前路减压植骨融合术后颈椎相邻节段生物力学变化

Biomechanical changes of the adjacent segments after anterior cervical decompression and fusion

目的观察颈椎前路减压植骨融合术后相邻节段生物力学变化。方法采用EB复合树脂黏合的方法模拟颈椎前路减压植骨术后融合的效果，检测颈椎融合前、后相邻节段运动范同及生物力学的变化。结果在2．0Nm力矩不变的情况下，融合节段相邻间隙的运动范围为4．3°～8．0°，与融合前比较差异无统计学意义（P〉0．05）；加大力矩使融合后的颈椎尽量达到术前正常运动范围时融合节段相邻间隙运动范围明显增加，与融合前比较差异有统计学意义（P〈0．05）。结论颈椎融合术后如果仍要达到术前正常的运动范围，其相邻节段的运动范围明显增加，这可能是造成其退变的主要原因。限制颈部术后活动可以减少、甚至避免术后退变的发生。

Objective To study the biomechanical changes of the adjacent segments after anterior cervical decompression and fusion （ACDF）. Methods EB composite resin was used to mimic the fuion effect after anterior cervical decompression. The motion range and biomechanical changes of the adjacent segments were measured. Results Under the same torque of 2. 0 Nm, the motion range of the adjacent segments was from 4. 3 to 8.0 degrees, which was not significantly different from that before fusion （ P 〉 O. 05 ）. Increasing the torque gradually to let the samples reach their normal range of motion, the range of motion of the adjacent segments increased significantly. There are significant differences of them after and before fusion （P 〈 0. 05）. Conclusion If people keep the normal range of motion of cervical spine after ACDF,their adjacent segment＇ s movement will increase significantly. This might be the main cause of the degeneration after fusion. By limiting the neck movement can reduce,or even avoid postoperative degenera- tion.