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).