Resident Duke University Durham, North Carolina, United States
Introduction: Anterior column realignment (ACR) via lateral lumbar interbody fusion is a novel minimally invasive (MIS) technique to restore sagittal alignment in patients with adult spinal deformity (ASD). As two-thirds of physiologic lordosis is found between L4 and S1, the ideal shape of the fused spine remains unclear.
Methods: A retrospective case series was performed of consecutive patients (n = 13) who underwent surgical treatment for ASD at a single tertiary referral center. All patients underwent MIS lateral interbody fusion technique with ACR above the level of L4, placement of either 20 or 30-degree hyper-lordotic cage, and reconstruction with posterior instrumented fusion. Pre- and post-operative radiographic and functional outcomes were reviewed by two independent reviewers. Demographic and surgical complications were recorded, as were visual analogue scale scores for back pain pre- and postoperatively.
Results: Patients were 49-82 years of age with an average BMI of 30.3. Mean SVA decreased from 12.5 cm to 6.8 cm (p < 0.001), PI-LL decreased from 31.4° to 10.6° (p < 0.001), and segmental lordosis (SL) increased from 2.2° to 23.2° (p < 0.001). Proximal lumbar lordosis (PLL) increased from 2.5° to 21.8° (p < 0.001), and distal lumbar lordosis (DLL) did not significantly change (p=0.65). Mean lordosis distribution index (LDI) decreased from 51% to 38.0% (p=0.18). Average visual analog back pain score (VAS) decreased from 7.5 to 2.6 (p=0.002). Major complication rate was 7.7%. Mean follow-up was 10.0 months.
Conclusion : Our results indicate that proximal lumbar ACR in ASD patients can achieve significant correction of sagittal spinopelvic malignment with low major complication rates. Differentially increasing PLL and lowering LDI does not have any obvious negative effects on clinical outcomes around 1-year.
How to Improve Patient Care: Our data suggests that proximal segment lumbar ACR can be utilized as a efficacious method for improving spinopelvic mismatch in deformity patients.
