The effect of minimally invasive lumbar decompression surgery on sagittal spinopelvic alignment in patients with lumbar spinal stenosis: a 5-year follow-up study — The International Society for the Study of the Lumbar Spine
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The effect of minimally invasive lumbar decompression surgery on sagittal spinopelvic alignment in patients with lumbar spinal stenosis: a 5-year follow-up study (#1140)

Hiromitsu Toyoda 1 , Hidetomi Terai 1 , Hamidullah Salimi 1 , Kentaro Yamada 2 , Masatoshi Hoshino 3 , Minori Kato 1 , Akinobu Suzuki 1 , Shinji Takahashi 1 , Koji Tamai 1 , Akito Yabu 1 , Hiroaki Nakamura 1
  1. Osaka City University Graduate School of Medicine, Osaka, OSAKA, Japan
  2. Orthopaedic Surgery, PL hospital, Osaka, Japan
  3. Orthopaedic Surgery, Osaka City General Hospital, Osaka, Japan

INTRODUCTION

Several studies have examined the relationship between sagittal spinopelvic alignment and clinical outcomes after spinal surgery. However, the long-term reciprocal changes of sagittal spinopelvic alignment in lumbar spinal stenosis after decompression surgery remain unclear. The aim of this study was to investigate the radiographic changes in sagittal spinopelvic alignment and clinical outcomes at 2-year and 5-year follow-up after minimally invasive lumbar decompression surgery.

METHODS

We retrospectively studied 110 patients who underwent bilateral decompression via a unilateral approach for lumbar spinal stenosis. The Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) scores for lower back pain (LBP), leg pain, leg numbness, and spinopelvic parameters were evaluated before surgery and at 2-year and 5-year follow-up. Sagittal malalignment was defined as a sagittal vertical axis (SVA) ≥50 mm.

RESULTS

Compared with baseline, lumbar lordosis was significantly increased after decompression surgery at 2-year (30.2⁰ vs 38.5⁰, respectively; p < 0.001) and 5-year (30.2⁰ vs 35.7⁰, respectively; p < 0.001) follow-up. SVA was significantly decreased at 2-year follow-up compared with baseline (36.1mm vs 51.5mm, respectively; p < 0.001). However, there were no differences in SVA at 5-year follow-up compared with baseline (50.6mm vs 51.5 mm, respectively; p = 0.812). At 5-year follow-up, 82.5% of patients in the preoperatively normal alignment group maintained normal alignment, while 42.6% of patients in the preoperatively malalignment group developed normal alignment. Preoperative sagittal malalignment was associated with VAS for LBP at baseline and 2-year and 5-year follow-up and JOA score at 5-year follow-up. Postoperative sagittal malalignment was associated with VAS for LBP at 2-year and 5-year follow-up and VAS for leg pain at 5-year follow-up. There was a trend towards a deterioration in clinical outcomes in persistent postural malalignment patients compared with the other groups.

DISCUSSION

Following minimally invasive surgery, spinal sagittal malalignment can convert to normal alignment at both short-term and long-term follow-up. Sagittal malalignment has a negative impact on VAS for LBP and a weak negative impact on the JOA score after decompression surgery.

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