骨形态发生蛋白2/Ⅰ型胶原凝胶修复前交叉韧带损伤

Bone morphogenetic protein-2/type Ⅰ collagen hydrogels for anterior cruciate ligament injury

背景:在前交叉韧带重建过程中,骨形态发生蛋白2/Ⅰ型胶原凝胶对腱-骨愈合的影响尚无定论。目的:观察兔前交叉韧带重建过程中,骨形态发生蛋白2/Ⅰ型胶原凝胶对前交叉韧带损伤腱-骨愈合的修复作用。方法:取18只新西兰大白兔,制作右膝前交叉韧带损伤模型,随机分为3组干预,空白对照组不进行任何干预,对照组胫骨股骨隧道内移植自体半腱肌肌腱,实验组胫骨股骨隧道内移植自体半腱肌肌腱后再向胫骨隧道内注射骨形态发生蛋白2/Ⅰ型胶原凝胶,移植后3个月,取胫骨骨隧道及近膝关节组织,进行Micro-CT影像学检查、苏木精-伊红染色及Masson染色。结果与结论:①Micro-CT影像学检查:空白对照组在胫骨隧道开口处、开口近1 cm处及隧道最宽处均未见明显骨组织再生;对照组骨隧道内出现不连续骨再生组织;实验组腱-骨部再生明显,胫骨骨隧道部分区域有连续骨连接;②苏木精-伊红染色:空白对照组骨隧道内可见稀疏纤维组织及骨再生;对照组骨隧道内可见新生骨长入肌腱,但肌腱与周围组织贴服疏松,交界处大量纤维细胞分布,新生骨面积较小;实验组骨隧道内大量新生骨长入肌腱,肌腱与周围骨组织交织分布,新生骨面积较多;③Masson染色:空白对照组腱-骨部未形成,原隧道部分充斥大量脂肪或纤维组织;对照组腱-骨界面可见软骨样组织及纤维组织,但纤维组织排列松散,与软骨组织间无紧密连接;实验组腱-骨部出现纤维组织-软骨-骨组织,纤维组织与软骨组织结合紧密,软骨组织下方为成熟骨组织;④结果表明:骨形态发生蛋白2/Ⅰ型胶原凝胶通过加强骨隧道骨再生和腱-骨结合部愈合促进前交叉韧带损伤的修复。

BACKGROUND：type I hydrogels on tendon-bone healing during the reconstruction of anterior cruciate ligament （ACL） is inconclusive.OBJECTIVE： To investigate the effect of BMP-2/collagen type I hydrogels to repair ACL injury.METHODS： ACL injury models were made in the right knees of 18 New Zealand rabbits. Model rabbits were randomizedinto three groups： blank control group with no intervention, control group with implantation of autologous semitendinosustendon into the tibial and femoral tunnels, and experimental group with implantation of autologous semitendinosustendon into the tibial and femoral tunnels combined with BMP-2/collagen type I hydrogel injection into the tibial tunnel.The Micro-CT, hematoxylin-eosin staining and Masson staining of the tendon-bone interface were conducted at 3months after implantation.RESULTS AND CONCLUSION： （1） Micro-CT imaging examination： No obvious bone tissue regeneration around thetibial tunnel （at the opening site, 1 cm distant to the opening site, and at the widest site of the tunnel） was observed in theblank control group. Discontinuous bone regeneration in the tibial tunnel was found in the control group. In theexperimental group, there was obvious tendon-bone regeneration and continuous bone connections in part of the tibialtunnel. （2） Hematoxylin-eosin staining： In the blank control group, sparse fibrous tissue and regenerated bone tissue were observed in the bone tunnel. In the control group, new bone tissues grew into the tendon, but the tendon and thesurrounding tissue were loose, with a large amount of fibrocytes and the small new bone area. In the experimental group,a large number of new bone tissues were regenerated in the tendon, the tendon was intertwined with the surroundingbone tissues, and the area of new bone was increased. （3） Masson staining： In the blank control group the tunnel waspartially filled with fat or fibrous tissues, and no tendon-bone interface appeared. In the control group, cartilage andfibrous tissues were visible on the tendon-bone interface, but the fibrous tissues were loosely arranged and had no closeconnection with the cartilage tissues. In the experimental group, fibrous-chondral-bone tissues were found on thetendon-bone interface, with fibrous tissues being tightly bound to the cartilage tissues, and mature bone tissues werevisible below the cartilage tissue. These results indicate that BMP-2/collagen type I hydrogel is beneficial to ACL repairby strengthening the bone regeneration in the bone tunnel and the healing of tendon-bone junction.