果：术前平均OPLL体积为1,677mm3，最终检查为1,705mm3，没有显着差异。在17例中的7例中观察到体积减少（41％）。尽管OPLL宽度和长度在术后显著增加，OPLL厚度从术前7.1mm明显减少到术后6.5mm（所有，p<0.05)。与体积增加组（-0.06mm/年）相比，体积减少组（-0.36mm/年）的年厚度变化显着差异（p<0.05）。
结论：PDF后胸部OPLL在前后方向变薄，但在水平方向和颅尾方向增加。OPLL厚度的减少与骨化体积的减少有关。我们认为胸部OPLL的体积减少受硬膜囊脉动的影响。
