title: Should 25-hydroxyvitamin D and bone density using DXA be tested in adolescents with lumbar stress fractures of the pars interarticularis?
abstract: METHODS
  Retrospective study.
  
  
  OBJECTIVE
  To determine if 25-hydroxyvitamin D (25[OH]D) level measurement and bone mineral density (BMD) using dual-energy x-ray absorptiometry (DXA) are indicated in children with a history of stress fracture of the pars interarticularis.
  
  
  BACKGROUND
  Healing rates of 4%-25% for bilateral and unilateral pars fractures, respectively, have previously been reported. Factors that may contribute to osteomalacia, rickets, and poor bone healing include low (25[OH]D) and low BMD.
  
  
  METHODS
  Patients were seen at the Nebraska Spine Center between 2008 and 2010. Selection criteria included a diagnosis of pars fracture with DXA Z-score values (lumbar and hip) and pretreatment serum (25[OH]D) level measurement. Twenty-four patients were included. Vitamin D was defined as sufficient when ≥ 32 ng/mL, insufficient when 20 to < 32 ng/mL, and deficient when < 20 ng/mL. BMD was interpreted from DXA Z-scores using reference intervals defined in the literature. A Z-score <-2.0 was considered low for chronological age.
  
  
  RESULTS
  The mean (± SD) vitamin D level was 29.9 ng/mL ± 10.8 (range, 9-56 ng/mL). Values were ≤ 10 ng/mL in 1 patient (4%), 11-20 ng/mL in 4 patients (17%), 21-30 ng/mL in 8 patients (33%), 31-50 ng/mL in 10 patients (42%), and > 50 ng/mL in 1 patient (4%). This correlated to 3 (13%) patients with deficient vitamin D (≤ 15 ng/mL), 12 (50%) patients with insufficient levels, and 9 (38%) with sufficient levels of vitamin D. The mean Z-scores were 0.43 ± 0.93 (lumbar, range, -1.3 to 2.8) and 1.0 ± 1.11 (hip, range, -0.5 to 3.0). All scores were consistent with normal bony mineralization for age.
  
  
  CONCLUSIONS
  On the basis of these data, we recommend routine vitamin D testing and do not recommend routine DXA in adolescents with lumbar stress fractures of the pars interarticularis.
authors: University of Nebraska Medical Center, Omaha, NE, USA.
authors: John W
authors: JW
authors: McClellan
authors: Brian A
authors: BA
authors: Vernon
authors: Michael A
authors: MA
authors: White
authors: Sarah
authors: S
authors: Stamm
authors: Kay L
authors: KL
authors: Ryschon
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology; D002648:Child; D003955:Diagnostic Tests, Routine; D005260:Female; D017102:Fracture Healing; D015775:Fractures, Stress / Q000097:blood / Q000000981:diagnostic imaging / Q000209:etiology*; D006801:Humans; D008159:Lumbar Vertebrae / Q000737:chemistry / Q000293:injuries*; D008297:Male; D009329:Nebraska / Q000453:epidemiology; D010018:Osteomalacia / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D012279:Rickets / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology; D016103:Spinal Fractures / Q000097:blood / Q000000981:diagnostic imaging / Q000209:etiology*; D013169:Spondylolysis / Q000453:epidemiology / Q000209:etiology; D014057:Tomography, X-Ray Computed; D019564:Unnecessary Procedures; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D