Hi, my name is Andrew Chan, and I'm one of the PGY-6s at UCSF, and today, on behalf of the Quality Outcomes Database Spondylolisthesis Study Group, I'd like to present to you our work investigating the differential impact of fusion versus decompression alone on the 10 sub-items of the Oswestry Disability Index. Here are my disclosures. I'd like to thank the NREF for their contribution to our study. We know that lumbar spondylolisthesis is associated with disability and affects many people worldwide, including up to 12% of the United States population. For a subset of patients who fail conservative management, surgical intervention has been shown to be effective in improving function and quality of life. To this point, in a 2007 New England Journal of Medicine as-treated analysis of participants with spondylolisthesis in a sport trial, the study showed a significant benefit of surgery compared to conservative management alone at two-year follow-up. However, what the study did not answer was what specific procedure patients should undergo, especially because greater than 90% of those undergoing surgery underwent fusion procedures. For the patients we see in clinic with spondylolisthesis, we are faced with the decision of whether to decompress the patient without fusion or decompress the patient with the addition of fusion. And the ideal surgical approach remains controversial despite some randomized controlled trials on the topic. In 2016, two RCTs investigating the utility of fusion for spondylolisthesis were published in the New England Journal of Medicine. In one study by Dr. Gogolwal and colleagues, in a study of stable, single-level spondylolisthesis, they found that those who underwent fusion in addition to decompression had a greater improvement in health-related quality of life using SF36, their primary outcome metric. Additionally, they found that those receiving decompression alone had a nearly 20% higher rate of reoperation within the study period. On the other hand, in the study by Dr. Forst and colleagues, in a study of one or two-level lumbar stenosis with and without spondylolisthesis, they found no additional benefit of fusion for patients with regards to ODI, their primary outcome metric. Additionally, their rates of reoperation between the two cohorts were similar. So why were these results different? Well, for one, there were different populations studied, with the former studying a population of stable, single-level spondylolisthesis, and the other studying a population with one or two levels of lumbar stenosis with and without spondylolisthesis. Also, the studies studied different outcome measures, with one studying SF36 and the other studying ODI. And some authors have suggested that the fourth study did not have enough power to detect a difference for their primary outcome, ODI. Additionally, an overarching issue in limitation of RCTs stems from the narrow inclusion criteria employed by RCTs, which may not be applicable to the patients we actually see in clinic. To investigate the real-world practice experience of those managing spondylolisthesis, we leveraged the Prospective Quality Outcomes Database Registry. This registry has over 100 enrolled sites and includes over 80 demographic, surgical, and patient-reported outcome variables, also known as PROs. These patient-centered outcome metrics are exactly what is important in this era of value-based care. We need to ask ourselves, when we are treating a patient, are we just treating a radiographic finding? Or rather, are we treating a patient in the radiographic finding in the context of the patient's specific symptomatology? Fortunately, we are able to leverage the Prospective Quality Registry to gather information about patient symptoms directly from them in the spine surgeon's office. The commonly utilized Oswetri Disability Index is one of the baseline and outcome variables collected. It is a measure of back pain-related disability scored on a range from 0 to 100, with higher scores indicating more disability. It is composed of 10 individual questions that assesses different domains of disability, with each item permitting a score of 0 to 5, with 5 indicating the most disability and 0 indicating no disability in a given domain. These domains include pain, personal care, lifting, walking, sitting, standing, sleeping, sex life, social life, and traveling. And investigating each item separately allows us to see if different items respond differently to different types of surgery. Specifically, it remains unclear if type of surgery, namely decompression alone vs. decompression infusion, impacts specific aspects of disability differentially. To this end, we set out to investigate the impact of decompression only vs. decompression infusion surgery on each of the domains of disability. We utilized data from the QOD Spondylolisthesis Study Group, which was a specialized subset of QOD sites who set out to investigate the effectiveness of fusion for grade 1 degenerative lumbar spondylolisthesis. Briefly, this represents a multidisciplinary, multi-center effort. We prospectively enrolled patients from July 1, 2014 to June 30, 2016 and followed these patients for 2-3 years. These were all patients that underwent single segment surgery or single disc level surgery for grade 1 spondylolisthesis. In all, we enrolled 608 patients, of which 140 underwent decompression alone, and 468 underwent decompression infusion. We compared outcomes at 24 months, and our primary outcome measure here were the 10 items contained within the ODI. Comparing the two cohorts, we found multiple differences in baseline characteristics, which I've highlighted in yellow here. We found that fusions were younger, had a higher proportion of females, had a higher BMI, were more often depressed, and had a lower proportion with diabetes mellitus. Fusions had a higher disability at baseline, worse back pain at baseline, and poor quality of life at baseline. Comparing clinical presentation, the fusion cohort less often had motor deficits at presentation and thus had a higher proportion that were independently ambulatory at the time of presentation. Also, the fusion cohort had a higher proportion with greater than 3 months of symptom duration. If we look at baseline socioeconomic demographic variables, fusions had lower levels of education, but were more often employed. If we look at perioperative outcome metrics, fusions had more blood loss, longer operative times, and longer hospitalizations, but discharge disposition to home or home health was not significantly different between the two cohorts. Now turning to our main outcome measure, we assessed the impact of decompression alone versus decompression and fusion on each of the 10 sub-items of the ODI at 24 months. If we compare the groups at baseline, fusions had globally worse symptoms except for the ability to walk at baseline. Otherwise, for the remaining 9 domains, fusions were more disabled. When assessing for treatment effect or the differences between 24-month and baseline values, there were significant improvements in each of the 10 domains regardless of whether the patient received decompression alone or decompression and fusion. To investigate if fusion is associated with individual items of the ODI, we created multivariable models for each sub-item, adjusting for factors reaching a p-value of less than 0.20 on univariate comparisons. In this table, we demonstrate the results of the 10 constructed models, here listing the independent effect of fusion when adjusting for covariates. We found that fusion was independently associated with superior outcomes for pain intensity, ability to lift heavy weights, ability to walk, ability to stand, impact on sex life, impact on social life, and ability to travel. However, there was no significant difference for the domains of ability for self-care including washing and dressing, ability to sit, or ability to sleep. In conclusion, regardless of treatment strategy, surgery was associated with significant improvements in each of the 10 domains of the ODI. Fusion, however, compared to decompression alone, was associated with superior outcomes for pain intensity, heavy weight lifting, walking, standing, sexual activity, social activity, and ability to travel. There were no significant associations between fusion and self-care, sitting, and sleeping. Thus, these results suggest that procedural type may carry less association with outcomes for self-care, sitting, and sleeping. I'd like to thank everyone that makes the Spondylolisthesis study possible, including those that spearhead it, including Dr. Praveen Moomineni, Dr. Erica Bisson, Dr. Mohamed Biden, and Dr. Tony Asher. I'd like to thank all the QLD Lombard Spondylolisthesis study site PIs, the coordinators, the NPA, and the NREF for making this study possible. Thank you so much. Please do reach out by email if you have any remaining questions.

fusion versus decompression alone

Oswestry Disability Index

lumbar spondylolisthesis

Prospective Quality Outcomes Database Registry

surgery outcomes