title: Factors affecting recompression of augmented vertebrae after successful percutaneous balloon kyphoplasty: a retrospective analysis.
abstract: BACKGROUND
  The instantaneously recovered stability and strength following vertebral augmentation prevent continuous micro-motion and further collapse of fractured vertebrae. Despite this, during follow-up of our patients, we observed recompression of augmented vertebrae with significant vertebral height loss and aggravation of local kyphotic deformity.
  
  
  OBJECTIVE
  To identify the risk factors related to recompression and to evaluate the clinical significance of recompression.
  
  
  METHODS
  One hundred and twenty-one patients who underwent single-level kyphoplasty for osteoporotic vertebral fractures were retrospectively analyzed and classified into the following two groups: group 1 with recompression and group 2 without recompression. Characteristics of patients and fractured vertebrae were compared between the two groups. Univariate and multivariate regression analyses were performed to identify risk factors for recompression. We evaluated the visual analogue scale (VAS) and the Oswestry disability index (ODI) scores in both groups to elucidate the clinical impact.
  
  
  RESULTS
  During an average of 20.75 ± 4.43 months of follow-up, 17 augmented vertebrae developed recompression. In the recompression group, vertebral height loss was accompanied by significantly aggravated local kyphotic deformity. The local kyphotic angle differed significantly between the two groups at final follow-up (P = 0.011). However, the VAS and ODI scores were maintained at final follow-up in both groups although the values were slightly higher in group 1. Solid lump distribution pattern (OR = 8.718; P = 0.003) and the degree of vertebral height restoration (OR = 1.260; P < 0.001) were identified as the most important risk factors for recompression.
  
  
  CONCLUSIONS
  Fractured vertebrae containing solid lump cement and those with more vertebral height restoration are at higher risk of recompression. More attention should be given to these patients considering the aggravated local kyphotic deformity.
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, PR China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Niu
authors.affiliation: Department of Clinical Radiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, PR China.
authors.forename: Haifei
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Department of Clinical Radiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Meng
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, PR China.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Shi
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Meng
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, PR China yhlpaper@126.com mbyang2000@126.com.
authors.forename: Huilin
authors.initials: H
authors.lastname: Yang
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D015519:Bone Density; D003952:Diagnostic Imaging; D004185:Disability Evaluation; D005260:Female; D050815:Fractures, Compression / Q000175:diagnosis / Q000601:surgery*; D006801:Humans; D058498:Kyphoplasty / Q000379:methods*; D008297:Male; D058866:Osteoporotic Fractures / Q000175:diagnosis / Q000601:surgery*; D010147:Pain Measurement; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D016103:Spinal Fractures / Q000175:diagnosis / Q000601:surgery*; D016896:Treatment Outcome
keywords: Percutaneous balloon kyphoplasty; augmented vertebrae; clinical efficacy; recompression; risk factors