title: The Influence of Pelvic Incidence and Lumbar Lordosis Mismatch on Development of Symptomatic Adjacent Level Disease Following Single-Level Transforaminal Lumbar Interbody Fusion.
abstract: BACKGROUND
  Annual incidence of symptomatic adjacent level disease (ALD) following lumbar fusion surgery ranges from 0.6% to 3.9% per year. Sagittal malalignment may contribute to the development of ALD.
  
  
  OBJECTIVE
  To describe the relationship between pelvic incidence-lumbar lordosis (PI-LL) mismatch and the development of symptomatic ALD requiring revision surgery following single-level transforaminal lumbar interbody fusion for degenerative lumbar spondylosis and/or low-grade spondylolisthesis.
  
  
  METHODS
  All patients who underwent a single-level transforaminal lumbar interbody fusion at either L4/5 or L5/S1 between July 2006 and December 2012 were analyzed for pre- and postoperative spinopelvic parameters. Using univariate and logistic regression analysis, we compared the spinopelvic parameters of those patients who required revision surgery against those patients who did not develop symptomatic ALD. We calculated the predictive value of PI-LL mismatch.
  
  
  RESULTS
  One hundred fifty-nine patients met the inclusion criteria. The results noted that, for a 1° increase in PI-LL mismatch (preop and postop), the odds of developing ALD requiring surgery increased by 1.3 and 1.4 fold, respectively, which were statistically significant increases. Based on our analysis, a PI-LL mismatch of >11° had a positive predictive value of 75% for the development of symptomatic ALD requiring revision surgery.
  
  
  CONCLUSIONS
  A high PI-LL mismatch is strongly associated with the development of symptomatic ALD requiring revision lumbar spine surgery. The development of ALD may represent a global disease process as opposed to a focal condition. Spine surgeons may wish to consider assessment of spinopelvic parameters in the evaluation of degenerative lumbar spine pathology.
authors.forename: Zachary J
authors.initials: ZJ
authors.lastname: Tempel
authors.forename: Gurpreet S
authors.initials: GS
authors.lastname: Gandhoke
authors.forename: Bryan D
authors.initials: BD
authors.lastname: Bolinger
authors.forename: Nicolas K
authors.initials: NK
authors.lastname: Khattar
authors.forename: Philip V
authors.initials: PV
authors.lastname: Parry
authors.forename: Yue-Fang
authors.initials: YF
authors.lastname: Chang
authors.forename: David O
authors.initials: DO
authors.lastname: Okonkwo
authors.forename: Adam S
authors.initials: AS
authors.lastname: Kanter
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D055959:Intervertebral Disc Degeneration / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery; D008141:Lordosis / Q000601:surgery; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D012086:Reoperation; D013123:Spinal Fusion / Q000009:adverse effects* / Q000379:methods; D013168:Spondylolisthesis / Q000601:surgery
keywords: Adjacent level disease; Lumbar fusion; Lumbar lordosis; Pelvic incidence; Spinopelvic alignment; Transforaminal lumbar interbody fusion