title: The prevalence of thoracolumbar kyphosis in achondroplasia: a systematic review.
abstract: OBJECTIVE
  Thoracolumbar kyphosis (TLK) is described as a common presentation in children with achondroplasia. However, the prevalence and development of TLK are ill-defined, as well as its clinical implications. The goal of this study was to assess the existing evidence on the prevalence and development of TLK from the literature.
  
  
  METHODS
  A systematic literature review was performed in PubMed, EMBASE, and Thomson Reuters (ISI) Web of Knowledge. Articles were selected and evaluated with the Newcastle-Ottawa Scale in duplicate. Articles were included when the included patients were diagnosed with achondroplasia and the prevalence of TLK in this population was reported.
  
  
  RESULTS
  Seven studies were included. The prevalence of TLK varied between 50 and 100%, but the populations differed significantly. Also, the measurement method and definition of TLK was not given in any of the included studies. Two studies reported TLK in different age categories, but the development of TLK through age could not be inferred. Overall, the methodological quality was low.
  
  
  CONCLUSIONS
  The prevalence rates of TLK in achondroplasia could not be assessed from the literature because the populations differed and the definition of TLK in the studies was not described. In future studies, this definition needs to be given and patients need to be assessed over a longer period of time, with repeated assessments.
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Engberts
authors.forename: Wilco C H
authors.initials: WC
authors.lastname: Jacobs
authors.forename: Sanne J A M
authors.initials: SJ
authors.lastname: Castelijns
authors.forename: Rene M
authors.initials: RM
authors.lastname: Castelein
authors.forename: Carmen L A
authors.initials: CL
authors.lastname: Vleggeert-Lankamp