Ren Chunpeng, Song Yueming, Xue Youdi, Yang Xi, Zhou Chunguang
Department of Orthopedics, Lianyungang No.1 People' s Hospital, Xuzhou Academy of Medical Sciences, Lianyungang, China.
Department of Orthopedics, West China Hospital, Sichuan University, Chengdu, China.
World Neurosurg. 2017 Jul;103:341-347. doi: 10.1016/j.wneu.2017.04.005. Epub 2017 Apr 10.
Currently, polylactide is the most popular material used to made bioabsorbable cages but too-quick degradation and osteolysis around the cage have been reported in the literature. This study evaluated the fusion effect, biomechanical stability, and histologic characteristics of a novel bioabsorbable multiamino acid copolymer/nanohydroxyapatite/calcium sulfate (MAACP/n-HA/CS) interbody cage in a goat model of anterior cervical discectomy and fusion.
A total of 24 goats underwent C3/C4 discectomy and fusion with 3 groups of intervertebral implants: MAACP/n-HA/CS cage group (n = 8), titanium cage group (n = 8), and autologous tricortical iliac crest bone group (n = 8). Disc space height and lordosis angle were measured pre- and postoperatively and after 4, 12, and 24 weeks. Range of motion (ROM) was evaluated through biomechanical testing. Histologic analysis was performed to evaluate fusion status and to detect any foreign body reactions associated with the bioabsorbable cages.
At 12 and 24 weeks, disc space height in MAACP/n-HA/CS cage group was greater than that of titanium cage group and tricortical iliac crest group (P < 0.05). Lordosis angle in MAACP/n-HA/CS cage group and titanium cage group were lower than that of tricortical iliac crest group (P < 0.05). Biomechanical test showed that ROM did not differ significantly between MAACP/n-HA/CS cage group and titanium cage group, whereas the value of ROM in bone graft group was the largest. Histologic evaluation showed a better interbody fusion in the MAACP/n-HA/CS cage group than in the other 2 groups. MAACP/n-HA/CS cage surface degraded and was absorbed at 24 weeks. All MAACP/n-HA/CS cages showed excellent biocompatibility.
MAACP/n-HA/CS cages can provide good fusion effect, enough biomechanical stability, and integrate closely with the surrounding bone.
目前，聚乳酸是用于制造生物可吸收椎间融合器最常用的材料，但文献报道其降解过快且椎间融合器周围存在骨质溶解现象。本研究在山羊颈椎前路椎间盘切除融合模型中评估了一种新型生物可吸收多氨基酸共聚物/纳米羟基磷灰石/硫酸钙（MAACP/n-HA/CS）椎间融合器的融合效果、生物力学稳定性及组织学特征。
总共24只山羊接受了C3/C4椎间盘切除及融合手术，使用3组椎间植入物：MAACP/n-HA/CS椎间融合器组（n = 8）、钛合金椎间融合器组（n = 8）和自体三面皮质髂嵴骨组（n = 8）。在术前、术后以及术后4周、12周和24周测量椎间隙高度和前凸角度。通过生物力学测试评估活动度（ROM）。进行组织学分析以评估融合状态并检测与生物可吸收椎间融合器相关的任何异物反应。
在12周和24周时，MAACP/n-HA/CS椎间融合器组的椎间隙高度大于钛合金椎间融合器组和三面皮质髂嵴骨组（P < 0.05）。MAACP/n-HA/CS椎间融合器组和钛合金椎间融合器组的前凸角度低于三面皮质髂嵴骨组（P < 0.05）。生物力学测试表明，MAACP/n-HA/CS椎间融合器组和钛合金椎间融合器组之间的活动度无显著差异，而植骨组的活动度值最大。组织学评估显示，MAACP/n-HA/CS椎间融合器组的椎间融合效果优于其他两组。MAACP/n-HA/CS椎间融合器表面在24周时降解并被吸收。所有MAACP/n-HA/CS椎间融合器均显示出良好的生物相容性。
MAACP/n-HA/CS椎间融合器可提供良好的融合效果、足够的生物力学稳定性，并与周围骨紧密整合。
