Defining threshold for sagittal correction in lumbar fractures

Area of Science:

• Spine surgery
• Radiology
• Biomechanical analysis

Background:

• Surgical decisions for thoraco-lumbar fractures depend on neurological status, instability, and kyphotic deformity.
• A kyphotic angulation exceeding 20° often indicates surgery to mitigate disability.
• Current literature lacks established theoretical lumbar lordosis values based on individual anatomy.

Purpose of the Study:

• To determine the mean segmental lumbar lordosis values in relation to pelvic incidence (PI) in a healthy adult population.
• To establish a normative dataset for segmental lordosis across different PI ranges.

Main Methods:

• Retrospective analysis of CT scans from 171 healthy adults.
• Measurement of pelvic incidence (PI) and segmental lordosis (L4-S1, L3-L5, L2-L4, L1-L3, T12-L2, T11-L1).
• Sub-group analysis of segmental lordosis based on PI ranges (<45°, 45°-60°, >60°).

Main Results:

• The mean PI for the cohort was 54.9°. Mean segmental lordosis values were L4-S1: -38.1°, L3-L5: -30.6°, L2-L4: -14.1°, L1-L3: -4.9°, T12-L2: +1.9°, T11-L1: +5.4°.
• Segmental lordosis varied significantly with PI ranges, e.g., L3-L5 lordosis was -26.8° (PI <45°), -30° (45°-60° PI), and -35.1° (PI >60°).

Conclusions:

• The study provides a reference chart of theoretical segmental lordosis values correlated with PI.
• This data can assist spinal surgeons in quantifying necessary sagittal correction for lumbar fractures.
• Tailoring surgical correction to individual PI and sagittal morphology is crucial for optimal patient outcomes.