股骨远端骨折内外侧锁定加压钢板的生物力学比较

发布时间：2018-06-29 11:39

本文选题：股骨远端骨折 + 内侧锁定加压钢板　；参考：《河北医科大学》2017年硕士论文

【摘要】：目的:股骨远端外侧锁定加压钢板成为大多数骨科医生治疗股骨远端骨折的首要选择,但是对于股骨远端粉碎性的内侧髁骨折,应用外侧钢板时,由于缺乏对内侧骨折线的固定而失去稳定性,会导致一系列的并发症,使得畸形愈合、骨折不愈合、功能障碍、旋转不良和植入失败的发生率仍很高。为此我们设计了一种股骨远端内侧锁定加压钢板,以弥补股骨远端粉碎性的内侧髁骨折失固定的不足,现我们通过垂直压缩试验、扭转试验及循环负载试验来比较股骨远端内侧锁定加压钢板与股骨远端外侧锁定加压钢板的生物力学特性,为临床治疗股骨远端骨折提供新方法。方法:选取24对成人新鲜尸股骨,造成股骨远端髁上骨折(AO分型为33-A3),每对标本随机分成内侧钢板固定组和外侧钢板固定组,内侧钢板固定组标为实验组,外侧钢板固定组标为固定组。分别做垂直压缩、扭转、循环负载三种生物力学实验研究,每件标本只能做三种生物力学中的一种。垂直加压试验中预先予以100N负载固定标本,使用材料试验机系统的红外线设备标定标记点,以50N/秒的速度加压直至800N,使用红外线设备记录干骺端截骨间隙量;然后给予持续加压,直至内固定失败或骨折;扭转试验中,预先予以1Nm的扭转力,设置最大扭矩20Nm,最大扭角6°,扭转速度10°/min,传感器上记录每个扭转角度所对应的扭矩;然后给予持续扭转,直至内固定失败或骨折;循环负载试验中,预先予以100N负载固定标本,设置频率为0.1Hz,然后给予从100N-300N的循环负载,循环10次,间隔10秒,再给予从100N-400N的循环负载,循环10次,间隔10秒。设置增量为100N,直至给予从100N-800N的循环负载,循环10次。记录每10次循环后的截骨间隙改变量及整个循环负载试验结束后最终的截骨间隙改变量。结果:在垂直加压试验中,内侧钢板的平均垂直刚度与外侧钢板的平均垂直刚度无明显差异(819.5 vs 821.4 N/mm;P=0.544);在扭转试验中,内侧钢板的平均扭转刚度比外侧钢板的平均扭转刚度小(1.97 vs 2.29Nm/degree;P0.05);内侧钢板与外侧钢板的屈服点在压力-位移曲线及扭矩-角度曲线上均未出现。在循环负载试验中,内侧钢板组的最终不可逆形变小于外侧钢板组的最终不可逆形变(0.035 vs 0.072 mm;P0.05)。结论:股骨远端内侧锁定加压钢板的稳定性强于股骨远端外侧锁定加压钢板,其弹性回缩力强于外侧钢板,这有利于内固定患者术后早期及长期功能锻炼,对于治疗股骨远端骨折,尤其是股骨远端内侧髁的骨折具有明显的临床应用价值。
[Abstract]:Objective: Lateral locking compression plate of distal femur is the first choice for most orthopedic doctors to treat distal femoral fracture, but for comminuted medial condylar fracture of distal femur, lateral plate is used. The loss of stability due to the lack of fixation of the medial fracture line can lead to a series of complications, resulting in a high incidence of malunion, nonunion, dysfunction, poor rotation and implant failure. So we designed a kind of medial locking compression plate of the distal femur to make up for the missing fixation of the comminuted medial condylar fracture of the distal femur. Now we have passed the vertical compression test. Torsion test and cyclic load test were used to compare the biomechanical characteristics of medial locking compression plate and lateral locking compression plate of distal femur, which provided a new method for clinical treatment of distal femoral fracture. Methods: 24 pairs of adult fresh cadaveric femur were selected to cause supracondylar fracture of distal femur (AO classified as 33-A3). Each pair of specimens was randomly divided into medial plate fixation group and lateral plate fixation group, and the medial plate fixation group was labeled as experimental group. The lateral plate fixation group was marked as fixation group. Vertical compression, torsion and cyclic loading were carried out in three biomechanics experiments. Each specimen can only do one of the three biomechanics. In the vertical compression test, the fixed specimen was preloaded with 100N. The mark points were labeled with infrared equipment of the material testing machine system, and the pressure was up to 800N at the speed of 50 Ns / s. The interspace of metaphyseal osteotomy was recorded by infrared equipment. In the torsion test, the torsion force of 1Nm was given in advance, the maximum torque was 20Nm, the maximum torsion angle was 6 掳, the torsion velocity was 10 掳/ min, and the torque corresponding to each torsion angle was recorded on the sensor. They were then given continuous torsion until the internal fixation failed or fracture; in the cyclic load test, 100 N loading was prefixed at a frequency of 0.1 Hz, and then given a cyclic load from 100N-300N for 10 cycles, at intervals of 10 seconds, Again give a loop load from 100N-400 N, loop 10 times, at intervals of 10 seconds. Set the increment to 100 N until the loop load from 100N-800N is given 10 times. The change of osteotomy space after 10 cycles and the final change of osteotomy space after the whole cycle load test were recorded. Results: in the vertical compression test, the mean vertical stiffness of the medial plate was not significantly different from that of the outer plate (819.5 vs 821.4 N / mm P0.544), while in the torsion test, the mean vertical stiffness of the inner plate was not significantly different from that of the outer plate (P 0.544). The mean torsional stiffness of the inner plate was smaller than that of the outer plate (1.97 vs 2.29 Nm / degree of degree P 0.05), and the yield points of the inner plate and the outer plate were not found on the pressure-displacement curve and the torque-angle curve. In the cyclic loading test, the final irreversible deformation in the medial plate group was less than that in the lateral plate group (0.035 vs 0.072 mm / kg, P0.05). Conclusion: the stability of medial locking compression plate of distal femur is stronger than that of lateral locking compression plate of distal femur, and its elastic retractive force is stronger than that of lateral plate, which is beneficial to the early and long term functional exercise after internal fixation. It has obvious clinical application value in the treatment of distal femoral fracture, especially the fracture of medial condyle of distal femur.
【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R687.3

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