Early Detection of Occult Fractures around the Hip with Magnetic Resonance Imaging
Hip fractures may not be evident on initial radiographs but can be demonstrated with special imaging studies. These “occult fractures” can displace if not promptly treated. In a four-year period, 34 occult fractures around the hip in 33 patients were diagnosed in one general hospital. There were 6 men and 27 women, with a mean age of 74 years (22/92). The medical records and imaging studies were retrospectively reviewed. Two patients presented with a displaced femoral neck fracture one month and 10 days respectively after a fall and initial radiographs resulting normal. In the remaining 31 patients with normal radiographs, 30 fractures were detected with MRI obtained at an average of 6.8 days (0/35) from the onset of symptoms, and one with bone scan. Treatment consisted in partial weight-bearing or surgery, depending on the location and displacement of the fracture. Fractures united in all patients treated non-operatively and in those treated with internal fixation. One patient with a displaced fracture underwent a hip arthroplasty. At an average follow-up of 16.7 months (6/46) all patients remained ambulatory. In a selected group of patients with high suspicion of hip fracture, full-sequence MRI proved to be useful for early diagnosis and localization of an occult fracture around the hip.