title: What is the importance of "halo" phenomenon around bone cement following vertebral augmentation for osteoporotic compression fracture?
abstract: We investigated the importance, risk factors, and clinical course of the radiolucent "halo" phenomenon around bone cement following vertebral augmentation for osteoporotic compression fracture. Preoperative osteonecrosis and a lump cement pattern were the most important risk factors for the peri-cement halo phenomenon, and it was associated with vertebral recollapse.
  
  
  BACKGROUND
  We observed a newly developed radiolucent area around the bone cement following vertebral augmentation for osteoporotic compression fractures. Here, we describe the importance of the peri-cement halo phenomenon, as well as any associated risk factors and long-term sequelae.
  
  
  METHODS
  In total, 175 patients (202 treated vertebrae) were enrolled in this study. The treated vertebrae were subdivided into two groups: Group A (with halo, n = 32) and Group B (without halo, n = 170), and the groups were compared with respect to multiple preoperative (age, sex, BMD, preoperative osteonecrosis) and perioperative factors (operative approach: vertebroplasty or kyphoplasty; cement distribution pattern; cement leakage; cement volume), and postoperative results (VAS score, recollapse). Logistic regression analysis was used to evaluate the relationship between the incidence of the peri-cement halo and all of the parameters described above.
  
  
  RESULTS
  Rates of osteonecrosis were also significantly higher in Group A than in Group B (62.5% vs. 31.2%, p < 0.05), and kyphoplasty (KP) was performed more frequently in Group A (43.8% vs. 17.6%, p < 0.05). Lump cement (93.8% vs. 30.6%, p < 0.05) and recollapse (78.1% vs. 24.7%, p < 0.05) were also more common among individuals in Group A. Logistic regression analysis also showed that preoperative osteonecrosis (OR = 3.679; 95% CI = 1.677-8.073; p = 0.001), KP (OR = 3.630; 95% CI = 1.628-8.095; p = 0.002), lump pattern (OR = 13.870; 95% CI = 2.907-66.188; p = 0.001), and vertebral recollapse (OR = 5.356; 95% CI = 1.897-15.122; p = 0.002) were significantly associated with peri-cement halo.
  
  
  CONCLUSIONS
  The peri-cement halo was found to be associated with vertebral recollapse, this sign likely represents a poor prognostic factor after vertebral augmentation for osteoporotic compression fractures.
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Gangnam Severance Hospital, Yonsei University College of Medicine, 712 Eongu-ro, Gangnam-gu, Seoul 135-720, Korea.
authors.forename: K H
authors.initials: KH
authors.lastname: Kim
authors.forename: S U
authors.initials: SU
authors.lastname: Kuh
authors.forename: J Y
authors.initials: JY
authors.lastname: Park
authors.forename: K S
authors.initials: KS
authors.lastname: Kim
authors.forename: D K
authors.initials: DK
authors.lastname: Chin
authors.forename: Y E
authors.initials: YE
authors.lastname: Cho
mesh_terms: D000368:Aged; D001843:Bone Cements / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D050815:Fractures, Compression / Q000209:etiology / Q000601:surgery*; D006801:Humans; D058498:Kyphoplasty / Q000009:adverse effects / Q000379:methods; D008297:Male; D008875:Middle Aged; D010020:Osteonecrosis / Q000150:complications; D058866:Osteoporotic Fractures / Q000601:surgery*; D011379:Prognosis; D011859:Radiography; D012008:Recurrence; D012307:Risk Factors; D016103:Spinal Fractures / Q000209:etiology / Q000601:surgery*; D013131:Spine / Q000000981:diagnostic imaging; D016896:Treatment Outcome; D054854:Vertebroplasty / Q000009:adverse effects / Q000379:methods
chemical_list: D001843:Bone Cements