Understanding rib fracture patterns: incomplete and buckle fractures

Reconstructing traumatic thoracic events, especially when soft tissues are absent, requires an advanced understanding of ribcage fracture patterns. The morphology and orientation of ribs complicate the fracture pattern, as a single blow often causes multiple fractures at various locations. Furthermore, fracture types observed in ribs are not explained easily by current bone biomechanic literature. Using evidential skeletal material archived at the Regional Forensic Center, Memphis, the ribs of 43 blunt force trauma cases were analyzed. A total of 195 incomplete fractures and 63 buckle fractures were noted. Incomplete fractures, previously thought to be common in children but rare in adults, were found among individuals ranging in age from 21-76 years. A buckle fracture, failure resulting from compressive instability, has been undefined previously in bone trauma literature but was repeatedly observed in this sample. This study elucidates recognizable rib fracture patterns while emphasizing gross bone examination for force and mechanical factors.     

Mechano- and morphogenesis of gunshot fractures in the flat bones

Gunshot fractures in flat bones, bullet defects in the continuum were studied in experiment. The laws of gunshot fracture formation were formulated. In far distance, bullet has a direct and radial blow action. The direct blow induces comminution and disintegration of the bone tissue with dislocation of bone fragments; radial blow potentiates bone destruction. Morphological characteristics of gunshot fractures of flat bones depend on the force of the direct and radial impact action and can be used for estimation of the far shot distance, kinetic energy and shape of the head of the shell.     

Histomorphology of healing of fractures, splits, and defects in the cranial bones

The histomorphology of healing of fractures in the calvarial bones were studied: 39 autopsies and 61 bioptic samples were investigated within the time span ranging from 1 to 5 years; as well as 32 experiments with dogs were made. A tight contact between fracture edges is the key condition for fracture healing (of the mentioned bones) through central callus. Should there be no such contact, the fracture edges were joined by fibrous tissue, which lacks any osseous structures. The periosteum of the internal bone lamella and the adjoining dura mater of brain are the main sources for bone regeneration in the calvarium.     

Pelvis and hip joint injuries as a reconstructive factors in car-to-pedestrian accidents.

The pelvic girdles of 371 pedestrian victims of road traffic accidents were evaluated during postmortem examinations. Additionally, 144 hip joints were opened. The pelvic injuries were found in 28% of the pedestrians hit exclusively in their upright position and 52% of the victims run over by a vehicle. The side of the body hit by a car was determined on the basis of the location of blood suffusions within the subcutaneous tissues and muscles of lower limbs as well as the character of injuries found in the knee and upper ankle joints. The findings were verified with the data from court records. It was shown that the injuries of the sacroiliac joints or vertical fractures of the posterior parts of iliac bones were useful parameters for determining the side (left or right) of the body hit by a vehicle. Moreover, it was found that a direct impact on the hip region was evidenced by the ipsilaterally localized fractures of the iliac ala, central hip fractures and intraosseous blood suffusions within the greater trochanter of the femur. The external dislocations of the hip joints (always) and bilateral injuries to the sacroiliac joints (usually) were observed in the victims run over by vehicles.     

Applicability of Cranial Models in Urethane Resin and Foam as a Substitute for Bone: Are Synthetic Materials Reliable?

As literature is poor in functional synthetic cranial models, in this study, synthetic handmade models of cranial vaults were produced in two different materials (a urethane resin and a self‐hardening foam), from multiple bone specimens (eight original cranial vaults: four human and four swine), in order to test their resemblance to bone structure in behavior, during fracture formation. All the vaults were mechanically tested with a 2‐kg impact weight and filmed with a high‐speed camera. Fracture patterns were homogeneous in all swine vaults and heterogeneous in human vaults, with resin fractures more similar to bone fractures. Mean fracture latency time extrapolated by videos were of 0.75 msec (bone), 1.5 msec (resin), 5.12 msec (foam) for human vaults and of 0.625 msec (bone), 1.87 msec (resin), 3.75 msec (foam) for swine vaults. These data showed that resin models are more similar to bone than foam reproductions, but that synthetic material may behave quite differently from bone as concerns fracture latency times.     

Case report: Forensic anthropological assessment in a suspected case of child abuse from South Africa

Not many case reports of suspected child abuse as assessed solely on skeletal remains are available. Forensic anthropologists have intimate knowledge of normal skeletal anatomy, bone trauma and processes of healing of bone and may therefore be of help in suspected cases of child abuse. Patterns of trauma in juvenile skeletal remains which are suggestive of abuse include fractures in different phases of healing, multiple fractures, typical fractures on ribs and long bones and severe, complicated cranial fractures. The aim of this paper is to report on the findings of the analysis of the skeletal remains of a 3.5 years old boy. Forensic pathological examination indicated that the boy had died from a massive cranial fracture, with multiple injuries present to the rest of the body. After the body had been buried for some time, it was exhumed and we were requested to look for signs of chronic, long-term abuse. Findings included a massive cranial fracture, another fracture in the roof of the orbit, two areas of non-specific subperiosteal bone growth and several untreated carious teeth. No clear healed fracture could be found, except for a possible healed cranial base fracture which stretched transversely across the petrosal bone. This area showed signs of recent bone activity. The court decided that this was not enough evidence of chronic abuse and found the accused guilty of murder but not of chronic child abuse. This case illustrates the difficulty to obtain clear signs of chronic injury on juvenile remains.     

Role of preoperative 3-dimensional computed tomography reconstruction in depressed skull fractures treated with craniectomy: a case report of forensic interest

Patients affected by cranial trauma with depressed skull fractures and increased intracranial pressure generally undergo neurosurgical intervention. Because craniotomy and craniectomy remove skull fragments and generate new fracture lines, they complicate forensic examination and sometimes prevent a clear identification of skull fracture etiology. A 3-dimensional reconstruction based on preoperative computed tomography (CT) scans, giving a picture of the injuries before surgical intervention, can help the forensic examiner in identifying skull fracture origin and the means of production.We report the case of a 41-year-old-man presenting at the emergency department with a depressed skull fracture at the vertex and bilateral subdural hemorrhage. The patient underwent 2 neurosurgical interventions (craniotomy and craniectomy) but died after 40 days of hospitalization in an intensive care unit. At autopsy, the absence of various bone fragments did not allow us to establish if the skull had been stricken by a blunt object or had hit the ground with high kinetic energy. To analyze bone injuries before craniectomy, a 3-dimensional CT reconstruction based on preoperative scans was performed. A comparative analysis between autoptic and radiological data allowed us to differentiate surgical from traumatic injuries. Moreover, based on the shape and size of the depressed skull fracture (measured from the CT reformations), we inferred that the man had been stricken by a cylindric blunt object with a diameter of about 3 cm.     

螺旋CT三维成像技术在疑难骨外伤中的应用价值

目的探讨螺旋CT(SCT)三维(3D)成像技术在法医疑难骨外伤中的诊断价值。方法选择11例骨外伤病人进行X线及螺旋CT3D检查,观察和分析骨折的位置、数量及性质。结果11例中,X线检查共发现肋骨骨折34处,肩胛骨骨折1处,鼻骨骨折2处,掌骨不完全性骨折1处,左胫、腓骨骨折1处,耻骨骨折1处。CT检查共发现肋骨骨折47处,肩胛骨粉碎性骨折1处,鼻骨骨折明显移位1处,排除骨折1处,上颌骨骨折1处,掌骨完全性骨折1处,左胫、腓骨陈旧性骨折1处,骶骼关节脱位1处,第5腰椎椎弓根骨折1处。结合三维图像,冠位状及矢位状重组图像清晰地显示出骨折线的部位、数量、性质和错位、复原等情况。结论螺旋CT三维成像应用对法医复杂骨外伤的客观诊断非常有效,优于常规X线检查。     

Healed fractures of the larynx and lingual bone in forensic autopsy]

Laryngohyoid fractures are a frequently investigated matter, especially in the forensic literature. On the other hand, there are only very few (old) forensic reports of such fractures in survived cases. However, healed fractures are not seldom found in forensic autopsies: In a personal series of 1160 forensic autopsies (adult persons) a careful dissection of the laryngohyoid complex was done by 1 investigator. Only a macroscopic examination of the cartilages was carried out; radiographs and histological slices were not regularly made. Therefore only a part of existing old fractures is detectable; for example, healed fissures are not visible with this simple method. Furthermore, asymmetries of the thyroid laminae cannot be declared as posttraumatic without additional examination, because this condition is described as possible anatomic anomaly. From that, the injury frequencies presented here only mark the lower threshold of the existence of such findings. Healed fractures of the upper thyroid horns and the major hyoid horns can be easily detected even in a routine examination, if healing resulted in a fixed dislocation or apposition of bone surrounding the former fracture site. In the present series, this was the predominant localization of old fractures: the upper thyroid horns (43 cases), followed by the hyoid cornua (12 cases), a combination of both sites (5) and cricoid fractures (5). Of the total 65 healed fractures (5.6%), 35 were found in the group of 290 chronic alcoholics (12.1%) and only 3.4% in non-alcoholics. In the subgroup of middle-aged alcoholics, the fracture rate increased up to 19%. However, this group did not present a higher rate of fresh laryngohyoid injuries (not related to strangulation) than the other cases. The old fractures probably resulted from minor "daily" injuries (like falls), which are common, especially in chronic alcoholics. The frequency of such findings should be in mind if an apparently fresh fracture, found in an actual autopsy, should be related to the cause of death: there is a real chance, that this fracture occurred prior, and without causal connection to the factors resulting in death. Therefore a histological examination of the age of this finding is necessary. Cricoid fractures are quite uncommon, except in serious external neck trauma. In 1 of our 5 cases, this fracture was caused by repeated cruelty, finally resulting in death.     

Structural analysis of human rib fracture and implications for forensic interpretation

Patterns of rib fractures are of significant clinical and forensic interest. Linking patterns of rib fracture with specific physical events provides a foundation for understanding the nature of traumatic events that are associated with rib fracture in forensic contexts. In this study, isolated human ribs (n = 8) were end-loaded to failure to investigate: (i) local deformations (bone strain) prior to and during structural failure, (ii) location of ultimate failure, and (iii) fracture mode. Structural properties of ribs were used to calculate theoretical stresses to determine whether such calculations could be used to predict site of fracture. Ribs fractured on the sternal side of midshaft in all experiments, but mode of failure varied with transverse, buckle, spiral, and "butterfly" fractures observed. Comparison of calculated stress with observed strain values suggest that experimental, rather than theoretical, approaches will be most productive in furthering understanding rib fracture in forensic contexts.     

Inadvertent clavicular fractures caused by "chiropractic" manipulations in an infant: an unusual form of pseudoabuse

A nine-month-old child was found unresponsive in his crib, five hours after his last feeding. At autopsy, there were no external or internal signs of abuse or neglect, and a few visceral pleural and epicardial petechiae were consistent with the sudden infant death syndrome (SIDS). However, postmortem total body radiographs revealed healing, symmetrical clavicular fractures and a healing left medial humeral epicondyle fracture. The parents had no explanation for these injuries and denied causing any harm to the child. The location and nature of the fractures strongly suggested abusive origin, and the case was reported to the police and the district attorney's office as child abuse. During the investigation, information from the parents indicated that the child had undergone "chiropractic" manipulations by an unlicensed therapist, between three and four weeks prior to death, to correct supposed "shoulder dislocations." This time interval correlated with the histologic age of the injuries, and the history explained their unusual bilateral location and appearance. The parents were exonerated of abuse charges, and the death was ascribed to SIDS.     

Sudden unexpected death in epilepsy: neuropathologic findings

Sudden unexpected death in epilepsy refers to sudden death of an individual with a clinical history of epilepsy, in whom a postmortem examination fails to uncover a gross anatomic, toxicologic, or environmental cause of death. Evidence of terminal seizure activity may not be present. One to two percent of natural deaths certified by the medicolegal death investigator are attributed to epilepsy. Detailed microscopic examination of the brain has increasingly afforded the identification of structural changes representative of epileptogenic foci. The authors present 70 cases of death attributed to sudden unexpected death in epilepsy. These cases were classified as follows: individuals who lacked a gross brain lesion, those who had a brain lesion demonstrable at autopsy, and those who lacked neuropathologic evaluation because of decomposition or because only an external examination was done. All of the subjects had a clinical history of seizures. The authors confirm that various microscopic findings, including neuronal clusters, increased perivascular oligodendroglia, gliosis, cystic gliotic lesions, decreased myelin, cerebellar Bergmann's gliosis, and folial atrophy, are present in a higher percentage of the brains of sudden unexpected death in epilepsy subjects than in the brains of age- and sex-matched control subjects.     

Punched with a fist: the etiology of a fatal depressed cranial fracture

We report a case in which a 33-year-old man was discovered unconscious following a fistfight with another man. Emergency neurosurgical efforts to repair a depressed temporoparietal skull fracture and associated brain injuries were unsuccessful. The forensic anthropologist and pathologist worked in tandem to sort out a complex combination of cranial evidence, including healed antemortem trauma, perimortem blunt force trauma, remote and recent neurosurgical intervention, and the craniotomy cut performed at autopsy. The victim had suffered head injuries and a right temporoparietal craniotomy ten years prior to death. The perimortem cranial fractures were centrally located within a surgically repaired roundel of bone involving portions of the right temporal and parietal bones. Reportedly, the victim was punched on the right side of his head as he was lying on the ground with the left side of his head against an asphalt surface. A primary question in the case was whether a blow with a fist could have produced the observed cranial injuries. To adequately answer that question, known data on the minimum amount of force required to fracture the temporoparietal region were compared to data on the amount of force generated by a blow with a fist. A biomechanics expert demonstrated that a single blow with a fist to the rigidly supported head of the victim could generate the required force to produce the observed fractures. The previous medical condition possibly predisposed the victim to the cranial fractures and contributed to the depressed nature of the fractures. Although depressed cranial fractures do not typically result from a blow with a fist, it was determined in this case that the fracture pattern was consistent with a punch to the head.     

Causes and Mechanisms of Death in Fatal Water Buffalo Attacks

Deaths due to buffalo attack have not been well described. A 72‐year‐old man was trampled by a water buffalo (Bubalus bubalis) while attempting to move the animal within an enclosed area at an abattoir. At autopsy, there were numerous injuries involving the chest, head, neck, and left upper arm. Blunt force injury had resulted in multiple rib fractures with a flail chest and fracture/dislocation of the mid‐cervical vertebrae caused either by physical crushing by the animal against the walls of the enclosure or by stomping. There was also evidence of crush asphyxia with bilateral conjunctival hemorrhages and petechial hemorrhages. In addition, there was a deep degloving injury of the upper left arm compatible with goring by one of the buffalo horns. While large animal attacks may result in death from multiple injuries, careful dissection and examination of specific injuries at autopsy may clarify the complex interaction of lethal mechanisms.     

Assessing Impact Direction in 3‐point Bending of Human Femora: Incomplete Butterfly Fractures and Fracture Surfaces,,

Current literature associates bending failure with butterfly fracture, in which fracture initiates transversely at the tensile surface of a bent bone and branches as it propagates toward the impact surface. The orientation of the resulting wedge fragment is often considered diagnostic of impact direction. However, experimental studies indicate bending does not always produce complete butterfly fractures or produces wedge fragments variably in tension or compression, precluding their use in interpreting directionality. This study reports results of experimental 3‐point bending tests on thirteen unembalmed human femora. Complete fracture patterns varied following bending failure, but incomplete fractures and fracture surface characteristics were observed in all impacted specimens. A flat, billowy fracture surface was observed in tension, while jagged, angular peaks were observed in compression. Impact direction was accurately reconstructed using incomplete tension wedge butterfly fractures and tension and compression fracture surface criteria in all thirteen specimens.     

Tongue bite injuries--a diagnostic criterium for death in epileptic seizure?

Bite marks of the tongue are often associated with epileptic seizures, although information about the real frequency of bite marks of the tongue is hard to find. This is also true for their presence in deaths of epileptics or in deaths in general. The purpose of this investigation was to analyze the frequency of bite marks of the tongue in deaths of epileptics in comparison to a control group. Further points of interest were the spectrum of the causes of death recorded, toxicological data as well as the presence and localization of external head injuries. The study group consisted of 105 individuals with a known history of epilepsy, the control group of 107 individuals with sudden cardiac death. Autopsy reports were analyzed retrospectively. In the first group bite marks of the tongue were seen in 21% (in the subgroup "observed death during seizure" even in 64%) and were thus significantly more frequent than in the control group (2%). In 35 cases of the study material an unnatural manner of death was found (trauma, especially craniocerebral trauma, drowning, asphyxia, intoxication) and in 70 cases a natural death was assumed. However, in 41 of these the exact cause of death was not ascertainable. According to the SUDEP criteria (Ficker 2000, Nilsson 1999) 29 of these cases could be categorized as possible or probable SUDEP (sudden unexpected death in epilepsy) with 17 showing bite marks of the tongue. The fact that half of the remaining 12 cases showed bite marks of the tongue suggests at least for these cases that death occurred during the seizure. Head injuries were reported in 41% of the epilepsy group--in the subgroup "observed death during seizure" in 73%. Our investigation did not produce evidence for a higher frequency of bite marks of the tongue in cases in which resuscitation had been attempted. In our experience the presence of fresh bite marks of the tongue--according to histological findings--is a useful signs for the assignment of death to an epileptic seizure and especially for death during acute convulsion.     

Morphological features of gunshot injuries of the cranial bones

Morphological characteristics of gunshot injuries of the cranial dome bones depend on bullet speed and are determined by various mechanisms of the harmful action. A contusion action of the bullet is characterized by disruption of the bone tissue with formation of linear or incomplete fracture. A wedged impact is accompanied with disruption of bone structures with formation of depressed or comminuted fractures due to radial dislocation of the fragments. A perforative impact produces a hole defect the shape of which depends on bullet speed. A bursting impact of the bullet causes disruption of the bone tissue outside the bullet defect as a result of an additional radial effect of high pressure of the air wave reaching in the wounds inflicted by high-speed bullets the effect of the hydrodynamic shock in the spongy layer of the flat bone. Resultant morphological manifestations are aggravated by damage caused by hydrodynamic shock coming from the cranial cavity.     

颅骨骨折断面细微结构的观察研究

作者利用扫描电子显微镜,对颅骨骨折断面上微细结构的形态学特征进行了观察与研究,发现在颅骨骨折断面上有微细的骨折裂线,向断面深部的骨质中延伸,其宽度为5至100um不等,主要分布在颅骨外板内,或外板与板障的交界处.分布于板障内的微细裂线可造成骨小梁横行、纵行和螺旋形骨折.骨折时,骨基质中的胶原纤维束可被分离或断裂,各胶原纤维层可分开.骨内血管可被骨折裂线横断或纵形撕裂,损伤的血管可被从哈佛氏管中拉出.生前骨折时,在微细裂线的深方可清楚见到纤维蛋白网和红细胞相互粘集,死后骨折则未见到此现象.本文还探讨了颅骨骨折发生的机理和推断生前骨折的可能性.     

122例鼻部骨折X线和CT诊断的法医学分析

目的　探讨CT在鼻部骨折诊断中的优点。方法　观察 12 2例鼻损伤伤者的鼻部CT和普通X线片 ,对鼻部诸骨骨折进行对比分析。结果　 12 2例鼻部骨折 (鼻骨骨折 3 2例 ,上颌骨额突骨折 3 3例 ,鼻中隔骨折 9例 ,多发性骨折 48例 )均经CT认定。其中 40例因X线片漏诊直接通过高分辨率鼻骨CT薄层扫描认定 ;82例通过鼻骨侧位X线片显示有鼻部骨折 ,因存在骨折类型认定不准确和 /或有漏诊鼻部其它部位骨折可能 ,通过鼻骨CT认定。结论　鼻骨侧位X线片易漏诊、误诊鼻部骨折 ;鼻骨CT能避免鼻部诸骨骨折的漏诊及误诊 ,且骨折认定准确。     

Rib fractures in infants due to cardiopulmonary resuscitation efforts

Although it is widely known that adults may sustain fractures of the anterior and/or lateral aspects of the ribs due to cardiopulmonary resuscitation (CPR) efforts, relatively little is written about the generation of CPR-related rib fractures in the infant age range. In a series of 70 consecutive autopsies in infants ranging in age from 2 weeks to 8 months, with no history or indications of injury, the parietal pleura of the thoracic cage was stripped and the ribs carefully examined for fracture. Subtle fractures of the anterolateral aspects of the ribs were discovered in 8 (11%) of the 70 cases. In 7 of the 8 cases, multiple ribs were fractured (ranging up to 10 rib fractures), and in 5 of these cases, the rib fractures were bilateral. All of the rib fractures were subtle, had little if any associated blood extravasation, and would have been easily missed had the parietal pleura not been stripped. These anterolateral rib fractures in infants are the likely correlate of anterolateral rib fractures that are not uncommonly seen in the adult population, resulting from resuscitation efforts. The rib fractures are subtle and may not be identified unless the parietal pleura is stripped.