Symptomatic adjacent segment disease (ASD) is a common challenge after anterior cervical discectomy and fusion (ACDF). The objective of this study was to compare the biomechanical effects of a second ACDF and laminoplasty for the treatment of ASD after primary ACDF. We developed a finite element (FE) model of the C2-T1 based on computed tomography images. The FE models of revision surgeries of ACDF and laminoplasty were simulated to treat one-level and two-level ASD after primary ACDF. The range of motion (ROM) and intradiscal pressure (IDP) of the adjacent segments, and stress in the cord were analyzed to investigate the biomechanical effects of the second ACDF and laminoplasty. The results indicated that revision surgery of one-level ACDF increased the ROM and IDP at the C2-C3 segment, whereas two-level ACDF significantly increased the ROM and IDP at the C2-C3 and C7-T1 segments. Furthermore, no significant changes in the ROM and IDP of the laminoplasty models were observed. The stress in the cord of the re-laminoplasty model decreased to some extent, which was higher than that of the re-ACDF model. In conclusion, both ACDF and laminoplasty can relieve the high level of stress in the spinal cord caused by ASD after primary ACDF, whereas ACDF can achieve better decompression effect. Revision surgery of the superior ACDF or the superior and inferior ACDF after the primary ACDF increased the ROM and IDP at the adjacent segments, which may be the reason for the high incidence of recurrent ASD after second ACDF.

中文翻译：

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不同手术方法治疗原发性颈椎前路椎间盘切除术和融合术后相邻节段疾病的生物力学评估：有限元分析。

症状性相邻节段疾病（ASD）是颈椎前路椎间盘切除融合术（ACDF）后的常见挑战。本研究的目的是比较二次 ACDF 和椎板成形术治疗原发性 ACDF 后 ASD 的生物力学效果。我们基于计算机断层扫描图像开发了 C2-T1 的有限元 (FE) 模型。模拟ACDF翻修手术和椎板成形术的有限元模型治疗原发性ACDF后一级和二级ASD。分析相邻节段的运动范围 (ROM) 和椎间盘内压力 (IDP) 以及脊髓中的应力，以研究第二次 ACDF 和椎板成形术的生物力学效应。结果表明，一级ACDF翻修手术增加了C2-C3段的ROM和IDP，而两级 ACDF 显着增加了 C2-C3 和 C7-T1 段的 ROM 和 IDP。此外，未观察到椎板成形术模型的 ROM 和 IDP 发生显着变化。再次椎板成形术模型的脊髓中的应力有一定程度的降低，这高于re-ACDF模型。总之，ACDF和椎板成形术均可缓解原发性ACDF后ASD引起的脊髓高水平应力，而ACDF可达到更好的减压效果。初次ACDF后上位ACDF或上下位ACDF的翻修术增加了相邻节段的ROM和IDP，这可能是二次ACDF后ASD复发率高的原因。没有观察到椎板成形术模型的 ROM 和 IDP 发生显着变化。再次椎板成形术模型的脊髓中的应力有一定程度的降低，这高于re-ACDF模型。总之，ACDF和椎板成形术均可缓解原发性ACDF后ASD引起的脊髓高水平应力，而ACDF可达到更好的减压效果。初次ACDF后上位ACDF或上下位ACDF的翻修术增加了相邻节段的ROM和IDP，这可能是二次ACDF后ASD复发率高的原因。没有观察到椎板成形术模型的 ROM 和 IDP 发生显着变化。再次椎板成形术模型的脊髓中的应力有一定程度的降低，这高于re-ACDF模型。综上所述，ACDF和椎板成形术都可以缓解原发性ACDF后ASD引起的脊髓高水平应力，而ACDF可以达到更好的减压效果。初次ACDF后上位ACDF或上下位ACDF的翻修术增加了相邻节段的ROM和IDP，这可能是二次ACDF后ASD复发率高的原因。ACDF和椎板成形术均可缓解原发性ACDF后ASD引起的脊髓高水平应力，而ACDF可达到更好的减压效果。初次ACDF后上位ACDF或上下位ACDF的翻修术增加了相邻节段的ROM和IDP，这可能是二次ACDF后ASD复发率高的原因。ACDF和椎板成形术均可缓解原发性ACDF后ASD引起的脊髓高水平应力，而ACDF可达到更好的减压效果。初次ACDF后上位ACDF或上下位ACDF的翻修术增加了相邻节段的ROM和IDP，这可能是二次ACDF后ASD复发率高的原因。