Missed fractures on emergency room ankle radiographs: An analysis of 433 patients

The purpose of this study was to review fractures and radiographic abnormalities that are detectable, but often overlooked, on a standard ankle radiographic series. We carried out a retrospective review of 556 consecutive ankle radiographic series obtained between June 1, 1995, and May 31, 1996. From this population, 433 complete ankle radiographic series on patients with suspected trauma were selected. The original radiologist's interpretation was compared to a twostep "gold standard" interpretation, consisting of reinterpretation by a musculoskeletal radiologist with the patient's medical and imaging records at hand, with review of discrepant cases by a consensus panel. Eighteen studies were incorrectly interpreted at the initial reading, yielding an overall error rate of 4.2%. Fifteen of the errors were missed fractures, ankle syndesmotic widening, or incorrect classification of old fractures as acute. The rate for this type of error was 3.5%. The most commonly missed fractures were of the talus (4 patients), followed by fracture of the base of the fifth metatarsal and calcaneal stress fracture (2 cases each); tibiofibular syndesmotic injury was missed in 2 cases. Missed fractures on ankle radiographs most commonly involved bones of the hindfoot, especially the talus. It is important to recognize these uncommon and easily missed fractures, so that a modified search pattern may result in improved accuracy of radiographic interpretation.[PUBLICATION ABSTRACT]