Point tenderness at 1 of 5 locations and limited elbow extension identify significant injury in children with acute elbow trauma: a study of diagnostic accuracy

Objective: Our goal was to determine whether the combination of tenderness at 1 of 5 commonly fractured sites and elbow extension accurately predicts the presence of acute elbow fractures or isolated effusions in children.

Methods: A prospective cohort study was performed using a convenience sample of patients. Children 0 to 18 years old with acute elbow injuries without elbow deformities or radial head subluxations were prospectively enrolled. The treating physicians assessed the injured elbow for the presence of tenderness at 5 locations and for abnormal active extension. The examination was defined as positive if any one component was present and negative if all were absent. The radiologist's report or a structured follow-up phone call was used as an a priori-determined composite reference standard for the diagnosis of (1) fracture or isolated effusion and (2) fracture.

Results: A total of 332 patients were enrolled; 183 (55.1%) were diagnosed with a fracture (31.0%) or effusion (24.1%). A negative examination result was present in 33 (9.9%), among whom 6 were diagnosed with a small effusion and 1 with a radial neck fracture. The examination's sensitivity, specificity, and positive and negative predictive values (95% confidence interval) were 96.2% (92.0-98.3), 17.4% (11.9-24.7), 58.4% (52.6-64.2), and 60.3% (47.8-72.9), respectively, for fracture or isolated effusion and 99.0% (97.1-100), 14.0% (9.5-18.5), 34.1% (28.7-39.5), and 97.0% (91.1-100.0), respectively, for fracture. A planned subgroup analysis of children younger than 3 years was performed; the elbow extension test was insensitive (sensitivity, 73.3% [51.0-95.7]) at excluding elbow injuries, albeit, when combined with point tenderness, it identified 100% of elbow fractures or effusions.

Conclusion: The addition of point tenderness to the elbow extension test is highly sensitive at identifying injuries in children with acute elbow injuries, albeit nonspecific. Although the significance of omitting 10% of radiographs is questionable, a cost-benefit analysis would help clarify its potential savings in terms of expenditure and/or radiation exposure when compared to the risk of missing 2% of children with elbow injuries (albeit mainly small effusions).