Comparison of Segmental Lordosis and Global Spinopelvic Alignment after Single-Level Lateral Lumbar Interbody Fusion or Transforaminal Lateral Interbody Fusion

Presented at SMISS Annual Forum 2018
By Y. Saadeh
With Steven DeLuca DO, MS,

Disclosures: Y. Saadeh None Steven DeLuca DO, MS B; Premia Spine, Spine Wave.,

Introduction:

Lateral lumbar interbody fusion (LLIF) has experienced a steady increase in popularity since its introduction. LLIF has been thought to allow for greater improvement in lordosis than TLIF. However, there is very limited direct comparison data on the degree of regional and global alignment change after single-level LLIF and TLIF procedures.

Aims/Objectives:

Our objective was to assess for any significant differences to changes in regional and global alignment when comparing lateral and posterior minimally invasive approaches for single level interbody fusion of the lumbar spine.

Methods:

A retrospective analysis of patients who underwent LLIF or TLIF for lumbar degenerative disease at a single institution was performed. Twenty patients who underwent single level LLIF were matched to 20 patients who underwent single level TLIF by gender and level of interbody fusion. All included patients had preoperative and postoperative standing scoliosis x-rays. Changes in segmental lordosis (SL) at the fused level, lumbar lordosis (LL), sagittal vertical axis (SVA), and pelvic incidence-lumbar lordosis mismatch (PI-LL) were measured. Statistical analysis was performed using unpaired t-tests. Means were reported with standard error.

Results:

Within each group, 2 patients had cages placed at L2-3, 4 patients had cages placed at L3-4, and 14 patients had cages placed at L4-5. The LLIF group demonstrated a statistically significantly increased change in degrees of segmental lordosis compared to the TLIF group (+4.9° ± 0.7 vs +2.6° ± 0.4, P=0.004). There were no statistically significant changes in global spinopelvic parameters in the LLIF vs the TLIF group, LL (+2.15° ± 0.8 vs +2.6° ± 0.6, P=0.06), ∆PI-LL (-1.05° ± 1.0 vs -2.15° ± 0.7, P=0.38), and change in SVA (-2.2 cm ± 0.8 vs -1.51 cm ± 0.5, P=0.48), respectively.

Conclusions:

LLIF achieved greater improvements in segmental lordosis than TLIF. However, regionally and globally, there were no significant differences with either procedure after a single level intervention. The increased lordosis from LLIF compared to TLIF may be more impactful globally in multi-level fusions.