Objective: Notwithstanding the increasing recognition of occult hip fracture the diagnosis is not suspected in some patients who present later with displaced hip fracture. We wished to investigate if the “missed occult fracture” group had any distinct demographic or clinical details and the eventual outcome of delayed diagnosis and treatment. Methods: Over a three year period we followed all patients admitted with fracture neck of femur to identify patients where the diagnosis was initially missed and compared them with patients admitted over the same period with a correct suspicion of occult hip fracture. Results: Out of 797 patients with hip fractures there were 24 occult hip fractures, the diagnosis was initially missed in 9 of them. In the correctly identified occult fracture patients 8/15 were independently mobile and 9/15 were living in own home compared to 0/9 independently mobile and 2/9 living in own home with missed occult fracture (both p< 0.001, Fisher exact test).7/9 patients with a missed diagnosis had mental confusion but none in the rest (p< 0.001). All patients presented within 10 days from the index visit (range 3–10). There was no obvious history of a fall in 2 patients. 4 patients had restricted straight leg raise ability on initial examination but were dismissed. 8/9 had intra-capsular fracture of which 6 had displaced at repeat presentation and required hemiarthroplasty. Maximum follow-up is 18 months (range 13–18 months) and 1 year mortality rate is 33%. Discussion: Patients with a missed diagnosis of occult hip fracture appear physiologically less robust compared to the patients who are correctly suspected and investigated for occult fracture. The patients with missed diagnosis have higher ASA grade and their mental confusion, restricted mobility and dependence for activities of daily living are statistically significantly different compared to patients where the diagnosis is correctly suspected. Most of them have sub-capital femoral neck fractures and will most likely return with a displaced fracture within a week. We suggest a low threshold for investigation for occult hip fracture in the elderly, infirm and mentally confused

Purpose: To investigate the value of various clinical signs to identify occult hip fracture. Methodology: MRI register was searched to identify all patients who had MRI scan between July 2000–June 2006 for suspected occult hip fracture. 64 patients were identified. 33 patients had occult proximal femoral fractures. 27 patients had no fracture. Results: 19 patients with fracture were not independently mobile compared to 6 patients without fracture. 7 patients with fracture and 2 patients without fracture were able to weight bear. 13 patients with fracture and 10 patients without fracture had unrestricted straight leg raise ability. 7 patients with fracture and 16 patients without fracture had no pain on axial loading. Fisher exact and chi square analysis was performed; with Bonferroni correction for multiple comparisons (10 tests) p< 0.005 was deemed significant. Pain on axial loading of limb and pre-fracture patient mobility were associated with fracture (p< 0.005). Both factors had positive predictive value = 0.76 and post-test probability of disease given a negative test = .30. Predictive values remained the same when both factors were considered together. Discussion: These data indicate that although patients who were independently mobile before the fall and who do not have pain on axial compression of the limb are less likely to have a fracture, these signs alone or in combination will not exclude a fracture. It is essential to perform MRI scanning of patients with severe hip pain but normal x rays after fall as it does not seem possible to clinically exclude fracture

Introduction: The possibility of occult hip fracture in older patients after a fall is a common problem. The value of various clinical signs to determine which patients require further investigation has not been reported. Methodology: MRI register was hand searched to identify all patients who had MRI scan between July 2000–June 2006 for suspected occult hip fracture. 64 patients were identified. 33 patients had occult proximal femoral fractures. 27 patients had no fracture. Results: More patients with fracture were living in their own home (20/26), were independent for daily living (20/26) and were not independently mobile(19/26) compared to patients without a fracture (14/22, 11/22 and 6/22 respectively). 7 patients with fracture and 2 patients without fracture were able to weight bear. 13 patients with fracture and 10 patients without fracture had unrestricted straight leg raise ability. 7 patients with fracture and 16 patients without fracture had no pain on axial loading. The value of individual tests was evaluated using Fisher exact and chi square analysis; with Bonferroni correction for multiple comparisons (10 tests) p< 0.005 was deemed significant. Pain on axial loading of the limb and pre-fracture patient mobility were both associated with the presence of a fracture (p< 0.005). Discussion: These data indicate that although patients who were independently mobile before the fall and who do not have pain on axial compression of the limb are less likely to have a fracture, these signs alone or in combination will not exclude a fracture. Other widely used signs (eg ability to straight leg raise) appear of little predictive value. On the basis of our data, we believe it is essential to have a policy of MRI scanning of patients with severe hip pain but normal x rays after a fall as it does not seem possible to clinically exclude a fracture

A delay in establishing the diagnosis of an occult fracture of the hip that remains unrecognised after plain radiography can result in more complex treatment such as an arthroplasty being required. This might be avoided by earlier diagnosis using MRI. The aim of this study was to investigate the best MR imaging sequence for diagnosing such fractures. From a consecutive cohort of 771 patients admitted between 2003 and 2011 with a clinically suspected fracture of the hip, we retrospectively reviewed the MRI scans of the 35 patients who had no evidence of a fracture on their plain radiographs. In eight of these patients MR scanning excluded a fracture but the remaining 27 patients had an abnormal scan: one with a fracture of the pubic ramus, and in the other 26 a T₁-weighted coronal MRI showed a hip fracture with 100% sensitivity. T₂-weighted imaging was undertaken in 25 patients, in whom the diagnosis could not be established with this scanning sequence alone, giving a sensitivity of 84.0% for T₂-weighted imaging.

If there is a clinical suspicion of a hip fracture with normal radiographs, T₁-weighted coronal MRI is the best sequence of images for identifying a fracture.

Introduction. Occult hip fractures occur in 3% of cases. Delay in treatment results in significantly increased morbidity and mortality. NICE guidelines recommend cross-sectional imaging within 24 hours and surgery on the day of, or day after, admission. MRI was the standard imaging modality for suspected occult hip fractures in our institution, but since January 2013, we have switched to multi-detector CT (MDCT) scan. Our aims were to investigate whether MDCT has improved the times to diagnosis and surgery; and whether it resulted in missed hip fractures. Patients/Materials & Methods. Retrospective review of a consecutive series of patients between 01/01/2013 and 31/08/2014 who had MDCT scan for suspected occult hip fracture. Missed fracture was defined as a patient re-presenting with hip fracture within six weeks of a negative scan. A comparative group of consecutive MRI scans from 01/01/2011 to 31/12/2012 was used. Results. Seventy-three MDCTs and 70 MRIs were included. MDCT identified nine hip fractures and other fractures in 27 patients. Mean time to scan for MDCT was 13 hours 37 minutes compared with 53 hours 36 minutes for MRI scan (p<0.001). 88.5% of MDCTs were performed within 24 hours compared with 33.3% of MRIs. Nine and 16 patients required surgery in the MDCT and MRI groups, respectively. Mean time to surgery for MDCT was 50 hours 41 minutes compared with 223 hours 21 minutes for MRI scan (p = 0.25). There were no missed hip fractures in the patients with negative MDCT scan. Discussion. MDCT scan has led to a significant reduction in time to diagnosis, and a large reduction in time to surgery. MDCT did not miss any hip fractures. Conclusion. We advocate the use of MDCT over MRI in suspected occult hip fractures as it is cheaper, quicker, and more readily available; and does not result in missed hip fractures

MRI is a well-tolerated, short procedure that would provide an early, accurate and cost effective diagnosis in elderly patients with negative plain films and persistent post-traumatic hip pain, thereby facilitating their correct management. It is 100% sensitive and specific to occult hip fractures and does not involve ionising radiation. Fractured necks of femur in the elderly population are common. This group of patients are responsible for a significant proportion of health care costs and efforts today. The diagnosis of hip fractures is not always clear-cut and plain radiographs may not show an undisplaced fracture. The management of this patient group is dependant upon the correct diagnosis via imaging and treatment decisions are based on these findings. If these fractures are missed, there is a significant chance of displacement and avascular necrosis presenting at a later date. This would complicate matters and result in more complex surgery. This also increases health care costs due to an extra admission, more expensive and difficult surgery with longer rehabilitation and after care. In our study, the management of the patients reviewed was significantly altered due to the imaging process used. We performed MRI scans on thirty-six patients who had post-traumatic hip pain and negative plain radiographs (reported as normal or equivocal). Twenty-three (64%) of the patients sustained a fracture, of which sixteen (44%) involved the neck of the femur, all of whom were above the age of 71 years. 100% of the elderly age group scanned were positive for a femoral neck fracture and eleven (31%) received operative intervention. The five patients who did not undergo operative management were deemed too unwell for surgery. Only three patients’ scans were negative. These results confirm that MRI (in the 71 years and above age group), is indicated in order to diagnose an undisplaced fractured neck of femur not recognised on plain radiographs, which requires operative intervention in the form of dynamic hip screw or cannulated hip screws to prevent further deterioration or displacement