AJR: X-ray often insufficient in detecting hip and pelvic fractures
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Charles Spritzer, MD, from the department of radiology at Duke University Medical Center, and colleagues studied 92 patients who underwent x-rays followed by MRI to evaluate hip and pelvic pain. The patient sample included 77 women and 15 men, with an average age of 70.8 years. Sixty-five of the patients had a history of trauma.
The x-ray exams of all the patients were retrospectively reviewed by one musculoskeletal radiologist (more than 20 years of experience) who was blinded to the results of each radiographic and MRI exam. Those obtained within one calendar day before MRI reviewed first, and MR images were assessed for fractures, bursitis, tendinopathy, muscle injury and other causes of pain.
Ninety-seven examinations were performed on the 92 patients (five of whom underwent bilateral exams. Radiographs were considered to be either positive or suggestive of a fracture in 26 patients. In 11 of those patients, the MRI showed no fracture. In the other 15 patients, MRI detected 12 addition additional pelvic fractures not identified on x-rays. Thirteen patients with normal radiograph findings were found to have 23 fractures by MRI.
There were several limitations to the study, according to the authors. Only parties who underwent MRIs were evaluated, so a workup bias may been present in the sample. In addition, there was no separate analysis of trauma patients even though many of the patients in the study had a history of trauma. Also, the MRI protocols performed and radiographs requested varied among the patients.
“Our study showed poor sensitivity and specificity of radiography of the proximal femur and pelvis in emergency department evaluation of patients with pain or suspected trauma around these structures,” said the authors, adding that they found a large number of both false-positive and false-negative diagnoses based on radiographic findings alone.
“Accurate diagnosis of hip and pelvic fractures in the emergency department can speed patients to surgical management, if needed, and reduce the rate of hospital admissions among patients who do not have fractures,” said Sprizer. “The distinction is important in terms of healthcare utilization, overall patient cost and patient inconvenience. Use of MRI in patients with a strong clinical suspicion of traumatic injury but unimpressive x-rays has a substantial advantage in the detection of pelvic and hip fractures, helping to steer patients to appropriate medical and surgical therapy.”