From the Research
The stable vertebra in spinal deformity surgery refers to the lowest vertebra that is most closely aligned with the central sacral vertical line (CSVL) and is substantially involved in the main curve of the spine, as identified by standing radiographs and other imaging modalities 1.
Key Characteristics of the Stable Vertebra
- Minimal rotation
- Relatively neutral in position
- Serves as the distal foundation for spinal fusion
- Minimal tilt
- Well-seated within the pelvis
- Provides adequate support for the corrected spine above it
Importance of the Stable Vertebra
- Crucial for determining the lower instrumentation level during fusion procedures
- Extending fusion to this level helps prevent decompensation and ensures balanced correction of the spinal deformity
- Proper identification is essential for achieving optimal surgical outcomes, as fusing too short may lead to progression of the curve below the instrumentation, while fusing too long unnecessarily restricts spinal mobility
Considerations for Selection
- Surgeons should consider the relationship of the vertebra to the CSVL and overall spinal alignment when selecting the stable vertebra
- The use of standing radiographs and other imaging modalities can help identify the stable vertebra
- Recent studies have highlighted the importance of proper spinopelvic alignment in achieving good clinical outcomes in adult spinal deformity patients 1, and the stable vertebra plays a critical role in achieving this alignment.
- A more recent study from 2022 2 analyzed key biomechanical properties of different fixation techniques, which may influence the selection of the stable vertebra, however the study from 2010 1 remains the most relevant to the definition and identification of the stable vertebra.