Research Fellow Hospital for Special Surgery Hospital for Special Surgery
Introduction: Literature suggests recovery after transforaminal lumbar interbody fusion (TLIF) occurs mostly within 6 months; however, some patients improve more rapidly. We compared rapid-improvers with non-rapid improvers after TLIF using a novel definition of improvement.
Methods: Patients > 18 years undergoing primary 1-level TLIF were included. Rapid improvers (RI) achieved significant Oswestry Disability Index (ODI) improvement between consecutive timepoints in the short-term (2 or 6 weeks), but not the mid-term (3 or 6 months) or late-term (1 or 2 years) postoperative periods. Significant ODI improvement was defined by optimal cutoff point of a receiver operating characteristic (ROC) curve using change in ODI to predict improvement on Global Rating of Change (GRC) between consecutive timepoints. Variables assessed included patient-reported outcomes (PROMs) (ODI, visual analog scale [VAS] for back and leg pain, and Patient-Reported Outcomes Measurement Information System for Physical Function [PROMIS-PF]), sagittal alignment, muscle health, and Goutallier. Poor muscle health was defined by lowest gender-specific quartile of L3-L4 cross-sectional area (CSA)/height-squared (psoas) and CSA/body mass index (paralumbars). Logistic regression covariates were determined using p < 0.20 on univariate analyses and clinical relevance.
Results: 157 patients (RI = 31, non-RI = 126) were included. AUC was 0.71. Optimal cutoff for ODI improvement was 6.4. There were no differences in demographics or preoperative PROMs. Non-RI cohort had a significantly higher rate of hypertension. At short-term, RI cohort had lower ODI, VAS back, VAS leg, and higher PROMIS-PF, with no differences in long-term PROMs. There were no differences in sagittal alignment (pelvic incidence [PI], tilt, lordosis [LL], PI-LL, sacral slope [SS]), psoas or paralumbar muscle health, or Goutallier. Logistic regression including hypertension, age, PI, PI-LL, and SS showed that hypertension was a negative predictor for rapid improvement (OR 0.17 [0.05 - 0.52], p = 0.002).
Conclusion : Baseline comorbidities, particularly hypertension, may be a negative predictor for rapid improvement in patients undergoing 1-level TLIF using our novel definition. This information may help spine surgeons with perioperative patient counseling and may predict patient recovery based on preoperative comorbidities. Further research is needed to better elucidate the impact of preoperative comorbidities on postoperative recovery after primary 1-level TLIF.