Defining a Critical Partition Zone for Sagittal Alignment in Lumbar Spine Fusion Surgery: A Systematic Review

Area of Science:

• Orthopedics
• Spinal Surgery
• Biomechanical Engineering

Background:

• Lumbar spine sagittal alignment is crucial for stability and surgical planning.
• Standardized lumbar partitioning and critical sagittal zones are not well-defined.
• This study aimed to establish a reliable lumbar partition for surgical guidance.

Purpose of the Study:

• To identify a critical sagittal alignment zone within the lumbar spine.
• To provide a stable reference for surgical planning in spinal deformity correction.
• To optimize clinical outcomes through improved lumbar partitioning.

Main Methods:

• Systematic review of 32 studies across four biomedical databases.
• Analysis of segmental lordosis data in asymptomatic adults stratified by pelvic incidence.
• Conversion of lumbar lordosis values to percentages for cross-study comparison and bias assessment.

Main Results:

• The L3-L5 interval, particularly around the L4 vertebra, was identified as a critical biomechanical zone.
• Lordosis distribution varied with pelvic incidence: higher incidence concentrated lordosis in lower segments, lower incidence in upper segments.
• The L3-L5 region demonstrated stability across diverse populations and pelvic incidence groups.

Conclusions:

• The L3-L5 interval is a key partition zone for lumbar sagittal alignment.
• This zone provides a stable reference for lumbar spine fusion procedures.
• Findings may enhance alignment outcomes and reduce postoperative complications.