All of these studies constitute retrospective series in which patients with negative radiographs but high clinical suspicion went on to receive a MRI scan at the discretion of the evaluating clinician. In one such study, 14% of patients with negative radiographs were found to have fractures of the hip or pelvis [23]. In this same study, Kirby et al [23] also reported 12% of patients with suspicious radiographs were found to have no fracture on MRI, illustrating limitations in the specificity of radiographs as well. Other studies have had more dramatic results, with Sankey et al [25] reporting 83 of 98 patients to have fractures after negative radiographs, 23 of whom required operative management. The variability is likely due to differing proportions of patients going on to MRI following negative radiographs in these retrospective studies. However, there is no accepted clinical decision rule to guide when patients with suspected hip fracture should have advanced imaging after negative radiographs. A new inability to bear weight is a clinically suspicious finding, although the sensitivity and specificity of this is unknown [20]. Allowing for variation between studies, the estimated prevalence of occult fracture after negative radiographs has been estimated at 4% to 10%, indicating the inability of negative radiographs alone to exclude fracture [21,26]. Risk factors for radiographically occult fracture in these studies included those age >65, low-force trauma, such as a ground-level fall, and female gender. These studies have almost exclusively included elderly patients. There is no relevant literature regarding the sensitivity and specificity of radiographs in the younger patient population, and clinicians are suggested to proceed with caution. Radiography Pelvis There is no specific literature regarding the use of an AP view of the pelvis alone for acute hip pain following low-force trauma.
Acute Hip Pain Suspected Fracture PCAs. All of these studies constitute retrospective series in which patients with negative radiographs but high clinical suspicion went on to receive a MRI scan at the discretion of the evaluating clinician. In one such study, 14% of patients with negative radiographs were found to have fractures of the hip or pelvis [23]. In this same study, Kirby et al [23] also reported 12% of patients with suspicious radiographs were found to have no fracture on MRI, illustrating limitations in the specificity of radiographs as well. Other studies have had more dramatic results, with Sankey et al [25] reporting 83 of 98 patients to have fractures after negative radiographs, 23 of whom required operative management. The variability is likely due to differing proportions of patients going on to MRI following negative radiographs in these retrospective studies. However, there is no accepted clinical decision rule to guide when patients with suspected hip fracture should have advanced imaging after negative radiographs. A new inability to bear weight is a clinically suspicious finding, although the sensitivity and specificity of this is unknown [20]. Allowing for variation between studies, the estimated prevalence of occult fracture after negative radiographs has been estimated at 4% to 10%, indicating the inability of negative radiographs alone to exclude fracture [21,26]. Risk factors for radiographically occult fracture in these studies included those age >65, low-force trauma, such as a ground-level fall, and female gender. These studies have almost exclusively included elderly patients. There is no relevant literature regarding the sensitivity and specificity of radiographs in the younger patient population, and clinicians are suggested to proceed with caution. Radiography Pelvis There is no specific literature regarding the use of an AP view of the pelvis alone for acute hip pain following low-force trauma.