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The two Distinct Functional Lordoses of the Lumbar Spine
David Gadoin1, Claudio Vergari2, Ayman Assi3
1Orthopedic surgery department, Spine unit, Georges-Pompidou European Hospital, AP-HP, Paris, France.
Spine
|July 10, 2026
Summary
Lumbar lordosis (LL) has distinct proximal and distal arcs influencing spinal alignment. The distal arc is pelvic-driven and becomes more dominant as pelvic incidence (PI) increases, impacting surgical planning.
Area of Science:
- Spine biomechanics
- Radiographic analysis
- Sagittal spinal alignment
Background:
- Lumbar lordosis (LL) is crucial for spinal alignment but its assessment is debated.
- Recent research indicates LL is composed of proximal and distal arcs with distinct biomechanical roles.
Purpose of the Study:
- Analyze the relationship between lumbar lordosis (LL) proximal and distal arcs with spinopelvic parameters.
- Determine how lordosis distribution varies with pelvic incidence (PI).
Main Methods:
- Retrospective radiographic study of 642 healthy volunteers.
- Full-body stereoradiographs used to assess maximum LL (LLmax), LL proximal (LLprox), and LL distal (LLdist).
- Correlation analysis with spinopelvic parameters, stratified by PI.
Main Results:
- LLdist strongly correlated with pelvic parameters (sacral slope, PI).
- LLprox correlated with both pelvic and thoracic parameters.
- Increasing PI led to a greater contribution of LLdist to LLmax and an increased number of vertebrae in the distal arc.
Conclusions:
- Lumbar lordosis (LL) consists of a pelvic-driven distal arc and a proximal arc influenced by overlying alignment.
- The distal arc becomes predominant as pelvic incidence (PI) increases.
- A segmental approach is recommended for clinical assessment and surgical planning, considering both arcs independently.
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