2 research outputs found
Surgery in Degenerative Spondylolisthesis: Does fusion improve outcome in subgroups? A secondary analysis from a randomized trial (NORDSTEN trial)
BACKGROUND CONTEXT
Patients with spinal stenosis and degenerative spondylolisthesis are treated surgically with decompression alone or decompression with fusion. However, there is debate regarding which subgroups of patients may benefit from additional fusion.
PURPOSE
To investigate possible treatment effect modifiers and prognostic variables among patients operated for spinal stenosis and degenerative spondylolisthesis.
DESIGN
A secondary exploratory study using data from the Norwegian Degenerative Spondylolisthesis and Spinal Stenosis (NORDSTEN-DS) trial. Patients were randomized to decompression alone or decompression with instrumented fusion.
PATIENT SAMPLE
The sample in this study consists of 267 patients from a randomized multicenter trial involving 16 hospitals in Norway. Patients were enrolled from February 12, 2014, to December 18, 2017. The study did not include patients with degenerative scoliosis, severe foraminal stenosis, multilevel spondylolisthesis, or previous surgery.
OUTCOME MEASURES
The primary outcome was an improvement of ≥ 30% on the Oswestry Disability Index score (ODI) from baseline to 2-year follow-up.
METHODS
When investigating possible variables that could modify the treatment effect, we analyzed the treatment arms separately. When testing for prognostic factors we analyzed the whole cohort (both treatment groups). We used univariate and multiple regression analyses. The selection of variables was done a priori, according to the published trial protocol.
RESULTS
Of the 267 patients included in the trial (183 female [67%]; mean [SD] age, 66 [7.6] years), complete baseline data for the variables required for the present analysis were available for 205 of the 267 individuals. We did not find any clinical or radiological variables at baseline that modified the treatment effect. Thus, none of the commonly used criteria for selecting patients for fusion surgery influenced the chosen primary outcome in the two treatment arms. For the whole cohort, less comorbidity (American Society of Anesthesiologists Classification [ASA], OR = 4.35; 95% confidence interval (CI [1.16–16.67]) and more preoperative leg pain (OR = 1.23; CI [1.02–1.50]) were significantly associated with an improved primary outcome.
CONCLUSIONS
In this study on patients with degenerative spondylolisthesis, neither previously defined instability criteria nor other pre-specified baseline variables were associated with better clinical outcome if fusion surgery was performed. None of the analyzed variables can be applied to guide the decision for fusion surgery in patients with degenerative spondylolisthesis. For both treatment groups, less comorbidity and more leg pain were associated with improved outcome 2 years after surgery.publishedVersio
Decompression with or without Fusion in Degenerative Lumbar Spondylolisthesis
BACKGROUND
In patients with lumbar spinal stenosis and degenerative spondylolisthesis, it is
uncertain whether decompression surgery alone is noninferior to decompression
with instrumented fusion.
METHODS
We conducted an open-label, multicenter, noninferiority trial involving patients with
symptomatic lumbar stenosis that had not responded to conservative management
and who had single-level spondylolisthesis of 3 mm or more. Patients were randomly
assigned in a 1:1 ratio to undergo decompression surgery (decompressionalone
group) or decompression surgery with instrumented fusion (fusion group).
The primary outcome was a reduction of at least 30% in the score on the Oswestry
Disability Index (ODI; range, 0 to 100, with higher scores indicating more impairment)
during the 2 years after surgery, with a noninferiority margin of −15 percentage
points. Secondary outcomes included the mean change in the ODI score
as well as scores on the Zurich Claudication Questionnaire, leg and back pain, the
duration of surgery and length of hospital stay, and reoperation within 2 years.
RESULTS
The mean age of patients was approximately 66 years. Approximately 75% of the
patients had leg pain for more than a year, and more than 80% had back pain for
more than a year. The mean change from baseline to 2 years in the ODI score was
−20.6 in the decompression-alone group and −21.3 in the fusion group (mean difference,
0.7; 95% confidence interval [CI], −2.8 to 4.3). In the modified intentionto-
treat analysis, 95 of 133 patients (71.4%) in the decompression-alone group and
94 of 129 patients (72.9%) in the fusion group had a reduction of at least 30% in
the ODI score (difference, −1.4 percentage points; 95% CI, −12.2 to 9.4), showing
the noninferiority of decompression alone. In the per-protocol analysis, 80 of 106
patients (75.5%) and 83 of 110 patients (75.5%), respectively, had a reduction of at
least 30% in the ODI score (difference, 0.0 percentage points; 95% CI, −11.4 to
11.4), showing noninferiority. The results for the secondary outcomes were generally
in the same direction as those for the primary outcome. Successful fusion was
achieved with certainty in 86 of 100 patients (86.0%) who had imaging available
at 2 years. Reoperation was performed in 15 of 120 patients (12.5%) in the decompression-
alone group and in 11 of 121 patients (9.1%) in the fusion group.
CONCLUSIONS
In this trial involving patients who underwent surgery for degenerative lumbar
spondylolisthesis, most of whom had symptoms for more than a year, decompression
alone was noninferior to decompression with instrumented fusion over a period
of 2 years. Reoperation occurred somewhat more often in the decompressionalone
group than in the fusion group. (NORDSTEN-DS ClinicalTrials.gov number,
NCT02051374.