title: Predicting delayed union in osteoporotic vertebral fractures with consecutive magnetic resonance imaging in the acute phase: a multicenter cohort study.
abstract: This study demonstrated the predictive values of radiological findings for delayed union after osteoporotic vertebral fractures (OVFs). High-signal changes on T2WI were useful findings.
  
  
  
  The purpose of the present study is to determine predictive radiological findings for delayed union by magnetic resonance imaging (MRI) and plain X-rays at two time points in the acute phase of OVFs.
  
  
  
  This multicenter cohort study was performed from 2012 to 2015. A total of 218 consecutive patients with OVFs ≤2 weeks old were enrolled. MRIs and plain X-rays were performed at the time of enrollment and at 1- and 6-month follow-ups. Signal changes on T1-weighted imaging (T1WI) were classified as diffuse low-, confined low-, or no-signal change; those on T2WI were classified as high (similar to the intensity of cerebrospinal fluid), confined low-, diffuse low-, or no-signal change. The angular motion of the fractured vertebral body was measured with X-rays.
  
  
  
  A total of 153 patients completed the 6-month follow-up. A high-signal change on T2WI was most useful in predicting delayed union. Sensitivity, specificity, and positive predictive values were 53.3, 87.8, and 51.6 % at enrollment and 65.5, 84.8, and 51.4 % at the 1-month follow-up, respectively. The positive predictive value increased to 62.5 % with observation of high- or diffuse low-signal changes at both enrollment and the 1-month follow-up. The cutoff value of vertebral motion was 5 degrees. Sensitivity and specificity at enrollment were 52.4 and 74.1 %, respectively.
  
  
  
  This study demonstrated the radiological factors predicting delayed union after an OVF. T2 high-signal changes showed the strongest association with delayed union. Consecutive MRIs were particularly useful as a differential tool to predict delayed union following OVFs.
authors.affiliation: Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585, Japan. shinji@med.osaka-cu.ac.jp.
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hoshino
authors.affiliation: Department of Orthopaedic Surgery, Seikeikai Hospital, Saitama, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Takayama
authors.affiliation: Department of Orthopaedic Surgery, Sato Hospital, Konan, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Iseki
authors.affiliation: Department of Orthopaedic Surgery, Yodogawa Christian Hospital, Osaka, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Sasaoka
authors.affiliation: Department of Orthopaedic Surgery, Shiraniwa Hospital, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tsujio
authors.affiliation: Department of Orthopaedic Surgery, Osaka General Hospital of West Japan Railway Company, Osaka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Yasuda
authors.affiliation: Department of Orthopaedic Surgery, Nishinomiya Watanabe Hospital, Nishinomiya, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sasaki
authors.affiliation: Department of Orthopaedic Surgery, Saiseikai Nakatsu Hospital, Osaka, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Kanematsu
authors.affiliation: Department of Orthopaedic Surgery, Ishikiri Seiki Hospital, Osaka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kono
authors.affiliation: Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Toyoda
authors.affiliation: Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D005599:Fractures, Ununited / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D058866:Osteoporotic Fractures / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011859:Radiography; D012680:Sensitivity and Specificity; D016103:Spinal Fractures / Q000000981:diagnostic imaging* / Q000473:pathology; D013131:Spine
keywords: Delayed union; Osteoporosis; Radiological finding; Vertebral fractures