CAJ | 학술논문

目的评估骨外固定支架动力化对兔胫骨干截骨骨折愈合的生物力学影响. 方法选取30只新西兰大白兔,雌雄各15只,体质量为2.0～2.5 kg.取其右侧胫骨干截骨骨折作为实验侧,左侧完整胫骨干作同期对照.将实验兔随机分为3组(n=10):动力化组:术后6周内维持双横杆构型坚强固定,6周后去除外固定支架内侧横杆,改为单横杆构型弹性固定直至骨折术后12周;坚强固定组:术后恒定维持双横杆构型,模拟坚强固定12周;弹性固定组:术后恒定维持单横杆构型,模拟弹性固定12周.术后观察各组实验兔一般状态,并摄X线片观察骨折愈合情况.骨折固定12周后处死全部实验兔后进行生物力学测试,测量并计算各组两侧骨标本最大弯曲强度、最大弯曲强度比率(实验侧/对照侧)、扭转强度和扭转强度比率(实验侧/对照侧). 结果术后各组实验兔骨折均愈合良好,无畸形愈合、骨不连发生.动力化组骨折愈合标本最大弯曲强度、最大弯曲强度比率、扭转强度和扭转强度比率均高于坚强固定组和弹性固定组,差异均有统计学意义(P＜0.05).仅动力化组实验侧骨折愈合标本与对照侧完整骨标本的扭转强度比较差异无统计学意义(P＞ 0.05). 结论兔胫骨截骨模型骨折愈合晚期通过减少外固定横杆数目,降低外固定支架刚度,实现骨外固定支架动力化,可促进骨折愈合.
목적 평고골외고정지가동력화대토경골간절골골절유합적생물역학영향. 방법 선취30지신서란대백토,자웅각15지,체질량위2.0～2.5 kg.취기우측경골간절골골절작위실험측,좌측완정경골간작동기대조.장실험토수궤분위3조(n=10):동력화조:술후6주내유지쌍횡간구형견강고정,6주후거제외고정지가내측횡간,개위단횡간구형탄성고정직지골절술후12주;견강고정조:술후항정유지쌍횡간구형,모의견강고정12주;탄성고정조:술후항정유지단횡간구형,모의탄성고정12주.술후관찰각조실험토일반상태,병섭X선편관찰골절유합정황.골절고정12주후처사전부실험토후진행생물역학측시,측량병계산각조량측골표본최대만곡강도、최대만곡강도비솔(실험측/대조측)、뉴전강도화뉴전강도비솔(실험측/대조측). 결과 술후각조실험토골절균유합량호,무기형유합、골불련발생.동력화조골절유합표본최대만곡강도、최대만곡강도비솔、뉴전강도화뉴전강도비솔균고우견강고정조화탄성고정조,차이균유통계학의의(P＜0.05).부동력화조실험측골절유합표본여대조측완정골표본적뉴전강도비교차이무통계학의의(P＞ 0.05). 결론 토경골절골모형골절유합만기통과감소외고정횡간수목,강저외고정지가강도,실현골외고정지가동력화,가촉진골절유합.
Objective To evaluate the biomechanical effect of late dynamization of external fixator on tibial diaphyseal fracture in a rabbit osteotomy model.Methods Tibial diaphyseal fractures were created by osteotomy in the right lower limbs of 15 male and 15 female New Zealand white rabbits weighing 0.2 to 0.5 kilograms.Their left intact lower limbs served as controls.They were randomly divided into 3 equal groups (n =10).In the dynamization group,rigid external fixation with double-bar configuration was maintained for 6 weeks but dynamized for the forthcoming 6 weeks by removing the inner bar at 6 weeks postoperation.In the rigid fixation group,rigid fixation with double-bar configuration was maintained for 12 weeks.In the elastic fixation group,elastic fixation with single-bar configuration was maintained for 12 weeks.After operation,the rabbits were observed and X-ray films were taken to assess fracture healing.At 12 weeks,the rabbits were euthanized for biomechanical tests.The maximum bending strength,maximum bending strength ratio (experimental side/control side),torsional strength,and torsional strength ratio (experimental side /control side) were measured and compared in all groups.Results In all groups,fractures healed well without any malunion or nonunion.The maximum bending strength,torsional strength,maximum bending strength ratio and torsional strength ratio in the dynamization group were all significantly higher than in the rigid and elastic fixation groups (P ＜ 0.05).There was no significant difference in the torsional strength between the experimental side and the control side in the dynamization group (P ＞ 0.05).Conclusion Late dynamization by reducing the double-bar configuration to decrease fixation stiffness may enhance fracture healing in a rabbit tibial osteotomy model.