Lumbar Facet Arthroplasty Versus Fusion for Grade-I Degenerative Spondylolisthesis with Stenosis: A Prospective Randomized Controlled Trial

Abstract

Background: The comparative effectiveness of decompression plus lumbar facet arthroplasty versus decompression plus instrumented lumbar spinal fusion in patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis is unknown.

Methods: In this randomized, controlled, Food and Drug Administration Investigational Device Exemption trial, we assigned patients who had single-level lumbar spinal stenosis and grade-I degenerative spondylolisthesis to undergo decompression plus lumbar facet arthroplasty (arthroplasty group) or decompression plus fusion (fusion group). The primary outcome was a predetermined composite clinical success score. Secondary outcomes included the Oswestry Disability Index (ODI), visual analog scale (VAS) back and leg pain, Zurich Claudication Questionnaire (ZCQ), Short Form (SF)-12, radiographic parameters, surgical variables, and complications.

Results: A total of 321 adult patients were randomized in a 2:1 fashion, with 219 patients assigned to undergo facet arthroplasty and 102 patients assigned to undergo fusion. Of these, 113 patients (51.6%) in the arthroplasty group and 47 (46.1%) in the fusion group who had either reached 24 months of postoperative follow-up or were deemed early clinical failures were included in the primary outcome analysis. The arthroplasty group had a higher proportion of patients who achieved composite clinical success than did the fusion group (73.5% versus 25.5%; p < 0.001), equating to a between-group difference of 47.9% (95% confidence interval, 33.0% to 62.8%). The arthroplasty group outperformed the fusion group in most patient-reported outcome measures (including the ODI, VAS back pain, and all ZCQ component scores) at 24 months postoperatively. There were no significant differences between groups in surgical variables or complications, except that the fusion group had a higher rate of developing symptomatic adjacent segment degeneration.

Conclusions: Among patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis, lumbar facet arthroplasty was associated with a higher rate of composite clinical success than fusion was at 24 months postoperatively.

Level of evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Fig. 1

Schematic (Fig. 1-A), anteroposterior radiograph (Fig. 1-B), and lateral radiograph (Fig. 1-C) demonstrating the TOPS device affixed to pedicle screws.

Fig. 2

Eligibility, randomization, and follow-up.

Fig. 3

Mean scores on the Oswestry Disability Index (scores range from 0 to 100, with higher scores indicating more disability related to back pain) (Fig. 3-A), visual analog scale for low back pain (Fig. 3-B) and worst leg pain (Fig. 3-C) (scores range from 0 to 100, with higher scores indicating more pain in the specified anatomic region), and each component of the Zurich Claudication Questionnaire (ZCQ; scores range from 1 to 5 on the symptom score and from 1 to 4 on the physical and satisfaction scores, with lower numbers representing less severe symptoms related to neurogenic claudication, greater physical function, and greater satisfaction, respectively) (Figs. 3-D, 3-E, and 3-F), before and after surgery, among patients who were randomly assigned to undergo decompression plus lumbar facet arthroplasty or decompression plus fusion. *A significant difference (p < 0.05) between groups at the indicated time point.

Fig. 4

Mean scores on the physical (Fig. 4-A) and mental (Fig. 4-B) component summary scores of the Short Form-12 Health Survey (SF-12; scores range from 0 to 100, with higher scores indicating better quality of life), before and 24 months after surgery, among patients who were randomly assigned to undergo decompression plus lumbar facet arthroplasty or decompression plus fusion. *A significant difference (p < 0.05) between groups at the indicated time point.