title: Subsequent vertebral fractures following spinal fusion surgery for degenerative lumbar disease: a mean ten-year follow-up.
abstract: METHODS
  Case-control study.
  
  
  OBJECTIVE
  To assess the long-term prevalence of vertebral fractures after lumbar spinal fusion with instrumentation.
  
  
  BACKGROUND
  The incidence of the adjacent and the nonadjacent, remote level subsequent vertebral fractures after lumbar spinal fusion is not well described in the literature.
  
  
  METHODS
  The study is a retrospective analysis of 100 consecutive patients of 55 years of age or older with spinal fusion for degenerative diseases between L1 and S1, and instrumentation for less than 4 segments. Patients with prevalent vertebral fractures defined at the time of surgery, or patients with secondary causes of osteoporosis were excluded. Mean follow-up period was 10.2 years (range, 7-14 years). Acute vertebral fractures were determined by magnetic resonance imaging and lateral spine radiographs.
  
  
  RESULTS
  Acute vertebral fractures were determined in 20 vertebrae in 14 (24%) of the 59 female patients, whereas 1 male patient (2%) had 1 vertebral fracture during the follow-up period. Eighteen of the 21 fractures occurred within 2 years of the spinal instrumentation surgery. Regarding time to fracture occurrence after surgery, adjacent level fractures occurred within 8 months, and remote level fractures occurred between 8 and 22 months after surgery.
  
  
  CONCLUSIONS
  Postmenopausal female patients who underwent lumbar spinal instrumentation surgery were susceptible to develop subsequent vertebral fractures within 2 years after surgery. The greater the number of spinal segments between the fracture and the instrumentation was, the longer the time after surgery.
authors.affiliation: Department of Orthopaedic Surgery, Teikyo University Chiba Medical Center, Ichihara-city, Chiba, Japan. tomotomot2001@aol.com
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Toyone
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Ozawa
authors.forename: Koya
authors.initials: K
authors.lastname: Kamikawa
authors.forename: Atsuya
authors.initials: A
authors.lastname: Watanabe
authors.forename: Keisuke
authors.initials: K
authors.lastname: Matsuki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamashita
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Shiboi
authors.forename: Masato
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Wada
authors.forename: Kunimasa
authors.initials: K
authors.lastname: Inada
authors.forename: Yasuchika
authors.initials: Y
authors.lastname: Aoki
authors.forename: Gen
authors.initials: G
authors.lastname: Inoue
authors.forename: Seiji
authors.initials: S
authors.lastname: Ohtori
authors.forename: Tadashi
authors.initials: T
authors.lastname: Tanaka
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000150:complications / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D058866:Osteoporotic Fractures / Q000453:epidemiology*; D011183:Postoperative Complications / Q000453:epidemiology*; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000453:epidemiology*; D013123:Spinal Fusion / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D055009:Spondylosis / Q000601:surgery