title: Testing the validity of preventing chronic regional pain syndrome with vitamin C after distal radius fracture. [Corrected].
abstract: OBJECTIVE
  The American Academy of Orthopaedic Surgeons recommends the use of vitamin C to prevent complex regional pain syndrome (CRPS) for patients with distal radius fractures (DRFs). We hypothesized that the evidence for supporting this recommendation is weak, based on epidemiological principles of association and causality. The specific aim of this project was to test the validity of this recommendation.
  
  
  METHODS
  We conducted a literature review to retrieve articles reporting on the use of vitamin C to prevent CRPS. Data collected included sample size, study design type, dose of vitamin C used, and outcome measures of association expressed as relative risk (RR) and odds ratio. We then applied Hill criteria to evaluate the relationship between vitamin C and CRPS.
  
  
  RESULTS
  We obtained 225 articles from the database search. After the exclusion of duplicates, unrelated articles, editorial letters, and commentaries, we found 4 articles and 1 systematic review relevant to our topic. Six of the 9 Hill criteria were met, and an earlier meta-analysis showed a quantified reduction in CRPS risk. However, criteria like biological plausibility, specificity, and coherence were not met.
  
  
  CONCLUSIONS
  The number of causal/association criteria met was adequate to support the scientific premise of the effect of vitamin C in preventing CRPS after DRF. Furthermore, vitamin C administration is of relatively low cost and has few complications unless administered in large doses. Owing to sufficient epidemiological evidence availability, the American Academy of Orthopaedic Surgeons recommendation of vitamin C to prevent CRPS has practical merit.
  
  
  METHODS
  Therapeutic II.
authors.affiliation: Section of Plastic Surgery, Department of Surgery, University of Michigan Health System, Ann Arbor, MI.
authors.forename: Sunitha
authors.initials: S
authors.lastname: Malay
authors.affiliation: Section of Plastic Surgery, Department of Surgery, University of Michigan Health System, Ann Arbor, MI. Electronic address: kecchung@umich.edu.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Chung
mesh_terms: D001205:Ascorbic Acid / Q000627:therapeutic use*; D020918:Complex Regional Pain Syndromes / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D011885:Radius Fractures / Q000150:complications*; D015203:Reproducibility of Results; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D014815:Vitamins; D001205:Ascorbic Acid
keywords: Bradford Hill criteria; CRPS; distal radius; prophylactic; vitamin C