title: [CT-based analysis of cement distribution in unipedicular vertebroplasty].
abstract: BACKGROUND
  Vertebroplasty and kyphoplasty are being increasingly used in the treatment of osteoporotic vertebral body fractures. Shortening the duration of operative time and radiation exposure as well as reduction of cannulation-related risks and costs are advantages of the unipedicular technique in contrast to less homogeneous cement distribution as a possible disadvantage. Biomechanical investigations have shown similar results with respect to strength and stiffness both for uni- and bipedicular vertebroplasty. Studies evaluating cement distribution with CT scans using a unipedicular approach have not been published yet.
  
  
  METHODS
  We present a prospective study on 92 vertebral body fractures (Th8-L5) in 60 patients, aged 76.8 (60-95) years, which were treated by unipedicular vertebroplasty using a para-/transpedicular approach. We evaluated needle position, injected cement volume, and cement deposition based on CT scans. The vertebral body was divided into nine segments in a frontal plane view. The needle was placed in the middle third in 85.9% (79/92), in the right in 11.9% (11/92), and in the left third in 2.2% (2/92). Complications associated with cannulation were not observed. The injectable cement volume was 4.5 (1.5-9.0) ml.
  
  
  RESULTS
  With respect to superior, middle, and inferior parts, filling of the middle third was achieved in 94.9%, of the right third in 76.1%, and of the left third in 80.4%. Only the right- and left-sided inferior segments showed a filling rate below 75%. Positioning the needle into the right or left third resulted in comparably high filling rates of the middle third (100/83.3%) but only 50.0/54.5% of the contralateral third of the vertebral body.
  
  
  CONCLUSIONS
  Unipedicular vertebroplasty using a modified approach permits a reliable placement of the needle into the middle third of the vertebral body, which is the optimal position regarding cement distribution. Unipedicular vertebroplasty allows homogeneous filling and augmentation of vertebral bodies without need for a second cannulation.
authors.affiliation: Abteilung für Unfall-, Hand- und Wiederherstellungschirurgie, Klinikum, Hagenskamp 34, 29525 Uelzen, Deutschland. walzmed@web.de
authors.forename: M
authors.initials: M
authors.lastname: Walz
authors.forename: E
authors.initials: E
authors.lastname: Esmer
authors.forename: B
authors.initials: B
authors.lastname: Kolbow
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001843:Bone Cements / Q000493:pharmacokinetics / Q000627:therapeutic use*; D002404:Catheterization; D004305:Dose-Response Relationship, Drug; D005119:Extravasation of Diagnostic and Therapeutic Materials / Q000000981:diagnostic imaging; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods*; D050815:Fractures, Compression / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007267:Injections / Q000295:instrumentation; D007738:Kyphosis / Q000000981:diagnostic imaging / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000601:surgery*; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D012117:Resins, Synthetic / Q000493:pharmacokinetics / Q000627:therapeutic use*; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D025321:Surgery, Computer-Assisted; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D014057:Tomography, X-Ray Computed
chemical_list: D001843:Bone Cements; C523913:Osteofirm; D012117:Resins, Synthetic