内减张技术辅助前交叉韧带重建促进滇南小耳猪跟腱移植物韧带化

Internal tension relieving technique assisted anterior cruciate ligament reconstruction to promote ligamentization of Achilles tendon grafts in small ear pigs in southern Yunnan province

背景:前期研究已经成功建立了内减张技术联合自体跟腱重建前交叉韧带的滇南小耳猪动物模型,并验证了模型的稳定性和可靠性,但内减张技术能否促进自体跟腱移植物的韧带化进程问题仍未被研究。目的:从大体观、组织学、电镜检测多方面探讨普通重建与内减张重建前交叉韧带韧带化进程的差异。方法:选取30只成年雌性滇南小耳猪,左后肢膝关节取同侧膝关节跟腱行前交叉韧带重建(普通组n=30),右后肢膝关节取同侧膝关节跟腱联合内减张增强系统行前交叉韧带重建(减张组n=30),以自体右前肢作为对照组,暴露前交叉韧带但不行离断及手术处理。在术后12,24,48周分别处死10只动物,取左右膝关节标本行大体形态学观察评估移植物形态,MAS评分评估各个时间点韧带优良率,苏木精-伊红染色评估韧带移植物血管化程度,观察胶原纤维及细胞核形态并进行细胞核形态学评分,扫描电镜与透射电镜评估超微结构重塑。结果与结论:①在术后各个时间点减张组的韧带愈合形态更好,可以获得更高的MAS评分优良率(P<0.05),并可以获得更高的韧带血管化评分(P<0.05);②两组移植物胶原束及纤维束的排列均逐渐趋于有序,胶原间的横向纤维连接逐渐增多增粗,提示移植物的强度和塑形程度逐渐提升,术后各个时间点减张组韧带的重塑始终快于普通组;③术后各个时间点减张组胶原纤维的直径、分布密度、排列有序度均优于普通组,尤其在胶原纤维直径的比较上,组间及组内比较减张组均优于普通组(P<0.05)。

BACKGROUND:We have successfully established an animal model of small ear pig in southern Yunnan province with internal tension relieving technique combined with autologous Achilles tendon for anterior cruciate ligament reconstruction,and verified the stability and reliability of the model.However,whether internal tension relieving technique can promote the ligamentalization process of autologous Achilles tendon graft has not been studied.OBJECTIVE:To investigate the differences in the process of ligamentalization between conventional reconstruction and internal reduction reconstruction of the anterior cruciate ligament by gross view,histology and electron microscopy.METHODS:Thirty adult female small ear pigs in southern Yunnan province were selected.Anterior cruciate ligament reconstruction was performed on the left knee joint with the ipsilateral knee Achilles tendon(n=30 in the normal group),and anterior cruciate ligament reconstruction was performed on the right knee joint with the ipsilateral knee Achilles tendon combined with the internal relaxation and enhancement system(n=30 in the relaxation group).The autogenous right forelimb was used as the control group;the anterior cruciate ligament was exposed but not severed or surgically treated.At 12,24,and 48 weeks after surgery,10 animals were sacrificed,respectively.The left and right knee joint specimens were taken for gross morphological observation to evaluate the graft morphology.MAS score was used to evaluate the excellent and good rate of the ligament at each time point.Hematoxylin-eosin staining was used to evaluate the degree of ligament graft vascularization.Collagen fibers and nuclear morphology were observed,and nuclear morphology was scored.Ultrastructural remodeling was evaluated by scanning electron microscopy and transmission electron microscopy.RESULTS AND CONCLUSION:(1)The ligament healing shape of the relaxation group was better at various time points after surgery,and the excellent and good rate of MAS score was higher(P<0.05).Moreover,the relaxation group could obtain higher ligament vascularization score(P<0.05).(2)The arrangement of collagen bundles and fiber bundles in the two groups gradually tended to be orderly,and the transverse fiber connections between collagen gradually increased and thickened,suggesting that the strength and shape degree of the grafts were gradually improved,but the ligament remodeling in the relaxation group was always faster than that in the normal group at various time points after surgery.(3)The diameter,distribution density,and arrangement degree of collagen fibers in the relaxation group were better than those in the normal group at all time points,especially in the comparison of collagen fiber diameter between and within the relaxation group(P<0.05).