Changes in Sagittal Alignment Following Short-Level Lumbar Interbody Fusion: Comparison between Posterior and Lateral Lumbar Interbody Fusions

Hiroaki Nakashima; Tokumi Kanemura; Kotaro Satake; Yoshimoto Ishikawa; Jun Ouchida; Naoki Segi; Hidetoshi Yamaguchi; Shiro Imagama

doi:10.31616/asj.2019.0011

Changes in Sagittal Alignment Following Short-Level Lumbar Interbody Fusion: Comparison between Posterior and Lateral Lumbar Interbody Fusions

Asian Spine J. 2019 Dec 31;13(6):904-912. doi: 10.31616/asj.2019.0011. Epub 2019 Jul 9.

Authors

Hiroaki Nakashima¹, Tokumi Kanemura¹, Kotaro Satake¹, Yoshimoto Ishikawa¹, Jun Ouchida¹, Naoki Segi², Hidetoshi Yamaguchi², Shiro Imagama²

Affiliations

¹ Department of Orthopedic Surgery, Konan Kosei Hospital, Konan, Japan.
² Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.

Abstract

Study design: Retrospective case-control study.

Purpose: We aimed to compare radiologic outcomes between posterior (PLIF) and lateral lumbar interbody fusion (LLIF) in short-level spinal fusion surgeries.

Overview of literature: Although LLIF enables surgeons to insert large lordotic cages, it is unknown whether LLIF more effectively corrects local and global sagittal alignments compared with PLIF in short-level spinal fusion surgeries.

Methods: Radiographic data acquired from patients with lumbar interbody fusion (≤3 levels) using PLIF or LLIF for degenerative lumbar diseases were analyzed. The following radiographic parameters were evaluated preoperatively and at 2 years postoperatively: segmental lordotic angle, disk height, lumbar lordosis (LL), pelvic tilt (PT), C7 sagittal vertical axis, and thoracic kyphosis (TK).

Results: In total, 144 patients with PLIF (193 fused levels) and 101 with LLIF (159 fused levels) were included. Patients' backgrounds and preoperative radiographic parameters for any level of fusion did not differ significantly between PLIF and LLIF procedures. The LLIF group exhibited significantly greater changes at 1-level fusion compared to the PLIF group in the parameters of segmental lordotic angle (5.1°±5.8° vs. 2.1°±5.0°, p<0.001), disk height (4.2±2.3 mm vs. 2.2±2.0 mm, p<0.001), LL (7.8°±7.6° vs. 3.9°±8.6°, p=0.004), and PI-LL (-6.9°±6.8° vs. -3.6°±10.1°, p=0.03). While, a similar trend was observed regarding 2-level fusion, significantly greater changes were only observed in LL (12.1°±11.1° vs. 4.2°±9.1°, p=0.047) and PI-LL (-11.2°±11.3° vs. -3.0°±9.3°, p=0.043), PT (-6.4°±4.9° vs. -2.5°±5.3°, p=0.049) and TK (7.8°±11.8° vs. -0.3°±9.7°, p=0.047) in the LLIF group at 3-level fusion.

Conclusions: LLIF provides significantly better local sagittal alignment than PLIF in 1- or 2-level fusion cases and improves spinopelvic alignment and local alignment for 3-level fusion cases. Thus, LLIF was demonstrated to be a useful lumbar interbody fusion technique, constituting a powerful tool for achieving sagittal realignment with minimal surgical invasiveness.

Keywords: Disc height; Global sagittal alignment; Lateral lumbar interbody fusion; Local sagittal alignment; Lumbar lordosis; Posterior lumbar interbody fusion.