Decompression alone may benefit patients with degenerative lumbar spondylolisthesis: NEJM
In patients with lumbar spinal stenosis and degenerative spondylolisthesis, it is uncertain whether decompression surgery alone is noninferior to decompression with instrumented fusion. In a recent trial conducted at the Orthopedic Department, Haukeland University Hospital, Oslo, USA 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.
The research is published in the New England Journal of Medicine.
Ivar M. Austevoll and associates 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 (decompression-alone group) or decompression surgery with instrumented fusion (fusion group). the mean age of patients was approximately 66 years. 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.
The study results showed that 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).
Also, in the modified intention-to-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, 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, 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.
As a result, the authors concluded that decompression alone was noninferior to decompression with instrumented fusion over a period of 2 years.