Comparison of polytomography and computed tomography for fracture assessment

Objective. To compare polytomography (PT) and computed tomography (CT) for visualizing fractures and arthrodeses, with and without metal hardware, to determine whether CT could adequately replace PT. Design and patients. An ex vivo bovine model containing fractures in three planes, reduced with metal hardware, was created to compare fractures using PT and CT. The radiation dose at the skin surface was calculated for both examinations. For in vivo assessment, images of 14 patients who underwent b oth PT and CT (15 fractures, five arthrodeses) were coded, sorted, and inde pendently read by four musculoskeletal radiologists. They rated the degree of certainty of their assessment. Time factors for patients and personnel a nd financial costs were also compared. Results. In the ex vivo model the fractures were well seen on both PT and C T. The radiation dose was higher for PT than for CT. In vivo, the degree of certainty in assessment of fractures and arthrodeses was higher for PT tha n CT in studies in which metal hardware was present, but there was no signi ficant difference in studies without metal hardware or in the combined (wit h and without hardware) studies. The patient's and technologist's time requ ired to perform a PT examination was greater than that or CT. Conclusion. In the assessment of fractures and arthrodeses containing metal hardware, PT is recommended. For studies without hardware, CT is equivalen t and can replace PT.