title: Height restoration of osteoporotic vertebral compression fractures using different intravertebral reduction devices: a cadaveric study.
abstract: BACKGROUND
  The treatment of osteoporotic vertebral compression fractures using transpedicular cement augmentation has grown significantly during the past two decades. Balloon kyphoplasty was developed to restore vertebral height and improve sagittal alignment. Several studies have shown these theoretical improvements cannot be transferred universally to the clinical setting.
  
  
  OBJECTIVE
  The aim of the current study is to evaluate two different procedures used for percutaneous augmentation of vertebral compression fractures with respect to height restoration: balloon kyphoplasty and SpineJack.
  
  
  METHODS
  Twenty-four vertebral bodies of two intact, fresh human cadaveric spines (T6-L5; donor age, 70 years and 60 years; T-score -6.8 points and -6.3 points) were scanned using computed tomography (CT) and dissected into single vertebral bodies. Vertebral wedge compression fractures were created by a material testing machine (Universal testing machine, Instron 5566, Darmstadt, Germany). The axial load was increased continuously until the height of the anterior edge of the vertebral body was reduced by 40% of the initial measured values. After 15 minutes, the load was decreased manually to 100 N. After postfracture CT, the clamped vertebral bodies were placed in a custom-made loading frame with a preload of 100 N. Twelve vertebral bodies were treated using SpineJack (SJ; Vexim, Balma, France), the 12 remaining vertebral bodies were treated with balloon kyphoplasty (BKP; Kyphon, Medtronic, Sunnyvale, CA, USA). The load was maintained during the procedure until the cement set completely. Posttreatment CT was performed. Anterior, central, and posterior height as well as the Beck index were measured prefracture and postfracture as well as after treatment.
  
  
  RESULTS
  For anterior height restoration (BKP, 0.14±1.48 mm; SJ, 3.34±1.19 mm), central height restoration (BKP, 0.91±1.04 mm; SJ, 3.24±1.22 mm), and posterior restoration (BKP, 0.37±0.57 mm; SJ, 1.26±1.05), as well as the Beck index (BKP, 0.00±0.06 mm; SJ, 0.10±0.06), the values for the SpineJack group were significantly higher (p<.05) CONCLUSION: The protocols for creating wedge fractures and using the instrumentation under a constant preload of 100 N led to reproducible results and effects. The study showed that height restoration was significantly better in the SpineJack group compared with the balloon kyphoplasty group. The clinical implications include a better restoration of the sagittal balance of the spine and a reduction of the kyphotic deformity, which may relate to clinical outcome and the biological healing process.
authors.affiliation: Department of Trauma and Reconstructive Surgery Philipps University of Marburg, University Hospital Giessen and Marburg, Baldingerstrasse, 35043 Marburg, Germany. Electronic address: antnkrueg@aol.com.
authors.forename: Antonio
authors.initials: A
authors.lastname: Krüger
authors.affiliation: Department of Trauma and Reconstructive Surgery Philipps University of Marburg, University Hospital Giessen and Marburg, Baldingerstrasse, 35043 Marburg, Germany.
authors.forename: Ludwig
authors.initials: L
authors.lastname: Oberkircher
authors.affiliation: Department of Diagnostic Radiology, Philipps University of Marburg, University Hospital Giessen and Marburg, Baldingerstrasse, 35043 Marburg, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Figiel
authors.affiliation: Department of Trauma and Reconstructive Surgery Philipps University of Marburg, University Hospital Giessen and Marburg, Baldingerstrasse, 35043 Marburg, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Floßdorf
authors.affiliation: Biomechanics Laboratory, IMFT UMR 5502 Purpan University Hospital, Place Dr. Baylac, 31059 Toulouse, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Bolzinger
authors.affiliation: Spine-Unit, University Hospital, Avenida de Ramon y Cajal 7, 47005 Valladolid, Spain.
authors.forename: David C
authors.initials: DC
authors.lastname: Noriega
authors.affiliation: Department of Trauma and Reconstructive Surgery Philipps University of Marburg, University Hospital Giessen and Marburg, Baldingerstrasse, 35043 Marburg, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Ruchholtz
mesh_terms: D000368:Aged; D001843:Bone Cements / Q000627:therapeutic use; D050815:Fractures, Compression / Q000601:surgery*; D006801:Humans; D058498:Kyphoplasty / Q000295:instrumentation / Q000379:methods*; D008159:Lumbar Vertebrae / Q000601:surgery; D008875:Middle Aged; D058866:Osteoporotic Fractures / Q000601:surgery*; D016103:Spinal Fractures / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000601:surgery
chemical_list: D001843:Bone Cements
keywords: Cadaver; Height restoration; Kyphoplasty; Vertebral compression fracture; Vertebroplasty