IMN与MIPPO治疗胫骨中下段骨折的生物力学性能及对骨折愈合的影响

目的比较交锁髓内钉(intramedullary nail,IMN)与微创经皮钢板内固定(minimally invasive percutaneous plate osteosynthesis,MIPPO)的生物力学性能以及在胫骨中下段骨折治疗中对骨折愈合的影响。方法 2013年1月—2015年12月郑州市第一人民医院骨二科收治的胫骨中下段骨折患者76例,按治疗方法不同分为IMN组(38例)和MIPPO组(38例),采用Mazur评分评价两组术后踝关节功能,统计两组术后下地时间、骨折愈合时间和愈合率。2014年2月选取郑州大学医学院解剖教研室提供的新鲜成人踝关节标本10具,建立胫骨中下段骨折模型,按随机数字法分为观察组和对照组,每组5例。分别采用IMN和MIPPO两种方法固定,进行三点弯曲实验、轴向压缩实验以及扭转强度实验,分析相关数据。结果两组均未发生内固定松动、断裂等内固定失败状况,IMN组患者出现骨折延迟愈合3例,骨折不愈合2例,愈合时间平均(13.6±2.1)周;MIPPO组患者骨折均愈合,愈合时间平均(11.3±1.7)周。术后1年两组患者踝关节功能比较差异无统计学意义(P0.05);MIPPO组弯曲偏移量、轴向压缩偏移量和扭转角度均大于IMN组,组间差异均有统计学意义(P0.05)。结论 MIPPO与IMN治疗胫骨中下段骨折各有利弊,MIPPO可减轻手术创伤,但力学性能不如IMN,临床使用时应严格掌握适应证。

Biomechanical properties of MIPPO and IMN in the treatment of distal tibial fractures and their effects on fracture healing

Objective To compare the biomechanical properties of interlocking intramedullary nail ( IMN) and minimally invasive percutaneous plate osteosynthesis ( MIPPO) and its effect on fracture healing in the treatment of distal tibial fractures .Methods Totally 76 patients with middle and distal tibial fractures , who were admitted to Zhengzhou First People's Hospital from Jan.2013 to Dec.2015,were divided into IMN group(38 cases) and MIPPO group(38 cases) randomly.Mazur score was used to evaluate the ankle function of the two groups .The postopera-tive time,healing time and healing rate of the two groups were statistically analyzed .Ten specimens were randomly selected to establish a distal tibial fracture model and were divided into observation group and control group .Two methods were used to fix the fracture .Three-point bending test , axial compression test and torsional strength test were performed to analyze the data .Results There was no internal fixation failure in either groups .In the IMN group,there were 3 cases of delayed union of fracture and 2 cases of nonunion of the fracture .The healing time was (13.6 ±2.1) weeks.In the MIPPO group,all patients achieved bone healing ,and the healing time was (11.3 ± 1.7) weeks.There was no significant difference in ankle joint function between the two groups (P>0.05).The bending deflection ,axial compression deviation and torsion angle in the MIPPO group were greater than those of the IMN group,and there was significant difference between the two groups (P<0.05).Conclusion MIPPO and IMN have advantages and disadvantages in the treatment of distal tibial fractures .MIPPO can reduce surgical trauma , but its mechanical properties are inferior to those of IMN .The clinical application should be strictly controlled .