CTA predicts healing of bone fractures

Findings of a study released Sunday at the 2009 RSNA meeting by researchers in Boston suggest CT angiography could help radiologists identify the factors that keep some types of lower extremity fractures from healing faster and better than other, similar lesions.

“Nonunion fracture can be a devastating clinical outcome,” said principal investigator Dr. Kevin P. Donahue, a radiology resident at Boston University.

“It’s important to identify anything that could potentially cause this kind of outcome, not only to prepare the patients for the possibility that this may be where their clinical situation is headed, but also to prepare our clinical colleagues,” Donahue said in an exclusive interview with Diagnostic Imaging.

Donahue and colleagues analyzed 230 cases of fractures from the hip through the ankle from 193 patients (149 male, 44 female) who were enrolled by their institution from January 2006 through December 2008. Patients underwent 64-slice CTA at the University’s level I trauma center and were classified according to the following factors:

• age

• open fracture(s)

• presence of vascular injury

• presence and extent of atherosclerosis in the lower extremities

The investigators compared previous findings with a subsequent series of x-rays that evaluated successful healing or nonunion. They used a statistical tool to measure the correlation between these factors and healing. They found a stronger association between nonunion and fractures with vascular injuries.

  X-ray of a patient with lower extremity fractures from shotgun injuries reveals a pseudo-aneurysm of the femoral artery that was later associated with nonunion. (Provided by K. Donahue)

Donahue’s group found no relationship between patient age or degree of atherosclerosis with healing failure. And despite the morbidity and complexity associated with open fractures, there was no significant association between these lesions and nonunion. Three of five cases of nonunion were correlated with vascular injury. The association was statistically significant (p = 0.059).

“In the traumatic setting of individuals with lower extremity fractures, CT angiography definitely plays a role to define clinical outcomes and the intervening steps when the patient is in the hospital,” Donahue said.