Indications for Plain Radiographs in Uncomplicated Lower Extremity Cellulitis

Cellulitis is a common cause for emergency department (ED) presentation and subsequent hospital admission. Underlying fracture, osteomyelitis, or foreign body is often considered in the clinical evaluation of these patients. Accordingly, plain radiographs (XRs) of the affected extremity are often ordered during the initial work-up. The utility of these imaging studies in the treatment of uncomplicated lower-extremity cellulitis, however, remains unclear. In an effort to treat this common problem more efficiently, we evaluated our imaging practices and results in a cohort of consecutive patients admitted to a large public city hospital for treatment of uncomplicated lower-extremity cellulitis.

Retrospective cohort study of 288 consecutive ED admissions for treatment of uncomplicated cellulitis, of which 214 met the inclusion criteria for this study. Patient demographics, history, vitals, laboratory values, and test results were evaluated with univariate and multivariate statistical analyses.

XRs of the affected lower extremity were obtained in 158 patients (73.8%). Positive XR findings were present in 19 patients (12.0%) and positively correlated with a history of acute trauma to the extremity (P < .001) or the presence of a chronic wound (P < .01). Multivariable logistic regression analysis revealed a history of trauma (P < .001) or the presence of a chronic wound (P < .05) to be independent predictors of positive XR findings with relative risks of 6.24 and 2.98, respectively.

The establishment of evidence-based guidelines for the treatment of lower-extremity cellulitis has potential to significantly improve clinical efficiency and reduce cost by eliminating unnecessary testing. Based on our results, patients without a recent history of trauma to the affected extremity or the presence of a chronic wound do not appear to warrant XRs. When applied to our cohort, only 48 of 158 patients had a history of trauma or chronic wound. This means that 110 patients unnecessarily had plain films taken as part of their initial work-up. In a largely uninsured inner city patient population such as this cohort, that extra cost falls on the public hospital system.