膝关节持续被动活动对兔重建前交叉韧带腱骨愈合的影响

The effects of continuous passive motion on tendon-bone healing of the tendon autograft used for anterior cruciate ligament reconstruction in a rabbit model

目的通过兔半腱肌腱腱后固定方法重建前交叉韧带（ACL）实验动物模型，研究持续被动活动（CPM）对移植物隧道内腱骨界面的组织学转归影响。方法对12只雄性新西兰大白兔右侧后肢膝关节行自体双股半腱肌腱移植重建ACL。术后随机分为两组：CPM组（n=6）术后第2天开始早期CPM康复6周；自由活动组（n=6）笼养。分别于术后第6、12、24周取材，采用HE和甲苯胺蓝染色观察腱骨愈合过程。结果前侧腱骨界面纤维组织较多且较后侧腱骨界面宽；后侧腱骨界面的成骨细胞和类软骨细胞较多，新骨沉积较多。在骨道内口（关节腔入口），破骨细胞较多。与自由活动组比较，CPM组界面组织改建塑形更成熟、胶原排列更有序，潮线结构出现较早，类软骨细胞、成骨细胞和类似潮线的结构较多。结论腱骨界面前侧张力较大，纤维较多；腱骨界面后侧压力较大，软骨较多。半腱肌腱重建ACL术后早期CPM加快移植物止点潮线结构恢复，增强移植物与骨组织之间整合。

Objective To study the effects of continuous passive motion on the tendon-bone healing of the semitendinous tendon autograft used for anterior cruciate ligament （ACL） reconstruction in rabbits. Methods In 12 healthy 8-month-old male rabbits, an ACL reconstruction was performed by using double semitendinous tendon autograft. Postoperatively these animals were treated by either continuous passive motion（CPM） or cage activity. Specimens of the grafts were collected at 6, 12, 24 weeks postoperatively. Histological change in the tendon-bone healing was studied by haematoxylin-eosin and toluidine blue. Results There was more new fiber tissue in the anterior half of the interface. Osteoclasts were most numerous at the tunnel aperttrre and in the anterior half of the interface. Cartilage in the tendon-bone interface was localized to the posterior aspect of tunnels, the area where compressive stress would be predicted. CPM group developed a denser connective tissue with less vascularity and cellularity. The bone tunnel had more areas with ingrowing denser connective tissue compared with cage activity specimens. With the growth of Sharpery＇s fibers and fibrocartilage into the interface, a direct ligament insertion was found. In the CPM specimens, the interface tissue was more mature and the direct insertion was broader and more structured. Condnsions Compressive stress promotes chondroid formation, and the tension promotes fiber formation. Tendon-bone healing may be optimized by CPM after tendon transplantation into a bone tunnel.