纤维环缝合对维持髓核摘除后椎间盘生物力学强度的影响

Experimental study of annulus fibrosus suture on intervertebral disc biomechanical strength

目的观察纤维环缝合对髓核摘除术后椎间盘生物力学强度及纤维环修复的影响。方法成年健康山羊36只，雌雄各18只，随机分为3组，对每只羊的腰椎（腰2/3、3/4、4/5）进行椎间盘纤维环暴露。A组为对照组，暴露后不进行任何处理直接缝合关闭切口。B组应用小尖刀切开纤维环，摘除部分髓核后关闭切口。C组应用小尖刀切开纤维环，摘除部分髓核后应用可吸收缝线进行纤维环间断缝合。48周后，通过生物力学方法测定椎间盘内压力；通过核磁共振成像及脱钙病理切片染色观察纤维环的修复效果，并对手术前后椎间隙高度进行测量。同时记录髓核摘除量。结果与对照组比较，纤维环缝合组术后椎间隙高度丢失为（0.90±0.25） mm，非缝合组为（2.41±0.85） mm；差异有统计学意义（P＝0.015）。对照组椎间盘强度为（3.91±0.78） mPa，非缝合组为（1.99±0.58） mPa，缝合组为（3.07±0.67） mPa；差异有统计学意义（P＝0.004）。对照组髓核摘除量为（0.83±0.60） cm^3，缝合组为（0.82±0.48） cm^3；非缝合组为（0.85±0.42） cm^3，差异无统计学意义（P＝0.058）。结论纤维环缝合术对维持椎间盘生物力学强度及术后纤维环修复起到积极作用，同时促进椎间盘结构完整性的恢复。

Objective Applicate annulus fibrosus suture to investigate its effect on the biomechanical strength of intervertebral disc.Methods A total of 36 sheep were underwent retroperitoneal 3 levels exposure of the lumbar spine （L2/3, L3/4, L4/5）. Three ways were used in these discs： （1） Did not penetrate into the annulus fibrosus in Group A. （2） Penetrate into the annulus fibrosus in Group B, and didn’t perform annulus fibrosus suture. （3） Penetrate into the annulus fibrosus and perform annulus fibrosus suture in Group C. At 48 weeks after surgery, MRI images were taken and these segments were underwent biomechanical testing to assess the strength of the disc and anulus. Histology was also conducted on these specimens.Results Compared with control group, the lost of intervertebral space height on annulus suture group was （0.90±0.25） mm, and non suture group was （2.41±0.85） mm, the difference was statistically significant （P=0.015）. The strength of intervertebral disc on control group was （3.91±0.78） mPa, non suture group was （1.99±0.58） mPa, suture group was （3.07±0.67） mPa; the difference was statistically significant （P=0.004）. The nucleus pulposus volume on control group was （0.83±0.60） cm^3, suture group was （0.82±0.48） cm^3, and non suture group was （0.85±0.42） cm^3, the difference was not statistically significant （P=0.058）.Conclusion Application of annulus fibrosus suture after resection of nucleus pulposus can effectively maintenance of biomechanical strength, it play a positive role in the repair of annulus fibrosus.