Introduction: Transforaminal lumbar interbody fusion (TLIF) with posterolateral fusion (PLF) or anterior lumbar interbody fusion (ALIF) with percutaneous pedicle screw fixation (PPSF) offer significantly higher radiographic fusion rates than other fusion techniques for L5-S1 isthmic spondylolisthesis (IS). Few studies have compared both techniques regarding clinical, radiographic, and financial outcomes for the treatment of L5-S1 IS. This study aims to provide evidence to guide spine surgeons towards the preferred surgical approach.
Methods: This retrospective study reviewed patients who underwent either TLIF with PLF or ALIF with PPSF for L5-S1 IS between 2009-2014. Quality of life outcome scores, radiographic data, and financial data were collected with a minimum of 1-year follow up. Continuous variables were compared using either independent t-tests assuming unequal variance or Whitney-Mann U tests
Results: 66 patients met inclusion criteria. In the ALIF cohort, Pain Disability Questionnairescores improved from 69 [47,82] to 26 [18.2,79.7],p=0.02. In the TLIF cohort, PDQ scores improved from 73 [46,85] to 48.5 [23, 67.5], p = 0.01. Both groups also showed a significant improvement in EuroQol-5 Dimension Health State scores at 1 year, but the ALIF group showed a significantly greater improvement in EQ-5D scores at 1 year (0.1 [0,0.2] vs 0.2 [0.1,0.4],p=0.02). Furthermore, only the ALIF cohort showed a significant improvement in segmental lordosis. The ALIF cohort showed a significantly greater improvement in disc height compared to TLIF(3.5 [2,5.5] v. 6.7 [4.1,10], p=0.01) No significant differences were found with regards to costs of both procedures.
Conclusions: Our findings are in support of the ALIF technique achieving better clinical outcomes compared to TLIF for the treatment of IS. We believe the superior radiographic outcomes achieved through ALIF, namely a greater restoration of segmental lordosis and disc height, may have contributed to the greater clinical outcomes presented in the current study.
Patient Care: To date, there is a relative paucity of data regarding clinical, radiographic, and financial outcomes directly comparing ALIF with PPSF to TLIF with PLF in the treatment of L5-S1 IS. The present study used data from a large, academic, tertiary medical center to evaluate this question. Based on the results of prior studies, , we hypothesized that ALIF with PPSF will be associated with better health related quality of life (HRQOL) outcomes compared to TLIF with PLF. However, we recognize the anteroposterior approach may lead to an increased risk of perioperative morbidity, longer hospital stays, and ultimately increased hospital costs as previous studies have shown the initial cost disparity favoring the TLIF procedure. With an increased focus on cost-conscious care, it is important to elucidate the financial impact and patient outcomes that can be anticipated with either procedure. Thus, our study aims to provide evidence to guide spine surgeons towards the preferred surgical approach of treating L5-S1 IS.
Learning Objectives: 1. To understand the common surgical procedures utilized for the treatment of L5-S1 isthmic spondylolisthesis (IS).
2. To recognize the unique advantages/disadvantages of both techniques.
3. To compare the clinical, radiographic, and financial outcomes in patients with L5-S1 IS undergoing either ALIF with PPSF or TLIF with PLF.