Study Design. Retrospective cohort. Objective. We evaluate the correlation of the Patient-Reported Outcomes Measurement Information System for physical function (PROMIS-PF) with legacy patient-reported outcome measures (PROMs) in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) up to 2 years postoperatively. Summary of Background Data. PROMIS-PF has not been validated past 6 months following MIS TLIF. Methods. A surgical registry was retrospectively reviewed for eligible MIS TLIFs between May 2015 and September 2017. Inclusion criteria were primary, one- or two-level MIS TLIFs for degenerative spinal pathology. Patients without preoperative or 2-year follow up PROMIS-PF surveys were excluded. Demographic, perioperative, and PROMs including Visual Analog Scale (VAS) back, VAS leg, Oswestry Disability Index (ODI), 12-Item Short Form (SF-12) physical component summary (PCS) scores, and PROMIS-PF at preoperative and postoperative timepoint (e.g., 6 weeks, 12 weeks, 6 months, 1 year, and 2 years). A paired t test evaluated PROM improvement from baseline. The relationship of PROMIS-PF with VAS back, VAS leg, SF-12 PCS, and ODI was evaluated with a Pearson correlation coefficient. Results. The 68-subject cohort was 41.2% female, with an average age of 52.9 years; 44.1% were obese, and the majority underwent one-level fusions (95.6%). Pain (VAS back, VAS leg) and disability metrics (ODI) demonstrated significant improvement at all timepoints following MIS TLIF when compared to baseline (all P < 0.001). Physical function (SF-12 PCS, PROMIS-PF) demonstrated significant postoperative improvement at 12 weeks, 6 months, 1 year, and 2 years (all P < 0.001). All evaluated timepoints, with the exception of preoperative VAS back scores, revealed strong PROMIS-PF correlations with VAS back, VAS leg, ODI, and SF-12 PCS. Conclusion. PROMIS-PF demonstrated a strong correlation with pain (VAS back, VAS leg), disability (ODI) and physical function (SF-12) at all postoperative follow-ups through 2 years. Our study provides longitudinal evidence for utilizing PROMIS-PF as a valid physical function measure among patients undergoing MIS TLIF. Level of Evidence: 4.

Objective: To assess the impact of bilateral versus unilateral interbody cages on outcomes for minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) procedures.Methods: A retrospective review for primary, elective, single-level MIS TLIF procedures with bilateral posterior instrumentation from 2008–2020 was performed. Patients were grouped according to unilateral or bilateral interbody cage use. Procedures performed without static interbody cages or indicated for trauma, infection, malignancy were excluded. Patient-reported outcomes (PROs) included visual analogue scale (VAS), Oswestry Disability Index, 12-item Short Form health survey physical composite score (SF-12 PCS), PatientReported Outcome Measurement Information System physical function (PROMIS-PF). PROs were collected preoperatively and postoperatively. Change in PROs (Δ) was calculated and compared between groups. Achievement of minimum clinically important difference (MCID) was calculated using established values from the literature. Achievement rates were compared between groups using logistic regression.Results: The study included 151 patients, with 111 unilateral and 40 bilateral cage placements. Charlson Comorbidity Index, diabetes, and insurance status differed between groups (p < 0.050). Prevalence of degenerative and isthmic spondylolisthesis (both p ≤ 0.002), operative level (p = 0.003), and postoperative length of stay (p = 0.022) significantly differed between groups. The unilateral group had lower 1-year arthrodesis rates (p = 0.035). Preoperative VAS leg (p = 0.017) and SF-12 PCS (p = 0.045) were worse for the unilateral group. ΔPROMIS-PF was greater for the bilateral group at 2 years (p = 0.001). Majority of patients achieved an overall MCID for all PROs, except VAS leg (bilateral group).Conclusion: While preoperative status and postoperative arthrodesis rates differed, patients achieved an MCID at similar rates regardless of use of unilateral or bilateral cages.

Study Design: This was a retrospective cohort study. Objective: The purpose of this study is to examine whether the time duration from symptom onset to operative treatment is associated with postoperative clinical improvement after anterior cervical discectomy and fusion (ACDF). Summary of Background Data: There is a paucity of literature regarding the influence of preoperative symptom duration on patient-reported outcomes (PROs) following ACDF. Methods: Patients who underwent primary, single-level ACDF were retrospectively reviewed and stratified according to preoperative symptom duration (<12 and ≥12 mo). Demographic and perioperative characteristics were compared using χ2 analysis and linear regression. Subgroup mean scores were compared and achievement of minimal clinically important difference (MCID) was assessed for the Neck Disability Index (NDI), Visual Analogue Scale (VAS) neck pain, VAS arm pain, and 12-Item Short-Form Physical Component Score. Results: A total of 109 patients underwent primary, single-level ACDF: 68 had duration of symptoms (DOS) <12 months and 41 had a DOS ≥12 months. When comparing DOS subgroup preoperative PROs, there was no preoperative difference in NDI, VAS arm or neck pain, and 12-Item Short-Form Physical Component Score. In the postoperative period, there were no significant differences in the improvement of PROs throughout the 12-month timepoint. A significantly larger proportion of the <12 months DOS cohort achieved NDI MCID at the 3-month (66.1% vs. 43.8%, P=0.039) and 6-month (76.8% vs. 53.6%, P=0.030) postoperative period. Conclusions: Among the patient subgroups with <12 and ≥12 months DOS, there were no statistically significant differences observed in any of the measured PRO means at any timepoint. When assessing MCID, however, patients with shorter DOS (<12 mo) were observed to attain NDI MCID at the 3- and 6-month timepoints more often than patients with DOS ≥12 months. Our findings suggest that delayed surgical intervention may impair functional recovery to MCID in patients with degenerative cervical disease.