【作者】 王宏川；

【导师】 阚世廉；

【作者基本信息】 天津医科大学 ， 外科学， 2010， 博士

【摘要】 第一部分LISS和DCS固定股骨转子下骨折的生物力学比较研究目的：对AO微创固定系统(Less Invasive Stabilization System, LISS)和动力髁螺钉(Dynamic Condylar Screw, DCS)两种内固定器固定股骨转子下骨折的生物力学进行比较。方法：选取股骨近端相似的成年(35～50岁)尸体干股骨标本12根,每个标本在小转子下方1cm处用斜切机截骨,做成2cm间隙,模拟粉碎性股骨转子下骨折模型。将12根股骨标本随机分成为2组,第1组采用倒置LISS固定,第2组采用DCS固定。分别在股骨标本内侧距骨折线近、远侧1 cm各放置一枚电阻应变片,将标本固定在Instron-8874液压伺服力学实验测试机上,连接端子引出的导线与转换箱,连接转换箱与静态电阻应变仪,进行非破坏性应力加载实验,采用电阻应变测量法(电测法)行应力测试。分别观察两组骨折模型的载荷—应变关系、股骨头的载荷—位移关系和股骨头的轴向刚度。之后再进行非破坏性循环加载实验。载荷的峰谷值设定为0～150N,加载频率为1Hz,循环周期为2000次。对实验所得生物力学各指标用Chauvent准则进行精度分析,误差处理,方差不齐者,进行数据转换,用t检验,P<0.05为差异有显著性意义。结果：轴向压缩实验中,载荷—应变关系结果为,LISS内固定组在应变片1和应变片2处的应变,均较DCS组相应的应变值小；载荷—位移关系结果为,在600N时LISS组和DCS组股骨纵向位移分别为2.87±0.84mm,9.12±0.74mm;载荷600N时,LISS固定组的轴向刚度为209.06±18.63 N/mm, DCS固定组为65.79±7.26 N／mm。动态疲劳实验中,在相同循环加载周期的情况下,LISS内固定组股骨头的最大下沉位移是小于DCS组的；LISS内固定组在股骨头最大下沉位移达到0.5mm时所承受的力为130.83±11.67 N,而DCS固定组此时所承受的力为80.76±7.35 N；当股骨头最大下沉位移达到0.5mm时,LISS内固定组已经是循环加载周期的1231±30次,而DCS内固定组只是第379±18个循环加载周期。经统计学分析,以上差异均存在显著统计学意义(P<0.01)。结论：在股骨转子下骨折的两个固定组中,股骨远端LISS倒置内固定比DCS内固定更牢固,且LISS抵抗轴向变形的能力要强于DCS内固定器。第二部分微创固定系统倒置治疗股骨转子下骨折的临床研究目的：探讨微创固定系统(Less Invasive Stabilization System, LISS)倒置治疗股骨转子下骨折的治疗方法和临床疗效。方法：2007年10月-2009年5月,采用倒置LISS治疗31例股骨转子下骨折。本组男23例,女8例；年龄27～83岁,平均48.6岁。致伤原因：交通伤12例,坠落伤6例,压砸伤4例,摔伤9例。骨折按Seinsheimer分型,ⅡC型4例,ⅢA型12例,ⅢB型6例,Ⅳ型6例,V型3例。手术方法：麻醉满意后利用牵引床对股骨转子下骨折进行闭合复位,此后通过大转子外侧切口将对侧的LISS钢板倒置插入,骨折复位满意、钢板位置适宜后,在瞄准臂引导下分别在远、近骨折段钻入4-5枚锁定螺钉。结果：本组手术时间35～80min,平均50min;术中出血60～150ml,平均失血量90ml。31例患者随访平均15.6个月,术后平均18.2周X线片显示明显骨痂形成或骨折线消失。无内固定松动及深部感染。患肢髋关节平均活动度为：屈曲115°,外旋35°,内旋15°,内收15°,外展36°。采用改良Harris髋关节评分法进行评估,最后随访平均92.6(82～100分),优24例,良7例,无疗效不良病例。结论：倒置LISS微创固定股骨转子下骨折效果良好,具有固定可靠、手术创伤小、不需植骨、骨折愈合好、术后并发症少等优点,是一种治疗股骨转子下骨折的有效方法。更多还原

【Abstract】 Part I Biomechanical comparison of LISS and DCS plating subtrochanteric femur fracturesObjective:To compare the biomechanical characteristics of less invasive stabilization system (LISS) and the dynamic condylar screw (DCS) in plating subtrochanteric femur fractures. Method:Twelve cadaveric femurs (35-50 years old) were selected, excluding any lesions. The twelve femur specimens were randomly divided into two groups, one group was fixed by LISS, and the other group was fixed by DCS. To saw off the specimens with a bias cutter 1cm below lesser trochanter, and simulate comminuted fracture models with 2cm gap between both ends. Paste respectively one resistance strain gage at the medial of the specimens and at the point 1cm beside the fracture line. The specimens were fixed at Instron-8874 servo-hydraulic mechanical testing machine. Stress loading experiments was carried out. It was observed that the Load-Strain relationship、Load-Displacement relationship of the femoral head and the axial stiffness of the femoral head in the two fracture models. Non-destructive cyclic loading experiment was then carried out. Set the peak valley value of load 0-150N, loading frequency 1Hz, period of batching cycle 2000 times. Did accuracy analysis and error processing to all the biomechanics indexs getted from the experiment by Chauvent Criterion, P<0.05 showed statistically significant differences. Results:In the experiment of Axial compression, on Load-Strain relationship conclusions, the strain of LISS internal fixation group in strain gauge 1 and strain gauge 2 was all smaller than the DCS group; The results of Load-Displacement relationship was that, femur vertical displacement of LISS group and DCS group were 2.87±0.84mm and 9.12±0.74mm in 600N respectively; when the load was 600N, the axial stiffness of LISS internal fixation group was 209.06±18.63 N/mm, while the DCS group was 65.79±7.26 N/mm. In the experiment of dynamic fatigue, under the same situation of cyclic loading cycle, the subsidence displacement of femoral head in LISS internal fixation group was smaller than DCS group; The force LISS fixation group to bear was 130.83±11.67 N when max subsidence displacement of the femoral head was 0.5mm, while the DCS group was 80.76±7.35N under the same situation; When the subsidence displacement was 0.5mm, LISS internal fixation group had been 1231±30 times of the cyclic loading cycle already, while the DCS group was the 379±18 times. According to the statistical analysis, all the differences were statistical significance (P<0.01). Conclusions:In the two fixation groups of subtrochanteric fracture, reverse LISS internal fixation group was much firmer than DCS group, and the ability of LISS against to the axial deformation was better than DCS internal fixation device.Part II Reverse LISS plating subtrochanteric femur fracturesObjective:To explore the technique and results of reverse LISS plating for subtrochanteric femur fractures. Methods:From October 2007 to May 2009,31 cases of fresh subtrochanteric femur fractures were treated with reverse LISS. There were 23 males and 8 females, with an average age of 48.6 years (range 27 to 83 years). Twelve injuries were the result of a traffic accident; six, a fall from a greater height; four, a crush of heavy object; nine, a fall from a standing height. According to Seinsheimer classification, four fractures were type IIC, twelve type IIIA, six IIIB, six type IV and three type V. Subtrochanteric fracture was reduced indirectly with patient on a fracture table. The reverse LISS plate was inserted through a lateral incision of the greater trochanter between the lateral vastus muscle and the periosteum. Four to five screws were inserted through stab incisions into the proximal and distal fragments, respectively. Results:Operative time average 50 (range,35～80) minutes and estimated blood loss averaged 90 (range,60～150) ml.31 patients were available for evaluation with an average follow-up of 15.6 months. All fractures healed at a mean of 18.2 weeks (range 13 to 32 weeks). There were no cases of failed fixation, or deep infection. Average range of motion of the hip joint was recorded as follows: flexion 115°,external rotation 35°, internal rotation 15°, adduction 15°, and abduction 36°. According to the modified Harris hip score, scores ranged from 82 to 100 (average,92.6), and there were 24 excellent and 7 good. Conclusions:Reverse LISS plating yield good results in subtrochanteric femur fractures, with stable fixation and minimal invasive procedure.更多还原