no significant statistical difference ..
In a landmark and somewhat controversial study, Herkowitz et al.  prospectively studied the surgical outcomes of two groups of patients with lumbar degenerative spondylolisthesis with associated stenosis. Specifically, one group (n=25) was treated with laminectomy, and the other group (n=25) was treated with laminectomy plus non-instrumented posterolateral fusion (PLF). Both groups were carefully followed after surgery for a minimum of two years in order to see how they were doing. At the final follow-up, which averaged three years from the date of surgery, the patient's who had undergone fusion plus decompression demonstrated statistically superior clinical outcomes, as compared to the group that had only had decompression. The authors concluded by saying:
No significant spondylolisthesis is identified.
78) Swan J, et al. Surgical Treatment for Unstable Low-Grade Isthmic Spondylolisthesis in Adults: a Prospective Controlled Study of Posterior Instrumented Fusion Compared with Combined Anterior-Posterior Fusion. Spine J 2006; 6:606-614.
What is the rate of surgery for isthmic spondylolisthesis? In 2016, Thirukumaran et al published the results of their study on this very question.  After analyzing over 47,000 surgeries, they discovered the annual rate of fusion surgery in 2011 for the treatment of isthmic spondylolisthesis was 122.6 surgeries per million adults. Because there are approximately 242 million adults in the United States, this translates into approximately 30,000 surgeries per year, in the United States alone!
Degenerative Spondylolisthesis - Spine - …
Correlation coefficients between clinical outcome (VAS/ODI) and the alteration in the various radiographic parameters at 6 weeks and one year follow-up are summarized in Table . Pearson’s coefficients for the correlation of slip reduction (Δ Listhesis) and the alteration of VAS leg pain after 6 weeks and one year were −0.097 and −0.204, respectively. As for the alteration of the ODI after 6 weeks and one year, the coefficients were −0.057 and 0.066. These results were not statistically significant and the relatively low coefficients indicate that no correlation could be established between slip reduction and clinical outcome. Correlation coefficients between changes in the other radiographic parameters and clinical outcome were also low and non-significantly different.
Laminectomy plus Fusion versus Laminectomy Alone …
In this study we were not able to establish a correlation between the amount of radiographic reduction of the slipped vertebra and clinical improvement of leg and back pain in patients treated with instrumented lumbar fusion for symptomatic low-grade spondylolisthesis. Although we were able to reduce the listhesis to some extent in 85% of patients at 6 weeks follow-up, some loss of reduction was commonly encountered. Nonetheless, clinical improvement was very satisfactory with a highly significant decrease in VAS leg pain and ODI at final follow-up, which is in accordance with two earlier reports [,]. In these studies, a mean loss of reduction of 5-6% was reported after instrumented fusion, without a statistically significant effect on good clinical outcome.
14/04/2016 · Original Article
*If you have jumped right to this page, it would be best to go back and read through the isthmic spondylolisthesis section first because much of that material and research directly relates to spondylolysis. Therefore, this section will be less comprehensive than the isthmic spondylolisthesis section.
Spinal Surgery: Laminectomy and Fusion - Medical …
A subgroup analysis was performed on clinical outcome in patients with a “fusion” on CT-scan at one year versus patients with a “non-union”. No significant differences in improvement in VAS or ODI could be established and a similar clinical outcome was achieved for both groups. A second analysis between the isthmic versus the degenerative spondylolisthesis subgroup revealed a higher preoperative VAS for leg pain (p0.01) in the degenerative group. However, at both postoperative follow-ups no statistically significant difference could be established in the improvements in VAS and ODI between these two subgroups.