Posterior Column Osteotomy (PCO), also known as Smith-Petersen Osteotomy (SPO), is a spinal realignment technique used to correct sagittal imbalance, such as kyphosis or flat-back syndrome.

• Location: Thoracolumbar or lumbar spine.
• Approach: Posterior-only.
• Levels: Can be performed at multiple contiguous levels for greater correction.

1. Bilateral complete facetectomy.
2. Partial or complete laminectomy as needed.
3. Resection of the interspinous and supraspinous ligaments.
4. The anterior column remains intact, acting as a hinge (anterior disc and anterior longitudinal ligament - ALL).
5. Correction is achieved by posterior column shortening and anterior lengthening (via spinal extension).

• Approximately 10° of lordosis per level (range: 5–15°).
• Less correction than PSO (Pedicle Subtraction Osteotomy) or VCR (Vertebral Column Resection).
• Often combined at multiple levels for flexible deformities.

• Moderate sagittal imbalance (SVA < 6–8 cm).
• Flexible kyphosis.
• Flat-back syndrome post-laminectomy or fusion.
• Scheuermann’s kyphosis (if flexible).

• Severe fixed kyphosis (>30–40° rigid).
• Ankylosed anterior column (e.g., fused anteriorly).
• Prior anterior cage or fusion at target level.
• Severe osteoporosis (risk of instability or fracture).

• Dural tear or CSF leak.
• Epidural venous bleeding.
• Junctional kyphosis or failure.
• Inadequate correction if used alone in rigid deformities.

• Ideal for flexible deformities or as an adjunct to PSO or VCR.
• Hinge mechanism relies on intact anterior column.
• Safe and effective when the anterior disc and ALL are mobile.
• Avoid PCO as the sole correction method in ankylosed or rigid spines.

In a prospective observational multicenter cohort Hassan et al. from the Och Spine Hospital / Columbia University Irving Medical Center, New York published in the Journal of Neurosurgery Spine to determine procedural, demographic, or radiographic factors tied to improved postoperative LEMS in ASD patients with baseline motor impairment. Lumbar posterior column osteotomies (PCOs) significantly increase odds of improved lower‑extremity motor scores at 6 weeks, compared to decompression alone.

* Study design & strengths

1. Multi‑center North American cohort from 2018–2023 ensures diversity and volume (121 patients).
2. Use of multivariable logistic regression adjusting for ΔL1 pelvic angle and IONM changes adds analytical rigor.

* Weaknesses & limitations

1. Short follow‑up limited to 6 weeks—we don’t know long‑term motor outcomes.
2. No standardized protocol for decompression vs PCO—potential selection bias.
3. 12 patients deteriorated—small subgroup may limit power for secondary comparisons.

* Key concerns

1. Short‑term endpoint: 6 week follow‑up may not capture delayed neurologic recovery or complications.

2. Selection bias: Surgeons may have preferentially selected PCO in more severe cases where improvement was expected—or vice‑versa.

3. IONM changes: Higher intraoperative monitoring events in deteriorated group suggests surgery complexity—not fully adjusted.

*Rating*: 6.5 / 10 Well‑conducted observational multicenter study with sound statistical analysis, but lacks long‑term data and carries potential selection bias.

Use of lumbar PCOs in ASD with preoperative motor weakness appears to significantly enhance early postoperative motor recovery. However, counsel patients about limited follow‑up data, operative complexity, and monitor closely for intraoperative neurophysiologic events.

PCO‑augmented decompression should be seriously considered in ASD patients with baseline motor impairment to improve short‑term motor outcomes—but further studies are needed for long‑term effects.

1. Publication date :: 18 July 2025

Adult spinal deformity Spine surgery Motor deficits posterior column osteotomy, lumbar decompression, adult spinal deformity, motor recovery, intraoperative neurophysiology