title: Ring apophysis fracture in pediatric lumbar disc herniation: a common entity.
abstract: OBJECTIVE
  Lumbar disc herniation (LDH) can be associated with ring apophysis fracture (RAF), which is found in 6% of adult cases. However, the incidence and management of RAF in pediatric LDH is not well documented. The purpose of this study is to determine the prevalence of RAF in pediatric LDH, identify risk factors and explore the influence of RAF on the surgical management and outcome of LDH patients.
  
  
  METHODS
  Hospital records and images were retrospectively reviewed for all pediatric patients (<18 years old) who underwent CT scanning for LDH at BC Children's Hospital from 1985 to 2010.
  
  
  RESULTS
  Forty-two patients met the study inclusion criteria. RAF was present in 38% of the pediatric patients with LDH. There was a significant correlation with gender (p = 0.021; 55% of the males had RAF, and 20% of the females) and association with central herniations (p = 0.003). At the last follow-up, 58% of the patients with RAF were symptom free, compared with 68% of the patients with no RAF.
  
  
  CONCLUSIONS
  RAF is more frequently associated with LDH in children than in adults. Gender and central disc herniation are associated with RAF. Given the frequency of RAF, to properly identify these fractures and anticipate their treatment, preoperative CT would be necessary.
authors.affiliation: Division of Pediatric Neurosurgery, Department of Surgery, University of British Columbia and B.C. Children's Hospital, Vancouver, B.C., Canada.
authors.forename: Ash
authors.initials: A
authors.lastname: Singhal
authors.forename: Anish
authors.initials: A
authors.lastname: Mitra
authors.forename: Doug
authors.initials: D
authors.lastname: Cochrane
authors.forename: Paul
authors.initials: P
authors.lastname: Steinbok
mesh_terms: D000293:Adolescent; D002648:Child; D017586:Diskectomy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D007431:Intraoperative Complications / Q000453:epidemiology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery*; D008297:Male; D011183:Postoperative Complications / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D014057:Tomography, X-Ray Computed