title: An approach for determining quantitative measures for bone volume and bone mass in the pediatric spina bifida population.
abstract: BACKGROUND
  The pediatric spina bifida population suffers from decreased mobility and recurrent fractures. This study aimed to develop a method for quantifying bone mass along the entire tibia in youth with spina bifida. This will provide information about all potential sites of bone deficiencies.
  
  
  METHODS
  Computed tomography images of the tibia for 257 children (n=80 ambulatory spina bifida, n=10 non-ambulatory spina bifida, n=167 typically developing) were analyzed. Bone area was calculated at regular intervals along the entire tibia length and then weighted by calibrated pixel intensity for density weighted bone area. Integrals of density weighted bone area were used to quantify bone mass in the proximal and distal epiphyses and diaphysis. Group differences were evaluated using analysis of variance.
  
  
  RESULTS
  Non-ambulatory children suffer from decreased bone mass in the diaphysis and proximal and distal epiphyses compared to ambulatory and control children (P≤0.001). Ambulatory children with spina bifida showed statistically insignificant differences in bone mass in comparison to typically developing children at these sites (P>0.5).
  
  
  CONCLUSIONS
  This method provides insight into tibial bone mass distribution in the pediatric spina bifida population by incorporating information along the whole length of the bone, thereby providing more information than dual-energy x-ray absorptiometry and peripheral quantitative computed tomography. This method can be applied to any population to assess bone mass distribution across the length of any long bone.
authors.affiliation: Department of Biomedical Engineering, University of Southern California, Los Angeles CA, United States. Electronic address: horenstein.r@husky.neu.edu.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Horenstein
authors.affiliation: Department of Mechanical and Industrial Engineering, Northeastern University, Boston MA, United States.
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Shefelbine
authors.affiliation: Children's Orthopaedic Center, Children's Hospital Los Angeles, Los Angeles CA, United States.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Mueske
authors.affiliation: Children's Orthopaedic Center, Children's Hospital Los Angeles, Los Angeles CA, United States.
authors.forename: Carissa L
authors.initials: CL
authors.lastname: Fisher
authors.affiliation: Department of Biomedical Engineering, University of Southern California, Los Angeles CA, United States; Children's Orthopaedic Center, Children's Hospital Los Angeles, Los Angeles CA, United States.
authors.forename: Tishya A L
authors.initials: TA
authors.lastname: Wren
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000704:Analysis of Variance; D015519:Bone Density / Q000502:physiology; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D016135:Spinal Dysraphism / Q000473:pathology* / Q000503:physiopathology; D013977:Tibia / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed
keywords: Bone density; Bone mass; Image analysis; Myelomeningocele; Spina bifida