title: The functional muscle-bone unit in children with cerebral palsy.
abstract: Our results suggest that the prevalence of bone health deficits in children with CP was overestimated, when using only age- and height-adjusted bone mineral content (BMC) and areal bone mineral density (aBMD). When applying the functional muscle-bone unit diagnostic algorithm (FMBU-A), the prevalence of positive results decreased significantly. We recommend applying the FMBU-A when assessing bone health in children with CP.
  
  
  
  The prevalence of bone health deficits in children with cerebral palsy (CP) might be overestimated because age- and height-adjusted reference percentiles for bone mineral content (BMC) and areal bone mineral density (aBMD) assessed by dual-energy X-ray absorptiometry (DXA) do not consider reduced muscle activity. The aim of this study was to compare the prevalence of positive DXA-based indicators for bone health deficits in children with CP to the prevalence of positive findings after applying a functional muscle-bone unit diagnostic algorithm (FMBU-A) considering reduced muscle activity.
  
  
  
  The present study was a monocentric retrospective analysis of 297 whole body DXA scans of children with CP. The prevalence of positive results of age- and height-adjusted BMC and aBMD defined as BMC and aBMD below the P3 percentile and of the FMBU-A was calculated.
  
  
  
  In children with CP, the prevalence of positive results of age-adjusted BMC were 33.3% and of aBMD 50.8%. Height-adjusted results for BMC and aBMD were positive in 16.8 and 36.0% of cases. The prevalence of positive results applying the FMBU-A regarding BMC and aBMD were significantly (p < 0.001) lower than using age- and height-adjusted BMC and aBMD (8.8 and 14.8%).
  
  
  
  Our results suggest that the prevalence of bone health deficits in children with CP was overestimated, when using age- and height-adjusted BMC and aBMD. When applying the FMBU-A, the prevalence decreased significantly. We recommend applying the FMBU-A when assessing bone health in children with CP.
authors.affiliation: Center of Prevention and Rehabilitation, University of Cologne, Lindenburger Allee 44, 50931, Cologne, Germany. Ibrahim.duran@unireha-koeln.de.
authors.forename: I
authors.identifier: http://orcid.org/0000-0003-4044-8822
authors.initials: I
authors.lastname: Duran
authors.affiliation: Center of Prevention and Rehabilitation, University of Cologne, Lindenburger Allee 44, 50931, Cologne, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Schütz
authors.affiliation: Institute of Medical Statistics, Informatics and Epidemiology, University of Cologne, Cologne, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Hamacher
authors.affiliation: Center of Prevention and Rehabilitation, University of Cologne, Lindenburger Allee 44, 50931, Cologne, Germany.|Children's Hospital, University of Cologne, Cologne, Germany.|Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Semler
authors.affiliation: Center of Prevention and Rehabilitation, University of Cologne, Lindenburger Allee 44, 50931, Cologne, Germany.|Children's Hospital, University of Cologne, Cologne, Germany.|Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Stark
authors.affiliation: Center of Prevention and Rehabilitation, University of Cologne, Lindenburger Allee 44, 50931, Cologne, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Schulze
authors.affiliation: Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Rittweger
authors.affiliation: Center of Prevention and Rehabilitation, University of Cologne, Lindenburger Allee 44, 50931, Cologne, Germany.|Children's Hospital, University of Cologne, Cologne, Germany.|Cologne Center for Musculoskeletal Biomechanics (CCMB), University of Cologne, Cologne, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Schoenau
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000293:Adolescent; D015519:Bone Density / Q000502:physiology*; D002547:Cerebral Palsy / Q000150:complications / Q000503:physiopathology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010024:Osteoporosis / Q000209:etiology / Q000503:physiopathology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012737:Sex Factors; D055815:Young Adult
keywords: Cerebral palsy; Dual-energy X-ray absorptiometry; Fracture; Muscle-bone interactions; Osteoporosis