Cost-Effective Analysis of Dual-Energy Computed Tomography for the Diagnosis of Occult Hip Fractures Among Older Adults.

OBJECTIVE: Early and accurate diagnosis of hip fractures minimizes morbidity and mortality. Although current guidelines favor magnetic resonance imaging (MRI) for the diagnosis of occult hip fractures, a new technology called dual-energy computed tomography (DECT) seems an effective alternative. This article investigates a potentially cost-effective strategy for the diagnosis of occult hip fractures in older adults in Singapore. METHODS: A decision tree model was developed to compare costs from a payer's perspective and outcomes in terms of quality-adjusted life-years (QALYs) of different imaging strategies for diagnosing occult hip fracture, comparing MRI with DECT supplementing single-energy computed tomography (SECT) and SECT alone. Model inputs were obtained from local sources where available. Sensitivity analyses are performed to test the robustness of the results. RESULTS: The MRI strategy was dominated by the DECT strategy, whereas DECT supplementing SECT provided 0.30 more QALYs at an incremental cost of SGD106.41 with an incremental cost-effectiveness ratio of SGD352.52 per QALY relative to SECT alone. DECT seemed a cost-effective strategy at a willingness-to-pay threshold of SGD50 000 per QALY. CONCLUSION: DECT supplementing SECT is a cost-effective imaging strategy to diagnose occult hip fractures among older adults in Singapore and should be included in clinical pathways to expedite timely treatment and considered for reimbursement schemes.

Negative predictive value of CT for occult fractures of the hip and pelvis with imaging follow-up.

PURPOSE: To determine the negative predictive value of multidetector CT for radiographically occult fracture of the hip or pelvis in an elderly population presenting to the emergency department. METHODS: Two hundred thirty-seven elderly patients with suspected fracture were identified over a 5-year period with negative radiographs acquired in the emergency department followed by an index CT of the hip/pelvis within 24 h. There were 81 cases with a negative index CT, as determined by 2 musculoskeletal radiologists, and with some form of imaging follow-up (MRI, CT, or x-ray) performed within 18 months of the index CT. Follow-up imaging was reviewed by 2 musculoskeletal radiologists for the presence of fracture to determine the performance of the index CT. The electronic medical record was used to exclude the possibility of intervening trauma between the time of the index CT and follow-up imaging. RESULTS: There were 39 cases with follow-up imaging performed within 6 weeks of the negative index CT, and 42 with follow-up imaging within 6 weeks to 18 months of the negative index CT. Eight of 81 patients demonstrated a fracture on follow-up imaging, with 3 of 8 involving the femoral neck or intertrochanteric femur. The negative predictive value of the index CT for the detection of a radiographically occult hip or pelvic fracture was 90.1%. If considering only surgically relevant fractures (femoral neck and intertrochanteric fractures), the negative predictive value improved to 96.3%. CONCLUSION: Computed tomography for occult hip fractures has a high negative predictive value but there are cases not detected with surgical implications.

Clinical utility of a focused hip MRI for assessing suspected hip fracture in the emergency department.

PURPOSE: A focused hip MRI (FHMR) for the detection of radiographically occult hip fractures was implemented in our emergency department (ED) in 2013. The goal of this study was to assess the clinical utility of this protocol. METHODS: We retrospectively reviewed radiology reports of 262 unique patients who underwent 263 FHMR (coronal T1, coronal STIR, axial T2 fat saturated) for suspected hip fracture in the ED from October 2013 to March 2020. Electronic medical records were reviewed for the ED course, follow-up imaging, and clinical management within 90 days. RESULTS: Seventy-one patients had one or more fractures identified by FHMR: one-third had proximal femoral fractures; two-third had pelvic fractures. Of these 71 patients, 53 (74%) had radiographically occult fractures, including 14 (20%) with occult proximal femoral fractures; 4 patients had fractures occult on CT. Nineteen patients with a suspected fracture on radiography were found to have no fracture on FHMR. Four fractures not reported on FHMR were later seen on follow-up imaging: these included 1 isolated greater trochanter, 1 additional ischial tuberosity, 1 additional superior pubic ramus, and 1 additional sacrum. All four fractures were treated non-operatively. Muscle/tendon injury was the most common type of injury, seen in 50% (130/262) patients with the most commonly torn tendons being the hamstring (44%; 15/34) followed by gluteus medius tendon (18%; 6/34). A full-hip or pelvis MRI was done after FHMR in only 5 patients, primarily for the purpose of better characterizing findings already identified on FHMR (2 for fracture, 2 for tendon injury, 1 for soft tissue metastasis). Only one of these five studies provided new information: ruling out a previously questioned fracture. Clinical management of the vast majority of patients was based solely on findings from the FHMR. CONCLUSIONS: FHMR offers reliable identification of radiographically occult hip fractures and muscle/tendon injuries. The protocol is well trusted in guiding patient management in our ED.

MRI-only occult geriatric hip fractures: is displacement common with nonoperative treatment?

INTRODUCTION: Although surgical fixation is routinely recommended for geriatric hip fractures, nonoperative treatment may be an option for certain stable fracture patterns. Occult hip fractures are nondisplaced fractures not evident on radiographs, but display intraosseous edema on MRI. Our aim is to report the rate of nonoperative treatment failure in patients with occult geriatric hip fractures. METHODS: All nonoperatively treated femoral neck or intertrochanteric femur fractures (AO/OTA 31A and 31B) from 2003 to 2018 were identified. Patients older than 65 years with negative radiographs but a hip fracture evident on MRI were included. Patients who died prior to fracture displacement or union were excluded. Charts and imaging were reviewed for demographic data, fracture type, clinical course, displacement, and whether corrective surgery was performed. RESULTS: Of 15 final study patients, there were 6 femoral neck and 9 intertrochanteric fractures. Two fractures displaced, both requiring surgery (2/15; 13.3%). Both displacements occurred in the femoral neck group (2/6; 33%) compared to none in the intertrochanteric cohort (0/9; 0%). This trend did not reach statistical significance (p = 0.14). CONCLUSION: Thirty-three percent (2/6, 33%) of femoral neck fractures displaced and required surgery. The remainder of the cohort (13/15, 87%) healed without complication, including all of the intertrochanteric fractures (9/9, 100%). Although this difference did not reach statistical significance, the results may better inform treatment discussions for geriatric patients with occult hip fractures diagnosed by MRI. LEVEL OF EVIDENCE: Level III.

Diagnostic Performance of CT for Occult Proximal Femoral Fractures: A Systematic Review and Meta-Analysis.

OBJECTIVE. The purpose of this study was to assess the diagnostic performance of CT for detection of occult proximal femoral fracture. MATERIALS AND METHODS. A systematic search adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed for studies of the sensitivity and specificity of CT for detection of hip fracture. Two independent investigators extracted data and assessed the quality of each study using the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). A qualitative systematic review and quantitative meta-analysis were performed. A Bayesian bivariate random effects meta-analysis model with integrated nested Laplace approximation was used to estimate sensitivity and specificity. RESULTS. Thirteen heterogeneously reported studies were assessed that included 1248 patients (496 with a hip fracture and 752 without) with MRI or clinical follow-up as the reference standard. There were 50 false-negative examinations. The summary estimate of sensitivity was 94% and of specificity was 100%. CONCLUSION. CT can be considered a reasonable choice when occult proximal femoral fracture is suspected clinically in patients for whom MRI is contraindicated or not readily available. However, for patients with ongoing clinical concern about hip fracture despite normal CT findings, MRI should be performed.

The patellar pubic percussion test: a simple bedside tool for suspected occult hip fractures.

PURPOSE: Patellar finger tapping produces a typical sound that can be detected by a stethoscope positioned on the pubic bone (patellar pubic percussion test (PPPT)). Characteristics of this sound are determined by continuity of bone between patella and pelvis. We hypothesized that a PPPT was able to detect overt hip fractures and occult hip fractures that may not be determined by a standard radiological examination. METHODS: Two independent observers performed a PPPT in patients with a suspected hip or pelvic fracture, just before a conventional radiograph (X-ray) was performed. The PPPT test was scored as negative (similar to contralateral side) or positive (different). Patients with a positive PPPT but with a negative X-ray underwent an additional CT scan. RESULTS: One hundred and ninety-one patients with suspected hip or pelvic fracture were included. A total of 161 patients (84%) were diagnosed with a fracture (hip, n = 142; pelvic, n = 19). An 85% sensitivity, a 70% specificity, a 0.94 positive predictive value, and a 0.47 negative predictive value of the PTTT were calculated. The inter-observer reliability (kappa) was 0.7. Eleven CT scans as indicated by a mismatch between PPPT (positive) and X-ray (no fracture) identified eight fractures (73%). A multivariate analysis demonstrated that a painful passive movement and the PPPT predicted a hip fracture. CONCLUSION: The PPPT is a simple bedside diagnostic tool that is sensitive in detecting clinically straight forward hip fractures as well as occult hip fractures. The PPPT can support decision-making for additional radiological examinations in case of potential occult pelvis or hip fractures.

Scaphoid fracture: Bone marrow edema detected with dual-energy CT virtual non-calcium images and confirmed with MRI.

We aimed to determine whether bone marrow edema (BME) in acute traumatic scaphoid fracture could be demonstrated with dual-energy CT (DECT) using MRI as the gold standard. In recent years, virtual non-calcium (VNCa) images have been used to demonstrate BME in trauma cases, for example, in vertebral compression fractures, hip trauma to detect occult fractures and knee fractures. We present three cases of acute scaphoid trauma. Two patients had subtle or invisible fractures on x-ray and conventional CT images, while DECT VNCa images clearly visualized the BME, which was confirmed by MRI. One patient had negative findings on both VNCa and MRI images. The DECT VNCa algorithm is a promising technique to demonstrate BME in scaphoid fractures, with potential for increasing the diagnostic value of CT in this type of injury.

Justifying CT prior to MRI in cases of suspected occult hip fracture. A proposed diagnostic protocol.

INTRODUCTION: Patients with clinical suspicion of hip fracture, but negative radiographs are suspected of having an occult hip fracture (OHF). Different diagnostic modalities are available for investigating OHF and various protocols have been suggested. MRI has the highest sensitivity and specificity, however availability is limited in many institutes. CT is readily accessible in the large majority of hospitals throughout the world but has lower sensitivity and may miss some fractures. In this article we investigate a protocol that balances these issues providing a practical and cost-effective solution. METHODS: During a four-year period between 2012 and 2016 a strict diagnostic protocol was followed at our Medical Center for patients suspected of OHF. This MRI selective protocol consisted of CT initially being performed and only when negative for fracture, followed by an MRI. Retrospective analysis of all patients who followed the protocol was performed. The patients were divided into two groups: those diagnosed by CT alone and those diagnosed by MRI after having a negative CT scan. Diagnostic performance, time to diagnosis and the cost of this protocol were evaluated. RESULTS: 103 patients were treated under the protocol. In 50 patients (49%) hip fracture was diagnosed by CT alone. In the remaining 53 patients (51%) no definitive diagnosis was reached by CT and MRI was subsequently performed. 12 of these 53 patients (23%) were diagnosed with hip fracture necessitating surgery. In the CT only group mean time from admission to diagnosis was 3 hours, in the CT + MRI group this rose to 40 hours. Cost analysis showed that this protocol was more cost-effective than performing MRI in all patients, saving an estimated 66,805 Euro during the study period. CONCLUSION: The clinical challenge of diagnosing OHF can be minimised by implementing a diagnostic protocol. The protocol should take into consideration the diagnostic sensitivity, availability and cost of different imaging modalities. An MRI selective strategy with initial CT scanning is recommended, as it reduces time to diagnosis and lowers overall costs.

Computed tomography-based diagnosis of occult fragility hip fractures offer shorter waiting times with no inadvertent missed diagnosis.

PURPOSE: Surgical delay due to the wait for advanced cross-sectional imaging in occult fragility hip fracture management is not well studied. Our study aims to investigate computed tomography (CT) as an alternative to the gold standard magnetic resonance imaging (MRI) in occult hip fracture workup to decrease surgical delay. METHODS: We conducted a retrospective review of all CTs and MRIs performed between 2015 and 2017 for patients with clinically suspected fragility hip fractures and negative plain radiographs to investigate surgical delay resulting from the wait for advanced imaging and representations due to missed fractures. RESULTS: A total of 243 scans (42 CTs and 201 MRIs) were performed for occult hip fracture workup over the study timeframe, of which 49 patients (20%) had occult hip fractures [CT: 6 (14%), MRI: 43 (21%), p = 0.296)]. There were no readmissions for fracture in the 12 months following a negative scan. The CT group had shorter waiting times (CT: 29 ± 24 h, MRI: 44 ± 32 h, p = 0.004) without significantly reducing surgical delay (CT: 82 ± 36 h, MRI: 128 ± 58 h, p = 0.196). The MRI group had a higher number of patients with a cancer history (p = 0.036), reflective of the practice for workup of possible metastases as a secondary intention. CONCLUSION: Advanced cross-sectional imaging wait times in occult hip fracture workup contribute significantly to surgical delay. Modern CT techniques are not inferior to MRI in detecting occult fractures and may be a suitable alternative in the absence of a cancer history if MRI cannot be obtained in a timely fashion or is contraindicated. Clinicians should utilize the more readily available imaging modality to reduce surgical delay.

Clinical characteristics and short to mid term functional outcomes of surgically treated occult hip fractures in the elderly.

BACKGROUND: Occult hip fractures in the elderly are challenging to diagnose and often result in surgical delays which may worsen outcomes. However, the minimally displaced nature of these fractures may conversely lead to better outcomes. The aim of this study was to determine if surgically treated occult hip fractures have better short to mid term functional outcomes when compared to non-occult fractures. The secondary aim was to determine if there are any differences in clinical characteristics of patients who present with occult hip fractures. METHODS: This was a retrospective cohort study of all elderly patients aged 65 years and above who presented with hip fractures in a single institution from January 2012 to December 2013. Elderly patients who presented with hip fractures were enrolled into an Ortho-geriatric carepath and were eligible for recruitment. The exclusion criteria included patients with pathological fractures and multiple injuries. Demographic and pre-injury variables were collected. The functional outcome measurement was the Modified Barthel's Index (MBI). Patients were divided into non-occult hip fractures (Group 1) and occult hip fractures (Group 2). RESULTS: A total of 1017 patients were admitted during this period into the hip fracture carepath, of which 49 (4.8%) were diagnosed to have occult hip fractures. There was no significant difference between the demographics, Charlson co-morbidity index, abbreviated mental test scores or pre-morbid patient dependence between the groups. There was a significant delay to surgery for occult hip fractures when compared to non-occult fractures. (p = 0.03) Subgroup analysis showed that pre-morbidly, patients with occult inter-trochanteric fractures were significantly more independent than patients with non-occult inter-trochanteric fractures. (p = 0.03) There was no significant difference between the length of stay, surgical complications and 1-year mortality between the 2 groups. Occult inter-trochanteric fractures had better MBI scores at all time points when compared to non-occult inter-trochanteric fractures. CONCLUSIONS: Despite the significant delay to surgical intervention for patients with occult hip fractures, the short to mid term functional outcomes for this group of patients are comparable to surgically treated non-occult hip fractures. There are no distinctive clinical characteristics of elderly patients who are more likely to suffer occult hip fractures.

Magnetic resonance imaging for verifying hip fracture diagnosis why, when and how?

INTRODUCTION: Hip fractures are commonly diagnosed by plain radiography. When a patient presents with negative radiographs and high clinical suspicion of fracture, guidelines recommend proceeding with magnetic resonance imaging (MRI) to diagnose the patient. The aim of this study was to assess the use of MRI in diagnosing hip fractures following trauma to the hip and describe clinical outcome after MRI-diagnosed hip fractures. The perspective was to develop new recommendations for MRI use. MATERIALS AND METHODS: 616 patients at a university hospital fulfilled the inclusion criteria of having an MRI scan of the hip following trauma between the years of 2005 and 2014. Data was collected from the patients' medical records. RESULTS: The annual number of MRIs increased over the ten-year period. Out of 616 MRI scans 228 (37%) showed fracture of the hip with a dominance of trochanteric fractures, 185 (30%) revealed pelvic fracture and 183 (29%) were negative. No patient with acute pelvic fracture had associated fracture of the hip. The main reason to proceed with MRI was a strong clinical suspicion of fracture in patients with negative initial radiographs. Amongst the 228 patients with fracture, 187 (82%) were treated operatively. Of patients with hip fracture, 90 (39%) patients suffered a general complication and 11 (5%) had hip complications. The complication rate of patients with fracture on MRI was compared to that of a cohort of general hip fracture patients at our hospital. No significant difference in twelve months' survival or general complications could be found, but the MRI group had a significantly lower hip complication rate. CONCLUSION: The diagnosis set by MRI, with high share of pelvic fractures or no fracture, reflects the difficulty in differential diagnosing this group of patients. The rate of occult hip fractures was low and patients with pelvic fractures already known from X-ray did not have additional hip fractures. We found an increase in the annual number of MRIs during the 10-year-period. MRI-diagnosed hip fracture patients do not suffer more complications than the regular hip fracture patient.

The sensitivity of ct scans in diagnosing occult femoral neck fractures.

Non-displaced hip fractures can be difficult to diagnose on plain film radiographs. When there is ongoing clinical suspicion of an occult fracture, further imaging is obtained. We investigated the sensitivity of computed tomography (CT) scans in detecting these fractures and the delays to surgery that three-dimensional imaging causes. We identified 78 CT scans performed for possible hip fractures over the past 3 years with the presence and absence of a fracture recorded. Based on subsequent imaging, the accuracy of CT scans was determined. CT scanning yielded sensitivity was 86% and specificity 98% for occult hip fracture (OHF). The median delay to definitive diagnosis was 37h. Our results demonstrate that CT scan does not bear sufficient sensitivity to detect all OHFs. We therefore recommend that MRI should be offered when a fracture is suspected. CT scans should be reserved for when MRI is not available, but a negative scan should be confirmed with subsequent MRI.

Sensitivity and specificity of CT- and MRI-scanning in evaluation of occult fracture of the proximal femur.

OBJECTIVE: To estimate sensitivity and specificity of CT and MRI examinations in patients with fractures of the proximal femur. To determine the interobserver agreement of the modalities among a senior consulting radiologist, a resident in radiology and a resident in orthopaedics surgery. MATERIALS AND METHODS: 67 patients (27 males, 40 females, mean age 80.5) seen in the emergency room with hip pain after fall, inability to stand and a primary X-ray without fracture were evaluated with both CT and MRI. The images were analysed by a senior consulting musculoskeletal radiologist, a resident in radiology and a resident in orthopaedic surgery. Sensitivity and specificity were estimated with MRI as the golden standard. Kappa value was used to assess level of agreement in both MRI and CT finding. RESULTS: 15 fractures of the proximal femur were found (7 intertrochanteric-, 3 femoral neck and 5 fractures of the greater trochanter). Two fractures were not identified by CT and four changed fracture location. Among those, three patients underwent surgery. Sensitivity of CT was 0.87; 95% CI [0.60; 0.98]. Kappa for interobserver agreement for CT were 0.46; 95% CI [0.23; 0.76] and 0.67; 95% CI [0.42; 0.90]. For MRI 0.67; 95% CI [0.43; 0.91] and 0.69; 95% CI [0.45; 0.92]. CONCLUSION: MRI was observed to have a higher diagnostic accuracy than CT in detecting occult fractures of the hip. Interobserver analysis showed high kappa values corresponding substantial agreement in both CT and MRI.