An Umbrella Review and Updated Meta-Analysis of Imaging Modalities in Occult Scaphoid and Hip and Femoral Fractures

Background: Occult fractures may cause multiple morbidities. If occult fractures were detected earlier, complications may be preventable. This umbrella review and updated meta-analysis will aim to evaluate the use of imaging modalities in detecting occult scaphoid and hip fractures. Methods: The protocol for this study is available in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42024525388). The literature search started and ended on 17 March 2024. We searched seven academic databases: MEDLINE, Cochrane Library, Pubmed, Science Direct, Google Scholar, WHO International Clinical Trials Registry Platform, and The Joanna Briggs Institute (JBI) database. The meta-analysis was conducted with the STATA program using the "midas" command. Results: There are four systematic reviews evaluating occult hip and femoral fractures with 6174 patients and two reviews evaluating occult scaphoid fractures with 1355 patients. The prevalence of occult scaphoid fracture and occult hip and femoral fractures is 23.87% (95% CI 18.25-29.49) and 44.8% (95% CI 39.38-51.4), respectively. Magnetic resonance imaging (MRI) had the best posterior probability of positive likelihood ratio (LR+) with 95% and 96% and negative likelihood ratio (LR-) with 0.15% and 1% for both occult scaphoid and hip fractures, respectively, assuming a 25% baseline. MRI could both confirm and exclude occult hip fractures while it can only confirm occult scaphoid fractures. Bone scans are inappropriate for either type of occult fractures The level of evidence for occult scaphoid fracture is weak while it is suggestive for occult hip fractures. Conclusion: The findings strengthen the use of MRI after an initially negative radiograph fracture for occult hip and femoral fractures, with a CT scan as a viable second option.

Radiologic blind spots in hip and pelvic radiographs

PURPOSE

The purpose of our study was to identify the locations at which hip and pelvic fractures are commonly missed on radiographs.

METHODS

A retrospective study was performed at four non-Level 1 trauma center emergency departments. IRB approval was obtained. All emergency department hip or pelvic radiographs with subsequent CT performed within 48 h were identified from 2017 to 2022. Reports for each radiograph and CT were scored for the presence or the absence of fracture in the following locations: ilium, sacrum, superior pubic ramus, inferior pubic ramus, pubis, acetabulum, subcapital femoral, femoral neck, greater trochanter, lesser trochanter, intertrochanteric, and subtrochanteric. The CT report was used as the gold standard. The false-negative radiography cases were reviewed on a PACS workstation to determine whether the case had an "unexpected miss" of a fracture, a subtle fracture, radiographically occult fracture, or exam was limited by artifact. The percentage of missed fractures at each location was calculated.

RESULTS

Nine hundred seventy-five radiography cases with subsequent CT were identified. One hundred forty-six cases did not meet entry criteria; therefore, 829 cases were analyzed further. Seventy-four percent of patients were female with age of 74 ± 16 (mean ± standard deviation) years (range 1-103). Three hundred fifty-two cases had at least one fracture, and many cases had multiple fractures. There were 68 false-negative cases. The most commonly missed fractures by percentage were pubis, ilium, and greater trochanter. The most common unexpectedly missed fractures were greater trochanter and femoral subcapital.

CONCLUSION

A careful systematic evaluation of hip and pelvic radiographs, with particular attention to the pubis, ilium, greater trochanter, and subcapital region, may improve radiographic fracture detection and decrease delays in diagnosis.

Imaging of the Acutely Injured Hip

Acute hip pain following injury more commonly originates locally in and around the hip joint rather than being referred from the lumbar spine, sacroiliac joints, groin, or pelvis. Clinical assessment can usually localize the pain source to the hip region. Thereafter, imaging helps define the precise cause of acute hip pain. This review discusses the imaging of common causes of acute hip pain following injury in adults, addressing injuries in and around the hip joint. Pediatric and postsurgical causes of hip pain following injury are not discussed.

Musculoskeletal Trauma and Infection

MR is often the most definitive imaging for assessment of musculoskeletal trauma and infection. Although it is not possible to address all the intricacies of these complex topics in a single article, this review will attempt to provide a useful toolbox of skills by discussing several common clinical scenarios faced by emergency radiologists in interpretation of adult trauma and infection. These scenarios include MR assessment of hip and pelvic fracture, traumatic soft tissue injuries, septic arthritis, soft tissue infection, and osteomyelitis.

Effect of Low-Dose Dexmedetomidine Combined with Lumbosacral Plexus Block Guided by Ultrasound Imaging Based on Image Segmentation Algorithm in Fracture Surgery

The aim of this study was to analyze the application of ultrasound-guided low-dose dexmedetomidine combined with lumbosacral plexus block based on artificial intelligence algorithm in the surgical treatment of proximal femoral fractures. 104 patients with proximal femoral fractures were divided into 52 cases in the experimental group (ultrasound-guided lumbosacral plexus block combined with dexmedetomidine based on local fitting image segmentation algorithm) and 52 cases in the routine group (endotracheal intubation and inhalation combined with general anesthesia). An image segmentation algorithm based on local fitting was constructed to enhance the ultrasound image. It was found that in the routine group, the heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) at the beginning of intravenous injection of dexmedetomidine, during skin incision, and half an hour after skin incision were significantly lower than those at admission (P < 0.05). The pressing times of patient-controlled intravenous analgesia (PCIA) in the conventional group (17.05 ± 6.85 times) were significantly higher than that in the experimental group (8.55 ± 4.12 times), and the difference was statistically significant (P < 0.05). The visual analogue scale (VAS) scores at 1, 5, 10, and 15 after operation in the routine group were significantly higher than those in the experimental group (P < 0.05). The number of dizziness, nausea, and vomiting, venous thrombosis of lower limbs, cardiovascular events, and pulmonary infection in the routine group on the 1st, 2nd, and 3rd days after operation were significantly higher than those in the experimental group (P < 0.05). In summary, the ultrasound-guided lumbar plexus-sacral plexus block combined with dexmedetomidine anesthesia based on image segmentation algorithm can effectively maintain the hemodynamic stability of patients, with remarkable analgesic effect and high safety.

The Necessity of CT Hip Scans in the Investigation of Occult Hip Fractures and Their Effect on Patient Management

The diagnostic challenge of negative plain radiography in the context of a previously ambulatory patient is increasing with the rise in geriatric trauma. These patients are often diagnosed with small undisplaced fractures of the pelvis and femur which may not alter management. This study aims to assess the frequency at which computed tomography (CT) hip scans altered patient management and whether two X-ray projections of the hip affected fracture detection rate. All CT hip scans performed over a three-year period were identified retrospectively. Only CT hips pertaining to the identification of occult fractures were included in the study. A total of 447 (63.6%) CT hips were performed to exclude an occult fracture, which was only detected in 108 (24.1%) of the scans requested. The majority were subcapital (n = 58, 53.7%) or intertrochanteric (n = 39, 36.1%). There was no significant difference between fracture detection rates when comparing one and two views of the pelvis. 82.4% (n = 89) of occult hip fractures were managed operatively. CT imaging led to a change in patient management in 20% of cases. The frequency at which CT scan detects and alters management in occult hip fractures confirms the justification for its use. Increasing the number of X-ray projection views does not decrease the reliance on CT. Pelvic ring fractures are common in nonambulatory patients following trauma, and if confirmed on initial imaging, subsequent imaging to exclude a concurrent occult hip is unnecessary. The focus of further research should be towards the development of investigation algorithms which decrease the reliance on CT and defining the optimal surgical criteria for occult hip fractures.

Reviewing acute hip fractures in adults

ABSTRACT

Hip fractures are considered a significant public health issue, representing a substantial burden on our healthcare system and society. They are one of the leading causes of disability among older adults, especially women. Globally, an estimated 18% of women and 6% of men will be affected by hip fractures at some time in life. Hip fractures are a major cause of long-term disability among older adults and more significant than mortality, as only 60% of patients regain their preinjury level of mobility. This has detrimental effects on quality of life and activities of daily living, imposing a level of dependence that has personal, social, and systemic consequences.

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.

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.

Dual-energy CT in musculoskeletal trauma

Dual-energy computed tomography (DECT) combines the advantages of conventional CT with the ability to detect bone marrow oedema (BMO), which was previously limited to magnetic resonance imaging (MRI). By analysing DECT virtual non-calcium (VNCa) maps, radiologists can improve the detection of subtle and occult fractures and approximate the acuity/healing of fractures of indeterminate age. This review highlights the role of DECT in the assessment of musculoskeletal trauma, particularly among elderly, post-menopausal women and those at risk for osteoporosis. DECT is especially useful in investigating trabecular bone predominant regions (e.g., vertebral bodies, pelvis, hip, and long bone metaphyses) for stress (i.e., fatigue or insufficiency) and fragility fractures. CT is often performed first due to its increased availability, especially in the emergency setting, shorter imaging duration, and possible patient contraindications to magnetic resonance imaging (MRI). By enabling BMO detection, DECT may have a role in triaging patients for definitive MRI assessment. Understanding the role of anatomical, pathological, and patient factors in image interpretation can improve radiologist adoption of DECT, increase diagnostic confidence, and improve patient management.

Diagnostic Accuracy of Limited MRI Protocols for Detecting Radiographically Occult Hip Fractures: A Systematic Review and Meta-Analysis

OBJECTIVE. This systematic review and meta-analysis aimed to evaluate the diagnostic accuracy of limited MRI protocols for detecting radiographically occult proximal femoral fractures. MATERIALS AND METHODS. A systematic review of MEDLINE, Embase, Scopus, the Cochrane Library, and the gray literature through November 15, 2019, was performed. Original articles with 10 or more patients evaluating limited MRI protocols for the diagnosis of radiographically occult proximal femoral fractures compared with multiparametric MRI with or without clinical outcome as the reference standard were included in the analysis. Patient, clinical, MRI, and performance parameters were independently acquired by two reviewers. Meta-analysis was performed using a bivariate mixed-effects regression model. RESULTS. Eleven studies with 938 patients and 247 proximal femoral fractures met inclusion criteria, and five of these studies were included in the meta-analysis. The pooled and weighted summary sensitivity and specificity and the area under the summary ROC curve for limited MRI protocols in detecting radiographically occult hip fractures were 99% (95% CI, 91-100%), 99% (95% CI, 97-100%), and 1 (95% CI, 0.99-1), respectively. The aggregate sensitivity and specificity values for a single-plane T1-weighted sequence only, STIR sequence only, T1-weighted and STIR sequences, and T2-weighted sequence only were as follows: 97% (89/92) and 100% (76/76), 99% (126/127) and 99% (865/873), 100% (118/118) and 99% (867/874), and 86% (51/59) and 97% (137/141), respectively. Sensitivity was 100% (58/58) when images were acquired on 3-T scanners only and 99% (284/288) when interpreted only by certified radiologists. The mean scanning time for the limited MRI protocols was less than 5 minutes. CONCLUSION. Limited MRI protocols can be used as the standard of care in patients with a suspected but radiographically occult hip fracture. A protocol composed of coronal T1-weighted and STIR sequences is 100% sensitive.

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.

Use of Advanced Imaging for Radiographically Occult Hip Fracture in Elderly Patients: A Systematic Review and Meta-Analysis

Background The overall rate of hip fractures not identified on radiographs but that require surgery (ie, surgical hip fractures) remains unclear in elderly patients who are suspected to have such fractures based on clinical findings. Moreover, the importance of advanced imaging in these patients has not been comprehensively assessed. Purpose To estimate the frequency of radiographically occult hip fracture in elderly patients, to define the higher-risk subpopulation, and to determine the diagnostic performance of CT and bone scanning in the detection of occult fractures by using MRI as the reference standard. Materials and Methods A literature search was performed to identify English-language observational studies published from inception to September 27, 2018. Studies were included if patients were clinically suspected to have hip fracture but there was no radiographic evidence of surgical hip fracture (including absence of any definite fracture or only presence of isolated greater trochanter [GT] fracture). The rate of surgical hip fracture was reported in each study in which MRI was used as the reference standard. The pooled rate of occult fracture, diagnostic performance of CT and bone scanning, and strength of evidence (SOE) were assessed. Results Thirty-five studies were identified (2992 patients; mean age, 76.8 years ± 6.0 [standard deviation]; 66% female). The frequency of radiographically occult surgical hip fracture was 39% (1110 of 2835 patients; 95% confidence interval [CI]: 35%, 43%) in studies of patients with no definite radiographic fracture and 92% (134 of 157 patients; 95% CI: 83%, 98%) in studies of patients with radiographic evidence of isolated GT fracture (moderate SOE). The frequency of occult fracture was higher in patients aged at least 80 years (44%, 529 of 1184), those with an equivocal radiographic report (58%, 71 of 126), and those with a history of trauma (41%, 977 of 2370) (moderate SOE). CT and bone scanning yielded comparable diagnostic performance in the detection of radiographically occult hip fracture (P = .67), with a sensitivity of 79% and 87%, respectively (low SOE). Conclusion Elderly patients with acute hip pain and negative or equivocal findings at initial radiography have a high frequency of occult hip fractures. Therefore, the performance of advanced imaging (preferably MRI) may be clinically appropriate in all such patients. © RSNA, 2020 Online supplemental material is available for this article.

Use of computed tomography and magnetic resonance imaging for occult neck of femur fractures: A single-centre study

OBJECTIVE

Neck of femur (NOF) fractures are common and serious injuries in the elderly. When a NOF fracture is suspected but is not clearly visible on radiographs, guidelines recommend magnetic resonance imaging (MRI), or computed tomography (CT) if MRI is not available/contraindicated. The aim of our study was to review the use of CT and subsequent MRI for suspected NOF fractures in patients with negative or equivocal radiographs.

METHODS

A retrospective review of adult patients with negative or equivocal plain radiographs with suspected NOF fractures presenting between 1 July 2015 and 30 June 2017 was performed. Review of CT and subsequent MRI studies was performed with documentation of reported findings, time intervals from plain radiographs to CT and MRI and final outcomes.

RESULTS

A total of 184 CT studies in 181 patients were reviewed; median age was 82 years (interquartile range 71-89 years) with 110 (60.8%) female patients. CT reported 20 occult fractures; all proceeded to surgery. MRI was performed in 23 patients and revealed additional four NOF fractures missed by CT. An additional fifth fracture missed by CT was confirmed by follow-up radiographs. Median time was approximately 4 h from radiographs to CT and approximately 56 h from radiographs to MRI.

CONCLUSION

Access to CT for evaluation of suspected occult NOF fractures is much quicker compared to MRI. When CT results are negative with on-going clinical suspicion of an occult fracture, MRI should be performed in a time efficient manner.

Is There a Role for CT Pan-Scans in the Initial Workup of Fragility Fracture Patients?

Introduction:

Computed tomography (CT) pan-scans have become increasingly commonplace as part of the initial diagnostic workup for patients sustaining traumatic injuries. They have proven effective in improving diagnostic accuracy in those with high-energy mechanisms of injury. However, the utility of pan-scans in the geriatric population sustaining low-energy traumatic injuries remains unproven.

Methods:

A retrospective review was conducted of patients who sustained a fragility fracture at a level-1 trauma center over a 15-month period. Radiologist interpretations of any CT pan-scans were reviewed for acute findings, and charts were reviewed for resulting changes in orthopedic and nonorthopedic management. Additionally, mechanism of injury, definitive management, time to surgery, length of stay, level of care at discharge, and demographic data were compared against similar patients who did not receive a pan-scan.

Results:

Of the 109 patients who underwent a CT pan-scan, 1 (0.92%) had a change in orthopedic treatment. Twelve (11.01%) patients had changes to their nonorthopedic management. In addition, 14 other patients had one or more consultations obtained based on pan-scan results that did not result in any change in management. Discussion: This study found that only 1 of the included patients had a change in orthopedic management and 12 had a change in nonorthopedic management, despite over half of the study population being found to have additional findings. Furthermore, patients who underwent a pan-scan did not have expedited surgical intervention or earlier discharges compared to those who were not pan-scanned.  

Conclusion:

This study demonstrates whole-body CT imaging provides little benefit in geriatric patients who sustain fragility fractures and should be utilized judiciously and in a targeted fashion instead of as a routine part of trauma surgery or emergency department protocol in this patient population.

Level of Evidence:

Level III Retrospective Study.