关键词: 颈椎, 前路, 植骨块高度, 临近节段

Abstract:

Objective　To discuss impact of graft height on zygapophyseal joint pressure and range of motion of adjacent segments following the cervical anterior fusion and to guide the choice of optimal graft height in clinic.　Methods　Eight fresh-frozen human cadaveric cervical spines were used in this series, specimens were tested in five conditions, normal(specimens with intact discs)and different graft height(120％,140％,160％of mean height) after Smith-Robinson discectomy between the fifth and sixth cervical vertebrae.Each specimens were subjected to flexion-extension. Lateral bending and axial rotation in material test system(BOSE ELECTROFORCE) were adopted to measure zygapophyseal joint pressure and rotation of the fourth to fifth segments and the sixth to seventh segments. Finally, The data for each state was used to determine the statistical significance of differences.　Results　The height of bone graft had little effect on the zygapophysial joints pressure values in neutral position with no statistical significance noted among each groups(P>0.05); The zygapophysial joints pressure value was the highest increase in extension position,but 120%M increased minimum of zygapophysial joints pressure value, and statistical significance were noted among each groups（P<0.05); the zygapophysial joints pressure value increased in various degrees under flexion and rotation positions, and statistical significance were noted among each groups（P<0.05）; but 120%M  increased minimum of zygapophysial joints pressure value.The range of motion at the upper and lower adjacent segments were not significantly changed between 120%M and complete condition (P>0.05), and statistical significance were noted in others groups（P<0.05）;The range of motion at the upper and lower adjacent segment  were not significantly changed among each groups (P>0.05).　Conclusion　The appropriate graft height after single discectomy may be 120％mean height.

Key words: Cervical, Anterior, Graft height, Adjacent segments