Iguchi Tetsuhiro, Kanemura Aritetsu, Kurihara Akira, Kasahara Koichi, Yoshiya Shinichi, Doita Minoru, Nishida Kotaro
Department of Orthopaedic Surgery, Kobe Rosai Hospital, Kobe, Japan.
J Neurosurg. 2003 Mar;98(2 Suppl):137-42. doi: 10.3171/spi.2003.98.2.0137.
The purpose of this study was to evaluate the usefulness of a high-porosity hydroxyapatite (HA) spacer in cervical laminoplasty. Bone-spacer bonding rates, complications associated with the implant, and factors related to bone bonding were examined.
The authors evaluated 33 consecutive patients with cervical myelopathy who underwent high-porosity HA spacer-assisted laminoplasty and were followed for at least 1 year (mean 30 months). The results of bone-spacer bonding of the 147 implants were evaluated using computerized tomography (CT) scanning. The symptoms significantly improved in 30 patients. No difference in results was detected between patients with cervical spondylosis and those with ossification of posterior longitudinal ligament. Breakage of seven spacers occurred in four patients without causing neck pain or neurological deficits. There were no other HA spacer-related complications. The spacers became rigidly bound to bone in 61% of the cases, and bone regrowth developed around the spacer in 91%. The rate of bone-spacer bonding increased over time, and the CT-documented attenuation value (Hounsfield unit) of the spacer adjacent to the bone-spacer junction in the group in which union occurred was significantly higher than in the nonunion group.
High-porosity HA spacer-augmented laminoplasty produced good bonding-related results. Bone bonding continued to progress 1 year after surgery, indicating the good osteoconductive capability of high-porosity HA. To avoid breakage of a spacer, a minimum 7-mm distance between spacers is necessary.
本研究旨在评估高孔隙率羟基磷灰石（HA）间隔器在颈椎椎板成形术中的实用性。研究了骨间隔器结合率、与植入物相关的并发症以及与骨结合相关的因素。
作者评估了33例连续接受高孔隙率HA间隔器辅助椎板成形术且随访至少1年（平均30个月）的脊髓型颈椎病患者。使用计算机断层扫描（CT）对147个植入物的骨间隔器结合结果进行评估。30例患者症状明显改善。颈椎病患者和后纵韧带骨化患者的结果无差异。4例患者发生7个间隔器断裂，但未引起颈部疼痛或神经功能缺损。未出现其他与HA间隔器相关的并发症。61%的病例中间隔器与骨牢固结合，91%的病例中间隔器周围有骨生长。骨间隔器结合率随时间增加，在发生融合的组中，与骨间隔器交界处相邻的间隔器的CT记录衰减值（亨氏单位）显著高于未融合组。
高孔隙率HA间隔器增强的椎板成形术产生了良好的与结合相关的结果。术后1年骨结合仍在继续，表明高孔隙率HA具有良好的骨传导能力。为避免间隔器断裂，间隔器之间至少需要7毫米的距离。
