Radiologic blind spots in hip and pelvic radiographs

Purpose The purpose of our study was to identify the locations at which hip and pelvic fractures are commonly missed on radiographs. Methods A retrospective study was performed at four non-Level 1 trauma center emergency departments. IRB approval was obtained. All emergency department hip or pelvic radiographs with subsequent CT performed within 48 h were identified from 2017 to 2022. Reports for each radiograph and CT were scored for the presence or the absence of fracture in the following locations: ilium, sacrum, superior pubic ramus, inferior pubic ramus, pubis, acetabulum, subcapital femoral, femoral neck, greater trochanter, lesser trochanter, intertrochanteric, and subtrochanteric. The CT report was used as the gold standard. The false-negative radiography cases were reviewed on a PACS workstation to determine whether the case had an “unexpected miss” of a fracture, a subtle fracture, radiographically occult fracture, or exam was limited by artifact. The percentage of missed fractures at each location was calculated. Results Nine hundred seventy-five radiography cases with subsequent CT were identified. One hundred forty-six cases did not meet entry criteria; therefore, 829 cases were analyzed further. Seventy-four percent of patients were female with age of 74 ± 16 (mean ± standard deviation) years (range 1–103). Three hundred fifty-two cases had at least one fracture, and many cases had multiple fractures. There were 68 false-negative cases. The most commonly missed fractures by percentage were pubis, ilium, and greater trochanter. The most common unexpectedly missed fractures were greater trochanter and femoral subcapital. Conclusion A careful systematic evaluation of hip and pelvic radiographs, with particular attention to the pubis, ilium, greater trochanter, and subcapital region, may improve radiographic fracture detection and decrease delays in diagnosis.