title: The BWM spinal fixator system. A preliminary report of a 2-year prospective, international multicenter study in a range of indications requiring surgical intervention for bone grafting and pedicle screw fixation.
abstract: METHODS
  A prospective, international, multicenter study of 400 patients who received the BWM fixator system.
  
  
  OBJECTIVE
  To assess the effectiveness and safety of the system in the management of various conditions requiring spinal fixation and bone grafting.
  
  
  BACKGROUND
  The BWM system was developed for the management of spinal instability of all etiologies occurring in the thoracic, thoracolumbar, and lumbosacral spine.
  
  
  METHODS
  Patients with fracture, tumor, spondylolisthesis, spondylitis, failed back, or other degenerative conditions of the spine received the BWM instrumentation as described in the study literature and were regularly reviewed for 2 years.
  
  
  RESULTS
  The results from the first 200 patients to complete the study showed an overall graft fusion rate of 94% (95% confidence interval: 91.3%-97.6%). There were marked improvements in measures of functional ability (P < 0.001, Wilcoxon test). Before surgery, less than half the patients were capable of outdoor activity. At 2 years, 80% were able to undertake outdoor activity. There were few perioperative difficulties reported. Postoperative complications associated with major surgery were seen in 18% patients. There were 23 (2.6%) pedicle screw failures, including two loosenings, and 13 (2.5%) spacer element failures, including three loosenings.
  
  
  CONCLUSIONS
  Clinical failure was not necessarily a consequence of component failure. The BWM fixator provided excellent stabilization during the process of bone graft consolidation. The risks of complication or component failure were no higher than those associated with similar devices.
authors.affiliation: Victoria Hospital, Department of Orthopaedics, University of Western Ontario, London, Canada.
authors.forename: S I
authors.initials: SI
authors.lastname: Bailey
authors.forename: P
authors.initials: P
authors.lastname: Bartolozzi
authors.forename: R
authors.initials: R
authors.lastname: Bertagnoli
authors.forename: S
authors.initials: S
authors.lastname: Boriani
authors.forename: A F
authors.initials: AF
authors.lastname: van Beurden
authors.forename: A T
authors.initials: AT
authors.lastname: Cross
authors.forename: H P
authors.initials: HP
authors.lastname: Friedl
authors.forename: K R
authors.initials: KR
authors.lastname: Gurr
authors.forename: H
authors.initials: H
authors.lastname: Halm
authors.forename: H J
authors.initials: HJ
authors.lastname: Kruls
authors.forename: P
authors.initials: P
authors.lastname: Metz-Stavenhagen
authors.forename: K J
authors.initials: KJ
authors.lastname: Schulze
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D016025:Bone Transplantation; D004867:Equipment Design; D005260:Female; D006801:Humans; D016268:Internal Fixators; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D019233:Retreatment; D013122:Spinal Diseases / Q000601:surgery*; D016103:Spinal Fractures / Q000601:surgery; D013125:Spinal Neoplasms / Q000601:surgery; D013166:Spondylitis / Q000601:surgery; D013168:Spondylolisthesis / Q000601:surgery