title: Analysis of halo-orthoses application in children less than three years old.
abstract: OBJECTIVE
  To evaluate the safety and efficacy of halo immobilization in children younger than 3 years.
  
  
  METHODS
  All children less than 3 years of age who were placed in a halo-orthosis at a tertiary pediatric center were reviewed to determine the indications, safety, and efficacy of this method. Adequacy of immobilization and correct technique was established considering the chronology of maturation (skull and brain development). The functional outcome was analyzed.
  
  
  RESULTS
  Ten patients (<3 years old) were identified from a total of 150 where halo ring/vest immobilization was used. There were six boys and four girls, with an average age of 2 years (range 10 months to 2 years and 10 months). The average time of immobilization in the halo-orthosis was 75 days (range 33-168 days), and the average follow-up time was 5 years and 2 months (range 1-12 years). There were two halo-related problems and four related to the index procedure. Halo-related problems included pin-site infection in one patient, and three pins loosening in another. There were four complications associated with the index procedure, all early in the series, including three cases of pseudarthrosis and one patient that had an insufficient decompression of basilar invagination. Two of the three failed fusions occurred at the occipito-cervical junction, which prompted us to develop new techniques for fusion at this level.
  
  
  CONCLUSIONS
  Halo-orthosis is a relatively safe and reliable device for immobilization of the upper cervical spine in children less than 3 years old. Understanding the developmental anatomy and a limited CT scan are helpful in pin placement. We recommend the use of a multiple pin construct, perpendicular insertion, and precise tightening with good pin-site care and frequent follow-up. The benefits seem to outweigh the risks in this population, considering the mechanical advantages of the halo-orthosis.
authors.affiliation: Department of Orthopaedics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Arkader
authors.forename: Harish S
authors.initials: HS
authors.lastname: Hosalkar
authors.forename: Denis S
authors.initials: DS
authors.lastname: Drummond
authors.forename: John P
authors.initials: JP
authors.lastname: Dormans