title: The epidemiology of primary anterior shoulder dislocations in patients aged 10 to 16 years.
abstract: BACKGROUND
  Clinical studies of shoulder dislocations typically include adult patients (>16 years of age). Only small case series of patients aged 10 to 16 years are available to guide management.
  
  
  OBJECTIVE
  Using a cohort of patients aged 10 to 16 years, this study sought to determine (1) the incidence density rate (IDR) of primary anterior shoulder dislocations requiring closed reduction (CR) and (2) the rate of and risk factors for repeat shoulder CR.
  
  
  METHODS
  Cohort study (prognosis); Level of evidence, 2.
  
  
  METHODS
  With use of administrative databases, patients aged 10 to 16 years who underwent CR of a primary anterior shoulder dislocation in Ontario, Canada, between April 2002 and September 2010 were gathered. IDRs for the entire cohort and demographic subgroups were calculated. The main outcome, repeat shoulder CR, was sought until September 2012. The cumulative incidence of repeat CR was calculated at multiple time points for the entire cohort and age subgroups. A competing risk model identified risk factors for repeat CR (reported as hazard ratios [HRs] with 95% CIs).
  
  
  RESULTS
  There were 1937 patients aged 10 to 16 years who underwent primary CR (median age, 15.0 years; 79.7% male). The incidence of primary CR was highest among male patients aged 16 years (164.4 per 100,000 person-years), but primary dislocations were rare in 10- to 12-year-old children (n = 115; 5.9% of all dislocations). Repeat CR was observed in 740 patients (38.2%) after a median of 0.8 years; however, the rate of repeat CR was age dependent: it was highest among 14- to 16-year-old patients (37.2%-42.3%) and considerably lower among 10- to 13-year-old patients (0%-25.0%). Male sex (HR, 1.2 [95% CI, 1.0-1.5]; P = .04) and older patient age (HR, 1.2 [95% CI, 1.1-1.3]; P < .001) significantly increased the odds of repeat CR.
  
  
  CONCLUSIONS
  Among 14- to 16-year-old patients, the rate of primary and recurrent shoulder CR mirrors that of high-risk adults (17-20 years of age) from previously published data; however, the rate of shoulder CR (primary or recurrent) is considerably lower among 10- to 13-year-olds. In addition to older patient age, male sex increased the odds of repeat shoulder CR. Going forward, clinicians should counsel male patients and those aged 14 to 16 years regarding their increased risk of recurrence after the nonoperative management of a primary anterior shoulder dislocation.
authors.affiliation: University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada Division of Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada timothy.leroux@mail.utoronto.ca.
authors.forename: Timothy
authors.initials: T
authors.lastname: Leroux
authors.affiliation: University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada Division of Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada University Health Network Arthritis Program, Toronto, Ontario, Canada.
authors.forename: Darrell
authors.initials: D
authors.lastname: Ogilvie-Harris
authors.affiliation: University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada Division of Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada University Health Network Arthritis Program, Toronto, Ontario, Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Veillette
authors.affiliation: University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada Division of Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada University Health Network Arthritis Program, Toronto, Ontario, Canada.
authors.forename: Jaskarndip
authors.initials: J
authors.lastname: Chahal
authors.affiliation: University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada Division of Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Tim
authors.initials: T
authors.lastname: Dwyer
authors.affiliation: Division of Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Amir
authors.initials: A
authors.lastname: Khoshbin
authors.affiliation: University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada Division of Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors.forename: Patrick
authors.initials: P
authors.lastname: Henry
authors.affiliation: Division of Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada University Health Network Arthritis Program, Toronto, Ontario, Canada Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
authors.forename: Nizar
authors.initials: N
authors.lastname: Mahomed
authors.affiliation: University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada Division of Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Wasserstein
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002648:Child; D016208:Databases, Factual; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D012008:Recurrence; D017678:Sex Distribution; D012783:Shoulder Dislocation / Q000453:epidemiology* / Q000601:surgery
keywords: epidemiology; pediatric; recurrent instability; shoulder dislocation