小夹板外固定与钢板内固定材料置入对骨折断端成骨活性的影响

背景: AO技术存在许多的缺陷,如"应力遮挡"产生的负面效应等.近年来国内外学者认为弹性固定法最合理,是最有利于骨折愈合的治疗理念.目的:观察小夹板外固定对兔长管状骨骨折断端成骨活性的影响,并与钢板内固定材料置入方法比较.设计:随机对照动物实验.单位:湖北中医学院骨伤科研究所.材料:实验于2006－04、2007－04在湖北中医学院骨伤实验室完成.30只家兔随机分成小夹板固定组、钢板固定组,每组15只.自制小夹板,由具有较好弹性的杉树皮制成.分前后、内外侧四块夹板,夹板上宽下窄,在前后侧夹板靠近胫骨结节部刺一小孔.钢板由江苏金鹿集团医疗有限公司提供.方法:在左胫骨中下1/3处造成3 mm骨缺损横行骨折模型,小夹板 固定组用石膏固定5 d后换成小夹板外固定,钢板固定组用4孔钢板 内固定.术后14,24,34 d时分批处死各组动物,通过肉眼观察骨折 处骨痂生长情况,并观察骨折愈合过程中骨痂组织形态学及骨生成细 胞情况. 主要观察指标:不同时期兔胫骨骨痂肉眼观察,骨痂组织形态学和骨 生成细胞情况.结果:小夹板固定组骨痂形成早,早期成骨细胞丰富且活跃,34 d时骨折全部骨性连接.钢板固定组:14 d时骨折端见少量的纤维骨痂,仍有肉芽组织,24d时见少量的软骨连接,34d时骨痂已跨过骨折端,但未完全连接.小夹板外固定组与钢板固定组比较,骨折各期形成的骨痂量多,骨折愈合快结论:小夹板外固定能促进骨折处成骨细胞的分化增殖和血肿的吸收、骨痂的钙化、骨小梁的生长改建.

Influence of external fixation by small splint versus Internal fixation by steel plate on osteogenetlc activity of fracture bones☆

BACKGROUND: Fixation of bone fracture is one of the fundamental methods for bone fracture healing. The technique of AO has a lot of defects, such as negative effect induced by "stress dodging". Recently, the technique of CO is praised highly by national and international scholars. OBJECTIVE: To observe the influence of external fixation of small splint on healing of long bone fracture of rabbit, and compare to the internal fixation of steel plate.DESIGN: Randomized and controlled animal trial. SETTING: Research Institute of Orthopedics, Hubei College of Traditional Chinese Medicine.MATERIALS: The experiment was performed at the Laboratory of Orthopedics, Hubei College of Traditional Chinese Medicine from April 2006 to April 2007. Thirty rabbits were randomly divided into small splint fixation group and steel plate fixation group with 15 rabbits in each group. Small splint was self-made of fir-barks with good elasticity, and composed of exterior, interior, front and back splints. The upper part of the splint was wide and the lower part was narrow. We sting an eyelet in the small splint that is used in front and behind part. A hole was drilled in the front and back splints close to the tubercle of tibia. Steel plate was provided by Jiangsu Golden Deer Group (Type HA2.0). METHODS: The standard models of transverse fracture of 3 mm in the meta-infer 1/3 of left tibia were established. In small splint fixation group (SSF group), the fracture was fixed by plaster stone, and 5 days later, replaced by external fixation of small splint. The steel fixation group (SF group) was fixed by steel plate with 4 holes. Animals were executed 14, 24, and 34 days after surgery, respectively. The growth condition of bony callus in fracture sites was observed, and the histomorphology of bony callus and bone cell production during fracture healing was observed. MAIN OUTCOME MEASURES: Macroscopic observation of rabbit tibial bony callus, and histomorphology of bony callus and bone cell formation. RESULTS: In SSF group, the bony callus formed early, and there were plentiful and active osteoblast. Thirty-four days after surgery, bony union was observed in fracture sites. In SF group, there was little fibrous bony callus in the fracture ends 14 days after surgery, accompanied by granulation tissue. Twenty-four days after surgery, sparing cartilage synostosis was observed. On day 34 days, bony callus span the fracture ends, but fracture ends did not connect completely yet. Compared with the SF group, the quantity of bony callus and the speed of fracture healing were superior in SSF group. CONCLUSION: The external fixation of small splint can promote osteoblastic differentiation and proliferation, absorption of hematoma, calcification of the bony callus, and the growth and rebuilding of bone trabecula.