title: Vertebral compression fracture in the middle of fused segments without a history of injury: a case report.
abstract: METHODS
  A case report and review of the literature.
  
  
  OBJECTIVE
  To report a rare case of a vertebral compression fracture in the middle of fused segments in the absence of a history of trauma, and to investigate the contributory factors.
  
  
  BACKGROUND
  Few articles have been published on vertebral fractures among fused segments. However, several articles have addressed fractures at juxtafused segments after implant removal. To the best of the authors' knowledge, only one case of compression fracture within fused segments has been previously reported.
  
  
  METHODS
  This study involved the case of a 62-year-old woman with vertebral compression fracture of L4 within a solid fused segment region after implant removal. An investigation was conducted to identify the factors that contributed to this compression fracture.
  
  
  RESULTS
  Plain radiographs and bone scanning showed a compression fracture of L4 within a region of fused segments (L3-S1) after implant removal without the history of injury. BMD revealed osteopenia of -2.3 SD on the neck of the femur. The patient's symptoms were relieved by conservative treatment. The contributory factors may have been persistent anterior motion, osteopenia and/or osteoporosis, and a subcortical substance defect associated with screw tracks after implant removal.
  
  
  CONCLUSIONS
  Vertebral compression fractures in solid fused segments may occur as a complication of implant removal. Accordingly, if spinal implant removal is needed for revision surgery, surgeons should be aware of this significant complication.
authors.affiliation: Department of Orthopaedic Surgery, Kang-Nam St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea. kyh@catholic.ac.kr
authors.forename: Kee-Yong
authors.initials: KY
authors.lastname: Ha
authors.forename: Soon-Eok
authors.initials: SE
authors.lastname: Kwon
authors.forename: Ki-Won
authors.initials: KW
authors.lastname: Kim
authors.forename: In-Soo
authors.initials: IS
authors.lastname: Oh
authors.forename: Yoon-Min
authors.initials: YM
authors.lastname: Lee
mesh_terms: D015502:Absorptiometry, Photon; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000209:etiology / Q000473:pathology; D019299:Decompression, Surgical; D020878:Device Removal; D005260:Female; D005272:Femur Neck / Q000473:pathology; D017102:Fracture Healing; D050815:Fractures, Compression / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology / Q000628:therapy; D006801:Humans; D007796:Laminectomy; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D012086:Reoperation; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology / Q000628:therapy; D013123:Spinal Fusion / Q000009:adverse effects* / Q000295:instrumentation; D016896:Treatment Outcome