title: Experience with the second-generation Wallis interspinous dynamic stabilization device implanted in degenerative lumbar disease: a case series of 50 patients.
abstract: OBJECTIVE
  This study aimed to evaluate the short- to medium-term outcomes of the second-generation Wallis interspinous dynamic stabilization device for treatment of lumbar degenerative disease.
  
  
  METHODS
  Fifty patients with lumbar degenerative disease treated from August 2007 to September 2009 were included in this retrospective study. The Japanese Orthopedic Association (JOA) score and the Oswestry Disability Index (ODI) were used for therapeutic efficacy evaluation. Odom's criteria were used to evaluate postoperative outcome with regard to symptoms. Anteroposterior X-rays were obtained after surgery. All patients were followed up for 2 years.
  
  
  RESULTS
  Based on Odom's criteria, 22, 24 and 4 patients had excellent, good, and fair results respectively. The JOA score at 3, 12, and 24 months after surgery was significantly higher than before surgery (all p < 0.001), and the ODI score at 3, 12, and 24 months after surgery was significantly lower than before surgery (all p < 0.001). The posterior intervertebral disc height and the neural foramina height at 12 and 24 months after surgery was significantly higher than before surgery (both p < 0.001).
  
  
  CONCLUSIONS
  Implantation of the second-generation Wallis interspinous dynamic stabilization device produced satisfactory clinical outcome at short- and medium-term follow-up in patients with lumbar degenerative disease.
authors.affiliation: 117th Hospital of PLA, Department of Orthopedics, Hangzhou, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Pan
authors.forename: Zhi-Jing
authors.initials: ZJ
authors.lastname: Zhang
authors.forename: Yi-Sheng
authors.initials: YS
authors.lastname: Lu
authors.forename: Wen-Gen
authors.initials: WG
authors.lastname: Xu
authors.forename: Chu-Di
authors.initials: CD
authors.lastname: Fu
mesh_terms: D000328:Adult; D004867:Equipment Design; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019736:Prostheses and Implants; D011859:Radiography; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods; D013130:Spinal Stenosis / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome