Clinical factors predicting fractures associated with an anterior shoulder dislocation.
OBJECTIVE
To identify risk factors for fractures associated with an anterior shoulder dislocation treated in an emergency department (ED).


METHODS
A retrospective case-control study over five years of patients with an anterior shoulder dislocation was accomplished in a university-affiliated ED. Chart review identified possible predictors of fractures. Comparing the profile of patients having a clinically important fracture associated with their shoulder dislocation (cases) with those sustaining a noncomplicated dislocation (controls) provided the outcome measure.


RESULTS
A total of 334 patients were included in the study. Eighty-five (25.5%) had a clinically important fracture-dislocation, and the remaining 249 (74.5%) sustained a noncomplicated shoulder dislocation. Chi-square, logistic regression, and recursive partitioning analysis showed three significant factors for the presence of fracture-dislocation: 1) age 40 years or older, 2) a first episode of dislocation, and 3) mechanism of injury (i.e., a fall greater than one flight of stairs, a fight/assault episode, or a motor vehicle crash). A multiple logistic regression model estimated the significant adjusted odds ratios (and their 95% confidence intervals [95% CIs]) for each of the three factors: 5.18 (95% CI = 2.74 to 9.78), 4.23 (95% CI = 1.82 to 9.87), and 4.06 (95% CI = 1.95 to 8.48), respectively. A predictive model using any one of the three factors reached a sensitivity of 97.7% (95% CI = 91.8% to 99.4%), a specificity of 22.9% (95% CI = 18.1% to 28.5%), and a negative predictive value of 96.6% (95% CI = 88.3% to 99.6%).


CONCLUSIONS
Three risk factors predict clinically important fractures that are associated with shoulder dislocation: age, first episode, and mechanism of dislocation. A prospective validation may lead to standardized use of prereduction radiographs of the shoulder in the ED.
Emond
Marcel
M
Trauma Research Unit, Centre Hospitalier Affilié Universitaire de Québec, Faculty of Medicine, Laval University, Quebec City, Quebec, Canada. marcelemond@hotmail.com
Le Sage
Natalie
N
Lavoie
André
A
Rochette
Louis
L
D000058:Accidental Falls / Q000706:statistics & numerical data; D000063:Accidents, Traffic / Q000706:statistics & numerical data; D000328:Adult; D017677:Age Distribution; D001265:Athletic Injuries / Q000453:epidemiology; D016022:Case-Control Studies; D015897:Comorbidity; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011792:Quebec / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D012783:Shoulder Dislocation / Q000453:epidemiology*; D012784:Shoulder Fractures / Q000175:diagnosis* / Q000453:epidemiology*; D014754:Violence / Q000706:statistics & numerical data