title: Clinical measurements of cement injection pressure during vertebroplasty.
abstract: METHODS
  Clinical study of injection pressure during vertebroplasty.
  
  
  OBJECTIVE
  To investigate the range of injection pressures during conventional vertebroplasty interventions and to study the influence of syringe design and cement polymerization time on injection pressure.
  
  
  BACKGROUND
  Vertebroplasty is an efficient procedure for the treatment of painful vertebral fractures. However, cement leakage is a potentially serious complication. Although injection pressure has been suggested as a factor for extravasation risk, to date, there are only anecdotal reports of pressure data for cement augmentation in the clinic.
  
  
  METHODS
  Using a syringe holder instrumented with load and displacement transducers, injection pressure and volume were recorded in vivo during conventional cement augmentation. Wide (3 mm opening) and normal (1.8 mm opening) syringes were alternated such that each type was evaluated for early (300-500 seconds postmixing) and late (>500 seconds postmixing) cement polymerization time. The influence of syringe type and polymerization time on injection pressure was evaluated using a multifactorial analysis of variance followed by Scheffe post hoc comparison.
  
  
  RESULTS
  The maximum peak injection pressure measured was 3215 kPa. The average pressure peaks for normal and wide syringes were 1693 +/- 653 kPa and 1727 +/- 597 kPa, respectively. No statistically significant differences were found between injection pressures with wide and normal syringes. Higher injection pressures were observed later in the polymerization process.
  
  
  CONCLUSIONS
  High injection pressures approaching 20 atmospheres are reached during conventional vertebroplasty. Widening the syringe tip diameter did not significantly change injection pressures, whereas elapsed time did. Further research is needed to improve injection equipment and materials for vertebroplasty.
authors.affiliation: M. E. Müller Institute for Surgical Technology and Biomechanics, Bern, Switzerland. jorg.krebs@MEMcenter.unibe.ch
authors.forename: Jörg
authors.initials: J
authors.lastname: Krebs
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Ferguson
authors.forename: Marc
authors.initials: M
authors.lastname: Bohner
authors.forename: Gamal
authors.initials: G
authors.lastname: Baroud
authors.forename: Thomas
authors.initials: T
authors.lastname: Steffen
authors.forename: Paul F
authors.initials: PF
authors.lastname: Heini
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001843:Bone Cements / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007267:Injections / Q000295:instrumentation / Q000379:methods; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000295:instrumentation* / Q000379:methods*; D011312:Pressure; D016103:Spinal Fractures / Q000601:surgery*; D013594:Syringes
chemical_list: D001843:Bone Cements