Impact of Time to Surgery for Patients Using Workers' Compensation Insurance Undergoing Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Preliminary Analysis of Clinical Outcomes

Abstract

Objective: To conduct a preliminary analysis on the impact of time to surgery (TTS) and duration of symptoms (DOS) on clinical outcomes in workers' compensation patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).

Methods: Patients using workers' compensation insurance undergoing primary, single-level MIS TLIF were identified. Patient-reported outcome measures (PROMs) were administered at preoperative/6-week/12-week/6-month postoperative time points and included visual analog scale (VAS) back/VAS leg/Oswestry Disability Index/12-Item Short-Form Physical Composite Score/12-Item Short-Form Mental Composite Score. Patients were grouped by TTS: <90 days, 90-179 days, and ≥180 days. Demographics were compared by χ²; perioperative characteristics, mean PROMs, and postoperative improvement (ΔPROM) were compared using 1-way analysis of variance. Minimum clinically important difference (MCID) achievement rates were compared using simple logistic regression. A secondary analysis was performed by grouping patients by DOS: <180 days, 180-364 days, and ≥365 days. Mean PROMs, ΔPROMs, and MCID achievement were similarly compared between DOS groups using 1-way analysis of variance and logistic regression.

Results: A total of 193 patients were included. Prevalence of herniated nucleus pulposus and initial appointment type were significantly associated with TTS (P < 0.042, all). No significant differences in mean PROMs or ΔPROMs were observed among TTS groups. MCID achievement was significantly lower for VAS back at 6 months in the longest TTS group. Mean PROMs were significantly different based on DOS for VAS leg at 6 weeks only. MCID achievement was significantly lower for the longest DOS group for VAS leg at 6 months only. ΔPROMs did not significantly differ among DOS groups.

Conclusions: Neither TTS nor DOS was significantly associated with MIS TLIF outcomes. Workers' compensation patients may achieve similar clinical improvement even with longer symptom burden and substantial delays in operative treatment.

Keywords: Duration of symptoms; Lumbar fusion; Patient-reported outcomes; Workers' compensation.