title: Quantitative volumetry of cement leakage in viscosity-controlled vertebroplasty.
abstract: METHODS
  This study was designed as a cohort study comparing a prospective sample to a historic control group.
  
  
  OBJECTIVE
  The aim of the actual trial was to compare the rate of cement leakage by quantitative volumetry comparing viscosity-controlled and non-viscosity-controlled vertebroplasty.
  
  
  BACKGROUND
  Percutaneous vertebroplasty (PVP) is a widespread safe and effective technique in the treatment of osteoporotic compression fractures and vertebral metastatic lesions. However, cement leakage has been identified as a problem of this technique. The leakage rates are reported to range from 7% to 90%. The main influence factor for leakage has been demonstrated to be cement viscosity. Assessment of appropriate injection viscosity is highly subjective and observer dependent. Viscosity-controlled vertebroplasty (Vertecem system) has been developed to objectively measure cement viscosity before injection. It introduces a viscosimeter to measure the actual cement viscosity before injection into the vertebra, and therefore may prevent leakages resulting from low-viscosity cement injections. Despite more than 800 Pubmed citations on PVP, there is only 1 report on distinct measurement of cement leakage by semiquantitative volumetry.
  
  
  METHODS
  A total of 111 vertebrae in 68 patients, in which PVP was performed for osteoporotic fractures, were included. Thirty-seven patients (76 operated vertebrae) were assessed prospectively using the viscosity-controlled vertebroplasty. The results were compared with a retrospective group of 31 patients (35 operated vertebrae) undergoing PVP without using a viscosimeter.
  
  
  RESULTS
  : There were no significant differences between the 2 groups in the applied volume of cement per fractured vertebra (P=0.73). The frequency of cement leakage in viscosimete-assisted vertebroplasty was 42.1% and 58.3% in the historic group. Cement leakage into the basivertebral vein (type B), was detected in 6.6% with and in 11.1% without viscosimetry.
  
  
  CONCLUSIONS
  The use of viscosity-controlled vertebroplasty led to a decrease in the leakage rate from 58.3% to 42.1%. Leakage into the basivertebral vein with the risk of compression of nerval structures was reduced to almost 50% when viscosimetry was performed. It revealed to be a helpful tool for more unexperienced surgeons to assess the appropriate viscosity for vertebroplasty.
authors.affiliation: Department of Orthopaedic Surgery, Medical University Innsbruck, Innsbruck, Austria. michaela.gstoettner@gmx.com
authors.forename: Michaela
authors.initials: M
authors.lastname: Gstöttner
authors.forename: Alexandra
authors.initials: A
authors.lastname: Angerer
authors.forename: Rafal
authors.initials: R
authors.lastname: Rosiek
authors.forename: Christian Michael
authors.initials: CM
authors.lastname: Bach
mesh_terms: D001843:Bone Cements / Q000009:adverse effects / Q000592:standards*; D015331:Cohort Studies; D005119:Extravasation of Diagnostic and Therapeutic Materials / Q000503:physiopathology / Q000517:prevention & control*; D005260:Female; D050815:Fractures, Compression / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D010024:Osteoporosis / Q000150:complications / Q000473:pathology; D011183:Postoperative Complications / Q000503:physiopathology / Q000517:prevention & control*; D011446:Prospective Studies; D011859:Radiography; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D013131:Spine / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome; D054854:Vertebroplasty / Q000379:methods*; D014783:Viscosity
chemical_list: D001843:Bone Cements