Are We Getting Better at Achieving Optimal Lumbar Segmental Sagittal Alignment in Complex Adult Spine Deformity...

Area of Science:

• Spine surgery and biomechanics.
• Orthopedic research and deformity correction.

Background:

• Adult Spinal Deformity (ASD) management has advanced significantly.
• The impact of these advances on surgical correction of lumbar segmental alignment is not well understood.

Purpose of the Study:

• To investigate the influence of surgical advancements on lumbar segmental alignment in ASD patients.
• To compare alignment outcomes between early and late surgical cohorts.

Main Methods:

• Retrospective multi-center study comparing early (2008-2017) and late (2018-present) ASD surgical cohorts.
• Patients stratified by pelvic incidence (PI) and Roussouly type.
• Segmental and regional alignment analyzed against normative values using statistical comparisons.

Main Results:

• The late cohort showed improved L5-S1 alignment (P=0.001), while the early cohort had better L4-5 alignment (P=0.001).
• Improved alignment correlated with better Oswestry Disability Index (ODI) scores and fewer mechanical complications.
• Both groups had suboptimal L4-S1 and L1-S1 alignment, with the late cohort showing a higher proportion of 'Aligned' patients based on lordosis distribution (15.9% vs. 11%, P<0.001).

Conclusions:

• Surgical techniques have improved lumbar segmental sagittal alignment restoration in ASD patients over the last 15 years.
• Ideal alignment correction is not consistent across all lumbar segments, highlighting opportunities for further surgical optimization.