Table 1 Comparison of the classical and evaluated techniques
From: Evidence-based support for S1 transpedicular screw entry point modification
Classical technique | Evaluated technique | |
|---|---|---|
Preparation | No particular preparation technique | Preparing osteotomy |
Entry point landmarks | Not precisely defined | Clearly defined |
Individual interpretation at the entry point definition | Possible | Less likely |
Technical difficulty | More lateral exposure of the sacrum and soft tissue traction | Less extensive lateral exposure demanded and soft tissue traction |
Screw trajectory definition in the operating field | Information cannot be drawn from local anatomy | After osteotomy, S1 facet orientation is close to optimal screw trajectory |
Ultimate screw trajectory | Optimal | Possible to be less convergent |
Cortical bone thickness in normal, osteopenic and osteoporotic bone | Decreasing lateralward | Higher compared to lateral position |
BMD values in normal, osteopenic and osteoporotic bone | Decreasing lateralward | Higher compared to lateral position |
Implantation in degenerated spine | No particular advantage | Potential increase of the cortical thickness due to the proximity of the degenerated facet and spurs formation |