Imaging of occult hip fractures: CT or MRI?

Comparison of CT and MRI in diagnosing occult hip fracture: a systematic review and meta-analysis

OBJECTIVE

To compare the diagnostic accuracy of computed tomography (CT) scans and magnetic resonance imaging (MRI) in detecting occult hip fractures.

METHODS

We conducted a systematic literature review and identified 12 articles involving 1,819 participants for inclusion. Data extraction and quality assessment were performed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Publication bias was assessed with the Deek funnel plot asymmetry test. We conducted a meta-analysis using a random-effects model to derive pooled estimates of sensitivity, specificity, positive and negative likelihood ratios, and the diagnostic odds ratio, along with their 95% confidence intervals. A summary receiver operating characteristic curve was generated to illustrate the overall diagnostic accuracy.

RESULTS

The methodological quality of the included studies was high, with minimal concerns about the applicability of the tests in clinical settings. Both CT and MRI showed good diagnostic efficacy for occult hip fractures. However, MRI consistently outperformed CT, exhibiting significantly higher sensitivity, specificity, and likelihood ratios, thereby providing superior accuracy in confirming or excluding occult fractures. Meta-regression analysis revealed that sequence parameters and sample size significantly influenced the differences in sensitivity and specificity between CT and MRI.

CONCLUSION

Both CT and MRI are effective modalities for detecting occult hip fractures, with MRI demonstrating greater diagnostic accuracy. This meta-analysis supports the use of MRI when higher sensitivity and specificity are required in clinical practice.

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.

The Role of Artificial Intelligence in the Identification and Evaluation of Bone Fractures

Artificial intelligence (AI), particularly deep learning, has made enormous strides in medical imaging analysis. In the field of musculoskeletal radiology, deep-learning models are actively being developed for the identification and evaluation of bone fractures. These methods provide numerous benefits to radiologists such as increased diagnostic accuracy and efficiency while also achieving standalone performances comparable or superior to clinician readers. Various algorithms are already commercially available for integration into clinical workflows, with the potential to improve healthcare delivery and shape the future practice of radiology. In this systematic review, we explore the performance of current AI methods in the identification and evaluation of fractures, particularly those in the ankle, wrist, hip, and ribs. We also discuss current commercially available products for fracture detection and provide an overview of the current limitations of this technology and future directions of the field.

Visual assessment and quantitative analysis of bone marrow edema in young and middle-aged versus elderly patients with vertebral compression fracture by spectral CT

BACKGROUND

For the diagnosis of bone marrow edema (BME), spectral computed tomography (CT) has emerged as a promising technique.

PURPOSE

To study the different performances of spectral CT in the diagnosis of vertebral BME in young and middle-aged versus elderly patients.

MATERIAL AND METHODS

Magnetic resonance imaging (MRI) was used as the gold standard. To determine the existence of BME, spectral CT color-coded images of the vertebral bodies of 82 patients with vertebral compression fractures (VCFs) were visually inspected. A quantitative analysis of the spectral CT vertebral water concentration in the diagnosis of BME was performed using a receiver operating characteristic (ROC) curve. Patients were divided into two groups for comparison: the young and middle-aged group; and the elderly group.

RESULTS

The sensitivity and specificity for visual assessment were 83.7% and 98.3%, respectively, in the young and middle-aged group and 96.8% and 98.2%, respectively, in the elderly group. The elderly group had a higher sensitivity than the young and middle-aged group (P < 0.05). With a threshold of 1046.2 mg/cm3, the ROC curve for the young and middle-aged group displayed an area under the curve (AUC) of 0.870, sensitivity of 86.0%, and specificity of 81.4%. The threshold of 1031.4 mg/cm3 yielded a sensitivity of 95.2% and a specificity of 98.4%, and the AUC of the elderly group was 0.997. The elderly group had a higher level of specificity than the young and middle-aged group (P < 0.05).

CONCLUSION

Spectral CT can reliably diagnose BME in VCFs, and it performs better in elderly people than in young and middle-aged people.

Dual-energy CT: Impact of detecting bone marrow oedema in occult trauma in the Emergency

Dual-energy computed tomography (DECT) is an advanced imaging technique that acquires data using two distinct X-ray energy spectra, typically at 80 and 140 kVp, to differentiate materials based on their atomic number and electron density. This capability allows for the enhanced visualisation of various pathologies, including bone marrow oedema (BMO), by providing high-resolution images with notable energy spectral separation while maintaining radiation doses comparable to conventional CT. DECT's ability to create colour-coded virtual non-calcium (VNCa) images has proven particularly valuable in detecting traumatic bone marrow lesions (BMLs) and subtle fractures, offering a reliable alternative or complement to MRI. DECT has emerged as a significant tool in the detection and characterisation of bone marrow pathologies, especially in traumatic injuries. Its ability to generate high-resolution images and distinguish between different tissue types makes it a valuable asset in clinical diagnostics. With its comparable diagnostic accuracy to MRI and the added advantage of reduced examination time and increased availability, DECT represents a promising advancement in the imaging of BMO and related conditions.

Additional Imaging is of Limited Value in Traumatic Hip Fractures With a History of Distant Malignancy and No Suspicious Lesion on Plain Radiographs

OBJECTIVE

To determine the value of obtaining additional preoperative imaging in patients with a traumatic hip fracture and a history of malignancy in whom plain radiographs show no lesion suspicious for metastases.

DESIGN

Retrospective review.

SETTING

Teaching NHS Trust in the United Kingdom, over an 8-year period treating 4421 hip fractures.

PATIENTS/PARTICIPANTS

Three hundred sixty-seven patients with hip fracture and a history of malignancy at a site distant to the hip. Three hundred thirty patients had a history of trauma and no lesion on the plain radiograph suspicious for metastases.

MAIN OUTCOMES MEASUREMENTS

Whether obtaining additional imaging preoperatively (MRI, CT, and bone scan) identified metastases or affected management.

RESULTS

32/330 patients had further preoperative imaging, none of which demonstrated a pathological fracture secondary to malignancy. On follow-up, 3/330 (0.9%) cases were found to have occult metastasis at the hip fracture site. All 3 had only plain radiographs before surgery. In 2, this was identified on histological examination of intraoperative samples, and in 1, radiologically as a metastatic metaphyseal lesion 18 months after a hemiarthroplasty. Only in the latter case, preoperative identification of hip metastasis could have altered surgical management. Patients undergoing further preoperative imaging waited significantly longer for surgery (35 ± 26 vs. 51 ± 26 hours, P = 0.0011).

CONCLUSIONS

In the absence of a suspicious metastatic lesion on initial plain radiographs, further preoperative imaging is unlikely to identify a lesion that will affect management and confers significant delays to surgery. Sending intraoperative histological samples may help guide postoperative oncological management, but further work is needed to prove its utility.

LEVEL OF EVIDENCE

Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Traumatic bone marrow lesions in dual-energy computed tomography

Traumatic bone marrow lesions (TBMLs) are considered to represent a range of concealed bone injuries, including haemorrhage, infarction, and localised oedema caused by trabecular microfracture occurring in the cancellous bone. If TBMLs are not managed timeously, they potentially cause a series of complications that can lead to irreversible morbidity and prolonged recovery time. This article reviews interesting image findings of bone marrow lesions in dual-energy computed tomography (DECT). In addition to combining the benefits of traditional CT imaging, DECT also reveals and identifies various structures using diverse attenuation characteristics of different radiographic spectra. Therefore, DECT has the capacity to detect TBMLs, which have traditionally been diagnosed using MRI. Through evaluating DECT virtual non-calcium maps, the detection of TBMLs is rendered easier and more efficient in some acute accidents.

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.

Management of isolated greater trochanteric fractures of the hip – Experience from a major trauma centre over a 24-month period

Introduction

Isolated greater trochanteric fractures (IGTfs) of the femur are uncommon. At least 10% of these fractures have an occult intertrochanteric extension. Mobilisation too early without care can lead to fracture propagation, requiring surgical fixation. There is no definite consensus in the literature on how to manage initially diagnosed IGTf with potential occult intertrochanteric extension. We reviewed the management of IGTf in our major trauma centre (MTC) and propose a management flow chart.

Methods

The electronic notes and images for all IGTf admitted under or referred to the orthopaedic team at a MTC, from June 2015 to July 2017, were reviewed. Data were collected on fracture pattern and diagnostic imaging modalities. Periprosthetic fractures were excluded.

Results

1550 neck of femur fracture patients were admitted over the 2-year period; 790 patients (51%) had a fracture around the intertrochanteric region and 49 (3.2%) were diagnosed with a IGTf on plain radiographs. 98% of patients had further imaging after initial plain film radiographs, and 58% of all IGTf were shown to have an intertrochanteric extension. Overall 16/49 patients (32.7%) needed an operation.

Conclusions

An IGTf not crossing the medullary canal into the calcar (i.e >50% of the diameter) does not require surgical fixation and can be managed with analgesia and supervised mobilisation. The 30-day mortalities in both operative and non-operative groups were similar at 2% and 2.2%, respectively. Overall mortality is half of the total neck of femur fracture population (4.1%) in our MTC. We propose a management flow chart for this patient cohort.

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.

Artificial intelligence improves the accuracy of residents in the diagnosis of hip fractures: a multicenter study

BACKGROUND

Less experienced clinicians sometimes make misdiagnosis of hip fractures. We developed computer-aided diagnosis (CAD) system for hip fractures on plain X-rays using a deep learning model trained on a large dataset. In this study, we examined whether the accuracy of the diagnosis of hip fracture of the residents could be improved by using this system.

METHODS

A deep convolutional neural network approach was used for machine learning. Pytorch 1.3 and Fast.ai 1.0 were applied as frameworks, and an EfficientNet-B4 model (a pre-trained ImageNet model) was used. We handled the 5295 X-rays from the patients with femoral neck fracture or femoral trochanteric fracture from 2009 to 2019. We excluded cases in which the bilateral hips were not included within an image range, and cases of femoral shaft fracture and periprosthetic fracture. Finally, we included 5242 AP pelvic X-rays from 4851 cases. We divided these 5242 images into two images per image, and prepared 5242 images including fracture site and 5242 images without fracture site. Thus, a total of 10,484 images were used for machine learning. The accuracy, sensitivity, specificity, F-value, and area under the curve (AUC) were assessed. Gradient-weighted class activation mapping (Grad-CAM) was used to conceptualize the basis for the diagnosis of the fracture by the deep learning algorithm. Secondly, we conducted a controlled experiment with clinicians. Thirty-one residents;young doctors within 2 years of graduation from medical school who rotate through various specialties, were tested using 300 hip fracture images that were randomly extracted from the dataset. We evaluated the diagnostic accuracy with and without the use of the CAD system for each of the 300 images.

RESULTS

The accuracy, sensitivity, specificity, F-value, and AUC were 96.1, 95.2, 96.9%, 0.961, and 0.99, respectively, with the correct diagnostic basis generated by Grad-CAM. In the controlled experiment, the diagnostic accuracy of the residents significantly improved when they used the CAD system.

CONCLUSIONS

We developed a newly CAD system with a deep learning algorithm from a relatively large dataset from multiple institutions. Our system achieved high diagnostic performance. Our system improved the diagnostic accuracy of residents for hip fractures.

LEVEL OF EVIDENCE

Level III, Foundational evidence, before-after study.

CLINICAL RELEVANCE

high.

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.

Current Trends in the Evaluation and Management of Nondisplaced Femoral Neck Fractures in the Elderly

Nondisplaced (Garden I and II) femoral neck (FN) fractures are commonly encountered by the practicing orthopaedic surgeon. Although these fractures are primarily classified based on the AP radiograph, the lateral radiograph should be closely scrutinized as well because posterior tilt has emerged as a consistent predictor of fixation failure. Internal fixation has for many years been the standard of care, with both cannulated screws and the sliding hip screw representing acceptable options. However, the outcomes after fixation of Garden I and II FN fractures have not been uniformly positive, with the rates of revision surgery ranging from 8% to 27%. Complications after fixation of nondisplaced FN fractures include nonunion, fixation failure, osteonecrosis, and femoral shortening causing inferior hip function. For these reasons, arthroplasty is increasingly considered a viable option in the treatment of these fractures, especially in the presence of factors that predispose to failure after fixation. Novel devices for FN fixation have recently been developed, although clinical data supporting their use are sparse at the present time.

Periprosthetic occult acetabular fracture: an unknown side effect of press-fit techniques in primary cementless total hip arthroplasty

BACKGROUND

This study sought to investigate the prevalence and risk factors of periprosthetic occult acetabular fracture occurring during cementless acetabular cup insertion in patients undergoing primary total hip arthroplasty (THA) and to assess the clinical consequences of these fractures.

METHODS

A total of 232 hips (n = 205 patients) were included in this study. A periprosthetic occult acetabular fracture was defined as that which was unrecognised intraoperatively and was undetectable on post-operative radiographs yet was successfully diagnosed on post-operative computed tomography (CT) images. Clinical (age, sex, body mass index, and preoperative diagnosis) and surgical (additional screw fixation, cup rim size, and cup type) variables were analysed to identify risk factors for periprosthetic occult acetabular fracture.

RESULTS

Sixteen (6.9%) periprosthetic occult intraoperative acetabular fractures were identified. In addition, one (0.4%) periprosthetic acetabular fracture was found during operation. The superolateral wall (9/16 hips; 56.3%) was the most frequent location. In addition, one (0.4%) periprosthetic acetabular fracture was found during operation. Male sex was the only factor associated with an increased risk for periprosthetic occult intraoperative acetabular fracture (odds ratio for male versus female sex: 4.28; p = 0.04). There was no significant association between cup type and the occurrence of periprosthetic occult acetabular fracture. All 16 hips with periprosthetic occult intraoperative acetabular fracture were healed at the final follow-up visit without the requirement for any additional surgical interventions.

CONCLUSION

The results of the current study suggest that periprosthetic occult acetabular fractures are common during press-fit acetabular cup insertion in primary THA. Surgeons should have a high index of suspicion and early CT imaging referral in male patients who present with unexplained early post-operative groin pain in primary THA using cementless acetabular cups.

A Human-Algorithm Integration System for Hip Fracture Detection on Plain Radiography: System Development and Validation Study

Background

Hip fracture is the most common type of fracture in elderly individuals. Numerous deep learning (DL) algorithms for plain pelvic radiographs (PXRs) have been applied to improve the accuracy of hip fracture diagnosis. However, their efficacy is still undetermined.

Objective

The objective of this study is to develop and validate a human-algorithm integration (HAI) system to improve the accuracy of hip fracture diagnosis in a real clinical environment.

Methods

The HAI system with hip fracture detection ability was developed using a deep learning algorithm trained on trauma registry data and 3605 PXRs from August 2008 to December 2016. To compare their diagnostic performance before and after HAI system assistance using an independent testing dataset, 34 physicians were recruited. We analyzed the physicians’ accuracy, sensitivity, specificity, and agreement with the algorithm; we also performed subgroup analyses according to physician specialty and experience. Furthermore, we applied the HAI system in the emergency departments of different hospitals to validate its value in the real world.

Results

With the support of the algorithm, which achieved 91% accuracy, the diagnostic performance of physicians was significantly improved in the independent testing dataset, as was revealed by the sensitivity (physician alone, median 95%; HAI, median 99%; P<.001), specificity (physician alone, median 90%; HAI, median 95%; P<.001), accuracy (physician alone, median 90%; HAI, median 96%; P<.001), and human-algorithm agreement [physician alone κ, median 0.69 (IQR 0.63-0.74); HAI κ, median 0.80 (IQR 0.76-0.82); P<.001. With the help of the HAI system, the primary physicians showed significant improvement in their diagnostic performance to levels comparable to those of consulting physicians, and both the experienced and less-experienced physicians benefited from the HAI system. After the HAI system had been applied in 3 departments for 5 months, 587 images were examined. The sensitivity, specificity, and accuracy of the HAI system for detecting hip fractures were 97%, 95.7%, and 96.08%, respectively.

Conclusions

HAI currently impacts health care, and integrating this technology into emergency departments is feasible. The developed HAI system can enhance physicians’ hip fracture diagnostic performance.

Ultra-low-dose CT versus radiographs for minor spine and pelvis trauma: a Bayesian analysis of accuracy

OBJECTIVES

To compare diagnosis performance and effective dose of ultra-low-dose CT (ULD CT) versus radiographs in suspected spinal or pelvic ring or hip fracture for minor trauma.

METHODS

ULD CT, in addition to radiography, was prospectively performed in consecutive patients admitted to the emergency department for minor traumas, during working hours over 2 months. Presence of a recent fracture was assessed by two blind radiologists independently. Sensitivities and specificities were estimated using the best valuable comparator (BVC) as a reference and using a latent class model in Bayesian inference (BLCM). Dosimetric indicators were recorded and effective doses (E) were calculated using conversion coefficient.

RESULTS

Eighty areas were analyzed in 69 patients, including 22 dorsal spine, 28 lumbar spine, and 30 pelvic ring/hip. Thirty-six fractures (45%) were observed. Applying the BVC method, depending on location, ULD CT sensitivity was 80 to 100% for reader 1 and 85 to 100% for reader 2, whereas radiographic sensitivity was 60 to 85% for reader 1 and 50 to 92% for reader 2. With BLCM approach for reader 2, ULD CT sensitivity for all locations/dorsal spine/lumbar spine and pelvic ring-hip was 87.1/75.9/84.2/76.9% respectively. Corresponding radiograph sensitivity was 73.8, 54.8, 80.4, and 68.7%. Effective doses of ULD CT were similar to radiographs for dorsal and hip locations whereas for lumbar spine, ULD CT effective dose was 1.83 ± 0.59 mSv compared with 0.96 ± 0.59 mSv (p < 0.001).

CONCLUSION

Sensitivity for fracture detection was higher for ULD CT compared with radiographs with an effective dose comparable to radiographs.

KEY POINTS

• Ultra-low-dose spine and pelvis CT demonstrates better fracture detection when compared with radiographs. • The effective dose of ultra-low-dose spine and pelvis CT scan and radiographs is comparable. • Replacement of radiographs by ULD CT in daily practice for trauma patients is an option to consider and should be evaluated by a randomized trial.

Deep learning evaluation of pelvic radiographs for position, hardware presence, and fracture detection

PURPOSE

Recent papers have shown the utility of deep learning in detecting hip fractures with pelvic radiographs, but there is a paucity of research utilizing deep learning to detect pelvic and acetabular fractures. Creating deep learning models also requires appropriately labeling x-ray positions and hardware presence. Our purpose is to train and test deep learning models to detect pelvic radiograph position, hardware presence, and pelvic and acetabular fractures in addition to hip fractures.

MATERIAL AND METHODS

Data was retrospectively acquired between 8/2009-6/2019. A subset of the data was split into 4 position labels and 2 hardware labels to create position labeling and hardware detecting models. The remaining data was parsed with these trained models, labeled based on 6 "separate" fracture patterns, and various fracture detecting models were created. A receiver operator characteristic (ROC) curve, area under the curve (AUC), and other output metrics were evaluated.

RESULTS

The position and hardware models performed well with AUC of 0.99-1.00. The AUC for proximal femoral fracture detection was as high as 0.95, which was in line with previously published research. Pelvic and acetabular fracture detection performance was as low as 0.70 for the posterior pelvis category and as high as 0.85 for the acetabular category with the "separate" fracture model.

CONCLUSION

We successfully created deep learning models that can detect pelvic imaging position, hardware presence, and pelvic and acetabular fractures with AUC loss of only 0.03 for proximal femoral fracture.

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.

Femoral neck fracture detection in X-ray images using deep learning and genetic algorithm approaches

Objectives

This study aims to detect frontal pelvic radiograph femoral neck fracture using deep learning techniques.

Patients and methods

This retrospective study was conducted between January 2013 and January 2018. A total of 234 frontal pelvic X-ray images collected from 65 patients (32 males, 33 females; mean age 74.9 years; range, 33 to 89 years) were augmented to 2106 images to achieve a satisfactory dataset. A total of 1,341 images were fractured femoral necks while 765 were non-fractured ones. The proposed convolutional neural network (CNN) architecture contained five blocks, each containing a convolutional layer, batch normalization layer, rectified linear unit, and maximum pooling layer. After the last block, a dropout layer existed with a probability of 0.5. The last three layers of the architecture were a fully connected layer of two classes, a softmax layer and a classification layer that computes cross entropy loss. The training process was terminated after 50 epochs and an Adam Optimizer was used. Learning rate was dropped by a factor of 0.5 on every five epochs. To reduce overfitting, regularization term was added to the weights of the loss function. The training process was repeated for pixel sizes 50x50, 100x100, 200x200, and 400x400. The genetic algorithm (GA) approach was employed to optimize the hyperparameters of the CNN architecture and to minimize the error after testing the model created by the CNN architecture in the training phase.

Results

Performance in terms of sensitivity, specificity, accuracy, F1 score, and Cohen’s kappa coefficient were evaluated using five- fold cross validation tests. Best performance was obtained when cropped images were rescaled to 50x50 pixels. The kappa metric showed more reliable classifier performance when 50x50 pixels image size was used to feed the CNN. The classifier performance was more reliable according to other image sizes. Sensitivity and specificity rates were computed to be 83% and 73%, respectively. With the inclusion of the GA, this rate increased by 1.6%. The detection rate of fractured bones was found to be 83%. A kappa coefficient of 55% was obtained, indicating an acceptable agreement.

Conclusion

This experimental study utilized deep learning techniques in the detection of bone fractures in radiography. Although the dataset was unbalanced, the results can be considered promising. It was observed that use of smaller image size decreases computational cost and provides better results according to evaluation metrics.

Imaging Modalities to Assess Fracture Healing

PURPOSE OF REVIEW

This review discusses imaging modalities for fracture repair assessment, with an emphasis on pragmatic clinical and translational use, best practices for implementation, and challenges and opportunities for continuing research.

RECENT FINDINGS

Semiquantitative radiographic union scoring remains the clinical gold standard, but has questionable reliability as a surrogate indicator of structural bone healing, particularly in early-stage, complex, or compromised healing scenarios. Alternatively, computed tomography (CT) scanning enables quantitative assessment of callus morphometry and mechanics through the use of patient-specific finite-element models. Dual-energy X-ray absorptiometry (DXA) scanning and radiostereometric analysis (RSA) are also quantitative, but technically challenging. Nonionizing magnetic resonance (MR) and ultrasound imaging are of high interest, but require development to enable quantification of 3D mineralized structures. Emerging image-based methods for quantitative assessment of bone healing may transform clinical research design by displacing binary outcomes classification (union/nonunion) and ultimately enhance clinical care by enabling early nonunion detection.

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.

Value of CT to detect radiographically occult injuries of the proximal femur in elderly patients after low-energy trauma: determination of non-inferiority margins of CT in comparison with MRI

PURPOSE

To determine the margins of non-inferiority of the sensitivity of CT and the sample size needed to test the non-inferiority of CT in comparison with MRI.

MATERIALS AND METHODS

During a 2-year period, elderly patients with suspected radiographically occult post-traumatic bone injuries were investigated by CT and MRI in two institutions. Four radiologists analyzed separately the CT and MRI examinations to detect post-traumatic femoral injuries. Their sensitivities at CT (SeCT) and MRI (SeMRI) were calculated with the reference being a best valuable comparator (consensus reading of the MRI and clinical follow-up). ROC analysis followed by an exact test (Newcombe's approach) was performed to assess the 95% confidence interval (CI) for the difference SeCT-SeMRI for each reader. A sample size calculation was performed based on our observed results by using a one-sided McNemar's test.

RESULTS

Twenty-nine out of 102 study participants had a post-traumatic femoral injury. SeCT ranged between 83 and 93% and SeMRI ranged between 97 and 100%. The 95% CIs for (SeCT-SeMRI) were [- 5.3%, + 0.8%], (p^R1 = 0.1250), [- 4.5%; + 1.2%] (p^R2 = 0.2188), [- 3.4%; + 1.1%] (p^R3 = 0.2500) to [- 3.8%; + 1.6%] (p^R4 = 0.3750) according to readers, with a lowest limit for 95% CIs superior to a non-inferiority margin of (- 6%) for all readers. A population of 440 patients should be analyzed to test the non-inferiority of CT in comparison with MRI.

CONCLUSION

CT and MRI are sensitive for the detection of radiographically occult femoral fractures in elderly patients after low-energy trauma. The choice between both these modalities is a compromise between the most available and the most sensitive technique.

KEY POINTS

• The sensitivity of four separate readers to detect radiographically occult post-traumatic femoral injuries in elderly patients after low-energy trauma ranged between 83 and 93% at CT and between 97 and 100% at MRI according to a best valuable comparator including MRI and clinical follow-up. • CT is a valuable alternative method to MRI for the detection of post-traumatic femoral injuries in elderlies after low-energy trauma if a 6% loss in sensitivity can be accepted in comparison with MRI. • The choice between CT and MRI is a compromise between the most available and the most sensitive technique.

Multi-detector CT for suspected hip fragility fractures: A diagnostic test accuracy systematic review and meta-analysis

To perform a systematic review (SR) and meta-analysis to determine the diagnostic test accuracy (DTA) of Multi-Detector Computed Tomography (MDCT) for detecting proximal femoral (hip) fragility fractures in patients with a negative initial radiograph. MEDLINE and EMBASE were searched to identify relevant studies published between January 2000 and May 2018. Articles underwent title and abstract screening followed by full-text screening. Study inclusion criteria are patients with suspected hip fracture, negative initial radiograph, MDCT as the index test, magnetic resonance imaging (MRI) or clinical follow-up as the reference standard, and DTA measure as the outcome. Demographic, methodologic, and study outcome data were extracted. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. DTA metrics were pooled using bivariate random-effects meta-analysis. From an initial 1385 studies, four studies reporting on 418 patients (174 with hip fractures) were included. Pooled summary statistics included the following: sensitivity (87%; 95% confidence interval [CI] 79-93), specificity (98%; 95% CI 95-99), and the area under the summary receiver operating characteristic (ROC) curve (0.972). MDCT has a high specificity for detecting hip fragility fractures, comparable to MRI, but a lower sensitivity. Local institutional factors may play a role in whether a patient receives MDCT or MRI, as imaging should not be delayed. If there is ongoing concern for fracture in a patient with a negative MDCT, MRI should be performed. Cautious interpretation of the results is warranted given the risk of bias and small sample size.

Fragility Fractures of the Pelvis Classification: A Multicenter Assessment of the Intra-Rater and Inter-Rater Reliabilities and Percentage of Agreement

BACKGROUND

The fragility fractures of the pelvis (FFP) classification was established to address the specific fracture morphology and dynamic instability in the elderly. Although this system is frequently used, data on the intra-rater and inter-rater reliabilities are lacking.

METHODS

Six experienced and 6 inexperienced surgeons and 1 surgeon trained by the originator of the FFP classification ("gold standard") each used the FFP classification 3 times to grade the computed tomography (CT) scans of 60 patients from 6 hospitals. We assessed intra-rater and inter-rater reliabilities using Fleiss kappa statistics and the percentage of agreement using the "gold standard," the submitting hospital, and the majority vote as references.

RESULTS

The intra-rater reliability for the FFP classification was mainly moderate, with a mean Fleiss kappa coefficient (and 95% confidence interval) of 0.46 (0.40 to 0.50) for the complete classification (i.e., both the main-group FFP ratings [I through III] and the subgroup ratings [a, b, and c]) and 0.60 (0.53 to 0.65) for the main group only. The inter-rater reliability was substantial for the main group classification (0.61 [0.54 to 0.66]) and moderate for the complete classification (0.53 [0.48 to 0.58]). The percentage of agreement was 68% to 80%. The lowest agreement was found for FFP II and III.

CONCLUSIONS

The FFP classification displayed moderate and substantial intra-rater and inter-rater reliabilities.

CLINICAL RELEVANCE

With moderate to substantial intra-rater and inter-rater reliabilities, the FFP classification forms a solid basis for future clinical investigations. The differentiation of FFP II from FFP III should be evaluated thoroughly, as the initial treatment changes from nonoperative for II to operative for III.

Application of a deep learning algorithm for detection and visualization of hip fractures on plain pelvic radiographs

Objective

To identify the feasibility of using a deep convolutional neural network (DCNN) for the detection and localization of hip fractures on plain frontal pelvic radiographs (PXRs).

Summary of background data

Hip fracture is a leading worldwide health problem for the elderly. A missed diagnosis of hip fracture on radiography leads to a dismal prognosis. The application of a DCNN to PXRs can potentially improve the accuracy and efficiency of hip fracture diagnosis.

Methods

A DCNN was pretrained using 25,505 limb radiographs between January 2012 and December 2017. It was retrained using 3605 PXRs between August 2008 and December 2016. The accuracy, sensitivity, false-negative rate, and area under the receiver operating characteristic curve (AUC) were evaluated on 100 independent PXRs acquired during 2017. The authors also used the visualization algorithm gradient-weighted class activation mapping (Grad-CAM) to confirm the validity of the model.

Results

The algorithm achieved an accuracy of 91%, a sensitivity of 98%, a false-negative rate of 2%, and an AUC of 0.98 for identifying hip fractures. The visualization algorithm showed an accuracy of 95.9% for lesion identification.

Conclusions

A DCNN not only detected hip fractures on PXRs with a low false-negative rate but also had high accuracy for localizing fracture lesions. The DCNN might be an efficient and economical model to help clinicians make a diagnosis without interrupting the current clinical pathway.

Key Points

• Automated detection of hip fractures on frontal pelvic radiographs may facilitate emergent screening and evaluation efforts for primary physicians.

• Good visualization of the fracture site by Grad-CAM enables the rapid integration of this tool into the current medical system.

• The feasibility and efficiency of utilizing a deep neural network have been confirmed for the screening of hip fractures.

The Frequency of Occult Intertrochanteric Fractures among Individuals with Isolated Greater Trochanteric Fractures

Purpose

Isolated greater trochanteric (GT) fractures are often identified using plain radiography of patients with post-traumatic hip pain. In many cases, the fracture extends to form an occult intertrochanteric fracture. We conducted a study to determine the frequency of occult intertrochanteric fractures in patients diagnosed with isolated GT fractures using plain radiographs.

Materials and Methods

Among 3,017 individuals who visited our emergency department with a trauma-induced pertrochanteric femur fracture between July 2004 and March 2018, 100 patients diagnosed with isolated GT fractures using plain radiographs were retrospectively analyzed. Patients were divided into two groups, those with: i) isolated GT fractures (group A) and ii) occult intertrochanteric fractures (group B). In addition, plain radiographs, magnetic resonance imaging results, and treatment methods were further analyzed in each group. If surgery treatment was needed, it was performed by one surgeon, and in all cases, a 2-hole dynamic hip screw was used.

Results

Among the 100 cases of isolated GT fractures diagnosed using plain radiograph, additional examinations revealed that 10 (10.0%) were suffering from isolated GT fractures alone, while the remaining 90 (90.0%) were further diagnosed with occult intertrochanteric fracture. Gender, age, mechanism of injury, and bone mineral density did not correlate with fracture type.

Conclusion

In our analysis, 90% of injuries initially diagnosed as isolated GT fractures were found to extend into occult intertrochanteric fractures upon further examination with additional imaging modalities. Therefore, additional evaluation should be performed to test for the potential presence of occult intertrochanteric fractures and to establish appropriate treatment plans.

Use of Multislice CT for Investigation of Occult Geriatric Hip Fractures and Impact on Timing of Surgery

Introduction:

The National Institute of Health and Clinical Excellence guidelines in the United Kingdom recommend magnetic resonance imaging (MRI) as the first-line investigation for radiographically occult hip fractures, if available within 24 hours. In our department, however, multislice computerized tomography (MSCT) is instead used as a first-line investigation due to significant delays associated with obtaining MRI. Our aim was to determine the validity and practicality of MSCT for diagnosis of occult hip fractures and its impact on timing of surgery.

Materials and Methods:

We retrospectively analyzed medical records and imaging for consecutive patients who underwent MSCT to investigate occult hip fractures between January 2014 and October 2016. We reviewed subsequent imaging and reattendances for patients with negative MSCT to exclude initially missed fractures.

Results:

Two hundred six patients underwent MSCT to investigate occult hip fracture during the study period. Hip fractures were identified in 59 patients, comprising 35 (59.3%) subcapital, 12 (20.0%) intertrochanteric, 8 (13.6%) transcervical, and 4 (6.8%) basicervical fractures. One missed hip fracture was identified: a patient with a negative MSCT was further investigated with MRI that demonstrated acute subcapital hip fracture. Multislice computerized tomography was obtained within 24 hours of initial radiograph in 145 (70.4%) patients. A total of 44.5% of occult hip fractures had surgery within the nationally recommended 36 hours of admission (hospital average for all hip fractures was 76.4% over the same period).

Discussion and Conclusions:

Multislice computerized tomography is a pragmatic approach to investigate the majority of occult hip fractures in a timely manner and minimize associated delay to surgery. However it cannot completely exclude the diagnosis, especially in abnormal anatomy. The lack of a true gold standard comparison (ie, MRI) means a true sensitivity and specificity cannot be calculated, although can be cautiously estimated by lack of subsequent reattendance or investigation. Further prospective randomized CT versus MRI trials are required.

BET 2: CT versus MRI for occult hip fractures

A short-cut review was carried out to establish whether CT or MRI is better at detecting an occult hip fracture. Six studies were directly relevant to the question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. The clinical bottom line is that CT is a valid first-line investigation for a suspected plain X-ray occult hip fracture. If clinical suspicion remains after a negative CT scan, then MRI should be used.

Occult intra-operative periprosthetic fractures of the acetabulum may affect implant survival

PURPOSE

Occult intra-operative periprosthetic acetabular fracture is a seldom-reported complication of primary total hip arthroplasty (THA). It may potentially be associated with cup instability and implant loosening. The present study aimed to investigate clinical consequences of this complication.

METHODS

Between 2003 and 2012, a total of 3390 cementless total hip arthroplasties (THA) were performed at our institution. Their medical histories were retrospectively reviewed to identify all patients who received a thin-layer computer tomography (CT) scan of the pelvis including the acetabulum within the first 30 post-operative days. They were evaluated and classified by two radiologists independently with respect to the presence of recent acetabular fractures. All cases with acetabular and periacetabular fractures were included in this study. Electronic medical records were reviewed to assess implant revision. Cup stability was measured with EBRA (Einzel-Bild-Röntgen-Analyse) from plain X-rays.

RESULTS

Periprosthetic fractures of the acetabulum were identified in 58 (50.4%) of 115 selected patients. Fractures close to but not including the acetabulum were identified in 45% (n = 26/58) of the patients, at the superolateral wall in 17% (n = 10/58), at the anterior wall of the acetabulum in 16% (n = 9/58) and in 10% (n = 6/58) each at the medial wall, and at the posterior wall respectively. One out of these 58 fractures could not be classified. Three of a total of six occult medial wall fractures had to be revised, and another two showed a high implant migration. The highest cup migration values however were found after fractures of the superolateral wall. Incomplete column fractures did not influence implant survival.

CONCLUSION

Central wall acetabular fractures, although unrecognized intra- and post-operatively may impair implant survival after THA.

Trabecular bone anisotropy imaging with a compact laser-undulator synchrotron x-ray source

Conventional x-ray radiography is a well-established standard in diagnostic imaging of human bones. It reveals typical bony anatomy with a strong surrounding cortical bone and trabecular structure of the inner part. However, due to limited spatial resolution, x-ray radiography cannot provide information on the microstructure of the trabecular bone. Thus, microfractures without dislocation are often missed in initial radiographs, resulting in a lack or delay of adequate therapy. Here we show that x-ray vector radiography (XVR) can overcome this limitation and allows for a deeper insight into the microstructure with a radiation exposure comparable to standard radiography. XVR senses x-ray ultrasmall-angle scattering in addition to the attenuation contrast and thereby reveals the mean scattering strength, its degree of anisotropy and the orientation of scattering structures. Corresponding to the structural characteristics of bones, there is a homogenous mean scattering signal of the trabecular bone but the degree of anisotropy is strongly affected by variations in the trabecular structure providing more detailed information on the bone microstructure. The measurements were performed at the Munich Compact Light Source, a novel type of x-ray source based on inverse Compton scattering. This laboratory-sized source produces highly brilliant quasi-monochromatic x-rays with a tunable energy.

NHSLA litigation in hip fractures: Lessons learnt from NHSLA data

Hip fractures are a major cause of trauma related death, usually occurring in vulnerable elderly patients. There are an estimated 70,000 hip fractures in the UK per year with numbers set to rise. The estimated annual cost to the healthcare economy is in the region of £2 billion. A 17-year review examining litigation related to hip fractures was undertaken. Under a freedom of information request, data was obtained relating to all orthopaedic claims made to the NHS Litigation Authority (NHSLA) between 1995 and 2012. Data was filtered to identify cases involving hip fractures examining litigation trends related to this specific area. 10263 NHSLA orthopaedic cases were identified, of which 13.3% (n=1364) cases related to the hip and femur. Hip fractures made up 16.7% (n=229). The total cost of hip fracture litigation was over £7 million with an average cost per case of £32,700. The commonest reasons for litigation were diagnostic errors (30.6%), issues with care (24.9%) alleged incompetent surgery (15.7%) and development of pressure sores (5.7%). This study highlights the main causes of litigation in patients sustaining hip fractures, with diagnosis in the emergency department and ward presenting a significant problem. In addition, the data identifies a range of care related issues, as well as several surgical factors and highlights the importance of pressure area care. We discuss these and make suggestions on how to improve practice in this area with the aim of improving patient care and reducing litigation.

Three-dimensional adiabatic inversion recovery prepared ultrashort echo time cones (3D IR-UTE-Cones) imaging of cortical bone in the hip

PURPOSE

We present three-dimensional adiabatic inversion recovery prepared ultrashort echo time Cones (3D IR-UTE-Cones) imaging of cortical bone in the hip of healthy volunteers using a clinical 3T scanner.

METHODS

A 3D IR-UTE-Cones sequence, based on a short pulse excitation followed by a 3D Cones trajectory, with a nominal TE of 32μs, was employed for high contrast morphological imaging of cortical bone in the hip of heathy volunteers. Signals from soft tissues such as muscle and marrow fat were suppressed via adiabatic inversion and signal nulling. T₂^⁎ value of the cortical bone was also calculated based on 3D IR-UTE-Cones acquisitions with a series of TEs ranging from 0.032 to 0.8ms. A total of four healthy volunteers were recruited for this study. Average T₂^⁎ values and the standard deviation for four regions of interests (ROIs) at the greater trochanter, the femoral neck, the femoral head and the lesser trochanter were calculated.

RESULTS

The 3D IR-UTE-Cones sequence provided efficient suppression of soft tissues with excellent image contrast for cortical bone visualization in all volunteer hips. Exponential single component decay was observed for all ROIs, with averaged T₂^⁎ values ranging from 0.33 to 0.45ms, largely consistent with previously reported T₂^⁎ values of cortical bone in the tibial midshaft.

CONCLUSIONS

The 3D IR-UTE-Cones sequence allows in vivo volumetric imaging and quantitative T₂^⁎ measurement of cortical bone in the hip using a clinical 3T scanner.

Effects of the acetabular fracture index and other factors of posterior wall acetabular fracture on functional outcome

Objective To analyze the effects of the acetabular fracture index (AFI) and other factors on the functional outcome of patients with acetabular fractures involving the posterior wall. Methods Forty-eight patients who underwent surgery in our department were reviewed. According to the AFI, which indicates the percentage of remaining intact posterior acetabular arc, the patients were divided into Group A (AFI ≤ 25%, 11 patients), Group B (25% < AFI ≤ 50%, 23 patients), Group C (50% < AFI ≤ 75%, 7 patients), and Group D (75% < AFI ≤ 100%, 7 patients). The AFI was measured with a computed tomography picture archiving and communication system or calculated with the cosine theorem. A nonparametric test and ordinal regression were used to determine the role of the AFI and other factors on the functional outcome. Perioperative information, including demographic and fracture-related data, reduction quality, physical therapy duration, association with a lower limb fracture and avascular necrosis of the femoral head were prospectively gathered. Results The mean AFIs of A, B, C, and D groups were 14.3%, 35.9%, 59.5%, and 81.2%, respectively. No statistically significant differences were observed among the groups for demographic and fracture-related data. A better reduction quality (OR = 4.21, 95%CI 1.42 ∼ 12.43, χ2 = 6.781, P = 0.009) and a larger value of AFI (OR = 2.56, 95%CI 1.18 ∼ 5.55, χ2 = 5.648, P = 0.017) result in a higher functional score. The functional outcome of a physical therapy duration of more than 12 months (OR = 0.15, 95%CI 0.02 ∼ 0.90, χ2 = 4.324, P = 0.038) was better than that of less than 12 months. Lower limb fracture (OR = 0.13, 95%CI 0.02 ∼ 0.74, χ2 = 5.235, P = 0.022) and avascular necrosis of femoral head (OR = 0.02, 95%CI 0.00 ∼ 0.87, χ2 = 4.127, P = 0.042) were found to correlate with a lower functional score. Conclusion With a greater of AFI, the functional outcome score would be better. Other factors, including reduction quality, physical therapy duration, association with a lower limb fracture, and avascular necrosis of the femoral head, most likely also affect hip functional recovery.

Rapid Geriatric Assessment of Hip Fracture

A comprehensive geriatric assessment, combined with a battery of imaging and blood tests, should be able to identify those hip fracture patients who are at higher risk of short- and long-term complications. This comprehensive assessment should be followed by the implementation of a comprehensive multidimensional care plan aimed to prevent negative outcomes in the postoperative period (short and long term), thus assuring a safe and prompt functional recovery while also preventing future falls and fractures.

Articular impaction injuries in the lower limb

The effective management of articular impacted fractures requires the successful elevation of the osteochondral fragment to eliminate joint incongruency and the stable fixation of the fragments providing structural support to the articular surface.The anatomical restoration of the joint can be performed either with elevation through a cortical window, through balloon-guided osteoplasty or direct visualisation of the articular surface.Structural support of the void created in the subchondral area can be achieved through the use of bone graft materials (autologous tricortical bone), or synthetic bone graft substitutes.In the present study, we describe the available techniques and materials that can be used in treating impacted osteochondral fragments with special consideration of their epidemiology and treatment options. Cite this article: EFORT Open Rev 2017;2. DOI: 10.1302/2058-5241.2.160072. Originally published online at www.efortopenreviews.org.

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.