title: Bone mineral density of the hip and knee in children with spinal cord injury.
abstract: OBJECTIVE
  To report on the bone mineral density (BMD) of the hip, distal femur, and proximal tibia in children with spinal cord injury (SCI) of at least 1-year duration and before skeletal maturity.
  
  
  METHODS
  BMD values were measured in 28 children (age, 9.6 +/- 2.5 years; range, 5-13 years) using dual-energy x-ray absorptiometry (DEXA) and were analyzed based on sex, injury, and time since injury. The hip values were compared with reported age- and sex-matched values in children without disability. No comparison was made at the knee because normative data were not available.
  
  
  RESULTS
  Average BMD values were 0.48 +/- 0.17 g/cm2 for the total hip, 0.48 +/- 0.17 g/cm2 at the femoral neck, 0.41 +/- 0.17 g/cm2 at the greater trochanter, 0.47 +/- 0.17 g/cm2 at Ward's triangle, 0.38 +/- 0.10 g/ cm2 at the distal femur, and 0.37 +/- 0.07 g/cm2 at the proximal tibia. Trends were observed with respect to sex, level of injury, and time since injury. Z-scores for the femoral neck, greater trochanter, and Ward's triangle were -1.65 +/- 1.02, -1.83 +/- 1.30, and -1.78 +/- 0.78, respectively, representing a 40% lower BMD in comparison with children without disability.
  
  
  CONCLUSIONS
  Children with a SCI seem to have a substantially lower BMD at the hip and knee in comparison with children without disability, placing them at the same risk for lower extremity fractures as adults with SCI, with potentially higher risks as they age given the lack of activity in a period of their life where exercise is essential for optimal bone health.
authors.affiliation: Research Department, Shriners Hospitals for Children, 3551 North Broad Street, Philadelphia, PA 19140, USA. rlauer@shrinenet.org
authors.forename: Richard
authors.initials: R
authors.lastname: Lauer
authors.forename: Therese E
authors.initials: TE
authors.lastname: Johnston
authors.forename: Brian T
authors.initials: BT
authors.lastname: Smith
authors.forename: Mary Jane
authors.initials: MJ
authors.lastname: Mulcahey
authors.forename: Randal R
authors.initials: RR
authors.lastname: Betz
authors.forename: Alan H
authors.initials: AH
authors.lastname: Maurer
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000293:Adolescent; D000367:Age Factors; D015519:Bone Density; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006615:Hip / Q000503:physiopathology*; D006801:Humans; D007717:Knee / Q000503:physiopathology*; D008297:Male; D012737:Sex Factors; D013119:Spinal Cord Injuries / Q000473:pathology* / Q000503:physiopathology