title: Clinical outcomes of the Dynesys dynamic neutralization system: 1-year preliminary results.
abstract: OBJECTIVE
  In this study the authors present the preliminary clinical outcomes of dynamic stabilization with the Dynesys spinal system as part of a multicenter randomized prospective Food and Drug Administration (FDA) investigational device exemption (IDE) clinical trial.
  
  
  METHODS
  This study included 101 patients from six IDE sites (no participants were omitted from the analysis) who underwent dynamic stabilization of the lumbar spine with the Dynesys construct. Patient participation was based on the presence of degenerative spondylolisthesis or retrolisthesis (Grade I), lateral or central spinal stenosis, and their physician's determination that the patient required decompression and instrumented fusion for one or two contiguous spinal levels between L-1 and S-1. Participants were evaluated preoperatively, postoperatively at 3 weeks, and then at 3-, 6-, and 12-month intervals. The 100-mm visual analog scale was used to score both lower-limb and back pain. Patient functioning was evaluated using the Oswestry Disability Index (ODI), and the participants' general health was assessed using the Short Form-12 questionnaire. Overall patient satisfaction was also reported. One hundred one patients (53 women and 48 men) with a mean age of 56.3 years (range 27-79 years) were included. The mean pain and function scores improved significantly from the baseline to 12-month follow-up evaluation, as follows: leg pain improved from 80.3 to 25.5, back pain from 54 to 29.4, and ODI score from 55.6 to 26.3%.
  
  
  CONCLUSIONS
  The early clinical outcomes of treatment with Dynesys are promising, with lessening of pain and disability found at follow-up review. Dynesys may be preferable to fusion for surgical treatment of degenerative spondylolisthesis and stenosis because it decreases back and leg pain while avoiding the relatively greater tissue destruction and the morbidity of donor site problems encountered in fusion. However, long-term follow-up care is still recommended.
authors.affiliation: University of Pittsburgh Medical Center-Health System, Presbyterian University Hospital, Pittsburgh, Pennsylvania 15213-2582, USA. Welchwc@upmc.edu
authors.forename: William C
authors.initials: WC
authors.lastname: Welch
authors.forename: Boyle C
authors.initials: BC
authors.lastname: Cheng
authors.forename: Tariq E
authors.initials: TE
authors.lastname: Awad
authors.forename: Reginald
authors.initials: R
authors.lastname: Davis
authors.forename: James H
authors.initials: JH
authors.lastname: Maxwell
authors.forename: Rick
authors.initials: R
authors.lastname: Delamarter
authors.forename: Jeffrey K
authors.initials: JK
authors.lastname: Wingate
authors.forename: John
authors.initials: J
authors.lastname: Sherman
authors.forename: M Mason
authors.initials: MM
authors.lastname: Macenski
mesh_terms: D000328:Adult; D000368:Aged; D019299:Decompression, Surgical / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017116:Low Back Pain / Q000000981:diagnostic imaging / Q000601:surgery; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011183:Postoperative Complications; D011859:Radiography; D012086:Reoperation; D012447:Sacrum / Q000000981:diagnostic imaging / Q000601:surgery; D013123:Spinal Fusion / Q000295:instrumentation*; D013130:Spinal Stenosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome