抄録
A comparison of pressure change in adjacent lumber intradisc after medial facetectomy, Graf ligamentoplasty (Graf), and pedicle screw fixation (PS) is made to clarify the mobile influence of the spinal instrumentation on the adjacent segment. The fresh porcine lumbar spines (L3-L6) with destabilized segment (L4-L5) were used to estimate the difference on the intradiscal pressure in each instrument. It is found from the intact segments that the intradiscal pressure increased with flexion and decreased with extension. The highest pressure for each case is measured under maximal flexion. For the stabilized segment with Graf system, the pressure in L4/5 intradisc is significantly higher under neutral position while the pressure increases during flexion. After Graf and PS, it is found that the pressure in L3/4 intradisc increased. The results may show that the influence of Graf on the adjacent segment seems to be more significant than that of PS.
