Noguchi Hiroshi, Koda Masao, Funayama Toru, Kumagai Hiroshi, Abe Tetsuya, Nagashima Katsuya, Miura Kousei, Mataki Kentaro, Fujii Kengo, Yamazaki Masashi
Department of Orthopaedic Surgery, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
Department of Orthopaedic Surgery, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
J Clin Neurosci. 2019 Apr;62:46-52. doi: 10.1016/j.jocn.2019.01.012. Epub 2019 Jan 14.
We used a newly developed, high-porosity unidirectional porous hydroxyapatite spacer (Regenos spacer, not approved by the FDA). To assess the short-term bone bonding capacity of Regenos spacer used in a double-door laminoplasty, including displacement, deformation, and absorption after implantation. Fifty patients underwent a double-door laminoplasty using Regenos spacers, with computed tomography (CT) images obtained at 2-4 weeks and 6-12 months, post-surgery, in 30 patients. Bone bonding rate, amount of displacement, and the incidence of deformation and absorption were evaluated from the early and late postoperative CT images. Bone bonding rate for Regenos spacers, using our modified classification, was 48.9% at 6 months, post- surgery, and 67.0% at 12 months. The change in anterior-posterior diameter of the spinal canal (ΔH) was significantly greater for Regenos spacers than for autologous bone spacers (p < 0.05). There was no difference in the change in angle between the vertebral arch and the posterior wall of the vertebral body (ΔR) between the Regenos and autologous bone spacers. Deformation was identified in 21.3% (10/47). Though, no evidence of breakage along their long axis was identified among these 10 cases on axial CT images with passable clinical results. Regenos spacers lowered the risk of early dislocation after implantation and facilitated bone bonding due to infiltration of surrounding tissue. However, the deformation and absorption was observed at high rates because of their insufficient mechanical strength, we need to require a longer term follow-up to more clearly evaluate their adverse impact in clinically.
我们使用了一种新开发的、高孔隙率的单向多孔羟基磷灰石间隔器（Regenos间隔器，未获美国食品药品监督管理局批准）。以评估Regenos间隔器在双开门椎板成形术中使用后的短期骨结合能力，包括植入后的移位、变形和吸收情况。50例患者接受了使用Regenos间隔器的双开门椎板成形术，其中30例患者在术后2至4周和6至12个月时获得了计算机断层扫描（CT）图像。从术后早期和晚期的CT图像评估骨结合率、移位量以及变形和吸收的发生率。根据我们改良的分类方法，Regenos间隔器术后6个月时的骨结合率为48.9%，术后12个月时为67.0%。Regenos间隔器导致的椎管前后径变化（ΔH）显著大于自体骨间隔器（p<0.05）。Regenos间隔器与自体骨间隔器在椎弓与椎体后壁之间角度的变化（ΔR）方面没有差异。21.3%（10/47）的患者出现了变形。不过，在这10例患者的轴向CT图像上未发现沿其长轴的断裂迹象，临床结果尚可。Regenos间隔器降低了植入后早期脱位的风险，并由于周围组织的浸润促进了骨结合。然而，由于其机械强度不足，观察到较高的变形和吸收率，我们需要进行更长时间的随访，以便在临床上更清楚地评估其不良影响。
