Introduction: For patients with lumbar isthmic spondylolisthesis (IS) whose symptoms do not resolve with conservative treatments, fusion is recommended, and they may undergo posterolateral fusion (PLF), interbody fusion (PLIF or TLIF), or circumferential fusion (ALIF). While previous studies have analyzed the surgical outcomes associated with various techniques, there are no studies that have focused on multiple quality of life (QOL) outcome measures or correlated these results with the cost-effectiveness of each surgical technique.
Methods: A single-institution retrospective analysis of all patients diagnosed with lumbar IS and who underwent surgical treatment between 2004-2014 was conducted. 46 patients who had at least 1 year of follow-up data were identified. Patients received 1 of 3 treatments: ALIF, PLF, or PLIF/TLIF +PLF. Four quality of life outcome measures were analyzed: the Visual Analog Scale for pain, EuroQol 5 Dimensions (EQ-5D), Pain Disability Questionnaire (PDQ), and Patient Health Questionnaire 9 (PHQ-9). Direct costs were estimated using Medicare national payment amounts, and indirect costs were estimated based on patients’ missed workdays. Postoperative 1-year cost-utility ratios and incremental cost-effectiveness ratios (ICERs) were calculated using a cost-effectiveness threshold of $100,000/Quality Adjusted Life Year (QALY) gained.
Results: At 1-year follow up, each surgical technique provided significant improvement (p<0.05) in at least 3 of 4 QOL measures. There were no significant differences (p>0.05) between surgical groups in any QOL measure or overall costs. The 1-year cost-utility ratio was lowest for those who underwent PLIF/TLIF+PLF ($57,665/QALY) compared to PLF ($70,256/QALY) or ALIF ($80,424/QALY). The 1-year ICERs compared to PLIF/TLIF+PLF were: PLF ($15,671) and ALIF ($5,498).
Conclusions: ALIF, PLF, and PLIF/TLIF+PLF each provide significant improvement in 1-year postoperative quality of life outcomes for patients with isthmic spondylolisthesis. While each surgical technique is cost-effective based on the threshold, PLIF/TLIF+PLF provided the best cost-utility ratio. These results support the need for further studies using longer-term follow-up periods.
Patient Care: There are many surgical options when treating lumbar isthmic spondylolisthesis; however, a gold standard of treatment has yet to be identified. With the increasing importance of providing cost-effective care, this study provides a necessary analysis of the relationship between quality of life outcomes and the cost-effectiveness of three different surgical treatment options. These results can help surgeons provide more consistent, cost-effective care to all patients.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) discuss the improvements in quality of life outcomes provided by three different surgical approaches for treating lumbar isthmic spondylolisthesis, and 2) Have an understanding of the relative costs and cost-utility ratios of each surgical technique.