通用型脊柱内固定系统稳定性的生物力学评价

目的　评价通用型脊柱内固定系统经椎弓根内固定装置的生物力学稳定性。　方法取 12具正常成人新鲜尸体T12 ～S3 节段脊柱标本 ,制成L2 3 、L4 5滑脱模型 ,测试标本在正常、滑脱、通用型脊柱内固定系统 (generalspinesystem ,GSS)与SOCON固定后、疲劳试验后、GSS与SOCON翻修后、再次疲劳试验后 6种请状况下的三维运动状况 ,比较各个工况数据的差异。　结果　L2 3 节段 ,正常状态前屈运动范围平均值为 8 3° ;制成滑脱标本后 ,运动范围平均值为 14 7° ;SOCON固定后 ,节段运动范围减至 3 0°,比正常状态的运动范围减小 ,差异有显著性意义 (P <0 0 5 ) ,说明SOCON固定后可产生明显的即刻稳定作用。疲劳试验后节段运动范围平均值为 3 6°,与正常状态比较 ,差异有显著性意义 (P <0 0 5 ) ,说明经过疲劳试验SOCON固定仍有良好的稳定作用。L4 5节段 ,正常状态前屈运动范围平均值为 8 6°;制成滑脱标本后 ,运动范围平均值为 13 7° ;GSS固定后 ,节段运动范围减至 3 2°,该节段的稳定性得到加强 ,运动范围比正常状态时还要小 ,差异有显著性意义 (P <0 0 5 ) ,说明GSS固定后可产生明显的即刻稳定作用。疲劳试验后节段运动范围平均值为 3 7°。与正常状态比较 ,差异有显著性意义 (P

Biomechanical evaluation of the stability of General spine system

OBJECTIVE: To evaluate the biomechanical stability of Shen's instrumentation in the management of thoracolumbar fractures. METHODS: The ranges of movement (ROM) in three dimensions of twelve T(12) - S(3) specimen of fresh adult cadavers were measured sequentially in the states of normal, injured, GSS and SOCON fixation, fatigued GSS and SOCON fixation. Data were then compared. RESULTS: For the L(2 - 3) segment, the average normal ROM in flexion was 8.3 degrees. In the established spondylolisthesis models, the ROM was 14.7 degrees. After fixation with SOCON, the ROM was decreased to 3.0 degrees, indicating that SOCON fixation can produce good stability. The ROM after fatigue test was 3.6 degrees, significantly lower than that of the normal state, indicating that SOCON still produces good stability after fatigue. For the L(4 - 5) segment, the average normal ROM in flexion was 8.6 degrees. In the established spondylolisthesis models, the ROM was 13.7 degrees. After GSS fixation, the ROM was decreased to 3.2 degrees, significantly lower than that in the normal state, indicating that GSS fixation can produce good stability. ROM after fatigue test was 3.7 degrees, significantly lower than that of the normal state, indicating that GSS can produce good stability after fatigue. The ROM measurements in the other five directions were similar to those for flexion described above. CONCLUSION: GSS produces good stability for spondylolisthesis, good fatigue resistance, and can be used in pedicle screw revision surgery. There were no significant differences between GSS and SOCON.