Surgical Management of Hangman's Fracture: A Systematic Review

BACKGROUND

Hangman's fractures are bilateral fractures of the C2 pars interarticularis produced during hyperextension injuries. The Levine-Edwards classification divides these fractures into 4 categories determined by injury stability. While stable fracture patterns are typically managed conservatively, prolonged traction required in unstable fractures may be superseded by surgery in its practicality. Surgical approaches can be divided into anterior and posterior: the anterior approach allows access to the disc and is used for anterior cervical discectomy and fusion (ACDF); the posterior approach includes C2 direct pedicle screw (DPS), which preserves motion segments and may be done with a minimally invasive surgery (MIS) approach. Multilevel rod and screw fusion provide the strongest biomechanical fixation. This systematic review compares indications, complications, and functional outcomes of different approaches.

METHODS

A search of multiple databases with keywords "hangman fracture," "hangman's fracture," "axis fracture," and "C2 fracture" was conducted; articles were included if they described the surgical technique and included at least one of the primary outcomes: functional outcomes, complication rates, operation time, and blood loss.

RESULTS

A total of 1889 abstracts were screened, 137 full text articles were analyzed, and 36 articles were included, yielding a combined total of 627 patients. ACDF was preferred in unstable fracture patterns. Pre- and postoperative visual analog scale (VAS) scores fell in all groups, with MIS DPS producing the lowest VAS scores. Approaches had excellent neurological improvement and fusion rates. Reported complication rates were generally low; self-limiting dysphagia was most common in the anterior approach and higher volumes of blood loss occured with the posterior approach (255.9 mL in open posterior approach, 75.8 mL in MIS, and 64.3 mL in ACDF).

CONCLUSION

All surgical methods of hangman's fracture fixation have their indications and advantages; surgeons should be equipped to perform all options. Anterior approaches may be preferred for their lower blood loss and access to the disc; however, MIS may improve outcomes in posterior approach.

CLINICAL RELEVANCE

This systematic review can assist spinal surgeons in the selection of the most appropriate surgical option for hangman's fracture and allow surgeons to inform patients of the risks and benefits.

LEVEL OF EVIDENCE: 3

The learning preferences of aspiring orthopaedic surgeons in the UK

BACKGROUND/AIMS

The workload of orthopaedic trainees is rapidly increasing at the expense of training. Trainees are expected to assimilate large quantities of information efficiently. This prospective cohort study explores the learning styles, resource preferences and educational needs of aspiring orthopaedic trainees.

METHOD

A 21-item questionnaire was distributed to delegates of an orthopaedic teaching series. Data were obtained pertaining to demographics, visual, aural, read/write and kinaesthetic learning styles, study materials used and teaching exposure.

RESULTS

Participants had a strong preference for visual (48.0%) and kinaesthetic (43.0%) learning modalities. Most participants prepared for written exams using online question banks (85.9%), clinical exams using question banks (37.5%) and discussion with colleagues (27.3%), and surgical procedures intraoperatively (43.8%). Only 12.4% of participants felt the teaching they received was consistently adapted to their visual, aural, read/write or kinaesthetic learning preference.

CONCLUSIONS

The surgical landscape is rapidly changing. It is vital that trainers take into consideration how budding orthopaedic surgeons learn and make the relevant accommodations, to ensure optimal learning.

The Experiences, Influences and Concerns of Future Orthopaedic Surgeons: Comparing Uk and non-UK Perspectives

AIMS/BACKGROUND

This study aims to identify and analyse the factors that influence or discourage junior doctors in the UK and across the world from wanting to pursue a career in orthopaedics.

METHODS

A prospective, cohort study was carried out via an online questionnaire targeted at aspiring orthopaedic surgeons.

RESULTS

A total of 654 respondents met inclusion criteria; 370 (56.6%) were UK-based and 284 (43.4%) were based abroad. The practical and technical nature of orthopaedics was the biggest influencing factor globally. UK respondents were notably more concerned by the financial impact of training (49%) followed by poor work-life balance (36%). Themes from the comments section revealed concern regarding gender bias and a lack of diverse role models within orthopaedics.

CONCLUSIONS

Reducing the cost and length of training, diversification of role models, removal of bias and increasing positive early experiences may help to encourage people of all backgrounds to pursue a career in orthopaedic surgery.

Bullying in trauma and orthopaedics: a survey of staff in orthopaedic departments in the UK

Background/aims

An orthopaedic department requires good teamwork and communication to function. This is undermined by bullying and harassment, which may affect the victim's health and career.

Methods

A 26-item questionnaire was sent to all delegates who registered for a free orthopaedic webinar teaching series via email and social media. This study includes the responses from all those who had worked in a UK orthopaedic department.

Results

There were 168 respondents from varying backgrounds; 17.9% had experienced bullying or harassment in their orthopaedic department, while 36.3% had witnessed it. Women and people from ethnic minority backgrounds suffered 10.2% and 6.9% higher rates of bullying than their male or white counterparts respectively.

Conclusions

The results demonstrate that despite attempts to reduce bullying in orthopaedics, it remains prevalent, and particularly affects women and those from ethnic minority backgrounds. Orthopaedic departments must adapt to reflect changes in society.

5 Cervical Spine Pedicle Screw Accuracy in Open Fluoroscopic, Navigated and Template Guided Systems- a Systematic Review

Aim

Pedicle screws provide excellent fixation for a wide range of indications; their adoption in the cervical spine has been slower than in the thoracic and lumbar spine, largely due to the smaller pedicle sizes and proximity to neurovascular structures in the neck. Recent years have seen the development of technology to improve accuracy and thereby safety in cervical pedicle screw placement over traditional fluoroscopic techniques, including intraoperative 3D navigation, computer assisted systems and physical templates with screw guides. We have performed a systematic review into the accuracy rates of the various systems.

Method

PubMed and Cochrane Library databases were searched; keywords "pedicle screw cervical spine" were searched; 9 valid papers involving 1427 screws were found.

Results

Accuracy rates were 80.6% for fluoroscopy, 91.4% for navigation methods, and 96.7% for templates.

Conclusions

Superior results for templates are complemented by reduced radiation exposure to patient and surgeon; however, the technology requires prolonged pre-operative planning to create the bespoke template, and the development of an infrastructure to allow for their rapid production and delivery is needed before they become more widely available.

Two broad methods of navigation currently exist: intraoperative CT scanning providing real-time 3D navigation and preoperative CT registration in relation to a fixed reference with intraoperative computer assistance. At present, these methods are more commonly used, due to their proven improved accuracy rates over fluoroscopy, availability in emergencies and alongside minimally invasive techniques.

Despite their novelty and limitations, templates provide promising accuracy scores, although practical considerations may inhibit their proliferation.

AB0039 AGRIN REPAIRS BONE AND CARTILAGE IN VIVO

Background:

Cartilage defects in the joints are reported in 61% of all arthroscopies1&2. The size of the cartilage repair market is estimated to be $2.195 million by 20253. Cartilage defects can evolve into osteoarthritis, in which abnormal load results in cartilage breakdown, joint pain and reduced mobility. Osteoarthritis is the leading cause of permanent disability and absenteeism and affects up to 1/3 of the people over 60yrs. In western countries osteoarthritis costs 1.5-2% of the GDP4. Joint replacement with a prosthesis restores some degree of independence but in up to 20% of patients it does not meet expectations 5 and has a limited life span. There is no pharmacological intervention that arrests or reverts the course of osteoarthritis, despite the desperate need.

We previously published that agrin plays an important role in cartilage homeostasis6. The addition of agrin to chondrocytes in vivo resulted in enhanced cartilage formation, suggesting a potential role for agrin in cartilage repair.

Objectives:

Investigate the potential of agrin for use in cartilage repair.

Methods:

Critical size osteochondral defects were generated in mice and sheep and injected intraarticularly with type I collagen gel containing agrin or vehicle. Animals were monitored for 8 weeks or 6 months respectively. MicroCT, histological analysis, qPCR, linage tracking, reporter assays, chondrogenesis assay, immunohistochemistry were performed.

Results:

A single intraarticular administration of agrin induced regeneration of critical-size osteochondral defects in mice, restoring the tissue architecture and bone-cartilage interface. Agrin stem cells to the site of injury and, through simultaneous activation of CREB and suppression of canonical WNT signalling, induced GDF5 expression and differentiation into stable articular chondrocytes, forming stable articular cartilage. In sheep, agrin treatment resulted in regeneration of bone and cartilage, which promoted increased ambulatory activity.

Conclusion:

Agrin orchestrates repair morphogenesis at the joint surface by modulating multiple signalling pathways, supporting the therapeutic use of agrin for joint surface regeneration.

References:

[1]Curl, W. W. et al. Cartilage injuries: a review of 31,516 knee arthroscopies. Arthrosc. J. Arthrosc. Relat. Surg. Off. Publ. Arthrosc. Assoc. N. Am. Int. Arthrosc. Assoc. 13, 456–460 (1997).

[2]Hjelle, K., Solheim, E., Strand, T., Muri, R. & Brittberg, M. Articular cartilage defects in 1,000 knee arthroscopies. Arthrosc. J. Arthrosc. Relat. Surg. Off. Publ. Arthrosc. Assoc. N. Am. Int. Arthrosc. Assoc. 18, 730–734 (2002).

[3]Cartilage Repair Market Size, Share, Industry Analysis 2018-2025 | AMR. Allied Market Research https://www.alliedmarketresearch.com/cartilage-repair-market.

[4]Hiligsmann, M. et al. Health economics in the field of osteoarthritis: an expert’s consensus paper from the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO). Semin. Arthritis Rheum. 43, 303–313 (2013).

[5]Dieppe, P., Lim, K. & Lohmander, S. Who should have knee joint replacement surgery for osteoarthritis? Int. J. Rheum. Dis. 14, 175–180 (2011).

[6]Eldridge, S., et al. Agrin mediates chondrocyte homeostasis and requires both LRP4 and α-dystroglycan to enhance cartilage formation in vitro and in vivo. Annals of the rheumatic diseases 75 (6), 1228-1235 (2016).

Acknowledgements:

We thank the technical staff in the ARM Lab and Staff at the University of Aberdeen’s Animal Facility and Microscopy and Histology Facility for support. Funding: We gratefully acknowledge funding support of this work by the MRC (MR/L022893/1, MR/N010973/1,and MR/P026362/1), Versus Arthritis (19667, 21515, 20886, and 21621), Rosetrees Trust (A1205), the Medical College of St Bartholomew’s Hospital Trust, and the William Harvey Research Foundation.

Disclosure of Interests:

Suzanne Eldridge: None declared, Aida Barawi: None declared, Hui Wang: None declared, Anke Roelofs: None declared, Magdalena Kaneva: None declared, Zeyu Guan: None declared, Helen Lydon: None declared, Bethan Thomas: None declared, Anne-Sophie Thorup: None declared, Beatriz F Fernandez: None declared, Sara Caxaria: None declared, Danielle Strachan: None declared, Ahmed Ali: None declared, Kanatheepan Shanmuganathan: None declared, Costantino Pitzalis: None declared, James Whiteford: None declared, Fran Henson: None declared, Andrew McCaskie: None declared, Cosimo De Bari: None declared, Francesco Dell’Accio Consultant of: F.D. has received consultancy fees from Samumed and UCB.

Trampolines injuries are bouncing back

Aims

This observational study examines the effect of the COVID-19 pandemic upon the paediatric trauma burden of a district general hospital. We aim to compare the nature and volume of the paediatric trauma during the first 2020 UK lockdown period with the same period in 2019.

Methods

Prospective data was collected from 23 March 2020 to 14 June 2020 and compared with retrospective data collected from 23 March 2019 to 14 June 2019. Patient demographics, mechanism of injury, nature of the injury, and details of any surgery were tabulated and statistically analyzed using the independent-samples t-test for normally distributed data and the Mann-Whitney-U test for non-parametric data. Additionally, patients were contacted by telephone to further explore the mechanism of injury where required, to gain some qualitative insight into the risk factors for injury.

Results

The 2020 lockdown resulted in 30% fewer paediatric trauma presentations (441 vs 306), but no significant change in the number of patients requiring surgery (47 vs 51; p = 0.686). Trampolining injuries increased in absolute numbers by 168% (p < 0.001), almost four times more common when considered as percentage of all injuries observed in 2020 vs 2019. There was a decrease in high energy trauma from road traffic accidents and falls from height (21.5% decrease, p < 0.001). Despite a shift towards more conservative treatment options, trampolining injuries continued to require surgery in similar proportions (19.4 vs 20%; p = 0.708). Qualitative investigation revealed that the most common risk factor for trampolining injury was concurrent usage, especially with an older child.

Conclusion

COVID-19 lockdown has resulted in a decrease in paediatric orthopaedic presentations and high energy trauma. However, due to a marked increase in home trampolining injuries, and their unchanged requirement for surgery, there has been no change in the requirement for surgery during the lockdown period. As home exercise becomes more prevalent, a duty of public health falls upon clinicians to advise parents against trampoline usage.

Cite this article: Bone Jt Open 2021;2(2):86–92.

Agrin induces long-term osteochondral regeneration by supporting repair morphogenesis

Cartilage loss leads to osteoarthritis, the most common cause of disability for which there is no cure. Cartilage regeneration, therefore, is a priority in medicine. We report that agrin is a potent chondrogenic factor and that a single intraarticular administration of agrin induced long-lasting regeneration of critical-size osteochondral defects in mice, with restoration of tissue architecture and bone-cartilage interface. Agrin attracted joint resident progenitor cells to the site of injury and, through simultaneous activation of CREB and suppression of canonical WNT signaling downstream of β-catenin, induced expression of the chondrogenic stem cell marker GDF5 and differentiation into stable articular chondrocytes, forming stable articular cartilage. In sheep, an agrin-containing collagen gel resulted in long-lasting regeneration of bone and cartilage, which promoted increased ambulatory activity. Our findings support the therapeutic use of agrin for joint surface regeneration.

Quantification of Iodine Leakage on Dual-Energy CT as a Marker of Blood-Brain Barrier Permeability in Traumatic Hemorrhagic Contusions: Prediction of Surgical Intervention for Intracranial Pressure Management

BACKGROUND AND PURPOSE

Hemorrhagic contusions are associated with iodine leakage. We aimed to identify quantitative iodine-based dual-energy CT variables that correlate with the type of intracranial pressure management.

MATERIALS AND METHODS

Consecutive patients with contusions from May 2016 through January 2017 were retrospectively analyzed. Radiologists, blinded to the outcomes, evaluated CT variables from unenhanced admission and short-term follow-up head dual-energy CT scans obtained after contrast-enhanced whole-body CT. Treatment intensity of intracranial pressure was broadly divided into 2 groups: those managed medically and those managed surgically. Univariable analysis followed by logistic regression was used to develop a prediction model.

RESULTS

The study included 65 patients (50 men; median age, 48 years; Q1 to Q3, 25-65.5 years). Twenty-one patients were managed surgically (14 by CSF drainage, 7 by craniectomy). Iodine-based variables that correlated with surgical management were higher iodine concentration, pseudohematoma volume, iodine quantity in pseudohematoma, and iodine quantity in contusions. The regression model developed after inclusion of clinical variables identified 3 predictor variables: postresuscitation Glasgow Coma Scale (adjusted OR = 0.55; 95% CI, 0.38-0.79; P = .001), age (adjusted OR = 0.9; 95% CI, 0.85-0.97; P = .003), and pseudohematoma volume (adjusted OR = 2.05; 95% CI, 1.1-3.77; P = .02), which yielded an area under the curve of 0.96 in predicting surgical intracranial pressure management. The 2 predictors for craniectomy were age (adjusted OR = 0.89; 95% CI, 0.81-0.99; P = .03) and pseudohematoma volume (adjusted OR = 1.23; 95% CI, 1.03-1.45; P = .02), which yielded an area under the curve of 0.89.

CONCLUSIONS

Quantitative iodine-based parameters derived from follow-up dual-energy CT may predict the intensity of intracranial pressure management in patients with hemorrhagic contusions.

Dual-Energy CT in Hemorrhagic Progression of Cerebral Contusion: Overestimation of Hematoma Volumes on Standard 120-kV Images and Rectification with Virtual High-Energy Monochromatic Images after Contrast-Enhanced Whole-Body Imaging

BACKGROUND AND PURPOSE

In patients with hemorrhagic contusions, hematoma volumes are overestimated on follow-up standard 120-kV images obtained after contrast-enhanced whole-body CT. We aimed to retrospectively determine hemorrhagic progression of contusion rates on 120-kV and 190-keV images derived from dual-energy CT and the magnitude of hematoma volume overestimation.

MATERIALS AND METHODS

We retrospectively analyzed admission and follow-up CT studies in 40 patients with hemorrhagic contusions. After annotating the contusions, we measured volumes from admission and follow-up 120-kV and 190-keV images using semiautomated 3D segmentation. Bland-Altman analysis was used for hematoma volume comparison.

RESULTS

On 120-kV images, hemorrhagic progression of contusions was detected in 24 of the 40 patients, while only 17 patients had hemorrhagic progression of contusions on 190-keV images (P = .008). Hematoma volumes were systematically overestimated on follow-up 120-kV images (9.68 versus 8 mm³; mean difference, 1.68 mm³; standard error, 0.37; P < .001) compared with 190-keV images. There was no significant difference in volumes between admission 120-kV and 190-keV images. Mean and median percentages of overestimation were 29% (95% CI, 18-39) and 22% (quartile 3 - quartile 1 = 36.8), respectively.

CONCLUSIONS

The 120-kV images, which are comparable with single-energy CT images, significantly overestimated the hematoma volumes, hence the rate of hemorrhagic progression of contusions, after contrast-enhanced whole-body CT. Hence, follow-up of hemorrhagic contusions should be performed on dual-energy CT, and 190-keV images should be used for the assessment of hematoma volumes.

Hyperintense Optic Nerve due to Diffusion Restriction: Diffusion-Weighted Imaging in Traumatic Optic Neuropathy

BACKGROUND AND PURPOSE

Abnormal signal intensity of the optic nerve due to diffusion restriction may be seen in traumatic optic neuropathy. In addition to evaluating optic nerve hyperintensity on diffusion-weighted imaging, we compared the group differences of ADC values between the injured and uninjured contralateral nerve and identified the relation between measured ADC values and admission visual acuity.

MATERIALS AND METHODS

We retrospectively evaluated 29 patients with traumatic optic neuropathy who underwent MR imaging with DWI. Uninjured contralateral optic nerves were used as controls. Two attending radiologists, blinded to the side of injury, independently reviewed the DWI for the presence of signal-intensity abnormality and obtained ADC values after manually selecting the ROI.

RESULTS

Hyperintensity of the optic nerve was demonstrated in 8 of the 29 patients, with a sensitivity of 27.6% (95% CI, 12.8-47.2) and a specificity of 100% (95% CI, 87.9-100). ADC values were obtained in 25 patients. The mean ADC in the posterior segment of the injured nerve was significantly lower than that in the contralateral uninjured nerve (Welch ANOVA, F = 9.7, P = .003). There was a moderate-to-strong correlation between low ADC values and poor visual acuity in 10 patients in whom visual acuity could be obtained at admission (R = 0.7, P = .02). Patients with optic nerve hyperintensity presented with worse visual acuity.

CONCLUSIONS

Hyperintensity of the optic nerve due to diffusion restriction can serve as a specific imaging marker of traumatic optic neuropathy. When paired with reduced ADC values, this finding may be an important surrogate for visual acuity.

Mechanically adaptive intracortical implants improve the proximity of neuronal cell bodies

The hypothesis is that the mechanical mismatch between brain tissue and microelectrodes influences the inflammatory response. Our unique, mechanically adaptive polymer nanocomposite enabled this study within the cerebral cortex of rats. The initial tensile storage modulus of 5 GPa decreases to 12 MPa within 15 min under physiological conditions. The response to the nanocomposite was compared to surface-matched, stiffer implants of traditional wires (411 GPa) coated with the identical polymer substrate and implanted on the contralateral side. Both implants were tethered. Fluorescent immunohistochemistry labeling examined neurons, intermediate filaments, macrophages, microglia and proteoglycans. We demonstrate, for the first time, a system that decouples the mechanical and surface chemistry components of the neural response. The neuronal nuclei density within 100 µm of the device at four weeks post-implantation was greater for the compliant nanocomposite compared to the stiff wire. At eight weeks post-implantation, the neuronal nuclei density around the nanocomposite was maintained, but the density around the wire recovered to match that of the nanocomposite. The glial scar response to the compliant nanocomposite was less vigorous than it was to the stiffer wire. The results suggest that mechanically associated factors such as proteoglycans and intermediate filaments are important modulators of the response of the compliant nanocomposite.

Diffusion tensor MR imaging in cervical spine trauma

BACKGROUND AND PURPOSE

Our aim was to investigate the extent and severity of changes in spinal cord diffusion tensor imaging (DTI) parameters in patients with cervical cord injury.

MATERIALS AND METHODS

DTI was performed in 20 symptomatic patients (mean, 45.7 +/- 17.7 years of age; 2 women, 18 men) with cervical spine trauma and 8 volunteers (mean, 34.2 +/- 10.7 years of age; 6 men, 2 women). The whole cord and regional apparent diffusion coefficient (ADC), fractional anisotropy (FA), relative anisotropy (RA), and volume ratio (VR) of patients and volunteers were compared. DTI parameters were calculated in 16 patients. MR imaging demonstrated hemorrhagic cord contusions (n = 6), nonhemorrhagic cord contusions (n = 4), and soft-tissue injury (n = 6). Medical records were reviewed for extent of neurologic deficit.

RESULTS

Regional ADC values differed significantly between upper and mid and upper and lower (both, P < .004) cervical cord sections. FA was significantly different between upper and lower sections (P < .03). Whole cord ADC values were significantly lower in patients than in volunteers (P < .0001). Whole spine FA was not significantly decreased in patients (P < .06). ADC and FA values were significantly decreased at injury sites when compared with volunteers (P < .031 and .0001, respectively). The greatest differences in whole cord ADC, FA, RA, and VR were in patients with hemorrhagic cord contusions compared with healthy volunteers (P < .0001, .003, .0005, and .008, respectively).

CONCLUSION

DTI parameters are sensitive markers of cervical cord injury, with ADC showing the greatest sensitivity. Changes in DTI parameters are most marked at injury sites and reflect the severity of cord injury.

Diagnosis of blunt traumatic aortic injury 2007: still a nemesis

In recent years, the use of multidetector computed tomography (MDCT) for the diagnosis of acute thoracic injury in blunt trauma has expanded. MDCT has shown high accuracy for the diagnosis or exclusion of injury to the aorta and its primary branches, decreasing the need for thoracic angiography and allowing earlier treatment of this often rapidly fatal lesion. With increasing use of MDCT, more subtle injuries and variants of vascular anatomy are being recognized that create pitfalls in the diagnosis. Of perhaps more concern is the recognition that aortic injury can occur with little or no associated mediastinal hematoma, the principle chest radiographic finding indicating a need for further imaging. The importance of recognizing unusual sites of aortic injury, congenital variants of mediastinal anatomy, the precise extent of injury, and the anatomic pathology present as key factors in deciding among treatment options is emphasized.

Chance-Type Fractures of the Thoracolumbar Spine: Imaging Analysis in 53 Patients

OBJECTIVE

Chance-type fractures are subtle unstable injuries that are often associated with intraabdominal injuries. CT-based observations made during routine interpretations revealed involvement of a burst component to this fracture pattern and a clue on the transaxial images to its presence. The purpose of this review was to determine how often these features occurred in a retrospective study of a large sample because these findings influence diagnosis and management.

MATERIALS AND METHODS

A retrospective review of all patients identified from the University of Maryland Shock Trauma Center trauma registry and IDXRad system diagnosed with flexion-distraction injuries of the thoracolumbar spine over an 8-year period was performed. Three trauma radiologists assessed the admission spinal radiographs, CT studies with multiplanar images, and available MRI examinations. Imaging findings were confirmed by consensus. Abdominopelvic CT studies and surgical reports were reviewed for evidence and type of intraabdominal injury. A literature review of previous similar series was performed.

RESULTS

Fifty-three patients were identified for inclusion in the study. Associated intraabdominal injury occurred in 40% and most commonly involved the bowel and mesentery. A close examination of the fracture patterns on CT revealed that a burst-type fracture with posterior cortex buckling or retropulsion was a common finding (48%). Also, serial transaxial CT images often (76%) showed a gradual loss of definition of the pedicles that we refer to as the "dissolving pedicle" sign. The study showed that the horizontally oriented fracture planes through the posterior elements can often be recognized radiographically, but these fractures can be very subtle.

CONCLUSION

Intraabdominal injuries occurred in 40% of flexion-distraction thoracolumbar fractures in our study cohort, which is slightly lower than previously reported. About half of the patients with this injury displayed a burst-type component that could have a significant influence on surgical management. The dissolving pedicle sign can assist in recognition of this often subtle injury on transaxial CT.

Multidetector-Row Computed Tomography Imaging of Splenic Trauma

The spleen is the intra-abdominal organ most often injured as a result of blunt trauma. Multidetector-row computed tomography (MDCT) plays an important role in the detection and characterization of splenic injury. It has been shown to be highly accurate and can detect splenic vascular lesions, the presence of which has been shown to be a predictor of failure of nonoperative management. The increased use of angiography and splenic artery embolization in the management of such injuries has led to improved success rates with nonoperative management. This article reviews the various appearances of the injured spleen and discusses the use of MDCT in the initial evaluation of injury. The indications for angiography and embolization are reviewed, with examples of appearances of the postembolization spleen.

Multidetector CT evaluation of abdominal trauma

CT is the imaging modality of choice to evaluate blunt abdominal trauma. With the advent of multidetector CT (MDCT), scanning times have progressively decreased while image resolution has increased owing to thinner collimation and reduced partial volume and motion artifacts. MDCT also allows high quality two-dimensional and three-dimensional multiplanar reformatted images to be obtained, which aid in the diagnosis of the complex multisystem injuries seen in the trauma patient. This article describes the authors' current imaging protocol with 16-detector MDCT, the spectrum of CT findings seen in patients with blunt abdominal injuries, and the role MDCT has in guiding injury management.

Multidetector-row CT of right hemidiaphragmatic rupture caused by blunt trauma: a review of 12 cases

AIM

To determine the usefulness of multidetector-row CT (MDCT) with multiplanar reformatted (MPR) images in the sagittal and coronal plane in diagnosing acute right hemidiaphragmatic rupture.

MATERIALS AND METHODS

Twelve patients were identified who received chest and abdominal MDCT after major blunt trauma diagnosed with right diaphragmatic injury. Sagittal and coronal reformations were performed in all cases. The images were retrospectively reviewed by two experienced radiologists for signs of right diaphragm injury, such as direct diaphragm discontinuity, the "collar sign", the "dependent viscera sign", and intra-thoracic location of herniated abdominal contents.

RESULTS

Of the 12 cases of right hemidiaphragm rupture, diaphragm discontinuity was seen in seven (58%) cases, the collar sign in five (42%), the dependent viscera sign in four (33%), and transdiaphragmatic herniation of the right colon and fat in another. Two variants of the collar sign were apparent on high-quality sagittal and coronal reformations. The first, termed the "hump sign", describes a rounded portion of liver herniating through the diaphragm forming a hump-shaped mass, and the second, termed the "band sign," is a linear lucency across the liver along the torn edges of the hemidiaphragm. The hump sign occurred in 10 (83%) patients and the band sign in four (33%).

CONCLUSION

MDCT is very useful in the diagnosis of right hemidiaphragm injury caused by blunt trauma when sagittal and coronal reformatted images are obtained, and should allow more frequent preoperative diagnosis.

Ultrasonography for Interval Assessment in the Nonoperative Management of Hepatic Trauma

Abdominal ultrasonography (US) is gaining widespread acceptance as a valuable diagnostic tool in the initial evaluation of trauma victims. We investigated the utility of US as a follow-up radiologic study in nonoperative hepatic trauma. Patients with liver injury designated for non-operative management were prospectively studied over a 2-year period at our primary adult resource center for trauma. Computed tomography (CT) and radiologist-performed US were obtained at admission and at 1 week. The ability of US to detect lesions, fluid, and complications was evaluated by comparing with the corresponding CT. Twenty-five hepatic trauma patients in the study were successfully managed nonoperatively and had both initial and follow-up US and CT scans: 1 (4%) grade I, 5 (20%) grade II, 7 (28%) grade III, 7 (28%) grade IV, and 5 (20%) grade V. Four complications developed [biloma (3) and biliary fistula (1)] in 3 patients with grade IV injury and 1 with a grade II injury. Interval US appropriately detected a complication or confirmed the absence of complication in all (13/13, 100%) patients with low-grade (I–III) injury and only missed a small biloma in one patient with a grade IV injury. Interval US and CT agreement was 92 per cent for change in hemoperitoneum or parenchymal lesion. Ultrasonography is a convenient imaging modality in the evaluation of hepatic trauma. US is sufficient to detect or exclude complications in low-grade injuries. In high-grade injuries, US may be an adjunct to CT for definitive interval assessment.

Ultrasonography for interval assessment in the nonoperative management of hepatic trauma

Abdominal ultrasonography (US) is gaining widespread acceptance as a valuable diagnostic tool in the initial evaluation of trauma victims. We investigated the utility of US as a follow-up radiologic study in nonoperative hepatic trauma. Patients with liver injury designated for nonoperative management were prospectively studied over a 2-year period at our primary adult resource center for trauma. Computed tomography (CT) and radiologist-performed US were obtained at admission and at 1 week. The ability of US to detect lesions, fluid, and complications was evaluated by comparing with the corresponding CT. Twenty-five hepatic trauma patients in the study were successfully managed nonoperatively and had both initial and follow-up US and CT scans: 1 (4%) grade I, 5 (20%) grade II, 7 (28%) grade III, 7 (28%) grade IV, and 5 (20%) grade V. Four complications developed [biloma (3) and biliary fistula (1)] in 3 patients with grade IV injury and 1 with a grade II injury. Interval US appropriately detected a complication or confirmed the absence of complication in all (13/13, 100%) patients with low-grade (I-III) injury and only missed a small biloma in one patient with a grade IV injury. Interval US and CT agreement was 92 per cent for change in hemoperitoneum or parenchymal lesion. Ultrasonography is a convenient imaging modality in the evaluation of hepatic trauma. US is sufficient to detect or exclude complications in low-grade injuries. In high-grade injuries, US may be an adjunct to CT for definitive interval assessment.

Blunt Abdominal Trauma Patients: Can Organ Injury Be Excluded without Performing Computed Tomography?

PURPOSE

The purpose of this study was to determine whether admission non-computed tomography (CT) criteria can exclude intra-abdominal injury in stable patients sustaining blunt abdominal trauma.

METHODS

Seven hundred fourteen hemodynamically stable patients with suspicion of blunt abdominal trauma were included in the study. Admission data for clinical examination, sonography, routine laboratory studies, chest/pelvic radiographic findings, and Glasgow Coma Scale (GCS) score were recorded. Each patient underwent helical abdominal CT. Injuries were considered major if they required surgery or angiographic intervention. At the authors' institution, angiography is routinely performed if there is a splenic injury of American Association for the Surgery of Trauma grade II or higher or a liver injury of American Association for the Surgery of Trauma grade III or higher. Statistical analysis was performed to determine the value of isolated and combined clinical, radiologic, and laboratory parameters in depicting an intra-abdominal injury with regard to CT results and clinical follow-up.

RESULTS

The best combination of criteria to identify a major abdominal injury was obtained when sonography, chest radiography, and three laboratory parameters (serum glutamic oxaloacetic transaminase, white blood cell count, and hematocrit) were normal: 22% (129 of 589) of patients without major injuries fulfilled these criteria. The only combination of criteria that completely excluded intra-abdominal injury was obtained when clinical criteria combined with a Glasgow Coma Scale score > 13, bedside radiologic studies, and laboratory data were all normal, but only 12% (68 of 578) of patients without abdominal injury fulfilled these criteria.

CONCLUSION

After blunt abdominal trauma, admission non-CT criteria can at best identify 12% of patients without intra-abdominal injuries and 22% of patients without major injuries.

CT diagnosis of splenic infarction in blunt trauma: imaging features, clinical significance and complications

AIM

The object of this study is to describe the appearance, complications, and outcome of segmental splenic infarctions occurring after blunt trauma using computed tomography (CT).

MATERIALS AND METHODS

Thirteen blunt trauma patients were identified with splenic infarction on contrast-enhanced CT. CT images were retrospectively reviewed and the percentage of infarcted splenic tissue and presence of splenic injury separate from the site of infarction were identified. Splenic angiograms were reviewed and follow-up CT images were assessed for interval change in the appearance of the infarcts.

RESULTS

The mean age of patients was 32 years and the most common mechanism of injury was road traffic accident. The majority (54%) had 25-50% infarction of the spleen. Splenic angiograms were performed in nine patients and seven demonstrated wedge-shaped regions of decreased perfusion corresponding to the infarction seen on CT with no need for intervention. Eleven patients underwent a follow-up CT that demonstrated the following: no significant change in six, near-complete resolution in two, delayed appearance of infarction in one, abscess formation in one, and delayed splenic rupture in one.

CONCLUSION

Segmental splenic infarction is a rare manifestation of blunt splenic trauma. The diagnosis is readily made using contrast-enhanced CT. The majority will decrease in size on follow-up CT and resolve without clinical sequelae. Resolution of infarction is also seen and these cases are best described as temporary perfusion defects. Splenic abscess or delayed rupture are uncommon complications that may necessitate angiographic or surgical intervention.

Penetrating torso trauma: triple-contrast helical CT in peritoneal violation and organ injury--a prospective study in 200 patients

PURPOSE

To assess the accuracy of computed tomography (CT) in demonstrating the presence or absence of peritoneal violation and type of intraperitoneal organ injury, if any, in hemodynamically stable patients with penetrating torso trauma but without definite peritoneal signs or radiographic evidence of free intraperitoneal air.

MATERIALS AND METHODS

During a 29-month period, helical CT with oral, rectal, and intravenous contrast material (triple-contrast) was performed in 200 hemodynamically stable patients, including 169 men (age range, 15-85 years; mean age, 31 years) and 31 women (age range, 17-45 years; mean age, 28 years) with penetrating torso trauma. The study group included 86 patients with gunshot wounds, 111 with stab wounds, and three impaled by sharp objects. CT scans were evaluated prospectively by three trauma radiologists for evidence of peritoneal violation to determine injury to intra- or retroperitoneal solid organs, bowel, mesentery, vascular structures, diaphragm, and urinary tract. Sensitivity, specificity, and accuracy of CT in the diagnosis of peritoneal violation were determined.

RESULTS

CT findings aided diagnosis of peritoneal violation in 34% of patients (68 of 200) and were negative for peritoneal violation in 66% of patients (132 of 200). Two patients with negative CT findings failed to improve with observation and underwent therapeutic laparotomy. CT had 97% sensitivity (66 of 68 findings), 98% specificity (130 of 132 findings), and 98% accuracy (196 of 200 findings) for peritoneal violation. CT aided diagnosis of 28 hepatic, 34 bowel or mesenteric, seven splenic, and six renal injuries. Laparotomy based on CT findings in 38 patients was considered therapeutic in 87% (33 of 38) and nontherapeutic in 8% (three of 38) and had negative results in 5% (two of 38).

CONCLUSION

Triple-contrast helical CT accurately demonstrates peritoneal violation and visceral injury in patients with penetrating torso wounds.

Imaging of traumatic diaphragmatic injuries

Traumatic diaphragmatic injury (TDI) occurs in approximately 6% of patients after major blunt trauma to the abdomen. Detection of such injuries is often problematic because of nonspecific clinical signs and the presence of additional intra-abdominal injuries. As the use of nonsurgical management to treat solid organ injuries increases, helical computed tomography (CT) must play a much greater role in the detection of intra-abdominal injuries. Therefore, it is crucial that diaphragmatic injuries are not overlooked, as fewer will be diagnosed at exploratory laparotomy. This article reviews the recent advances in helical CT that are helpful in diagnosing TDI and addresses the selected application of magnetic resonance imaging.

Triple-contrast helical CT in penetrating torso trauma: a prospective study to determine peritoneal violation and the need for laparotomy

OBJECTIVE

A prospective study was performed to determine the usefulness of triple-contrast helical CT in predicting peritoneal violation and the need for laparotomy in the treatment of penetrating torso trauma.

SUBJECTS AND METHODS

Triple-contrast helical CT scans were obtained in 104 hemodynamically stable patients with penetrating injuries to the torso (thoracoabdominal region including tangential wounds to the anterior abdomen, flank, back, and pelvis) over a 17-month period. The study group included 54 patients with gunshot wounds and 50 with stab wounds. No patient had a radiographic or clinical indication for immediate laparotomy. A positive finding on CT was defined as evidence of peritoneal violation or injury to the retroperitoneal colon, major vessel, or urinary tract. Patients with a positive CT, except patients with isolated liver injury or free fluid, underwent laparotomy. Patients with a negative finding on CT were initially observed.

RESULTS

CT studies were positive in 35 (34%) of 104 patients and negative in 69 (66%) of 104 of patients. Laparotomy was performed in 21 (60%) of 35 patients with positive CT; 19 (86%) of 22 were therapeutic, two (9%) were nontherapeutic, and one (5%) was negative (no injury was found). Nine patients with isolated hepatic injuries were successfully treated without laparotomy. Among patients with a negative CT, 67 (97%) of 69 were treated nonoperatively with success. CT had 100% (19/19) sensitivity, 96% (69/72) specificity, 100% (69/69) negative predictive value, and 97% (101/104) accuracy in predicting the need for laparotomy.

CONCLUSION

Triple-contrast helical CT can accurately predict the need for laparotomy and exclude peritoneal violation in penetrating torso trauma including tangential abdominal wounds.

Determining the need for laparotomy in penetrating torso trauma: a prospective study using triple-contrast enhanced abdominopelvic computed tomography

BACKGROUND

The nontherapeutic laparotomy rate in penetrating abdominal trauma remains high and the morbidity rate in these cases is approximately 40%. Selective management, rather than mandatory laparotomy, has become a popular approach in both stab wounds and gunshot wounds. The advent of spiral technology has stimulated a reassessment of the role of computed tomography (CT) in many aspects of trauma care. We prospectively investigated the current utility of triple-contrast CT as a diagnostic tool to facilitate initial therapeutic management decisions in penetrating torso trauma.

METHODS

We studied hemodynamically stable patients with penetrating injury to the torso (abdomen, pelvis, flank, back, or lower chest) without definite indication for laparotomy, admitted to our trauma center during the 1-year period from 7/99 through 6/00. Patients underwent triple-contrast enhanced spiral CT as the initial study. A positive CT scan was defined as any evidence of peritoneal violation (free air or fluid, contrast leak, or visceral injury). Patients with positive CT, except those with isolated solid viscus injury, underwent laparotomy. Patients with negative CT were observed.

RESULTS

There were 75 consecutive patients studied: mean age 30 years (range 15-85 years); 67 (89%) male; 41 (55%) gunshot wound, 32 (43%) stab wound, 2 (3%) shotgun wound; mean admission systolic blood pressure 141 mm Hg (range 95-194 mm Hg); 26 (35%) had positive CT and 49 (65%) had negative CT. In patients with positive CT, 18 (69%) had laparotomy: 15 therapeutic, 2 nontherapeutic, and 1 negative. Five patients had isolated hepatic injury and 2 had hepatic and diaphragm injury on CT and all were successfully managed without laparotomy. Of these seven patients, three had angioembolization and two had thoracoscopic diaphragm repair. In patients with negative CT, 47/49 (96%) had successful nonoperative management and 1 had negative laparotomy. The single CT-missed peritoneal violation had a left diaphragm injury at laparotomy. CT accurately predicted whether laparotomy was needed in 71/75 (95%) patients.

CONCLUSION

In penetrating torso trauma, triple-contrast abdominopelvic CT can accurately predict need for laparotomy, exclude peritoneal violation, and facilitate nonoperative management of hepatic injury. Adjunctive angiography and investigation for diaphragm injury may be prudent.

Helical computed tomography of bowel and mesenteric injuries

BACKGROUND

The role of computed tomography in diagnosing hollow viscus injury after blunt abdominal trauma remains controversial, with previous studies reporting both high accuracy and poor results. This study was performed to determine the diagnostic accuracy of helical computed tomography in detecting bowel and mesenteric injuries after blunt abdominal trauma in a large cohort of patients.

METHODS

One hundred fifty patients were admitted to our Level I trauma center over a 4-year period with computed tomographic (CT) scan or surgical diagnosis of bowel or mesenteric injury. CT scan findings were retrospectively graded as negative, nonsurgical, or surgical bowel or mesenteric injury. The CT scan diagnosis was then compared with surgical findings, which were also graded as negative, nonsurgical, or surgical.

RESULTS

Computed tomography had an overall sensitivity of 94% in detecting bowel injury and 96% in detecting mesenteric injury. Surgical bowel cases were correctly differentiated in 64 of 74 cases (86%), and surgical mesenteric cases were correctly differentiated from nonsurgical in 57 of 76 cases (75%).

CONCLUSION

Helical CT scanning is very accurate in detecting bowel and mesenteric injuries, as well as in determining the need for surgical exploration in bowel injuries. However, it is less accurate in predicting the need for surgical exploration in mesenteric injuries alone.

Using CT to diagnose tracheal rupture

OBJECTIVE

A retrospective study was performed to assess CT sensitivity for diagnosing tracheal rupture. Intubated cadaver tracheas were examined to assess endotracheal tube balloon overdistention and deformity and to evaluate the relationship of balloon pressures to tracheal injury.

MATERIALS AND METHODS

Neck or chest CT scans of 14 patients with tracheal rupture and 41 control trauma patients with pneumomediastinum but without tracheal injury were reviewed and compared to assess the presence and location of extrapulmonary air, whether direct visualization of tracheal wall disruption was possible, the size and shape of endotracheal tube balloon, signs of transtracheal balloon herniation in intubated patients, and the location of the extratracheal endotracheal tube. Intact and experimentally injured cadaver tracheas were used to evaluate tube balloon pressure and configuration.

RESULTS

All 14 patients with tracheal rupture had deep cervical air and pneumomediastinum. Overdistention of the tube balloon occurred in 71% (5/7) of the intubated patients, and balloon herniation occurred in 29% (2/7). Direct tracheal injury was seen in 71% (10/14) of the patients as a wall defect (n = 8) or deformity (n = 2). Overall, CT was 85% sensitive for detecting tracheal injury. Patients with tracheal injury had a significantly lower incidence of pneumothorax (p = 0.01) than did the control group. The CT appearance of balloon herniation through defects in the cadaver tracheas closely mimicked those of patients with tracheal injury. The amount of balloon pressure required to rupture the intubated trachea was extremely high and rupture was difficult to obtain.

CONCLUSION

CT can reveal tracheal injury and can be used to select trauma patients with pneumomediastinum for bronchoscopy, leading to early confirmation and treatment.

CT findings after embolization for blunt splenic trauma

PURPOSE

To determine complications after transcatheter embolization for blunt splenic injury as recognized with computed tomography (CT).

MATERIALS AND METHODS

From March 1997 to January 2000, 80 patients underwent transcatheter embolization after blunt splenic injury, of whom 53 underwent abdominal CT examination before and after embolization. Preembolization CT scans were reviewed to determine grade of injury, and postembolization CT scans were reviewed to identify complications secondary to embolization. Arteriography results were reviewed to determine findings and method and location of embolization.

RESULTS

Splenic infarcts occurred in 63% of patients after proximal embolization and in 100% of patients after distal embolization. Infarcts after distal embolization tend to be larger and occur just distal to the embolization material, whereas infarcts after proximal embolization tend to be smaller, multiple, and located in the periphery. Most infarcts resolved without sequelae. Seven patients developed gas within an infarct or subcapsular fluid collection. Two collections were drained and found to be sterile and one patient had a splenic abscess at laparotomy.

CONCLUSIONS

Infarcts are common after splenic embolization. Gas may be present within an infarct after embolization with Gelfoam; however, the presence of air/fluid level is a better predictor of abscess.

Nonsurgical management of blunt splenic injury: use of CT criteria to select patients for splenic arteriography and potential endovascular therapy

PURPOSE

To determine if contrast material-enhanced spiral computed tomography (CT) can be used to select patients with blunt splenic injuries to undergo arteriographic embolization.

MATERIALS AND METHODS

During a 15-month period, 78 patients who were hemodynamically stable and required no immediate surgery underwent contrast-enhanced spiral CT followed by splenic arteriography. CT scans were assessed for splenic vascular contrast material extravasation or posttraumatic splenic vascular lesions. Medical records were reviewed for splenic arteriographic results and clinical outcome.

RESULTS

There were 25 grade I, 12 grade II, 27 grade III, 12 grade IV, and two grade V splenic injuries. CT showed active contrast material extravasation in seven patients and splenic vascular lesions in 19 patients. At CT, splenic vascular contrast material extravasation was 100% (seven of seven patients) and a posttraumatic splenic vascular lesion was 83% (10 of 12 patients) sensitive on the basis of arteriographic or surgical outcome in predicting the need for transcatheter embolization or splenic surgery. Overall, CT had a sensitivity of 81% (17 of 21 patients), a specificity of 84% (48 of 57 patients), negative and positive predictive values of 92% (48 of 52 patients) and 65% (17 of 26 patients), respectively, and an accuracy of 83% (65 of 78 patients) in predicting the need for splenic injury treatment.

CONCLUSION

Contrast-enhanced spiral CT plays a valuable role in selecting hemodynamically stable patients with splenic vascular injury who may be treated with transcatheter therapy and potentially improves the success rate of nonsurgical management.

CT criteria for management of blunt liver trauma: correlation with angiographic and surgical findings

PURPOSE

To determine the contrast material-enhanced computed tomographic (CT) criteria for selection of hemodynamically stable patients with blunt hepatic injury for angiographic evaluation.

MATERIALS AND METHODS

Seventy-two patients with blunt liver injury underwent CT and hepatic angiography. Hepatic injuries were graded with CT-based classification. Scans were assessed for evidence of contrast extravasation and laceration or contusion extending into the hepatic vein(s), inferior vena cava, porta hepatis, or gallbladder fossa. Medical, angiographic, and surgical records were reviewed to determine angiographic findings, surgical indications and findings, and outcomes.

RESULTS

Compared with hepatic angiography, CT was 65% (11 of 17 patients) sensitive and 85% (41 of 48 patients) specific for detection of arterial vascular injury. When CT severity grades 2 and 3 were analyzed, the sensitivity and specificity of CT were 100% (three of three patients) and 94% (34 of 36 patients), respectively (P <.001). Injury involving at least one major hepatic vein was found in 15 (88%) of 17 patients who required liver-related surgery and in 23 (42%) of 55 of the other patients (P <.01).

CONCLUSION

CT-based criteria, including hepatic injury grade, signs of arterial vascular injury, and presence or absence of major hepatic venous involvement assists in selecting patients for hepatic angiography and those at increased risk of ongoing or delayed hepatic bleeding or other posttraumatic complications.

Using CT to diagnose traumatic lumbar hernia

OBJECTIVE

The objective of this study was to determine the CT findings of traumatic lumbar hernia in 15 patients and to discuss the mechanism and treatment of injury.

CONCLUSION

CT can reveal traumatic lumbar hernia and show both the anatomy of disrupted muscular layers and the presence of herniated intraabdominal viscera or retroperitoneal fat.

Imaging of diaphragmatic injuries

Multiple imaging modalities are available for the preoperative diagnosis of diaphragmatic injury. Chest radiographs are the initial and most commonly performed imaging study to evaluate the diaphragm after trauma. When chest radiography is indeterminate, spiral computed tomography (CT) with thin sections and reformatted images is the next study of choice, particularly because most hemodynamically stable patients with blunt diaphragm injury will require an admission CT examination to evaluate the extent and anatomical sites of coexisting thoracoabdominal injuries. Magnetic resonance imaging is used to evaluate the diaphragm for patients with clinical suspicion but an indeterminate diagnosis after chest radiography and spiral CT.

MR imaging of thoracic trauma

Although MR imaging and MR angiography should not be considered a primary study for patients sustaining blunt or penetrating thoracic trauma, it has achieved importance as an ancillary problem-solving modality. In general, the authors have found MR imaging to be a useful ancillary study to confirm or exclude diaphragm injury, if spiral CT scan with reformations are equivocal; to help assess the aorta and mediastinum in cases of potential injury that are not clarified by CT scan or thoracic angiography; and to identify the true origin of trauma-related masses that may simulate thoracic neoplasms.

Helical CT of diaphragmatic rupture caused by blunt trauma

OBJECTIVE

The purpose of this study was to determine the diagnostic sensitivity and specificity of helical CT with sagittal and coronal reformatted images in detecting diaphragmatic rupture after blunt trauma.

MATERIALS AND METHODS

Chest and abdominal helical CT scans obtained in 41 patients with suspected diaphragmatic injury after major blunt trauma were reviewed by three observers who were unaware of surgical findings. Coronal and sagittal reformatted images were reviewed for each patient as well. Findings consistent with diaphragmatic injury, such as waistlike constriction of abdominal viscera (i.e., the "collar sign"), intrathoracic herniation of abdominal contents, and diaphragmatic discontinuity were recorded. Sensitivity and specificity of helical CT were calculated on the basis of surgical findings and clinical follow-up.

RESULTS

Helical CT was performed preoperatively in 23 patients with diaphragmatic rupture (left, n = 17; right, n = 5; bilateral, n = 1). An additional 18 patients underwent helical CT to further evaluate suspicious findings seen on chest radiography at admission and were found to have an intact diaphragm. Sensitivity for detecting left-sided diaphragmatic rupture was 78% and specificity was 100%. Sensitivity for the detection of right-sided diaphragmatic rupture was 50% and specificity was 100%. The most common CT finding of diaphragmatic rupture was the collar sign, identified in 15 patients (sensitivity, 63%; specificity, 100%). Diaphragmatic discontinuity was seen in four patients.

CONCLUSION

Helical CT, especially with the aid of reformatted images, is useful in the diagnosis of acute diaphragmatic rupture after blunt trauma. Helical CT can be used to detect 78% of left-sided and 50% of right-sided injuries.

Hemoperitoneum as the sole indicator of abdominal visceral injuries: a potential limitation of screening abdominal US for trauma

PURPOSE

To determine, at screening ultrasonography, the prevalence, severity, and clinical outcome of clinically important abdominal visceral injuries, without associated hemoperitoneum, that result from blunt abdominal trauma.

MATERIALS AND METHODS

Computed tomography (CT) was performed at admission in 466 patients with visceral injury. A retrospective review was performed of findings from surgery and contrast material-enhanced spiral and conventional CT performed to verify abdominal visceral injuries in 467 (4%) of 11,188 patients with blunt trauma. These patients were admitted to a level 1 trauma center over 33 months to determine the presence of hemoperitoneum and to identify the grade of injury. Medical records of patients with abdominal visceral injury without hemoperitoneum were reviewed for the management required and for results of focused abdominal sonography for trauma (FAST).

RESULTS

A total of 575 abdominal visceral injuries were identified at CT and/or surgery. Findings of CT at admission (n = 156) and of surgery (n = 1) revealed no evidence of hemoperitoneum in 157 (34%) patients with abdominal visceral injury; 26 (17%) of whom also had negative FAST studies. Abdominal visceral injuries diagnosed in patients without hemoperitoneum included 57 (27%) of 210 splenic injuries, 71 (34%) of 206 hepatic injuries, 30 (48%) of 63 renal injuries, four (11%) of 35 mesenteric injuries, and two (29%) of seven pancreatic injuries. Surgical and/or angiographic intervention was required in 26 (17%) patients without hemoperitoneum.

CONCLUSION

Reliance on the presence of hemoperitoneum as the sole indicator of abdominal visceral injury limits the value of FAST as a screening diagnostic modality for patients who sustain blunt abdominal trauma.

Imaging diagnosis of nonaortic thoracic injury

Chest radiographs remain the initial imaging modality to rapidly screen patients with blunt chest trauma. Spiral CT is more sensitive and specific in diagnosing most thoracic pathology seen in blunt trauma patients. This article reviews the major clinical and radiologic findings that occur with blunt injuries to the chest, excluding mediastinal vascular injuries.

Imaging of acute thoracic aortic injury due to blunt trauma: a review

Much recent work on the use of computed tomography (CT) and transesophageal echocardiography in screening for and facilitating the diagnosis of acute thoracic aortic injury in the patient with blunt chest trauma has shown favorable results. This has led some physicians to question whether conventional thoracic aortography is still the reference standard. The purpose of this review article is to summarize the epidemiology and pathophysiology of acute thoracic aortic injury, the current status of the individual imaging modalities in use, and the surgeon's perspective. Despite a burgeoning literature and a confounding array of clinical and imaging advances, timely diagnosis of acute thoracic aortic injury remains a challenge. To overcome this problem, some trauma centers have used CT, transesophageal echocardiography, or both, in their diagnostic algorithm for acute thoracic aortic injury. These diagnostic algorithms are individually tailored by each institution and are still under investigation; therefore, no definite conclusions can be reached.

Use of spiral computed tomography for the assessment of blunt trauma patients with potential aortic injury

PURPOSE

The purpose of this study was to prospectively examine the accuracy of contrast-enhanced spiral thoracic computed tomography (CEST-CT) for direct detection of traumatic aortic injury resulting from blunt thoracic trauma.

METHODS

During a 25-month period, all blunt trauma patients who had abnormal mediastinal contours on admission chest radiographs underwent CEST-CT. The presence and location of mediastinal blood and any direct signs of aortic injury, such as pseudoaneurysm, were recorded. Computed tomographic results were compared with results of aortography, when performed, surgery, or clinical status at discharge.

RESULTS

There were 7,826 patients classified as having blunt trauma admitted during the study. Of these, 1,104 (14.3%) had CEST-CT performed. Mediastinal hemorrhage was detected on 118 (10.7%) of all thoracic computed tomographic scans. Direct evidence of aortic injury was detected in 24 patients (20.3%) with mediastinal hemorrhage and 2.2% of all patients undergoing CEST-CT. In this prospective series, CEST-CT was 100% sensitive based on clinical follow-up; it was 99.7% specific, with 89% positive and 100% negative predictive values and an overall diagnostic accuracy of 99.7%.

CONCLUSION

CEST-CT is a valuable ancillary study for the detection of traumatic aortic injury. Spiral computed tomography is accurate for the detection and localization of both hemomediastinum and direct signs of aortic injury.