Impact of Preoperative Symptom Duration on Patient-reported Outcomes After Minimally Invasive Transforaminal Interbody Fusion for Degenerative Spondylolisthesis

Study Design: Retrospective cohort study. Objective: To assess the impact of preoperative symptom duration (PSD) on patient-reported outcome measures (PROMs) after minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF) for degenerative spondylolisthesis (DSpond). Background: A prolonged duration of preoperative symptoms may implicate inferior long-term outcomes postsurgery. Prior studies of lumbar fusion recipients are limited by the inclusion of heterogeneous populations. Methods: A single-surgeon registry was retrospectively queried for privately insured patients who had undergone primary, elective, single-level MIS-TLIF for DSpond with a recorded symptom start date. Cohorts were formed by PSD: shorter duration (PSD <1 y) or greater duration (GD; PSD >= 1 y). PROMs evaluated included Patient-reported Outcomes Measurement Information System-Physical Function, Oswestry Disability Index, Visual Analog Scale-Back, Visual Analog Scale-Leg, and 9-item Patient Health Questionnaire. The magnitude of PROM (triangle PROM) improvement from preoperative baseline to 6 weeks and final follow-up (triangle PROM-FF) were compared between cohorts. Intercohort achievement rates of a minimum clinically important difference in each PROM were compared. Results: A total of 133 patients included 85 patients with GD cohort. There were no significant differences in pre hoc demographics and perioperative characteristics between cohorts, as well as preoperative, 6-week, or final follow-up PROMs between cohorts. Both cohorts demonstrated significant improvement in all PROMs at 6 weeks and final follow-up (P <= 0.049, all). There were no significant intercohort differences demonstrated in minimum clinically important difference achievement rates, triangle PROM-6W, or triangle PROM-FF in any PROM. Conclusions: Regardless of the symptom duration before MIS-TLIF for DSpond, patients demonstrate significant improvement in physical function, pain, disability, and mental health. Patients with a GD of preoperative symptoms did not report inferior scores in any PROM domain. Patients with a GD of preoperative symptoms did not suffer inferior rates of clinically meaningful improvement after surgical intervention. These findings should be considered when counseling patients before surgical intervention for DSpond.