title: Vitamin D Deficiency in Slipped Upper Femoral Epiphysis: Time to Physeal Fusion.
abstract: BACKGROUND
  Slipped upper femoral epiphysis (SUFE) has an incidence of 1 to 7 per 100,000 adolescents in the United Kingdom and its link with obesity is well established. With an increasing number of pediatric orthopaedic patients presenting with vitamin D deficiency, the aim of our study was to establish the prevalence of vitamin D deficiency in SUFE patients presenting to an orthopaedic department in the United Kingdom and whether a low vitamin D level increases the time to proximal femoral physeal fusion after surgical fixation.
  
  
  METHODS
  A total of 27 pediatric patients, with a female to male ratio of 17:10 and a mean age of 11.5 years (SD=1.99), range 8 to 16 years, presented with a SUFE and their vitamin D level was assessed during the study period, June 2007 to July 2012 (inclusive). The majority of these patients (85.2%) were assessed as vitamin D deficient, with a serum 25-(OH)D<52 nmol/L. The time taken for >50% physeal fusion on anteroposterior radiography after surgical fixation reported in the literature is 9.6 months, with no reported vitamin D deficiency or insufficiency.
  
  
  RESULTS
  In our study, the median time to physeal fusion in the vitamin D-deficient and vitamin D-insufficient patients was 25 months (interquartile range, 17 to 43 mo; mean of 29 mo, SD=16.8). A negative correlation was also observed between vitamin D level and the time taken for physeal fusion after surgical fixation.
  
  
  CONCLUSIONS
  We conclude that a high prevalence of vitamin D deficiency has been observed in our SUFE patients. Comparing the time taken for physeal closure of 9.6 months in the literature with vitamin D-deficient patients, this is prolonged. Indeed, a negative correlation has been shown between vitamin D level and time to physeal fusion. This study highlights the need for regular vitamin D status assessment in SUFE patients to allow early implementation of treatment with vitamin D supplementation. The impact of vitamin D screening and supplementation on SUFE outcomes should be investigated further.
authors.affiliation: *Child Health §NIHR Research Design Service South Central, Southampton General Hospital †Faculty of Medicine ∥Southampton General Hospital, University of Southampton, Southampton ‡Bristol Children's Hospital/Bristol Royal Infirmary, Bristol, UK.
authors.forename: Julia
authors.initials: J
authors.lastname: Judd
authors.forename: Rachel
authors.initials: R
authors.lastname: Welch
authors.forename: Anna
authors.initials: A
authors.lastname: Clarke
authors.forename: Isabel C
authors.initials: IC
authors.lastname: Reading
authors.forename: Nicholas M P
authors.initials: NM
authors.lastname: Clarke
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006132:Growth Plate / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D008297:Male; D015995:Prevalence; D060048:Slipped Capital Femoral Epiphyses / Q000453:epidemiology* / Q000601:surgery*; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000453:epidemiology* / Q000601:surgery; D014945:Wound Healing
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D