Sensitivity analysis of skull fracture

1. Jeff E. Schunk, MD* 2. Sara A. Schutzman, MD† 1. *Professor, Division of Pediatric Emergency Medicine, Department of Pediatrics, University of Utah School of Medicine, Primary Children’s Medical Center, Salt Lake City, UT. 2. †Assistant Professor, Department of Pediatrics, Harvard Medical School, Senior Associate Physician in Medicine, Division of Emergency Medicine, Department of Medicine, Children’s Hospital Boston, Boston, MA. * Abbreviations: BSF: : basilar skull fracture CSF: : cerebrospinal fluid CT: : computed tomography EDH: : epidural hemorrhage GCS: : Glasgow Coma Scale ICI: : intracranial injury ICP: : intracranial pressure PECARN: : Pediatric Emergency Care Applied Research Network SAH: : subarachnoid hemorrhage SDH: : subdural hemorrhage TBI: : traumatic brain injury Recent studies have provided updated guidelines for the diagnosis of head injury and the management of patients who experience concussions. A multidisciplinary panel has recently issued new guidelines for return to play after head injury. After reading this article, readers should be able to: 1. Understand the anatomy and pathophysiology relevant to pediatric head injuries. 2. Take an appropriate history, perform an appropriate physical examination, and decide what imaging, if any, is warranted in the case of a child with a head injury. 3. Know the characteristics of the various types of intracranial injuries. 4. Understand the proper management of both minor and severe head injuries in children. Pediatric head injury is extremely common. Although the vast majority of children with head trauma have minor injuries, a small number, even among well-appearing children, will have more serious injuries with the potential for deterioration and significant sequelae. The clinician is challenged to discern which few among the many injured are at high risk for intracranial complications. Clinical symptoms are neither completely sensitive nor specific for significant injury: vomiting may be associated with intracranial injury (ICI), but most children who experience vomiting do not have a complication. Computed tomography (CT) accurately identifies ICIs requiring intervention, but also identifies minor lesions with unclear clinical importance (ie, not requiring intervention) and exposes developing brains to ionizing radiation with the associated risks. Although clinical decision rules determine which children are at highest risk and provide a useful clinical framework, they may not necessarily direct care. Additionally, in this era of reliance on imaging, it is important to remember what the clinical examination tells us regarding brain function, information that …

Background: Road traffic accidents (RTAs) are a primary global health concern, causing about 1.3 million deaths annually, with low- and middle-income countries bearing most of the burden. Head injuries, particularly skull fractures, are a leading cause of death in RTAs, reflecting the force and mechanism of impact. Fracture patterns vary by accident type, victim role, and protective gear use, with the cranial vault, especially the frontal and parietal bones, most frequently affected. Basal fractures, often involving the middle cranial fossa, are linked to high-energy impacts. Understanding fracture distribution through autopsy studies aids forensic analysis, clinical management, and the development of targeted injury prevention strategies. Aim of the study: The present study aims to analyze the pattern and distribution of skull fractures in fatal road traffic accidents based on medico-legal autopsies. Methods: This retrospective descriptive study was conducted in the Department of Forensic Medicine, North Bengal Medical College, Sirajganj, Bangladesh, analyzing 115 medico-legal autopsy cases of fatal road traffic accident victims over 12 months. Inclusion criteria comprised all RTA victims who died from head injuries with complete autopsy records, while cases with incomplete records, decomposition, or non-RTA deaths were excluded. Data on demographics, accident details, and skull fracture characteristics, including anatomical site, specific bones, cranial fossae involvement, and fracture type, were extracted from autopsy reports and related documents. Skull examinations followed standard medico-legal protocols. Data were analyzed using SPSS 26.0, with results expressed as frequencies and percentages. Results: Among 115 fatal RTA cases, most victims were young adults aged 21–30 years (33.91%), predominantly male (86.09%). Two-wheeler accidents were the leading cause (73.91%), with drivers comprising the majority of victims (53.04%). Skull fractures most commonly involved the cranial vault (65.22%), particularly the frontal bone (32.43%), followed by multiple bones (21.62%) and temporal bone fractures (16.22%). Basal skull fractures primarily affected the middle cranial fossa (61.54%). Linear fractures were the most frequent type (61.74%), followed by combination (19.13%) and comminuted fractures (13.91%), highlighting the severity and distribution of cranial injuries in fatal RTAs. Conclusion: In fatal RTAs, young adult males are most affected, with two-wheeler collisions predominating. The cranial vault, particularly the frontal bone, and the middle cranial fossa in basal fractures are most commonly involved. Linear fractures are predominant, underscoring the need for improved road safety, helmet use, and trauma care.

Accidents in children represent a significant cause of morbidity and mortality in the United States. Falls are the most frequent cause of accidental injury and rank fourth behind motor vehicle accidents, fires, and drowning as the cause of accidental death in children.1 Falling out of bed is a relatively common occurrence. Although childhood falls from bed frequently will prompt an urgent visit to the pediatrician, rarely do they produce significant injury.2-4 We present a case in which a fall of 24 inches from bed resulted in an uncomplicated, simple depressed skull fracture. A 7-month-old infant was brought to the emergency department by her parents after an unwitnessed fall from bed. On multiple, independent interviews, her parents provided a consistent, unwavering history. The patient and her father were lying in bed, when the father was called out to help the mother with the 2-year-old brother. After leaving the bedroom, the father heard a thud and returned immediately to find the patient on the floor crying. She was consoled after 5 minutes, at which time the father noted a depression on the right side of her head. The parents sought medical attention immediately. A thorough evaluation in the emergency department showed a normal physical and neurologic exam, with no evidence of external trauma except for a 2 × 4 × 0.5-cm depression of the skull in the right parietal region. A computerized tomography image showed a depressed skull fracture of the right parietal bone, with no evidence of underlying brain injury. The patient was admitted to the hospital for close observation and additional evaluation of suspected …

The mammalian skull vault consists mainly of 5 flat bones, the paired frontals and parietals, and the unpaired interparietal. All of these bones are formed by intramembranous ossification within a layer of mesenchyme, the skeletogenic membrane, located between the dermal mesenchyme and the meninges surrounding the brain. While the frontal bones are of neural crest in origin, the parietal bones arise from mesoderm. The present study is a characterization of frontal and parietal bones at their molecular level, aiming to highlight distinct differences between the neural crest-derived frontal and mesodermal-derived parietal bone. We performed a detailed comparative gene expression profile of FGF ligands and their receptors known to play crucial role in skeletogenesis. This analysis revealed that a differential expression pattern of the major FGF osteogenic molecules and their receptors exists between the neural crest-derived frontal bone and the paraxial mesoderm-derived parietal bone. Particularly, the expression of ligands such as Fgf-2, Fgf-9 and Fgf-18 was upregulated in frontal bone on embryonic day 17.5, postnatal day 1 and postnatal day 60 mice. Frontal bone also elaborated higher levels of Fgf receptor 1, 2 and 3 transcripts versus parietal bone. Taken together, these data suggest that the frontal bone is a domain with higher FGF-signaling competence than parietal bone.

Commentary on the Differential Healing Capacity of Calvarial Bone

Pediatric Head Injury

BackgroundTraumatic brain injuries (TBIs) are significant causes of morbidity and mortality worldwide. A compound depressed skull fracture (DSF) occurs when a laceration over the fracture exposes the internal cranial cavity to the external environment. DSFs are considered surgical emergencies that require prompt intervention to reduce morbidity and mortality. Currently, the literature lacks comprehensive information regarding the risks of intracranial infection and seizures, surgical indications, and the impact of surgical management on the functional and neurological outcomes of penetrating craniocerebral injuries (PCCIs). Our case report aims to enhance the existing literature by providing an overview of the management of frontal bone and frontal sinus fractures. We will emphasize key aspects such as the timing of surgery (early vs. delayed), the risks of infection and seizures, and the selection of prophylactic antibiotics. We present a case of PCCI with DSF that resulted in a favorable functional outcome.Case DescriptionWe present a 21-year-old male who was involved in an MVA with an unknown mechanism and was brought by ambulance to our emergency department at Dammam Medical Complex. Initially, the patient was vitally stable, conscious, alert, and oriented. He had multiple scalp lacerations, including a mid-forehead open wound laceration with bone fragments and some brain tissue protruding out of the lacerated wound defect. After clinical deterioration, the patient underwent an urgent surgical exploration and elevation of skull fracture along with primary skull reconstruction. The mid-forehead wound defect was repaired in collaboration with the plastic surgery team.ConclusionsAlthough a depressed frontal skull fracture involving both the outer and inner tables of the frontal sinus needs to be addressed on a case-by-case basis, cranialization of the inner table is preferred. Titanium mesh is a satisfactory alternative in case of inapplicable use of the patient’s own bone fragments and chips. Collaborating with the plastic surgery team when dealing with complex mid-forehead wounds is also advisable to ensure optimal cosmetic outcomes. It is advisable to use anti-seizure medications (ASMs) prophylactically to prevent early, but not late, post-traumatic seizures (PTSs). A short course of broad-spectrum antibiotics is recommended in cases of open (compound) depressed fractures.

Cephalohematoma in the newborn is of common occurrence. Its clinical features are well known, but the roentgenographic changes have received little study, and no reference to this common condition is found in the American radiological literature. Although the clinical diagnosis would seem to be simple, cephalohematoma has been confused with encephalocele and depressed skull fractures. The former diagnosis is usually suggested when the hematoma presents posteriorly in the mid-portion of the occipital bone. A depressed skull fracture is suggested by the presence of a palpable rim of calcium which is found in the early calcifying lesions. It is the purpose of this paper to present the interesting roentgen findings in cephalohematoma of the newborn and to analyze statistically the cases seen at the Vanderbilt University Hospital (Nashville, Tenn.) over a five-year period (1944–49). One of the earliest reports on cephalohematoma was given in 1885 by John M. Keating (4), who accurately postulated that the tumefaction was due to the effusion of blood between the periosteum of the skull and the calvarium itself. Later authors have added little to his fundamental description, but have confined their writings to the incidence and clinical characteristics of the condition. Incidence Sjövall (7) in 1936 reported an incidence of 0.41 per cent in a series of 171 newborn infants. In the present study, a series of 126 cephalohematomata were observed in a total of 7,563 deliveries, an incidence of 1.66 per cent (Table II). Of the 126 cases, 58 involved the right parietal bone, 36 the left parietal bone, 17 were biparietal, and 15 were occipital in origin. None were found in the frontal or temporal bones. The greater number of cephalohematomata occurring in the parietal region is in accord with the previous reports on this subject (7). Etiology Various factors have been suggested as causes of neonatal cephalohematoma. Chief among these is prolonged and difficult delivery. Hartley and Burnett (3) suggested that the fall in infant blood prothrombin seen on the second and third postpartum day might be a factor in the etiology. In the present series of cases, the following factors were considered: birth weight of the infant, sex of the infant, prenatal administration of vitamin K, fetal presentation, maternal parity, and instrumental delivery. A study of the infant birth weight in this series reveals that this factor was of significance in neonatal cephalohematoma. The average weight of newborn infants at the Vanderbilt University Hospital over this period (1944–49) was 7 lb. 5 oz. The average weight of the infants with cephalohematoma was 7 lb. 12 oz. However, when the infants are grouped according to weight and compared with the grouping by weight of a similar series of normal infants, it can be seen that a significant difference exists.

Emergency department (ED) management of skull fractures in children remains controversial. Because infants incurring head trauma have a high incidence of skull fracture, we chose to describe fractures in this subset of patients and to determine if there are clinical predictors of associated intracranial injury (ICI) that may have utility in developing more efficient management schemes in these patients. A retrospective medical record review was conducted on all awake patients < 13 months of age with an acute skull fracture from non-birth trauma, presenting to the ED of a university-affiliated children's hospital during a three-year period. Clinical and radiographic data extracted were used to describe skull fractures in these patients. The ability of various characteristics to determine the presence of ICI was assessed by calculating sensitivity, specificity, positive predictive value, and negative predictive value for each. The predominant mechanism of injury for the 102 infants was falls (91%). Suspicion of abuse was found in only one case. The parietal bone was fractured in 87 infants, and 34 had nonparietal fractures. The most prevalent fracture type was linear (92 infants), and 31 had > 1 cranial bone fractured. CT scans obtained on 32 infants (CT group) revealed 21 ICIs in 15 patients. Two with temporoparietal fractures required emergent evacuation of epidural blood. In the CT group, seven of the 15 (47%) with ICI (ICI group) were lethargic compared to two of the 17 (12%) without ICI (No ICI group) (P = 0.035). Five (33%) in the ICI group had temporal bone fractures compared to 0 in the No ICI group (P = 0.015). The presence of any sign or symptom had a sensitivity and negative predictive value of 100%, but only a specificity of 35%. The presence of lethargy had a positive predictive value of 78%. The presence of temporal and frontal bone fractures had positive predictive values of 100 and 75%, respectively. This study reports a high prevalence of fracture characteristics often associated with inflicted injury in other studies when virtually all injuries in our sample were accidental. Several clinical characteristics were demonstrated to be potentially useful in predicting ICI associated with skull fracture; however, prospective study is recommended to validate these findings prior to clinical application.

Complex Skull Fracture in a Toddler.

BackgroundAs a culmination of efforts over the last years, our knowledge of the embryonic origins of the mammalian frontal and parietal cranial bones is unambiguous. Progenitor cells that subsequently give rise to frontal bone are of neural crest origin, while parietal bone progenitors arise from paraxial mesoderm. Given the unique qualities of neural crest cells and the clear delineation of the embryonic origins of the calvarial bones, we sought to determine whether mouse neural crest derived frontal bone differs in biology from mesoderm derived parietal bone.MethodsBrdU incorporation, immunoblotting and osteogenic differentiation assays were performed to investigate the proliferative rate and osteogenic potential of embryonic and postnatal osteoblasts derived from mouse frontal and parietal bones. Co-culture experiments and treatment with conditioned medium harvested from both types of osteoblasts were performed to investigate potential interactions between the two different tissue origin osteoblasts. Immunoblotting techniques were used to investigate the endogenous level of FGF-2 and the activation of three major FGF signaling pathways. Knockdown of FGF Receptor 1 (FgfR1) was employed to inactivate the FGF signaling.ResultsOur results demonstrated that striking differences in cell proliferation and osteogenic differentiation between the frontal and parietal bone can be detected already at embryonic stages. The greater proliferation rate, as well as osteogenic capacity of frontal bone derived osteoblasts, were paralleled by an elevated level of FGF-2 protein synthesis. Moreover, an enhanced activation of FGF-signaling pathways was observed in frontal bone derived osteoblasts. Finally, the greater osteogenic potential of frontal derived osteoblasts was dramatically impaired by knocking down FgfR1.ConclusionsOsteoblasts from mouse neural crest derived frontal bone displayed a greater proliferative and osteogenic potential and endogenous enhanced activation of FGF signaling compared to osteoblasts from mesoderm derived parietal bone. FGF signaling plays a key role in determining biological differences between the two types of osteoblasts.

Head trauma is a common cause of morbidity and mortality in the pediatric population and often results in a skull fracture. Pediatric skull fractures are distinct from adult fractures. Pediatric fractures have a greater capacity to remodel, but the pediatric brain and craniofacial skeleton are still developing. Although pediatric head trauma has been extensively studied, there is sparse literature regarding skull fractures. The authors' aim was to investigate the characteristics, injuries, complications, and outcomes of the patients in whom surgical intervention was needed for skull fractures. The authors performed a retrospective review of patients presenting to the emergency department of a pediatric Level I trauma center between 2000 and 2005 with skull fractures. Patient demographics, mechanism of injury, associated injuries, fracture bone involvement, surgical intervention, complications, and outcomes were analyzed. Groups treated nonoperatively, for skull fracture repair, and for traumatic brain injury were compared. A total of 897 patients with a skull fracture were analyzed. Most patients (n = 772, 86.1%) were treated nonoperatively (Non-Op group). Fifty-eight patients (6.5%) underwent repair of the fracture (Repair group) and 67 (7.5%) required intervention for treatment of traumatic brain injury (TBI group). The Non-Op group was significantly younger, and the TBI group had a lower initial Glasgow Coma Scale (GCS) score. A fall (51.2%) was the most common mechanism of injury in the Non-Op group, whereas a motor vehicle crash (23.9%) and being hit in the head with an object (48.2%) were most prevalent in the TBI and Repair groups, respectively. Associated injuries were seen in all 3 groups, with brain injury (hematoma) being the most common. Frontal bone fracture was seen most in the Repair and TBI groups, and the parietal bone was the most frequent bone fractured in the Non-Op group. Patients in the TBI group were much more likely to have 2 or 3 skull bones fractured. In the Repair group, 36.2% had a complication (38.0% intervention related and 62.0% trauma related), but no patient had a worsening of their neurological status. In the TBI group, 48.7% of the patients suffered a complication, the vast majority (90.6%) of which were related to the trauma. The majority of pediatric skull fractures can be managed conservatively. Of those requiring surgical intervention, fewer than half of the surgeries are performed solely for skull fracture repair only. Patients hit in the head with an object or involved in a motor vehicle crash are more likely to need surgical intervention either to repair the skull fracture or for TBI management, respectively. Frontal bone fractures are more likely to necessitate repair, and those patients treated for TBI have a greater incidence of 2 or 3 bones involved in the fracture. Complications occurred but most were related to underlying trauma, not the surgery. No patients who underwent intervention for repair of their skull fracture only had a worsening of their neurological status.

Post-mortem computed tomography (PMCT) enables the creation of subject-specific 3D head models suitable for quantitative analysis such as finite element analysis (FEA). FEA of proposed traumatic events is an objective and repeatable numerical method for assessing whether an event could cause a skull fracture such as seen at autopsy. FEA of blunt force skull fracture in adults with subject-specific 3D models in forensic pathology remains uninvestigated. This study aimed to assess the feasibility of FEA for skull fracture analysis in routine forensic pathology. Five cases with blunt force skull fracture and sufficient information on the kinematics of the traumatic event to enable numerical reconstruction were chosen. Subject-specific finite element (FE) head models were constructed by mesh morphing based on PMCT 3D models and A Detailed and Personalizable Head Model with Axons for Injury Prediction (ADAPT) FE model. Morphing was successful in maintaining subject-specific 3D geometry and quality of the FE mesh in all cases. In three cases, the simulated fracture patterns were comparable in location and pattern to the fractures seen at autopsy/PMCT. In one case, the simulated fracture was in the parietal bone whereas the fracture seen at autopsy/PMCT was in the occipital bone. In another case, the simulated fracture was a spider-web fracture in the frontal bone, whereas a much smaller fracture was seen at autopsy/PMCT; however, the fracture in the early time steps of the simulation was comparable to autopsy/PMCT. FEA might be feasible in forensic pathology in cases with a single blunt force impact and well-described event circumstances.Supplementary informationThe online version contains supplementary material available at 10.1007/s00414-024-03186-3.

The humble skull fracture is a bit of a Cinderella— viewed as largely irrelevant and not worthy of much attention by many traumatic brain injury (TBI) investigators, but often perceived as having great importance by primary care providers and, especially, by parents. The literature on pediatric skull fractures remains sparse, and so the article by Bonfield et al.1 provides some welcome information for pediatric neurosurgeons when teaching colleagues, writing chapters, or counseling families regarding this common occurrence. The authors provide a retrospective, single-center series of 897 patients with skull fractures and analyze the patients by treatment groups—those treated without surgery, those treated surgically specifically for the fracture, and those treated surgically for associated TBI.1 They report the distribution of fracture location, fracture mechanisms, patient age, and complications. While the report has the typical limitations of a retrospective study, including few data regarding rationale for specific management decisions, the authors provide a useful snapshot of an often under-described part of the injury complex. The analysis shows that trauma involving motor vehicles and being struck in the head by an object more often resulted in the need for surgery than did falls. While the parietal bone was the most common site of fracture overall, fractures requiring surgery more often involved the frontal bone or multiple bones, usually to treat open or depressed fractures. Not surprisingly, patients with skull fractures who underwent surgery primarily for their associated brain injuries often had hematomas and underwent hematoma evacuation, decompression, and/or external ventricular drainage. Also of interest to surgeons is the finding that a significant number of complications involved hardware that required subsequent removal, and the authors noted an evolution in their practice from the use of permanent to absorbable hardware. Whether this will lead to fewer complications and is cost effective remains to be studied. Several questions about skull fractures in the pediatric population remain unanswered. Pediatric neurosurgeons have joined with other specialties in attempting to reduce radiation exposure in young patients, but if substituting rapid MRI techniques in acute trauma assessment leads to missed linear skull fractures, is this important? This study would suggest that open and depressed fractures—those most likely to require surgery for the fracture alone—are likely to be obvious on clinical grounds and might be expected to be sufficiently characterized by most rapid MRI techniques. In the functional realm, are patients who sustain enough force to create a skull fracture at risk for similar “mild traumatic brain injury” signs and symptoms—and vulnerabilities to shortand longterm consequences—as those without skull fracture? In practical terms, should you treat a patient with a linear skull fracture with similar restrictions as you typically treat a patient with a “concussion,” even if there are few neurological symptoms? Alternatively, does the energy “absorbed” by the skull, resulting in fracture, somehow protect the brain? Does any of this vary with skull deformability, which varies with age? It will be for future studies, in which skull and brain injuries are prospectively characterized and correlated with functional outcome measures, to help determine whether fractures independently influence neurocognitive outcome, and whether patients with isolated skull fractures not requiring surgical intervention or associated with a significant brain injury should be managed in any particular way. (http://thejns.org/doi/abs/10.3171/2014.3.PEDS14104)

The aim of this study was to determine how reliable scalp bruising and soft tissue swelling/cephalohematomas (STS) are for underlying young child skull fractures. This was a retrospective clinical and imaging review from 2011 to 2012 of children younger than 4 years with skull fractures from 2 tertiary care hospitals. Imaging was reread by 3 pediatric radiologists. Descriptive statistics were utilized. The retrospective review had institutional review board approval. We identified 218 subjects for review: 210 unintentional and 8 abusive. One hundred forty-three had available 3-dimensional computed tomography reconstructions: 136 unintentional and 7 abused. Two-thirds were younger than 1 year. Twelve subjects had visible scalp bruising, but 73% had clinically and 93% radiologically apparent fracture-associated STS. There was no difference in clinical STS with simple (79%) versus complex (68%) fractures. Nor was there difference in subjects with fractures from minor (77%) versus major (70%) trauma. Unintentionally injured infants did not differ from abused for detectable STS (74% vs 50%). Parietal and frontal bones most frequently sustained fractures and most consistently had associated STS. Clinically apparent STS is present in approximately three-fourths of children with skull fractures. It may not be important to consistently identify skull fractures in unintentionally injured children. Point-of-care ultrasound may be adequate. For abuse concerns, it is important to identify skull fractures as evidence of cranial impacts and intracranial hemorrhages. The most sensitive, widely available imaging technique, cranial computed tomography scan with 3-dimensional skull reconstruction, should be utilized. Scalp bruising is present in a minority of young children with skull fractures. Its absence does not exclude cranial impact injury.