Department of Neurosurgery, Mie Chuo Medical Center, Tsu, Mie, Japan.
Department of Neurosurgery, Mie University Graduate School of Medicine, Tsu, Mie, Japan.
Spine (Phila Pa 1976). 2024 Nov 1;49(21):1504-1511. doi: 10.1097/BRS.0000000000005051. Epub 2024 Jun 7.
Retrospective multicenter study.
To examine the shape change of screw-rod constructs over time after short-segment lumbar interbody fusion and to clarify its relationship to clinical characteristics.
No study has focused on the shape change of screw-rod constructs after short-segment fusion and its clinical implications.
One hundred eight patients who had single-level lumbar interbody fusion with pedicle screws and cages were enrolled. Three-dimensional (3D) images of screw-rod constructs were generated from baseline CT on the day after surgery and follow-up CT and were superposed on the right and left side, respectively, using the iterative closest point algorithm. The shape change was quantitatively assessed by computing the median distance between the 3D images, which was defined as the shape change value. Among the 5 time-course categories of follow-up CT (≤1, 2-3, 4-6, 7-12, and ≥13 months), the shape change values were compared. The relationships between the shape change values and clinical characteristics, such as age, CT-derived vertebral bone mineral density, screw and rod materials, and postoperative interbody fusion status, cage subsidence, and screw loosening, were evaluated.
A total of 237 follow-up CTs were included (≤1 [34 scans], 2-3 [33 scans], 4-6 [80 scans], 7-12 [48 scans], and ≥13 months [42 scans]) because many patients underwent multiple follow-up CTs. There were significant differences in shape change values among the time-course categories ( P <0.001 in Kruskal-Wallis test). Most shape changes occurred within 6 months postoperatively, with no significant changes observed at 7 months or more. There were no significant relationships between the shape change values and each clinical characteristic.
The temporal shape changes of screw-rod constructs following short-segment lumbar interbody fusion progressed up to 6 months after surgery but not significantly thereafter.
回顾性多中心研究。
研究短节段腰椎椎间融合术后螺钉-棒结构的形状变化，并阐明其与临床特征的关系。
尚无研究关注短节段融合术后螺钉-棒结构的形状变化及其临床意义。
共纳入 108 例接受单侧经皮椎弓根螺钉和椎间融合器融合的单节段腰椎融合术患者。使用迭代最近点算法分别对术后第 1 天的 CT 及随访 CT 的螺钉-棒结构进行三维（3D）图像生成，并对左右两侧图像进行叠加。通过计算 3D 图像之间的中位数距离来定量评估形状变化，该距离定义为形状变化值。在 5 个随访 CT 时间类别（≤1、2-3、4-6、7-12 和≥13 个月）中比较形状变化值。评估形状变化值与临床特征（如年龄、CT 衍生的椎体骨密度、螺钉和棒材料以及术后椎间融合状态、椎间融合器下沉和螺钉松动）之间的关系。
共纳入 237 份随访 CT（≤1[34 份扫描]、2-3[33 份扫描]、4-6[80 份扫描]、7-12[48 份扫描]和≥13 个月[42 份扫描]），因为许多患者进行了多次随访 CT。时间类别之间的形状变化值存在显著差异（Kruskal-Wallis 检验 P<0.001）。大多数形状变化发生在术后 6 个月内，7 个月或更长时间后无明显变化。形状变化值与每个临床特征之间均无显著关系。
短节段腰椎椎间融合术后螺钉-棒结构的时间性形状变化在术后 6 个月内进展，但此后无明显变化。
