Initially missed occult fractures of the proximal femur in elderly patients: implications for need of operation and their morbidity

Occult fractures of the proximal femur are not evident on radiographs and the diagnoses are often missed or delayed. We tried to determine whether the delay of diagnosis in elderly patients lead to increased morbidity and increased need for operation. We identified 26 elderly patients (a parts per thousand yen65 years of age) who were diagnosed as having an occult fracture of the proximal femur over a 3-year period. In 17 patients (17 hips, non-delayed group), the occult fracture was suspected at the first visit and the diagnosis was made on CT and/or MR images (MRI). In the remaining nine patients (9 hips, 34.6% delayed group), the diagnosis was delayed by a mean of 8.4 days (range 4-25 days). We compared the occurrence of fracture displacement, need for operation, change in activity level, and mortality between the non-delayed and delayed groups. Displacement of fracture occurred in 4 of 9 delayed patients and none of 17 non-delayed patients. Ten non-delayed patients needed operative treatment, whereas eight delayed patients needed operative treatment (p = 0.190). The activity level decreased in 6 of 7 surviving patients of the delayed group, whereas it decreased in 4 of 15 surviving patients of the non-delayed group (p = 0.020). A delayed diagnosis of occult fracture in elderly patients resulted in increased rate of secondary displacement of the fracture and increased morbidity. In patients suspected of having occult hip fractures, additional studies, such as MRI and/or CT scans should be recommended to confirm the presence of hip fracture.