Traumatic elbow effusions in pediatric patients: are occult fractures the rule?

OBJECTIVE: Elbow joint effusion with no fracture seen on radiographs of pediatric patients after acute trauma has become synonymous with occult fracture. This study evaluates the incidence of occult fractures in such cases as determined by findings on follow-up radiographs.
MATERIALS AND METHODS: Initial and follow-up radiographs were reviewed for 54 children (mean age, 7 years) with a history of trauma who had joint effusion but no identifiable fracture on initial radiographs. The presence of periosteal reaction or bony sclerosis on follow-up radiographs was considered to be evidence of occult fracture. Mean time between initial and follow-up radiographs was 18 days (range, 14-50 days).
RESULTS: Only nine (17%) of the 54 patients showed evidence of a healing occult fracture on follow-up radiographs. However, we found a statistically significant relationship (p = .001) between persistent joint effusion on follow-up radiographs and occult fracture. Seventy-eight percent of cases with occult fracture, versus 16% of cases without occult fracture, had persistent effusions.
CONCLUSION: Joint effusion without visualized fracture on initial radiographs after trauma does not correlate with the presence of occult fracture in most cases (83%). Therefore, joint effusion as revealed by radiography should not be considered synonymous with occult fracture.