title: Evaluation of efficacy of a new hybrid fusion device: a randomized, two-centre controlled trial.
abstract: BACKGROUND
  The 360° fusion of lumbar segments is a common and well-researched therapy to treat various diseases of the spine. But it changes the biomechanics of the spine and may cause adjacent segment disease (ASD). Among the many techniques developed to avoid this complication, one appears promising. It combines a rigid fusion with a flexible pedicle screw system (hybrid instrumentation, "topping off"). However, its clinical significance is still uncertain due to the lack of conclusive data.
  
  
  METHODS
  The study is a randomized, therapy-controlled, two-centre trial conducted in a clinical setting at two university hospitals. If they meet the criteria, outpatients presenting with degenerative disc disease, facet joint arthrosis or spondylolisthesis will be included in the study and randomized into two groups: a control group undergoing conventional fusion surgery (PLIF - posterior lumbar intervertebral fusion), and an intervention group undergoing fusion surgery using a new flexible pedicle screw system (PLIF + "topping off"), which was brought on the market in 2013. Follow-up examination will take place immediately after surgery, after 6 weeks and after 6, 12, 24 and 36 months. An ongoing assessment will be performed every year.Outcome measurements will include quality of life and pain assessments using validated questionnaires (ODI - Ostwestry Disability Index, SF-36™ - Short Form Health Survey 36, COMI - Core Outcome Measure Index). In addition, clinical and radiologic ASD, sagittal balance parameters and duration of work disability will be assessed. Inpatient and 6-month mortality, surgery-related data (e.g., intraoperative complications, blood loss, length of incision, surgical duration), postoperative complications (e.g. implant failure), adverse events, and serious adverse events will be monitored and documented throughout the study.
  
  
  CONCLUSIONS
  New hybrid "topping off" systems might improve the outcome of lumbar spine fusion. But to date, there is a serious lack of and a great need of convincing data on safety or efficacy, including benefits and harms to the patients, of these systems. Health care providers are particularly interested in such data as these implants are much more expensive than conventional implants. In such a case, randomized clinical trials are the best way to evaluate benefits and risks.
  
  
  BACKGROUND
  NCT01852526.
authors.affiliation: Department of Orthopaedic and Trauma Surgery, University of Cologne, Kerpener Strasse 62, 50924 Cologne, Germany. jan.siewe@uk-koeln.de.
authors.forename: Jan
authors.initials: J
authors.lastname: Siewe
authors.forename: Jan
authors.initials: J
authors.lastname: Bredow
authors.forename: Johannes
authors.initials: J
authors.lastname: Oppermann
authors.forename: Timmo
authors.initials: T
authors.lastname: Koy
authors.forename: Stefan
authors.initials: S
authors.lastname: Delank
authors.forename: Peter
authors.initials: P
authors.lastname: Knoell
authors.forename: Peer
authors.initials: P
authors.lastname: Eysel
authors.forename: Rolf
authors.initials: R
authors.lastname: Sobottke
authors.forename: Kourosh
authors.initials: K
authors.lastname: Zarghooni
authors.forename: Marc
authors.initials: M
authors.lastname: Röllinghoff
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D065289:Pedicle Screws / Q000592:standards*; D011788:Quality of Life; D013122:Spinal Diseases / Q000175:diagnosis / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods* / Q000592:standards*; D016896:Treatment Outcome