Study design: Retrospective.
Object: This study aims to examine whether the time spanning from symptom onset to surgical intervention has an effect on postoperative clinical improvement in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).
Summary of background data: Evidence is limited regarding the influence of preoperative symptom duration on patient-reported outcomes (PROs).
Methods: Patients undergoing a primary, single-level minimally invasive transforaminal lumbar interbody fusion were retrospectively reviewed and stratified according to preoperative symptom duration (<12 mo and ≥12 mo). Differences in PROs, including Oswestry Disability Index (ODI), 12-Item Short-Form Physical Component Score (SF-12 PCS), Visual Analogue Scale (VAS) back pain, and VAS leg pain, at each postoperative timepoint and were compared between duration of symptoms (DOS) cohorts using linear regression. Achievement of minimal clinically important difference (MCID) for PROs was compared using χ analysis.
Results: A total of 248 patients were included: 96 had a DOS <12 months and 152 had a DOS >12 months. When comparing PROs preoperatively, the shorter DOS cohort had significantly worse ODI, VAS leg pain, and SF-12 PCS compared with patients with longer DOS. However, there was no preoperative difference in VAS back pain between cohorts. Postoperatively, there were no significant differences in improvement of PROs throughout the 12-month timepoint. The shorter DOS cohort had a comparable number of patients achieving MCID for ODI, VAS back pain, VAS leg pain, and SF-12 PCS relative to the longer DOS cohort.
Conclusions: In our study, patients with DOS <12 months exhibited significantly worse ODI and VAS leg pain scores at the time of surgery compared with patients with longer DOS. However, these patients demonstrated similar clinical improvement postoperatively regardless of preoperative symptom duration. These findings suggest that delayed surgical intervention may not lead to impaired functional recovery in patients with degenerative lumbar disease.