Does kyphofic malalignment after anterior cervical fusion promote the degenerative process in adjacent intervertebral levels?

我们回顾性研究了接受前路减压和融合术并随访超过5年的患者中融合附近椎间节段退行性变化的原因。本研究的目的是确定颈椎前路融合术后由于植骨塌陷而导致的对线不良（如后凸模式）是否会促进融合相邻节段的退行性变化，我们在重新评估时通过X线检查颈椎对线和相邻节段的退行性变化，并分析它们之间的关系。我们还研究了有症状患者与无症状患者之间的差异，这些患者在固定附近的椎间隙发生退行性变化。在对线不良的患者中，相邻椎间节段的退行性变化比脊柱前凸对线的患者进展程度更大。与无症状患者相比，融合附近椎间隙退行性变症状恶化的患者椎管直径较小。

We retrospectively studied the causes of degenerative change of intervertebral levels adjacent to fusion in patients who had undergone anterior decompression and fusion and who had been followed for more than 5 years. The aim of this study was to determine whether malalignment, such as kyphotic pattern, due to collapse of graft bone after anterior cervical fusion promotes degenerative change of intervertebral levels adjacent to fusion.We examined cervical alignment and degenerative change of adjacent intervertebral levels roentgenographically at the time of reassessment, and analyzed their relationship. We also examined the differences between symptomatic patients with degenerative change of intervertebral spaces adjacent to fixation and asymptomatic patients. In patients with malalignment, degenerative change of adjacent intervertebral levels progressed to a greater extent than in those with lordotic alignment. Patients with symptomatic deterioration of degenerative change of intervertebral spaces adjacent to fusion have a smaller spinal canal diameter than do asymptomatic patients.