title: Usefulness of prone cross-table lateral radiographs in vertebral compression fractures.
abstract: BACKGROUND
  Dynamic radiographs are recommended to investigate non-healing evidence such as the dynamic mobility or intravertebral clefts in osteoporotic vertebral compression fractures (VCFs). However, it is difficult to examine standing flexion and extension lateral radiographs due to severe pain. The use of prone cross-table lateral radiographs (PrLRs) as a diagnostic tool has never been proposed to our knowledge. The purpose of this study is to clarify the usefulness of PrLRs in diagnosis and treatment of VCFs.
  
  
  METHODS
  We reviewed 62 VCF patients examined with PrLRs between January 1, 2008 and June 30, 2011. To compare the degree of pain provoked between standing extension lateral radiographs (StLRs) and PrLRs, numeric rating scale (NRS) scores were assessed and compared by a paired t-test. Vertebroplasty was done for 40 patients and kyphoplasty was done for 9 patients with routine manners. To assess the degree of postural reduction, vertebral wedge angles (VWA) and vertebral height ratios (VHR) were calculated by using preoperative StLRs, PrLRs, and postoperative lateral radiographs. Two variables derived from changes in VWA and VHR between preoperative and postoperative radiographs were compared by a paired t-test.
  
  
  RESULTS
  The average NRS scores were 6.23 ± 1.67 in StLRs and 5.18 ± 1.47 in PrLRs. The degree of pain provocation was lower in using PrLRs than StLRs (p < 0.001). The average changes of VWA between preoperative and postoperative status were 5.24° ± 6.16° with PrLRs and 3.46° ± 3.47° with StLRs. The average changes of VHR were 0.248 ± 0.178 with PrLRs and 0.148 ± 0.161 with StLRs. The comparisons by two variables showed significant differences for both parameters (p = 0.021 and p < 0.001, respectively). The postoperative radiological status was reflected more precisely when using PrLRs than StLRs.
  
  
  CONCLUSIONS
  In comparison with StLR, the PrLR was more accurate in predicting the degree of restoration of postoperative vertebral heights and wedge angles, and provoked less pain during examination. The PrLR could be a useful diagnostic tool to detect intravertebral cleft or intravertebral dynamic instability.
authors.affiliation: Department of Orthopedic Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Jae Hwan
authors.initials: JH
authors.lastname: Cho
authors.forename: Sang Ik
authors.initials: SI
authors.lastname: Shin
authors.forename: Jae Hyup
authors.initials: JH
authors.lastname: Lee
authors.forename: Jin Sup
authors.initials: JS
authors.lastname: Yeom
authors.forename: Bong-Soon
authors.initials: BS
authors.lastname: Chang
authors.forename: Choon-Ki
authors.initials: CK
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D050815:Fractures, Compression / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D008297:Male; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000473:pathology; D011187:Posture / Q000502:physiology; D011859:Radiography / Q000379:methods*; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000000981:diagnostic imaging* / Q000601:surgery; D013131:Spine / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D054854:Vertebroplasty
keywords: Intravertebral cleft; Kyphoplasty; Osteoporosis; Prone lateral radiograph; Vertebral fracture; Vertebroplasty