α-氰基丙烯酸正辛酯黏接兔桡骨横断骨折的效果

Effect of octyl-alpha-cyanoacrylate in adhesive bonding of rabbit radial transverse fracture

目的:采用α-氰基丙烯酸正辛酯医用胶进行兔体内桡骨中段横断骨折的黏接固定,观察其在体内降解的速度以及对桡骨横断骨折黏接固定的效果。方法:实验于2003-09/2004-03在四川大学华西医院完成。选择健康成年新西兰大白兔72只,随机分为α-氰基丙烯酸正辛酯组、模型对照组,36只/组。①全部动物腹腔麻醉后常规方法锯断桡骨制作桡骨中段横断骨折模型。②α-氰基丙烯酸正辛酯组拭干骨折断端血迹后在断端间滴入一两滴α-氰基丙烯酸正辛酯黏接胶(由α-氰基丙烯酸正辛酯添加催化剂及辅助成分精制而成),加压并维持1min,以使胶体充分固化;模型对照组不采用内固定,以尺骨为支架进行自然固定。③术后2,4,6,8,10,12周分批处死动物,6只/组。对断端骨折愈合情况以及胶体残留情况进行大体观察、X线片和组织学检查。结果:实验选用大白兔72只,全部进入结果分析。①术后不同时间两组大体观察和X线片检查结果:两组均于术后4周可见骨痂形成,8周骨折线模糊并有较多骨痂形成,12周骨折线完全消失;但前8周α-氰基丙烯酸正辛酯组的骨折愈合速度均较模型对照组为慢,8周以后材料已经基本降解吸收,两组骨折愈合速度基本相同。②术后不同时间两组组织学观察结果:α-氰基丙烯酸正辛酯组随着胶体的降解,骨折逐步愈合,术后4周时纤维细胞和软骨细胞逐渐长入,6周时可见材料被软骨细胞和纤维细胞包裹,8周时材料降解破碎,材料逐渐吸收并可见软骨化骨。12周时编织骨密度基本接近骨组织,连接骨折断端,骨折基本骨性愈合。模型对照组在各时间点的愈合程度基本与α-氰基丙烯酸正辛酯组相似。结论:在黏接固定兔桡骨骨折过程中,α-氰基丙烯酸正辛酯在体内2周即开始降解,10～12周完全降解消失,未形成板障效应,骨折愈合效果良好。提示α-氰基丙烯酸正辛酯具有较高的生物力学强度,是黏接固定骨折的新方法。

AIM： Oetyl-α-eyanoaerylate is used to bond the radial medium-segment transverse fracture in vivo in rabbits, and to observe its degradation rate and its adhesive effect in radial transverse fracture. METHODS： This experiment was conducted at the West China, Sichuan University from September 2003 to March 2004. Totally 72 healthy adult New Zealand rabbits were chosen and randomly divided into octyl-α- cyanoacrylate group and model control group with 36 rabbits in each one. ①Radius of all the animals were cut with routine method after intraperitoneal anesthesia to make radial medium-segment transverse fracture models . ②In the octyl-α-cyanoacrylate group, blood of fracture stump was cleaned , then 1 to 2 drops of octyl-α-cyanoacrylate adhensivel （made of octyl-α-cyanoacrylate , catalyst and helper constituents） was dripped be- tween the stumps, pressurized and maintained for Ⅰ minute to make gel solidify sufficiently; Internal fixation was not used in the model control group and ulna was used as scaffold for natural fixation. ③2,4,6,8,10,12 weeks after opration, animals were put to death in batch, 6 rats in each group. Fracture healing condition and residual colloid were performed gross observation, X-ray and histological examination. RESULTS： Totally 72 rabbits were enrolled in the experiment, and all of them entered the stage of result analysis. ①Gross observation and X-ray examination at the different time points after operation ： In the two groups, bone callus was found at 4 weeks after operation; fracture line was blurry and many bone callus formed at 8 weeks; fracture line completely disappeared at 12 weeks; but the healing rate at the first 8 weeks was slower in the octyl-α-cyanoacrylate group than in the control group; 8 weeks later, the materials were degraded and absorbed basically, and the healing rate of fracture was the same in the two groups. ②Histological observation at different time points after operation： In the octyl-α-cyanoacrylate group, with the gradual fracture healing, fibrocyte and cbondrocyte appeared ingrowth gradually at 4 weeks after operation. Materials were enwrapped by fibrecyte and chondrocyte at 6 weeks, degraded at 8 weeks and absorbed gradually and os cartilaginea appeared. At 12 weeks, the density of woven bone approached to bone tissue basically and stump was connected to woven bone. Fracture was basically bone union. The healing degree at various time points in the model control group was basically similar to that in the octyl- α-cyanoacrylate group. CONCLUSION： In the process of adhesive fixation of radial fracture of rabbits, octyl-α-cyanoacrylate begins to degrade at 2 weeks, degrades and disappears completely at 10 to 12 weeks. No diploic effect forms and fracture heals well. It suggests that octyl-α-cyanoacrylate has very high biomechanical intensity and is new for adhesive fixation of fracture.