Friday, September 28, 2018 1:00 PM–2:30 PM abstracts: achieving lumbar interbody fusion: 194. The Effect of preoperative symptom duration on postoperative outcomes following transforaminal lumbar interbody fusion

Abstract

BACKGROUND CONTEXT Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) is commonly used in the treatment of lumbar degenerative disease. However, there exists a paucity of knowledge regarding the influence of preoperative symptom duration on patient reported outcomes (PROs) following lumbar fusion PURPOSE To examine whether the time spanning from symptom onset to surgical intervention has an effect on postoperative clinical improvement in patients undergoing MIS TLIF. STUDY DESIGN/SETTING Retrospective analysis of a prospectively managed surgical database. PATIENT SAMPLE A total of 195 patients who underwent a MIS TLIF procedure from 2013 to 2016. OUTCOME MEASURES Improvements in Oswestry Disability Index (ODI), Visual Analog Scale (VAS) back pain, VAS leg pain, and inpatient narcotic consumption, as calculated Oral Morphine Equivalents (OMEs). METHODS A prospectively maintained surgical registry was reviewed. Patients who underwent a MIS TLIF procedure for degenerative pathology from 2013 to 2016 were identified. Patients were grouped based on preoperative symptom duration (≤6 months, >6 months). Pain was measured using the VAS, and narcotic consumption was measured using OMEs. Demographics and perioperative outcomes were compared using chi-squared analyses for categorical data and independent Student t-tests for continuous variables. PROs including ODI, VAS back and VAS leg scores were collected at preoperative and postoperative visits (6-weeks, 12-weeks and 6 months). The percentage of patients achieving minimal clinically important difference (MCID) following surgery was compared between groups. RESULTS A total of 195 patients following MIS TLIF were included in this analysis. 80% (N=156) had a symptom duration >6 months and the remaining 20% (N=39) had a symptom duration ≤6 months. No differences in demographics and comorbidity burden were identified between groups. Operative characteristics including operative time, estimated blood loss, inpatient pain, narcotic consumption and length of stay were also similar between symptom duration groups. When comparing PROs, patients with shorter symptom duration had significantly higher ODI scores preoperatively and had greater improvements in ODI scores at 6 weeks, 12 weeks, and 6 months (p CONCLUSIONS Patients undergoing MIS TLIF with shorter symptom duration exhibited significantly higher preoperative ODI scores. However, these patients demonstrated greater clinical improvement postoperatively. These findings suggest delayed surgical intervention may lead to impaired functional recovery in patients with degenerative lumbar disease. As such, further studies evaluating differences in outcomes between early and delayed surgical intervention are required to gain better understanding of the efficacy of nonoperative management of lumbar degenerative disease.