骨外固定技术不植骨治疗复杂性骨不连与骨缺损

External skeletal fixation technique without bone graft for treating complex bone nonunion and defects

目的 探讨应力促进骨愈合的机制及骨外固定技术不植骨治疗复杂性骨不连与骨缺损的临床疗效。方法 （1）5例10根新鲜尸体完整胫骨及安装外固定器后测定骨表面应变、应力值。再制成胫骨中段骨折进行等体重加压，测定压力衰减情况。60只兔胫骨干制成骨折模型并施行骨外固定器三维立体固定，分别施加兔自身体重0倍（A组，对照组）、1／2倍（B组）、等体重（C组）、1．5倍（D组）的压力加压固定，测定术后即刻及1，2，4，6周骨折断端应力电位，并取骨折处标本行HE染色，光镜下观察。术后6周摄X线片，并取胫骨行扭转试验，测定骨愈合强度。（2）1978—2005年共收治195例复杂性骨不连、骨缺损患者，通过骨外固定施加1／2至等体重的压应力不植骨治疗，观察骨愈合及伤肢负重情况。结果（1）胫骨表面不同点应变、应力值相差显著；各点上架前后差异无统计学意义。加压固定后5h内骨断端压力以每小时5％～10％的速度衰减，24h后不到初始值的60％。兔胫骨骨折后应力电位变为负电位，A组及加压组（B、C、D组）分别于术后2周、6周恢复正电位。X线片、组织学及力学试验表明，加压组骨愈合速度及强度均好于对照组，但1．5倍体重加压量会造成骨坏死。（2）临床观察194例获得骨性愈合，愈合率99．5％。骨断端愈合时间3～7个月，平均5个月，骨延长区愈合时间4～11个月，骨愈合指数平均为37．8d／cm。全部患者取外固定器后伤肢可负重行走，无一例再骨折及截肢。结论 应力产生的负电荷可促进骨愈合，最佳生理性加压量应以自身体重为标准，经皮穿针骨外固定不植骨方法在复杂性骨不连与骨缺损的治疗中可视为一种疗效确切的微创生物学治疗技术。

Objective To discuss the mechanism of stress promoting bone union and the clinical effect of external skeletal fixation technology without bone graft in treating complex bone nonunion and defects. Methods （ 1 ） The straining value and stress value of 10 fresh human tibia were measured before and after installation of half-ring sulcated external fixator. Then, middle tibia fractures were made and the compression with same weight was conducted to measure the stress decays. The tibia fractures of 60 rabbits were fixed tridimensionally with the half-ring sulcated external fixators and given pressures equal to 0 time （Group A, Control group）, 1/2 time （Group B）, the same （Group C）, 1.5 times （ Group D） of the rabbit＇ s weight to press and fixate the fractures. Stress potential of fracture ends was measured immediately and at 1, 2, 4, 6 weeks after operation. The histological examination of the fracture specimen was carried out under microscope. X-ray and torsion test of the 6-week tibia were conducted to evaluate the intensity of bone union. （2） From 1978 to 2005 in our hospital, a total of 195 cases with complex bone nonunion and bone defect were treated with external skeletal fixation without bone graft by exerting stress of 1/2 time of or the same with their own weight, when the state of bone union and loading with the injured limb was assessed. Results There was a statistical difference upon straining value and stress value between different points on the surface of tibia. While no difference existed before and after fixation with the half-ring sulcated external fixator. In 5 hours, the pressure decay of fracture was at a speed of 5%-10% per hour and 24 hours later, the pressure was less than 60% of that at the beginning.The stress potential of rabbit tibia turned to be negative after fracture, and the potential of Group A and pressurization groups （Groups B, C and D） turned to be positive at the 2nd week and the 6th week respectively after operation. X-ray, histology and torsion test showed that the speed and intensity of fracture healing in Groups B, C and D were better than those in Group A. However, the stress with 1.5 times of the weight caused osteoneerosis. （2） According to clinical observation, 194 eases got fracture healing, with healing rate of 99.5%. The healing time of the fracture area and the extending area was 3-7 months （average 5 months） and 4-11 months （average healing index of 37.8 d/cm） respectively. All eases could walk with weight bearing, without refracture or amputation. Conclusions Negative electric charges generated by stress can promote bone union. The best pressed physical stress should be according to individual＇ s own weight. The clinical effect of external skeletal fixation technology without bone graft is good for treating complex bone nonunion and defeels.