A new study published in The Spine Journal examines sagittal imbalance among patients with lumbar spinal stenosis and how that affects outcomes after simple decompression surgery.
The researchers examined 83 consecutive patients who underwent decompression surgery and followed up for at least one year. The study authors defined sagittal imbalance as C7-sagittal vertical axis of 40 or greater on a 36-inch lateral whole spine radiograph. The researchers found:
1. There was sagittal imbalance in 54 percent of the patients.
2. Risk factors for sagittal imbalance include:
• Old age
• Large mismatch between pelvic incidence and lumbar lordosis
3. After one year, the normalization rate was 73 percent among patients who had decompression surgery. The median time to normalization was one month to three months.
4. The patients who didn’t experience sagittal vertebral axis normalization had low thoracic kyphosis and spondylolisthesis before surgery.
5. The researchers concluded the imbalance was correctable in 70 percent of the patients with sagittal imbalance.