兔腰椎前柱间盘切除后髓核组织对椎体间植骨融合的影响

背景：文献报道腰椎融合治疗腰椎疾病，有近20%不能达到有效的融合，出现治疗后疼痛、椎间隙塌陷、迟发性后凸畸形等一系列并发症。目的：进一步验证兔腰椎前柱结构切除后髓核组织对椎体间植骨融合效果。方法：健康成年日本大耳白兔36只，随机分为3组，每组12只。①剥离前纵韧带＋植骨组在L3间盘水平剥离前纵韧带，使其与 L3间盘前缘形成间隙，植入同种异体髂骨。②切除1/3间盘组织＋植骨组切除 L3前1/3间盘组织，终板间植入同种异体髂骨，缝合同剥离前纵韧带＋植骨组。③切除1/3间盘组织＋内固定组在切除1/3间盘组织＋植骨组的基础上行前柱的内固定。结果与结论：生物力学测定：剥离前纵韧带＋植骨组治疗后12周融合节段垂直拉伸力明显优于其他2组，能够承受更强的外界拉伸力。腰椎侧位X射线检查：切除1/3间盘组织＋植骨组12周植入骨块吸收，椎间隙无新生骨长入；切除1/3间盘组织＋内固定组12周椎间有连续骨桥形成；剥离前纵韧带＋植骨组12周完全骨性融合。组织学观察：切除1/3间盘组织＋植骨组12周未见骨组织生成；切除1/3间盘组织＋内固定组12周少量的成熟骨小梁及成骨细胞；剥离前纵韧带＋植骨组12周大量成熟骨小梁及骨细胞，重塑后的板状骨及哈弗氏结构。结果证实腰椎前柱的稳定性对椎体间植骨融合的效果有显著的影响，切除前1/3间盘组织后，游离的间盘、髓核物质影响了植入骨融合，有效地恢复前柱稳定性能够促进椎体间植骨融合，但仍不能达到有效融合。

Effect of rabbit nucleus pulposus tissue after anterior column disc removal on interbody fusion

BACKGROUND：In treatment of lumbar diseases, lumbar fusion therapy fails in 20%of cases and may lead to a series of complications such as pain, intervertebral space col apse, and delayed kyphosis deformity. OBJECTIVE：To observe the effect of nucleus pulposus on interbody fusion after removing the anterior column disc of rabbit lumbar vertebra. METHODS：A total of 36 healthy Japanese white rabbits were randomly and equal y divided into three groups, with 12 rabbits in each group. （1） Group of anterior longitudinal ligament＋bone grafting：The L3 intercalated disc were wel exposed and anterior longitudinal ligament was stripped, obtaining a space to L3 intercalated disc, then the iliac bone was implanted. （2） Group of excising anterior 1/3 disc＋bone grafting：After the anterior 1/3 disc tissue was excised, the iliac bone was implanted and sutured as Group of anterior longitudinal ligament＋bone grafting. （3） Group of excising anterior 1/3 disc＋fixation：After the anterior 1/3 disc tissue was excised, the iliac bone was implanted and the anterior column fixation was performed. RESULTS AND CONCLUSION：Biomechanical testing showed that, at 12 weeks, the verticality tensile force in the group of anterior longitudinal ligament＋bone grafting was obviously higher than other two groups, and have better fusion rate and could bear stronger force. Lateral position lumbar radiography showed that, the bone graft was absorbed and no new bone grew into the intervertebral space in the group of excising anterior 1/3 disc＋bone grafting at 12 weeks;the formation of osseous bridge was found in the group of excising anterior 1/3 disc＋fixation;complete bony fusion was found in the group of anterior longitudinal ligament＋bone grafting. Histological＆nbsp;examinations showed that, at 12 weeks, no bone tissue formed in the group of excising anterior 1/3 disc＋bone grafting;a smal amount of bone trabecula and osteocytes were observed in the group of excising anterior 1/3 disc＋fixation;a great quantity of newborn bone trabecula and osteocytes, remodeling lamel ar bone and canalis haversi structure were observed in the group of anterior longitudinal ligament＋bone grafting. The stability of anterior column has notable effect on interbody fusion, after the anterior column disc is destroyed, the free nucleus pulposus may affect spinal fusion, so restoring the stability of the anterior column may promote interbody fusion, but stil cannot get solid spinal fusion.