title: Value of preoperative magnetic resonance imaging measurements in thoracic percutaneous vertebroplasty using unilateral.
abstract: BACKGROUND
  Increasing the successful puncture rate of the percutaneous vertebroplasty (PVP) in thoracic vertebral compression fracture by unilateral puncture is a problem that spinal surgeons are trying to solve. The aim of this study was to assess the value of preoperative MRI imaging measurements for PVP using a unilateral puncture.
  
  
  METHODS
  We performed a retrospective, comparative study of two groups of osteoporotic thoracic vertebral compression fracture patients who had received a PVP using a unilateral puncture. Group A (22 patients with 27 valid vertebrae) received PVP with a unilateral puncture between October 2005 and February 2007. Group B (18 patients with 24 valid vertebrae) received a routine MRI imaging measurements before a PVP between March 2007 and June 2008. We determined the target area to puncture based on the preoperative MRI cross-sectional images of vertebra. The PVP used a simultaneous puncture through a unilateral posterolateral approach, so the vertical distance from the point of skin puncture to the posterior median line, as well as the puncture angle, were measured using the MRI. The results were used to guide the PVP operation. We compared these two groups based on the average time for a single vertebra operation, the achievement ratio of puncture, and the incidence of bone cement leakage during surgery. The mean follow-up period was 14.2 months (range 12 - 23 months). The pre- and post-operative visual analogue score (VAS) (3 and 12 months post-surgery), the variation of Oswestry disability index (ODI) and the incidence of long-term complications were also compared.
  
  
  RESULTS
  The average time of a single vertebra operation in groups A and B were (34.7 ± 5.4) and (23.3 ± 4.2) minutes, respectively. In groups A and B, the success rates of puncture were 74.1% and 91.7%, respectively. Postoperative reduction of the average VAS scores in groups A and B at 3 and 12 months post-surgery were 5.8 ± 2.1, 6.1 ± 1.8, 6.1 ± 2.0, 6.2 ± 1.6, respectively. However, the ODI increase was 41.6% ± 5.7%, 40.6% ± 6.0%, 46.3% ± 5.2%, 46.1% ± 6.7%. Paired t test evaluation of the values above showed a significant difference in the time of single-vertebra operation and the success rates between groups A and B (P < 0.05), but no significant difference was seen in the reduction of VAS scores and ODI (P > 0.05). There was no statistically significant difference in the complication rate between the two groups.
  
  
  CONCLUSIONS
  A preoperative MRI measurement effectively reduced the time of PVP with a unilateral puncture, which improved the success rate of the puncture without an additional risk of operation related complication.
authors.affiliation: Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ma
authors.forename: Li-Xun
authors.initials: LX
authors.lastname: Wang
authors.forename: Hong-Li
authors.initials: HL
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Jiang
authors.forename: Fei-Zhou
authors.initials: FZ
authors.lastname: Lu
authors.forename: Jian-Yuan
authors.initials: JY
authors.lastname: Jiang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D050815:Fractures, Compression / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D054854:Vertebroplasty / Q000379:methods*