title: Reducible and irreducible os odontoideum in childhood treated with posterior wiring, instrumentation and fusion. Past or present?
abstract: BACKGROUND
  The aim of the study was to evaluate the results of instrumented rod and wire fusion in children with craniovertebral junction (CVJ) instability and os odontoideum.
  
  
  METHODS
  We evaluated seven children (mean age 9.85 years) with Down and Morquio's syndromes and primary os odontoideum. X-ray, computerized tomography (CT) scan and magnetic resonance (MR) imaging of the CVJ showed reducible instability in all of the cases but one. All the children underwent surgical correction by means of posterior wiring, instrumentation, fusion and external orthosis. A posterior wiring technique was also utilized in the only child with irreducible preoperative atlantoaxial instability, which, however, proved to be reducible under general anesthesia.
  
  
  RESULTS
  At maximum follow-up (observation range 28 to 106 months, mean 59.42 months), the clinical picture was improved in all the patients. The postoperative neuroradiological investigations demonstrated satisfactory bony fusion with neural decompression in all patients.
  
  
  CONCLUSIONS
  A wiring technique to correct atlantoaxial instabilities has been shown to be more relevant in these children with syndromic atlantoaxial dislocation and os odontoideum due to its simplicity, safety (continuous fluoroscopic assistance is not necessary and there is no risk of neuro-vascular injuries) and lower costs (no complex hardware devices; no neuronavigation systems are required). Preoperative irreducibility of the C1-C2 shift is not an absolute criterion for transoral decompression in children since os odontoideum can be reduced under general anesthesia.
authors.affiliation: Institute of Neurosurgery, Catholic University School of Medicine, Rome, Italy. mvisocchi@hotmail.com
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Visocchi
authors.forename: Eduardo
authors.initials: E
authors.lastname: Fernandez
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ciampini
authors.forename: Concezio
authors.initials: C
authors.lastname: Di Rocco
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001268:Atlanto-Axial Joint / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery*; D001864:Bone Wires; D002648:Child; D004314:Down Syndrome / Q000150:complications; D005260:Female; D006801:Humans; D016268:Internal Fixators; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D009085:Mucopolysaccharidosis IV / Q000150:complications; D009809:Odontoid Process / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000254:growth & development; D011183:Postoperative Complications / Q000517:prevention & control; D013117:Spinal Cord Compression / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D013122:Spinal Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome