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.
Trauma Research Unit, Centre Hospitalier Affilié Universitaire de Québec, Faculty of Medicine, Laval University, Quebec City, Quebec, Canada. marcelemond@hotmail.com
Marcel
M
Emond
Natalie
N
Le Sage
André
A
Lavoie
Louis
L
Rochette
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