[Imaging in pediatric traumatology and orthopedics]. / Bildgebung in der Kindertraumatologie/Kinderorthopädie.

Conventional or digital radiography is still the basis of imaging diagnostics of the skeletal system in pediatric patients. It is considered the gold standard for diagnosis, treatment selection, and follow-up. In addition, procedures such as ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and also nuclear medicine techniques can and should be used. It is advantageous to use trained radiology technicians who are familiar with the handling of children in X­ray diagnostics. If there is no dedicated pediatric radiology department, it is recommended to follow the guidelines from radiology societies (as low as reasonably achievable [ALARA]) and radiation protection commissions. The present article describes how state-of-the-art tools such as dose monitoring systems and software-controlled image processing and also postprocessing can be used. The article provides information on how the various modalities can be optimally used in order to achieve the best result, i.e., diagnosis, with the least possible effort and burden for the child.

Minor head trauma in infants - how accurate is cranial ultrasound performed by trained radiologists?

Correct management of infants after minor head trauma is crucial to minimize the risk to miss clinically important traumatic brain injury (ciTBI). Current practices typically involve CT or in-hospital surveillance. Cranial ultrasound (CUS) provides a radiation-free and fast alternative. This study examines the accuracy of radiologist-performed CUS to detect skull fracture (SF) and/or intracranial hemorrhage (ICH). An inconspicuous CUS followed by an uneventful clinical course would allow exclusion of ciTBI with a great certainty. This monocentric, retrospective, observational study analyzed CUS in infants (< 12 months) after minor head trauma at Bern University Children's Hospital, between 7/2013 and 8/2020. The primary outcome was the sensitivity and specificity of CUS in detecting SF and/or ICH by comparison to the clinical course and to additional neuroimaging. Out of a total of 325 patients, 73% (n = 241) had a normal CUS, 17% (n = 54) were found with SF, and ICH was diagnosed in 2.2% patients (n = 7). Two patients needed neurosurgery and three patients deteriorated clinically during surveillance. Additional imaging was performed in 35 patients. The sensitivity of CUS was 93% ([0.83, 0.97] 95% CI) and the specificity 98% ([0.95, 0.99] 95% CI). All false-negative cases originated in missed SF without clinical deterioration; no ICH was missed.  Conclusion: This study shows high accuracy of CUS in exclusion of SF and ICH, which can cause ciTBI. Therefore, CUS offers a reliable method of neuroimaging in infants after minor head trauma and gives reassurance to reduce the duration of in-hospital surveillance. What is Known: • Minor head trauma can cause clinically important traumatic brain injury in infants, and the management of these cases is a challenge for the treating physician. • Cranial ultrasound (CUS) is regularly used in neonatology, but its accuracy after head trauma in infants is controversial. What is New: • CUS performed by a trained radiologist can exclude findings related to clinically important traumatic brain injury (ciTBI) with high sensitivity and specificity. It therefore offers reassurance in the management of infants after minor head trauma.

Partial Remodeling after Conservative Treatment of Trampoline Fractures in Children.

(1) Background: Trampoline fractures (proximal tibia fracture with positive anterior tilt) are increasing. This study represents the first attempt to determine the extent of remodeling in these fractures after conservative treatment (2) Methods: This Swiss prospective multicenter study included children aged 2 to 5 years with a trampoline fracture who were radiologically examined on the day of the accident and after one year. In addition, the anterior tilt angle was compared between the injured and unaffected tibia. Remodeling was defined as complete (final anterior tilt angle ≤ 0°), incomplete (smaller but still >0°), or no remodeling. (3) Results: The mean extent of remodeling was -3.5° (95% CI: -4.29°, -2.66°, p < 0.001). Among the 89 children included in the study, 26 (29.2%) showed complete, 63 (70.8%) incomplete, and 17 patients (19.1%) no remodeling. Comparison of the anterior tilt angles between the fractured and healthy tibia showed that the anterior tilt angle on the fractured leg was, on average larger by 2.82° (95% CI: 2.01°, 3.63°; p < 0.001). (4) Conclusions: Although the anterior tilt angle decreased during the study period, the majority of patients showed incomplete remodeling. In contrast, children with radiological examinations >1 year after the trauma showed advanced remodeling, suggesting that one year is too short to observe complete remodeling.

Effects of elexacaftor/tezacaftor/ivacaftor therapy in children with cystic fibrosis - a comprehensive assessment using lung clearance index, spirometry, and functional and structural lung MRI.

BACKGROUND: With improvement in supportive therapies and the introduction of cystic fibrosis transmembrane conductance regulator (CFTR)-modulator treatment in patients with cystic fibrosis (CF), milder disease courses are expected. Therefore, sensitive parameters are needed to monitor disease course and effects of CFTR-modulators. Functional lung MRI using matrix-pencil decomposition (MP-MRI) is a promising tool for assessing ventilation and perfusion quantitatively. This study aimed to assess the treatment effect of elexacaftor/tezacaftor/ivacaftor combination regimen (ELX/TEZ/IVA) on measures of structural and functional lung abnormalities. METHODS: 24 children with CF underwent lung function tests (multiple breath washout, spirometry), functional and structural MRI twice (one year apart) before and once after at least two weeks (mean 4.7 ± 2.6 months) on ELX/TEZ/IVA. Main outcomes were changes (Δ) upon ELX/TEZ/IVA in lung function, defect percentage of ventilation (VDP) and perfusion (QDP), defect distribution index of ventilation and perfusion (DDIV, DDIQ), and Eichinger score. Statistical analyses were performed using paired t-tests and multilevel regression models with bootstrapping. RESULTS: We observed a significant improvement in lung function, structural and functional MRI parameters upon ELX/TEZ/IVA treatment (mean; 95%-CI): ΔLCI2.5 (TO) -0.84 (-1.62 to -0.06); ΔFEV1 (z-score) 1.05 (0.56 to 1.55); ΔVDP (% of impairment) -6.00 (-8.44 to -3.55); ΔQDP (% of impairment) -3.90 (-5.90 to -1.90); ΔDDIV -1.38 (-2.22 to -0.53); ΔDDIQ -0.31 (-0.73 to 0.12); ΔEichinger score -3.89 (-5.05 to -2.72). CONCLUSIONS: Besides lung function tests, functional and structural MRI is a suitable tool to monitor treatment response of ELX/TEZ/IVA therapy, and seems promising as outcome marker in the future.

Low Birth Weight and Impaired Later Lung Function: Results from a Monochorionic Twin Study.

Rationale: Fetal growth restriction (FGR) and resulting low birth weight are risk factors for impaired lung development. However, both are often correlated with other factors, especially prematurity. Therefore, the question whether lung function changes in individuals with FGR are driven by gestational age, fetal growth, or both often remains unanswered. Objectives: To examine the association of birth weight with lung function in monochorionic twins with selective FGR in one twin. Methods: We included 20 monochorionic twin pairs with selective FGR and subsequent discordant birth weight with a minimum age of 6 years. In this unique case-control design, the smaller twin represents the case and the cotwin the almost identical counterpart. They performed spirometry and underwent body plethysmography, multiple-breath washout, and magnetic resonance imaging (MRI). We compared lung function and MRI outcomes between the smaller twins and their cotwins by paired t tests, and we used mixed linear models to assess the association between birth weight and outcomes. Results: Mean study age was 18.4 years (range, 7.5-29.4), and mean difference in birth weight within the twin pairs was 575 g (range, 270-1,130). The mean difference of forced expiratory volume in 1 second z-score was -0.64 (95% confidence interval [CI], -0.98 to -0.30), and -0.55 (95% CI, -0.92 to -0.18) of forced vital capacity z-score between the smaller twins and their cotwins. Both were associated with birth weight: per 500 g of birth weight, forced expiratory volume in 1 second z-score increased by 0.50 (95% CI, 0.35-0.65; P < 0.001) and forced vital capacity z-score increased by 0.44 (95% CI, 0.31-0.57; P < 0.001). Sacin from multiple-breath washout, as a marker for ventilation inhomogeneity of acinar airways, was elevated in the smaller twins and was associated with low birth weight. There was no difference for MRI outcomes. The results remained similar after adjustment for study height. Conclusions: Low birth weight was associated with reduced large and small airway function independent of gestational age and body growth. Our findings suggest that intrauterine impairment of lung development induced by FGR has significant consequences on lung function until early adulthood.

School-age structural and functional MRI and lung function in children following lung resection for congenital lung malformation in infancy.

BACKGROUND: The management of asymptomatic congenital lung malformations is debated. Particularly, there is a lack of information regarding long-term growth and development of the remaining lung in children following lung resection for congenital lung malformations. In addition to conventional pulmonary function tests, we used novel functional magnetic resonance imaging (MRI) methods to measure perfusion and ventilation. OBJECTIVE: To assess functionality of the remaining lung expanded into the thoracic cavity after resection of congenital lung malformations. MATERIALS AND METHODS: A prospective, cross-sectional pilot study in five children who had surgery for congenital lung malformations during infancy. Participants had structural and functional MRI as well as spirometry, body plethysmography and multiple breath washout at school age. RESULTS: Structural MRI showed an expansion of the remaining lung in all cases. Fractional ventilation and relative perfusion of the expanded lung were locally decreased in functional MRI. In all other parts of the lungs, fractional ventilation and relative perfusion were normal in all children. There was an association between overall impairment of perfusion and elevated lung clearance index. The results of spirometry and body plethysmography varied between patients, including normal lung function, restriction and obstruction. CONCLUSION: Fractional ventilation and relative perfusion maps from functional MRI specifically locate impairment of the remaining lung after lung resection. These changes are not captured by conventional measures such as structural MRI and standard pulmonary function tests. Therefore, following lung resection for congenital lung malformation, children should be investigated more systematically with functional lung MRI.

Effect of Salbutamol on Lung Ventilation in Children with Cystic Fibrosis: Comprehensive Assessment Using Spirometry, Multiple-Breath Washout, and Functional Lung Magnetic Resonance Imaging.

BACKGROUND: Inhalation therapy is one of the cornerstones of the daily treatment regimen in patients with cystic fibrosis (CF). Recommendations regarding the addition of bronchodilators, especially salbutamol are conflicting due to the lack of evidence. New diagnostic measures such as multiple-breath washout (MBW) and functional magnetic resonance imaging (MRI) have the potential to reveal new insights into bronchodilator effects in patients with CF. OBJECTIVE: The objective of the study was to comprehensively assess the functional response to nebulized inhalation with salbutamol in children with CF. METHODS: Thirty children aged 6-18 years with stable CF performed pulmonary function tests, MBW, and matrix pencil-MRI before and after standardized nebulized inhalation of salbutamol. RESULTS: Lung clearance index decreased (improved) by -0.24 turnover (95% confidence interval [CI]: -0.53 to 0.06; p = 0.111). Percentage of the lung volume with impaired fractional ventilation and relative perfusion decreased (improved) by -0.79% (CI: -1.99 to 0.42; p = 0.194) and -1.31% (CI: -2.28 to -0.35; p = 0.009), respectively. Forced expiratory volume (FEV1) increased (improved) by 0.41 z-score (CI: 0.24-0.58; p < 0.0001). We could not identify specific clinical factors associated with a more pronounced effect of salbutamol. CONCLUSIONS: There is a positive short-term effect of bronchodilator inhalation on FEV1 in patients with CF, which is independent of ventilation inhomogeneity. Heterogeneous response between patients suggests that for prediction of a therapeutic effect this should be tested by spirometry in every patient individually.

Ventilation and perfusion assessed by functional MRI in children with CF: reproducibility in comparison to lung function.

BACKGROUND: Chronic lung diseases such as cystic fibrosis (CF) can be monitored by imaging and lung function modalities. Magnetic resonance imaging (MRI) techniques such as matrix pencil (MP) decomposition allows for evaluation of regional impairment of fractional ventilation (RFV) and relative perfusion (RQ). However, reproducibility of MP MRI outcomes in children with CF is unknown. We examined short-term variability of ventilation and perfusion impairment from MP MRI and compared this to lung function outcomes. METHOD: Twenty-threeCF and 12 healthy school-aged children underwent MRI and lung function tests on the same day on two occasions 24 h apart. Global ventilation inhomogeneity was assessed by the lung clearance index (LCI) from nitrogen-multiple breath washout (N2-MBW) technique. Intra-class-coefficient (ICC), percentage change, and Bland-Altman limits of agreement were evaluated to assess reproducibility. RESULTS: Sixty-nine measurements from MP MRI and N2-MBW were performed. The ICC between two visits for RFV, RQ and LCI ranged between 0.60 and 0.90 in individuals with CF and healthy controls. In individuals with CF, percentage of change between the visits was 0.02% for RFV, -1.11% for RQ and 2.91% for LCI and limits of agreement between visits were - 4.3% and 3.9% for RFV, -4.4% and 3.7% for RQ, and -2.6 and 3.0 for LCI. CONCLUSIONS: Functional imaging is reproducible and short-term changes in RFV and RQ greater than ±4.4% can be considered clinical meaningful. Very good short-term reproducibility, and easy application without the need for breathing maneuvers or contrast agent, makes MP MRI a promising surveillance method for CF.

Structural and Functional Lung Impairment in Primary Ciliary Dyskinesia. Assessment with Magnetic Resonance Imaging and Multiple Breath Washout in Comparison to Spirometry.

RATIONALE: Primary ciliary dyskinesia (PCD) is an inherited disorder characterized by heterogeneous airway disease. Traditional lung function techniques (e.g., spirometry) may underestimate severity and complexity of PCD. OBJECTIVES: We assessed lung impairment in individuals with PCD using structural and functional magnetic resonance imaging (MRI) and different lung function techniques. METHODS: A total of 30 study participants with PCD (median, 13.4 yr; range, 5-28 yr) underwent structural and functional MRI, spirometry, and multiple breath washout (MBW) on the same day. Primary endpoints included structural MRI morphology scores, relative ventilation, and perfusion impairment from functional MRI, forced expiratory volume in 1 second (FEV1) from spirometry, and lung clearance index (LCI) from MBW. RESULTS: Severity and complexity of PCD lung disease varied significantly between individuals. Structural lung disease was detected in all subjects with a median (interquartile range) extent score of 10.3 (7-19; maximum score = 60). Functional MRI ventilation impairment was present in 52% of subjects, affecting 24.2% (21.1 to 25.2%) of the lung. Relative perfusion impairment was detected in 78% of individuals affecting 21.1% (19.4 to 25.9%) of the lung. LCI was abnormal in 83% (median, 8.3 [2.6 to 13.2] z-scores) and FEV1 was abnormal in 27% (-0.5 [-1.6 to 0.3] z-scores) of individuals. Concordance between spirometry and imaging outcomes was poor, with 52% of patients showing both abnormal MRI and LCI values, but normal FEV1. CONCLUSIONS: Discordance between lung function and imaging outcomes in patients with PCD supports the use of both imaging and lung function, such as MBW, for surveillance of this heterogeneous disease.

Novel magnetic resonance technique for functional imaging of cystic fibrosis lung disease.

Lung function tests are commonly used to monitor lung disease in cystic fibrosis (CF). While practical, they cannot locate the exact origin of functional impairment. Contemporary magnetic resonance imaging (MRI) techniques provide information on the location of disease but the need for contrast agents constrains their repeated application. We examined the correlation between functional MRI, performed without administration of contrast agent, and lung clearance index (LCI) from nitrogen multiple-breath washout (N2-MBW).40 children with CF (median (range) age 12.0 (6-18) years) and 12 healthy age-matched controls underwent functional and structural MRI and lung function tests on the same day. Functional MRI provided semiquantitative measures of perfusion (RQ) and ventilation (RFV) impairment as percentages of affected lung volume. Morphological MRI was evaluated using CF-specific scores. LCI measured global ventilation inhomogeneity.MRI detected functional impairment in CF: RFV 19-38% and RQ 16-35%. RFV and RQ correlated strongly with LCI (r=0.76, p<0.0001 and r=0.85, p<0.0001, respectively), as did total morphology score (r=0.81, p<0.0001). All indices differed significantly between patients with CF and healthy controls (p<0.001).Noninvasive functional MRI is a promising method to detect and visualise perfusion and ventilation impairment in CF without the need for contrast agents.

Bone subtraction radiography in adult patients with cystic fibrosis.

Background Bone subtraction radiography allows reading pulmonary changes of chest radiographs more accurately without superimposition of bones. Purpose To evaluate the value of bone subtraction chest radiography using dual energy (DE) bone subtracted lung images compared to conventional radiographs (CR) in adult patients with cystic fibrosis (CF). Material and Methods Forty-nine DE radiographs of 24 patients (16 men) with CF (mean age, 32 years; age range, 18-71 years) were included. Lung function tests were performed within 10 days of the radiographs. Two radiologists evaluated all CR, DE, and CR + DE radiographs using the modified Chrispin-Norman score (CNS) and a five-point score for the confidence. Findings were statistically evaluated by Friedman ANOVA and Wilcoxon matched-pairs test. Results There was significant difference of CNS between CR and DE ( P = 0.044) as well as CR and CR + DE ( P < 0.001). CNS of CR images showed moderate correlation with FEV1% (R = 0.287, P = 0.046) while DE and CR + DE correlated poorly with FEV1% (R = 0.023, P = 0.874 and R = 0.04, P = 0.785). A higher confidence was achieved with bone-subtracted radiographs compared to radiographs alone (median, CR 3.3, DE 3.9, CR + DE 4.1, for both P < 0.001). Conclusion DE radiographs are reliable for the evaluation of adult patients with CF in acute exacerbation. For yearly surveillance, CR and DE radiographs may play a limited role. However, in clinical routine, DE radiographs are useful for adult CF patients and may depict more accurately inflammatory changes than CR.

Odontoid Osteomyelitis in Children: Illustrative Case Reports and Review of the Literature.

Odontoid osteomyelitis is a rare disease which is frequently misdiagnosed as torticollis, leading to a delay in diagnosis. We present 2 illustrative cases and a systematic literature review summarizing previously reported cases. Odontoid osteomyelitis should be considered in children presenting with decreased head movements and with elevated erythrocyte sedimentation rate, particularly without improvement while receiving antiinflammatory treatment. Plain radiographs can be misleading, and magnetic resonance imaging should be performed for better visualization.

Can 3D ultrasound identify trochlea dysplasia in newborns? Evaluation and applicability of a technique.

Femoro-patellar dysplasia is considered as a significant risk factor of patellar instability. Different studies suggest that the shape of the trochlea is already developed in early childhood. Therefore early identification of a dysplastic configuration might be relevant information for the treating physician. An easy applicable routine screening of the trochlea is yet not available. The purpose of this study was to establish and evaluate a screening method for femoro-patellar dysplasia using 3D ultrasound. From 2012 to 2013 we prospectively imaged 160 consecutive femoro-patellar joints in 80 newborns from the 36th to 61st gestational week that underwent a routine hip sonography (Graf). All ultrasounds were performed by a pediatric radiologist with only minimal additional time to the routine hip ultrasound. In 30° flexion of the knee, axial, coronal, and sagittal reformats were used to standardize a reconstructed axial plane through the femoral condyle and the mid-patella. The sulcus angle, the lateral-to-medial facet ratio of the trochlea and the shape of the patella (Wiberg Classification) were evaluated. In all examinations reconstruction of the standardized axial plane was achieved, the mean trochlea angle was 149.1° (SD 4.9°), the lateral-to-medial facet ratio of the trochlea ratio was 1.3 (SD 0.22), and a Wiberg type I patella was found in 95% of the newborn. No statistical difference was detected between boys and girls. Using standardized reconstructions of the axial plane allows measurements to be made with lower operator dependency and higher accuracy in a short time. Therefore 3D ultrasound is an easy applicable and powerful tool to identify trochlea dysplasia in newborns and might be used for screening for trochlea dysplasia.

Pre- and postnatal imaging of Pai syndrome with spontaneous intrauterine closure of a frontal cephalocele.

Pai syndrome is a rare congenital disorder characterized by cutaneous polyps of the face, pericallosal lipoma and median cleft lip. We report on a newborn girl with a variant of Pai syndrome presenting with all typical findings except a median cleft. In addition, fetal sonography and MRI showed the unique intrauterine evolution of a cephalocele into an atretic cephalocele.

The anterior tilt angle of the proximal tibia epiphyseal plate: a significant radiological finding in young children with trampoline fractures.

OBJECTIVE: Evaluation of the anterior tilt angle of the proximal tibia epiphyseal plate in young children, which suffered a trampoline fracture in comparison with a normal population. MATERIALS AND METHODS: 62 children (31 females, 31 males) between 2 and 5 years of age (average 2 years 11 months, standard deviation 11 months) with radiographs in two views of the tibia were included in this retrospective study. 25 children with proximal tibia fractures were injured with a history of jumping on a trampoline. All other causes for tibia fractures were excluded. A normal age-mapped control cohort of 37 children was compared. These children had neither evidence of a trampoline related injury nor a fracture of the tibia. The anterior tilt angle of the epiphyseal plate of the tibia was defined as an angle between the proximal tibia physis and the distal tibia physis on a lateral view. Two radiologists evaluated all radiographs for fractures and measured the anterior tilt angle in consensus. An unpaired Student's t-test was used for statistical analysis (SPSS). Original reports were reviewed and compared with the radiological findings and follow-up radiographs. RESULTS: In the normal control group, the average anterior tilt angle measured -3.2°, SD ± 2.8°. The children with trampoline fractures showed an anterior tilt of +4.4°, SD ± 2.9°. The difference was statistically significant, P<0.0001. In 6 patients (24% of all patients with confirmed fractures) the original report missed to diagnose the proximal tibial fracture. CONCLUSION: Young children between 2 and 5 years of age are at risk for proximal tibia fractures while jumping on a trampoline. These fractures may be very subtle and difficult to detect on initial radiographs. Measurement of the anterior tilt angle of the proximal tibia epiphyseal plate on lateral radiographs is supportive for interpreting correctly trampoline fractures.

One-stage laparoscopic surgery for inspissated bile syndrome: case report and review of surgical techniques.

Inspissated bile syndrome in a 6 week old boy was unresponsive to oral ursodesoxycholic acid. Intraoperative cholangiography revealed complete obstruction of the common bile duct. Therefore, the gallbladder fundus was pulled out through a laparoscopy port site and sutured to the fascia. A catheter was positioned into the infundibulum for irrigation with ursodesoxycholic acid. At day 8 complete resolution of the plug and free passage of contrast medium into the duodenum was documented radiologically. The catheter was removed, skin closed spontaneously without a second surgery for closure of the gall bladder.

Trampoline related injuries in children: risk factors and radiographic findings.

BACKGROUND: Backyard trampolines are immensely popular among children, but are associated with an increase of trampoline-related injuries. The aim of this study was to evaluate radiographs of children with trampoline related injuries and to determine the risk factors. METHODS: Between 2003 and 2009, 286 children under the age of 16 with backyard trampoline injuries were included in the study. The number of injuries increased from 13 patients in 2003 to 86 in 2009. The median age of the 286 patients was 7 years (range: 1-15 years). Totally 140 (49%) patients were males, and 146 (51%) females. Medical records and all available diagnostic imaging were reviewed. A questionnaire was sent to the parents to evaluate the circumstances of each injury, the type of trampoline, the protection equipment and the experience of the children using the trampoline. The study was approved by the Institutional Ethics Committee of the University Hospital of Bern. RESULTS: The questionnaires and radiographs of the 104 patients were available for evaluation. A fracture was sustained in 51 of the 104 patients. More than 75% of all patients sustaining injuries and in 90% of patients with fractures were jumping on the trampoline with other children at the time of the accident. The most common fractures were supracondylar humeral fractures (29%) and forearm fractures (25%). Fractures of the proximal tibia occurred especially in younger children between 2-5 years of age. CONCLUSIONS: Children younger than 5 years old are at risk for specific proximal tibia fractures ("Trampoline Fracture"). A child jumping simultaneously with other children has a higher risk of suffering from a fracture.

Handlebar injuries in children.

INTRODUCTION: Handlebar injuries in children may lead to severe organ lesions despite minimal initial signs and without visible skin bruise. We present our experiences applying a diagnostic and therapeutic algorithm for blunt abdominal trauma, and present the history of two selected cases. MATERIALS AND METHODS: We retrospectively assessed the charts of children below 16 years of age, only who were observed for 24 h or more in our institution due to a handlebar injury between 2004 and 2011. All children were treated according to an institutional algorithm. RESULTS: 40 patients with a median age of 9.5 years were included. Diagnosed lesions were: ruptures of the liver (n = 6), spleen (n = 5), kidney (n = 1), and pancreas (n = 2), small bowel perforation (n = 3), and hernias of the abdominal (n = 2) or thoracic wall (n = 1). Surgical interventions were performed in 8 patients. The outcome was favorable in all the cases. Overall median hospitalization duration was 4.5 days (range 1-19 days). The overall duration between the accident and arrival at our emergency unit was 2.75 h (median, range 1-19 h). 20 children presented directly at our emergency unit after a median of 1.7 h (range 1-19.5 h). 20 children were referred by a family physician or a primary hospital after a median of 4.0 h (range 1-46 h). CONCLUSION: Handlebar injuries in children resulted in serious trunk lesions in half of the present patient series. The spectrum of injuries in handlebar accidents varies widely, especially injuries to the abdomen can unmask often only in the course. We advocate close observation of patients with thoracic and abdominal handlebar injuries which may be regarded as blunt stab wounds. An institutional algorithm for blunt abdominal trauma management is supportive for emergency care in patients with handlebar injuries.