Authors: Andrew K. Chan, MD; Andrew Chan, MD; Erica Bisson, MD, MPH; Mohamad Bydon, MD; Kevin Foley, MD; Christopher Shaffrey, MD; Mark Shaffrey, MD; John Knightly, MD; Paul Park, MD; Michael Wang, MD; Anthony Asher, MD; Regis Haid, MD; Praveen Mummaneni, MD (San Francisco, CA)

Introduction: The optimal minimally invasive surgical (MIS) approach for degenerative lumbar spondylolisthesis (DLS) is not clearly elucidated. This study compares patient reported outcomes (PRO) following MIS transforaminal lumbar interbody fusion (TLIF) and MIS decompression for DLS. Methods: 608 patients from twelve high-enrolling sites participating in the Quality Outcomes Database (QOD) Lumbar Spondylolisthesis Module underwent single-level surgery for grade 1 DLS of which 143 underwent minimally-invasive surgery (MIS) [72 MIS TLIF (50.3%), 71 MIS decompressions (49.7%)]. Surgeries were classified as MIS if there was utilization of percutaneous screw fixation and placement of a Wiltse-plane MIS intervertebral body graft (MIS TLIF) or if there was a tubular decompression (MIS decompression). Baseline and 24-month follow-up PROs were collected including Oswestry Disability Index (ODI), numeric rating scale (NRS) Back Pain, NRS Leg Pain, EuroQoL-5D (EQ-5D) Questionnaire, and North American Spine Society (NASS) Satisfaction Questionnaire. Multivariate models were constructed adjusting for patient characteristics and surgical variables. Results: The mean age was 67.1±11.3 years (MIS TLIF 62.1 years, MIS decompression 72.3 years; p< 0.001). The proportion in each cohort reaching 24-month follow up did not differ significantly (MIS TLIF 83.3%, MIS decompression 84.5%; p= 0.85). MIS TLIF was associated with higher blood loss (108.8 vs. 33.0 ml; p <0.001), longer operative times (228.2 vs. 101.8 min; p <0.001), and length of hospitalization (2.9 vs. 0.7 days; p< 0.001). MIS TLIF was associated with a lower reoperation rate (14.1% vs. 1.4%; p =0.004). Both cohorts demonstrated significant improvements in ODI, NRS back pain, NRS leg pain, and EQ-5D at 24 months ( p <0.001). In multivariate analyses, MIS TLIF—as opposed to MIS decompression—was associated with superior ODI change (β=-7.59;95%CI[-14.96- -0.23]; p =0.04), NRS back pain change (β=-1.54;95%CI[-2.78- -0.30]; p =0.02), and NASS satisfaction (OR=0.32;95%CI[0.12-0.82]; p =0.02). Conclusion: For symptomatic, single-level DLS, MIS TLIF was associated with fewer reoperations and superior outcomes for disability, back pain, and patient satisfaction compared to MIS decompression alone.