title: Influence of previous surgery on patient-rated outcome after surgery for degenerative disorders of the lumbar spine.
abstract: Few studies have used multivariate models to quantify the effect of multiple previous spine surgeries on patient-oriented outcome after spine surgery. This study sought to quantify the effect of prior spine surgery on 12-month postoperative outcomes in patients undergoing surgery for different degenerative disorders of the lumbar spine.
  
  
  
  The study included 4940 patients with lumbar degenerative disease documented in the Spine Tango Registry of EUROSPINE, the Spine Society of Europe, from 2004 to 2015. Preoperatively and 12 months postoperatively, patients completed the multidimensional Core Outcome Measures Index (COMI; 0-10 scale). Patients' medical history and surgical details were recorded using the Spine Tango Surgery 2006 and 2011 forms. Multiple linear regression models were used to investigate the relationship between the number of previous surgeries and the 12-month postoperative COMI score, controlling for the baseline COMI score and other potential confounders.
  
  
  
  In the adjusted model including all cases, the 12-month COMI score showed a 0.37-point worse value [95 % confidence intervals (95 % CI) 0.29-0.45; p < 0.001] for each additional prior spine surgery. In the subgroup of patients with lumbar disc herniation, the corresponding effect was 0.52 points (95 % CI 0.27-0.77; p < 0.001) and in lumbar degenerative spondylolisthesis, 0.40 points (95 % CI 0.17-0.64; p = 0.001).
  
  
  
  We were able to demonstrate a clear "dose-response" effect for previous surgery: the greater the number of prior spine surgeries, the systematically worse the outcome at 12 months' follow-up. The results of this study can be used when considering or consenting a patient for further surgery, to better inform the patient of the likely outcome and to set realistic expectations.
authors.affiliation: Spine Center, Schulthess Klinik, Lengghalde 2, 8008, Zurich, Switzerland.
authors.forename: Pascal
authors.initials: P
authors.lastname: Zehnder
authors.affiliation: Institute for Evaluative Research in Medicine, University of Bern, Stauffacherstrasse 78, 3012, Bern, Switzerland.
authors.forename: Emin
authors.initials: E
authors.lastname: Aghayev
authors.affiliation: Spine Center, Schulthess Klinik, Lengghalde 2, 8008, Zurich, Switzerland.
authors.forename: Tamas F
authors.initials: TF
authors.lastname: Fekete
authors.affiliation: Spine Center, Schulthess Klinik, Lengghalde 2, 8008, Zurich, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Haschtmann
authors.affiliation: Department of Neurosurgery, Walton Centre for Neurology and Neurosurgery, Lower Lane, Liverpool, L9 7LJ, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Pigott
authors.affiliation: Spine Center, Schulthess Klinik, Lengghalde 2, 8008, Zurich, Switzerland. anne.mannion@yahoo.com.
authors.forename: Anne F
authors.initials: AF
authors.lastname: Mannion
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000453:epidemiology / Q000601:surgery; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013168:Spondylolisthesis / Q000453:epidemiology / Q000601:surgery; D016896:Treatment Outcome
keywords: COMI; Degenerative disorders of the lumbar spine; Patient-rated outcome; Previous surgery; Spine Tango