皮质骨挤压钉固定重建前交叉韧带的实验观察

Experimental study of tendon graft fixation in anterior cruciate ligament reconstruction with cortical press-fit bolt in rabbits

目的观察皮质骨挤压钉固定重建ACL后的组织学转归。方法成年新西兰大白兔24只，采用配对设计方法，随机将双膝关节分为常规手术侧（对照组）和皮质骨挤压钉侧（实验组）。全麻下取自体趾长伸肌腱，行双侧膝关节ACL重建术，对照组只做常规ACL重建，实验组常规固定ACL后于胫骨隧道外口置入同种异体皮质骨挤压钉。分别于术后4、8、12周处死实验动物，取双侧膝关节标本，观察两组术后的影像学变化及组织学转归。结果术后4周皮质骨挤压钉组腱一骨界面及肌腱移植物的排列较对照组致密，大量新生骨及血管生成；术后8周皮质骨骨挤压钉组腱一骨界面移行带中新生血管比例为0．48±0．12，优于对照组的0．26±0．05（P〈0．05），骨挤压钉与骨隧道壁出现爬行替代；术后12周骨挤压钉组的腱一骨界面移行带出现成簇的软骨细胞，新生骨面积为（0．41±0．11）mm^2，对照组为（0．21±0．10）mm^2（P〈0．05）。结论ACL重建采用皮质骨挤压钉固定，组织相容性好，有利于腱骨界面再血管化和腱骨愈合，具有良好的应用前景。

Objective To explore the histological outcomes of tendon-bone healing in anterior cruciate ligament （ACL） reconstruction with cortical press-fit bolt （CPB）. Methods Twenty-four healthy female or male New Zealand White rabbits （2 -3 months old） underwent bilateral ACL reconstruction with extensor digitorum longus tendon. A random method was used to decide one knee would receive the routine ACL reconstruction （control group） and another cortical press-fit bolt fixation （experimental group）. After general anesthesia, extensor digitorum longus tendon was harvested and ACL reconstruction performed. All animals were sacrificed at 4, 8 and 12 weeks postoperation. Radiological and histological examinations were made at each timepoint. The specimens were stained with different methods to observe the pathological changes of tendon graft, bone tunnel and cortical press-fit bolt. Results More revascularization and massive new bone were found in tendon-bone junction of experimental group at 4, 8 and 12 weeks postoperation. The eircum-graft new vessel proportion of the experimental and control groups were 0. 48 ± 0. 12 and 0. 26 ± 0. 05 respectively （P 〈 0. 05 ）. In the experimental group, more cartilage cells were present in tendon-bone junction at 12 weeks and the circum-graft new bone areas in two groups were 0.41 ±0. 11 and 0. 21 ±0. 10 mm^2 respectively （ P 〈 0. 05 ）. Conclusion Cortical press-fit blot may improve tendon-bone healing after ACL reconstruction in rabbits. The application prospects of this procedure are promising.