Anterior Lumbar Interbody Fusion as a Supplement to Posterior Instrumentation in Adult Spinal Deformity Patients: A Pilot Randomized Study With a Median of Eight Years of Follow-Up

Aim We aim to assess the long-term revision rates in patients with adult spinal deformity (ASD) undergoing posterior instrumentation with or without supplemental anterior lumbar interbody fusion (ALIF) with a median of eight years of follow-up. Materials and methods Based on a previous pilot randomized controlled trial (RCT) from 2012, all previous participants were invited to a clinical and radiographic follow-up. Full medical records from the total cohort were reviewed from the time of operation to the follow-up, and information on revision surgery due to mechanical failure was obtained and compared between the groups. Results Of the original 17 patients included in the RCT, 15 were available for follow-up and 10 attended the clinical and radiographic examination. A retrospective review was performed of the entire original cohort. The median age at follow-up was 67 (61-71) years, and the median follow-up time was 7.7 (5.1-8.8) years. Revision rates among ALIF patients were three out of seven (43%) and eight out of 10 (80%) among non-ALIF patients with pseudoarthrosis and rod breakage being the main cause. Time to failure was longer in ALIF patients with a median of 47 (28-53) months compared with non-ALIF patients with a median of 26 (9-31) months. Conclusion This study revealed a lower rate of revision surgery and a longer time to failure in patients undergoing ASD surgery with supplemental ALIF compared with posterior instrumentation alone. Further studies with a larger sample size are needed to make conclusions on the effect of a supplemental ALIF to posterior instrumentation on lowering the risk of mechanical failure in patients with adult spinal deformity.