title: What Effects Does Necrotic Area of Contrast-Enhanced MRI in Osteoporotic Vertebral Fracture Have on Further Compression and Clinical Outcome?
abstract: OBJECTIVE
  The objective of this study was to analyze the correlation between further compression and necrotic area in osteoporotic vertebral fracture (OVF) patients with contrast-enhanced magnetic resonance imaging (CEMRI). In addition, we investigated the radiological and clinical outcome according to the range of the necrotic area.
  
  
  METHODS
  Between 2012 and 2014, the study subjects were 82 OVF patients who did not undergo vertebroplasty or surgical treatment. The fracture areas examined on CEMRI at admission were defined as edematous if enhancement was seen and as necrotic if no enhancement was seen. The correlation between further compression and the necrotic and edematous areas of CEMRI, age, and bone mineral density was examined. Also, necrotic areas were classified into those with less than 25% (non-necrosis group) and those with more than 25% (necrosis group) according to the percentages of the entire vertebral body. For both groups, further compression and the changes in wedge and kyphotic angles were examined at admission and at 1 week, 3 months, and 6 months after admission, while the clinical outcomes were compared using the visual analog scale (VAS) and Eastern Cooperative Oncology Group (ECOG) performance status grade.
  
  
  RESULTS
  Further compression was 14.78±11.11% at 1 month and 21.75±14.43% at 6 months. There was a very strong correlation between the necrotic lesion of CEMRI and further compression (r=0.690,p<0.001). The compression of the necrosis group was 33.52±12.96%, which was higher than that of the non-necrosis group, 14.96±10.34% (p<0.005). Also, there was a statistically significantly higher number of intervertebral cleft development and surgical treatments being performed in the necrosis group than in the non-necrosis group (p<0.005). Moreover, there was a statistical difference in the decrease in the height of the vertebral body, and an increase was observed in the kyphotic change of wedge angle progression. There was also a difference in the VAS and ECOG performance scales.
  
  
  CONCLUSIONS
  The necrotic area of CEMRI in OVF had a strong correlation with further compression over time. In addition, with increasing necrosis, intervertebral clefts occurred more frequently, which induced kyphotic changes and resulted in poor clinical outcomes. Therefore, identifying necrotic areas by performing CEMRI on OVF patients would be helpful in determining their prognosis and treatment course.
authors.affiliation: Department of Neurosurgery, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Ja Myoung
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Young Seok
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Young Baeg
authors.initials: YB
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Seung Won
authors.initials: SW
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Kang
authors.affiliation: Department of Neurosurgery, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Shin Heon
authors.initials: SH
authors.lastname: Lee
keywords: Further compression; Kyphotic change; Necrotic area; Osteoporotic vertebral fracture