一种新型人工颈椎间盘置换的生物力学研究

Biomechanical evaluation of one new artificial cervical disc prosthesis

目的研究新型人工颈椎间盘(Pretic-I)置换和颈椎前路椎间固定对颈椎活动范围(Range of motion,ROM)及邻近节段椎间盘髓核内压力(Intradiscal Pressures,IDPs)的影响。方法新鲜尸体颈椎标本6具,先后依次作为完整组(A组)、C_(5/6)人工椎间盘置换组(B组)和C5/6前路椎间固定组(C组)进行生物力学测试。给予75N跟随载荷,前屈/后伸、左/右侧弯及左/右轴向旋转均施加2.0Nm的纯力矩载荷,在0.2Nm/S的变化条件下测量手术节段及邻近节段ROM,以及邻近节段IDPs。结果 B组与A组在手术节段及邻近节段的ROM相比均无显著性差异(>0.05)。在C_(5/6)节段,C组的ROM明显小于A组和B组(<0.05)。在C_(4/5)、C_(6/7)节段,C组的ROM则明显大于其他两组(<0.05)。B组和A组的C_(4/5)及C_(6/7)节段IDPs相比均无显著性差异(>0.05),而C组的C_(4/5)和C_(6/7)节段IDPs均较其他两组显著增加(<0.05)。结论 Pretic-I人工颈椎间盘置换术较好的维持了手术节段及邻近节段的活动范围,并保持了邻近节段椎间盘髓核内压力。

Objective To study the effect of the new artificial cervical disc（Pretic-I） and anterior cervical plate systemon the cervical range of motion（ROM） and the intradiscal pressures（IDPs） of adjacent segments. Methods Six fresh cadaveric cervical specimens were made biomechanical test as intact group（A group）, C_（5/6）artificial disc replacement group（B group） and C_（5/6）anterior cervical decompression and fixation group（C group） sequentially. The ROM of surgical and adjacent segmentsand the IDPs of adjacent segments were measured under the condition of 75 N follower load and pure moments of 2.0 Nm for flexion/extension, left/right bending and left/right axial rotation with changes in 0.2Nm/S.Results The ROM of surgical and adjacent segments had no significant differences between B group and A group（ P〈0.05）.The ROM of C group was significantly less than A group and B group at C_（5/6）segment（ P〈0.05）, while significantly greater than the other two groups at C_（4/5）and C_（6/7）segments（ P〈0.05）. The IDPs of C_（4/5）and C_（6/7）segments showed no significant differences between B group and A group（ P〈0.05）; nevertheless, the IDPs of C group was significantly greater than the other two groups at C_（4/5）and C_（6/7）segments（ P〈0.05）. Conclusion The Pretic-I artificial cervical disc replacement can maintain the ROM of the surgical and adjacent segments well, and it alsocan keep the IDPs of adjacent segments.