Early diagnosis of occult hip fractures: MRI versus CT scan
Introduction
Hip fractures have become a widespread health and economic problem in the western world. Longer lifespan has increased the incidence of hip fractures in older people. In the USA, each year 250,000 patients sustain hip fractures. Most of them are treated in community hospitals. Estimates show that the number of hip fractures will double or triple in the coming 20–50 years.1, 2, 3, 4, 22 In 2–10% of the patients presenting with painful hip after trauma initial radiographs may not show the fracture.7, 17, 19
The first year mortality rate of hip fracture patients ranges between 14 and 36%.12 Early diagnosis is essential for improving the care and the recovery of the elderly patients,3, 10, 15, 20, 22 and the mortality rate doubles when the operation is performed after a delay of more than 2 days.13
Most hip fractures diagnosed on clinical history and physical examination are confirmed by plain radiographs. When initial X-rays are negative or equivocal, and there is a clinical suspicion of occult hip fracture, additional diagnostic tests are necessary.9 Failure to diagnose the fracture may result in displacement of a previously undisplaced fracture which may lead to a more complicated operation, longer hospitalisation and delayed rehabilitation.12
Re-assessment of the undiagnosed painful hip includes repeated X-rays several days later and a bone scan at 72 h; the reported sensitivity and specificity of bone scans in occult hip fractures is 93 and 95%, respectively.11, 14 However, a bone scan may produce false positive or false negative results,11 and therefore, it cannot serve as a sole indicator. Moreover, a bone scan does not provide the anatomical location of the fracture, and often necessitates further imaging. CT scan is usually available and very effective in the assessment of acetabular and pelvic fractures, but has not been reported as a diagnostic tool for occult hip fractures. An alternative is MRI examination5, 8, 9, 16, 18 but this is expensive,21 and is not readily available in many community hospitals. Early diagnosis of occult hip fractures would shorten hospitalisation by expediting definitive treatment, leading to reduced costs.
We compared the accuracy of CT Scan and MRI in diagnosing occult hip fractures.
Section snippets
Materials and methods
The study was conducted at a university hospital, treating 400 hip fractures a year.
Between May 2001 and October 2002, we admitted 590 patients with a suspected hip fracture. Of these, 13 (2.2%) had no evidence of fracture on plain radiographs (AP, lateral and full internal rotation X-rays). These patients were divided into two groups. Patients in Group A had CT followed immediately by an MRI (Table 1). Patients in Group B only had an MRI (Table 2).
CT Scan was conducted with an MX8000
Results
We studied 13 patients (11 women and two men) with clinically suspected hip fracture, eight in the left hip, and five in right hip, with no evidence of fracture according to plain films. The ages ranged from 58 to 82 years, mean 73 years. Ten patients were admitted within the first 24 h after the injury, one 3 days later, one 10 days later and one 30 days after the fall.
Discussion
The incidence of occult hip fracture is estimated to be 2–10%.7, 17, 19, 22 In this study, we examined the efficacy of MRI in the early diagnosis of occult hip fractures compared to CT Scan. Our experience shows that MRI provides a definitive early diagnosis in patients with painful hips, whereas a CT is liable to lead to misdiagnosis. The MRI results changed the treatment and ambulation instructions in eight out of the 13 patients. The CT led to misdiagnosis in 66% of patients. Out of the
References (22)
- et al.
Occult fractures of the femoral neck
Am J Emerg Med
(1992) - et al.
Limited magnetic resonance imaging in the diagnosis of occult hip fractures
Am J Emerg Med
(1998) - et al.
The role of MRI in the diagnosis of occult hip fractures
Injury
(1998) - et al.
Epidemiology of hip fractures
Epidemiol Rev
(1997) - et al.
Lifetime risk of hip falls or vertebral fracture and coronary artery disease among menopausal white women
Arch Intern Med
(1989) - et al.
The future of hip fractures in the United States: numbers, costs and potential effect on post menopausal oestrogen
Clin Orthopdkjdot
(1990) - et al.
Occult fractures of the proximal femur: MR imaging, radiology
Radiology
(1989) - et al.
Comparison of MRI with bone scanning for suspected hip fracture in elderly patients
J Bone Joint Surg Br
(1994) - et al.
Geriatric hip fractures: Preoperative decision making
J Musculoskelet Med
(1990) - et al.
The use of MRI in diagnosis of occult hip fractures in the elderly: A preliminary review
Orthopaedics
(1994)
Magnetic resonance imaging of occult fractures of the proximal femur
Skel Radiol
Cited by (122)
Fracture of the greater trochanter with occult intertrochanteric fracture in an adult treated by percutaneous screw fixation: Case report of an often missed injury
2023, International Journal of Surgery Case ReportsThe incidence and management of Isolated Greater Trochanteric Fractures – A systematic review of 166 cases
2021, Journal of Clinical Orthopaedics and TraumaHip and proximal femur
2021, Skeletal Trauma: A Mechanism-Based Approach of ImagingHierarchical fracture classification of proximal femur X-Ray images using a multistage Deep Learning approach
2020, European Journal of RadiologyACR Appropriateness Criteria<sup>®</sup> Acute Hip Pain-Suspected Fracture
2019, Journal of the American College of RadiologyCitation Excerpt :Thus, standard AP and cross-table lateral views have remained the mainstay for trauma assessment of the hip. Multiple studies have demonstrated that radiographs have limited sensitivity for fracture detection of the proximal femur, particularly in elderly osteoporotic patients [20-24]. 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.
Managing the Elderly Emergency Department Patient
2019, Annals of Emergency Medicine