Biomechanical Aspects of Odontoid Fracture Etiology: A Finite Element Investigation

1999 ◽  
Author(s):  
Christian M. Puttlitz ◽  
Vijay K. Goel ◽  
Charles R. Clark

Abstract Fractures of the odontoid process of the second cervical vertebra comprise 7–13% of all cervical spine fractures. Anderson and D’Alzono [1974] have classified these fractures into three categories: Type I, Type II, and Type III. Type I fractures are oblique, usually avulsion, fractures of the superior-most aspect of the odontoid. Type II fractures, the most commonly-occurring, are produced at the juxtaposition of the process and the C2 body. Type III fractures involve propagation of the fracture through the C2 body.

2021 ◽  
pp. 45-47
Author(s):  
B.D. B.S. Naik ◽  
M.V. Vijayasekhar ◽  
P Prahaladhu ◽  
K Satyavaraprasad ◽  
Nikhil Tadwalkar

Introduction- Odontoid fractures occur as a result of high impact trauma to the cervical spine. Hyperextension of the cervical spine is The most common mechanism of injury. Odontoid fractures occurs in 10 to 15% of all cervical spine fractures . Fracture of the odontoid process is classied into one of three types which are type I, type II, or type III fractures. Of all the types of odontoid fractures, type II is the most common and accounts for over 50% of all odontoid fractures . Materials and Methods- This is a prospective study conducted over 2 years in Neurosurgery Department, Andhra Medical College & King George Hospital, Visakhapatnam. Result: A total of 18 odontoid fractures were managed in the period of two years, out of which 2 were kept conservative and 16 were operated. Out of 16, 11were operated with odontoid screw and 2 underwent C1-C2 xation and 3 patients underwent Transoral Odontoidectomy with posterior occipito-cervical xation Conclusion: The treatment of odontoid fracture is complex and should be planned according to the type of odontoid fracture and neurological decit. Odontoid screw will sufce in patients with type II fracture with undisplaced fragments. Posterior C1-C2 xation is a better choice for complex odontoid fractures. Transoral odontoidectomy and occipito-cervical xation is reserved as the last option.


2000 ◽  
Vol 8 (6) ◽  
pp. 1-6 ◽  
Author(s):  
Terrence D. Julien ◽  
Bruce Frankel ◽  
Vincent C. Traynelis ◽  
Timothy C. Ryken

Object The management of odontoid fractures remains controversial. Evidence-based methodology was used to review the published data on odontoid fracture management to determine the state of the current practices reported in the literature. Methods The Medline literature (1966–1999) was searched using the keywords “odontoid,” “odontoid fracture,” and “cervical fracture” and graded using a four-tiered system. Those articles meeting selection criteria were divided in an attempt to formulate practice guidelines and standards or options for each fracture type. Evidentiary tables were constructed by treatment type. Ninety-five articles were reviewed. Five articles for Type I, 16 for Type II, and 14 for Type III odontoid fractures met selection criteria. All studies reviewed contained Class III data (American Medical Association data classification). Conclusions There is insufficient evidence to establish a standard or guideline for odontoid fracture management. Given the extent of Class III evidence and outcomes reported on Type I and Type III fractures, a well-designed case-controlled study would appear to provide sufficient evidence to establish a practice guideline, suggesting that cervical immobilization for 6 to 8 weeks is appropriate management. In cases of Type II fracture, analysis of the Class III evidence suggests that both operative and nonoperative management remain treatment options. A randomized trial or serial case-controlled studies will be required to establish either a guideline or treatment standard for this fracture type.


2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0017
Author(s):  
Scott M LaValva ◽  
Julien T Aoyama ◽  
Alexander J Adams ◽  
Sprikena Nako ◽  
R Justin Mistovich ◽  
...  

Background: Tibial spine fractures (TSFs) are intra-articular avulsion fractures of the intercondylar eminence which tend to afflict younger, skeletally immature patients. Given the relatively rare nature of these injuries, the epidemiology is not well-understood. There have been several estimates reported from single centers, though the potential for historical and regional variability in activities and risk factors limits the generalizability of their findings. Thus, the aim of the present investigation was to characterize the epidemiology of TSFs using pooled multicenter data. Hypothesis/Purpose: Report on the epidemiology of tibial spine fractures. Methods: This study was a retrospective analysis of patients with TSFs who were evaluated and treated at one of ten different sites across the United States. Information regarding patient demographics, injury mechanism, and imaging reports were collected. Fractures were classified according to the modified Meyers and McKeever method which groups the injuries as non-displaced (Type I), minimally displaced with an intact hinge (Type II), completely displaced (Type III), or completely displaced and comminuted (Type IV). Descriptive analyses were performed to evaluate the epidemiology of these fractures across the country. Results: We identified 469 patients (69% male; mean age 12.1 + 2.9 years) with TSFs over an eight-year period. 73% of patients were 14 years or younger. With respect to fracture severity, 5% of patients were Meyers and McKeever Type I, 35% Type II, and 50% Type III, and 10% Type IV. Overall, 60% of the fractures were completely displaced (Types III and IV). The most common mechanism of injury was a contact injury (48%), while 46% reported a non-contact twisting injury. With regard to activity at the time of injury, over half (53%) of patients were involved in sports and 14% of patients were biking recreationally. Less common causes included a fall from height (9%), motor vehicle accident (4%) recreational running (3%), and horseplay (3%). Of those injured playing sports, football (35%), skiing (21%), basketball (10%), and soccer (10%) accounted for almost 80% of the injuries in this cohort. Conclusion: Ultimately, our study represents the first multicenter analysis of the epidemiology of tibial spine fractures. The patient demographics and mechanism of injury for these injuries appears relatively consistent across geographic distributions. However, the recent rise in youth sports participation, single sport specialization, and year-round play in pediatric athletes appears to have generated a new principal risk factor for this injury in sports participation as opposed to the historically-described biking accidents. [Table: see text][Figure: see text]


Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.


2021 ◽  
Author(s):  
Timothy J Yee ◽  
Michael J Strong ◽  
Matthew S Willsey ◽  
Mark E Oppenlander

Abstract Nonunion of a type II odontoid fracture after the placement of an anterior odontoid screw can occur despite careful patient selection. Countervailing factors to successful fusion include the vascular watershed zone between the odontoid process and body of C2 as well as the relatively low surface area available for fusion. Patient-specific factors include osteoporosis, advanced age, and poor fracture fragment apposition. Cervical 1-2 posterior instrumented fusion is indicated for symptomatic nonunion. The technique leverages the larger posterolateral surface area for fusion and does not rely on bony growth in a watershed zone. Although loss of up to half of cervical rotation is expected after C1-2 arthrodesis, this may be better tolerated in the elderly, who may have lower physical demands than younger patients. In this video, we discuss the case of a 75-yr-old woman presenting with intractable mechanical cervicalgia 7 mo after sustaining a type II odontoid fracture and undergoing anterior odontoid screw placement at an outside institution. Cervical radiography and computed tomography exhibited haloing around the screw and nonunion across the fracture. We demonstrate C1-2 posterior instrumented fusion with Goel-Harms technique (C1 lateral mass and C2 pedicle screws), utilizing computer-assisted navigation, and modified Sonntag technique with rib strut autograft.  Posterior C1-2-instrumented fusion with rib strut autograft is an essential technique in the spine surgeon's armamentarium for the management of C1-2 instability, which can be a sequela of type II dens fracture. Detailed video demonstration has not been published to date.  Appropriate patient consent was obtained.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chen Li ◽  
Ao-Fei Liu ◽  
Han-Cheng Qiu ◽  
Xianli Lv ◽  
Ji Zhou ◽  
...  

Abstract Background Treatment of perforator involving aneurysm (piAN) remains a challenge to open and endovascular neurosurgeons. Our aim is to demonstrate a primary outcome of endovascular therapy for piANs with the use of perforator preservation technologies (PPT) based on a new neuro-interventional classification. Methods The piANs were classified into type I: aneurysm really arises from perforating artery, type II: saccular aneurysm involves perforating arteries arising from its neck (IIa) or dome (IIb), and type III: fusiform aneurysm involves perforating artery. Stent protection technology of PPT was applied in type I and III aneurysms, and coil-basket protection technology in type II aneurysms. An immediate outcome of aneurysmal obliteration after treatment was evaluated (satisfactory obliteration: the saccular aneurysm body is densely embolized (I), leaving a gap in the neck (IIa) or dome (IIb) where the perforating artery arising; fusiform aneurysm is repaired and has a smooth inner wall), and successful perforating artery preservation was defined as keeping the good antegrade flow of those perforators on postoperative angiography. The periprocedural complication was closely monitored, and clinical and angiographic follow-ups were performed. Results Six consecutive piANs (2 ruptured and 4 unruptured; 1 type I, 2 type IIa, 2 type IIb, and 1 type III) in 6 patients (aged from 43 to 66 years; 3 males) underwent endovascular therapy between November 2017 and July 2019. The immediate angiography after treatment showed 6 aneurysms obtained satisfactory obliteration, and all of their perforating arteries were successfully preserved. During clinical follow-up of 13–50 months, no ischemic or hemorrhagic event of the brain occurred in the 6 patients, but has one who developed ischemic event in the territory of involving perforators 4 h after operation and completely resolved within 24 h. Follow-up angiography at 3 to 10M showed patency of the parent artery and perforating arteries of treated aneurysms, with no aneurysmal recurrence. Conclusions Our perforator preservation technologies on the basis of the new neuro-interventional classification seem feasible, safe, and effective in protecting involved perforators while occluding aneurysm.


2021 ◽  
Vol 22 (1) ◽  
pp. 429
Author(s):  
Luca Bini ◽  
Domitille Schvartz ◽  
Chiara Carnemolla ◽  
Roberta Besio ◽  
Nadia Garibaldi ◽  
...  

Osteogenesis imperfecta (OI) is a heritable disorder that mainly affects the skeleton. The inheritance is mostly autosomal dominant and associated to mutations in one of the two genes, COL1A1 and COL1A2, encoding for the type I collagen α chains. According to more than 1500 described mutation sites and to outcome spanning from very mild cases to perinatal-lethality, OI is characterized by a wide genotype/phenotype heterogeneity. In order to identify common affected molecular-pathways and disease biomarkers in OI probands with different mutations and lethal or surviving phenotypes, primary fibroblasts from dominant OI patients, carrying COL1A1 or COL1A2 defects, were investigated by applying a Tandem Mass Tag labeling-Liquid Chromatography-Tandem Mass Spectrometry (TMT LC-MS/MS) proteomics approach and bioinformatic tools for comparative protein-abundance profiling. While no difference in α1 or α2 abundance was detected among lethal (type II) and not-lethal (type III) OI patients, 17 proteins, with key effects on matrix structure and organization, cell signaling, and cell and tissue development and differentiation, were significantly different between type II and type III OI patients. Among them, some non–collagenous extracellular matrix (ECM) proteins (e.g., decorin and fibrillin-1) and proteins modulating cytoskeleton (e.g., nestin and palladin) directly correlate to the severity of the disease. Their defective presence may define proband-failure in balancing aberrances related to mutant collagen.


2020 ◽  
pp. 1-15
Author(s):  
Zhiwei Yuan ◽  
Wen Guo ◽  
Dan Lyu ◽  
Yuanlin Sun

Abstract The filter-feeding organ of some extinct brachiopods is supported by a skeletal apparatus called the brachidium. Although relatively well studied in Atrypida and Athyridida, the brachidial morphology is usually neglected in Spiriferida. To investigate the variations of brachidial morphology in Spiriferida, 65 species belonging to eight superfamilies were analyzed. Based on the presence/absence of the jugal processes and normal/modified primary lamellae of the spiralia, four types of brachidium are recognized. Type-I (with jugal processes) and Type-II (without jugal processes), both having normal primary lamellae, could give rise to each other by losing/re-evolving the jugal processes. Type-III, without jugal processes, originated from Type-II through evolution of the modified lateral-convex primary lamellae, and it subsequently gave rise to Type-IV by evolving the modified medial-convex primary lamellae. The evolution of brachidia within individual evolutionary lineages must be clarified because two or more types can be present within a single family. Type-III and Type-IV are closely associated with the prolongation of the crura, representing innovative modifications of the feeding apparatus in response to possible shift in the position of the mouth towards the anterior, allowing for more efficient feeding on particles entering the mantle cavity from the anterior gape. Meanwhile, the modified primary lamellae adjusted/regulated the feeding currents. The absence of spires in some taxa with Type-IV brachidium might suggest that they developed a similar lophophore to that in some extant brachiopods, which can extend out of the shell.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1080
Author(s):  
Min Zhao ◽  
Zhenbo Ning ◽  
Baicun Wang ◽  
Chen Peng ◽  
Xingyu Li ◽  
...  

The evolution and application of intelligence have been discussed from perspectives of life, control theory and artificial intelligence. However, there has been no consensus on understanding the evolution of intelligence. In this study, we propose a Tri-X Intelligence (TI) model, aimed at providing a comprehensive perspective to understand complex intelligence and the implementation of intelligent systems. In this work, the essence and evolution of intelligent systems (or system intelligentization) are analyzed and discussed from multiple perspectives and at different stages (Type I, Type II and Type III), based on a Tri-X Intelligence model. Elemental intelligence based on scientific effects (e.g., conscious humans, cyber entities and physical objects) is at the primitive level of intelligence (Type I). Integrated intelligence formed by two-element integration (e.g., human-cyber systems and cyber-physical systems) is at the normal level of intelligence (Type II). Complex intelligence formed by ternary-interaction (e.g., a human-cyber-physical system) is at the dynamic level of intelligence (Type III). Representative cases are analyzed to deepen the understanding of intelligent systems and their future implementation, such as in intelligent manufacturing. This work provides a systematic scheme, and technical supports, to understand and develop intelligent systems.


Zootaxa ◽  
2020 ◽  
Vol 4834 (4) ◽  
pp. 451-501
Author(s):  
DOMINIQUE PLUOT-SIGWALT ◽  
PIERRE MOULET

The morphology of the spermatheca is described in 109 species of 86 genera representing all four currently recognised subfamilies of Coreidae, covering the undivided Hydarinae, both tribes of Pseudophloeinae, all three tribes of Meropachyinae and 27 of the 32 tribes of Coreinae. Three types of spermatheca are recognised. Type I is bipartite, consisting only of a simple tube differentiated into distal seminal receptacle and proximal spermathecal duct and lacks the intermediate part present in most Pentatomomorpha, in which it serves as muscular pump. Type II is also bipartite but more elaborate in form with the receptacle generally distinctly wider than the duct. Type III is tripartite, with receptacle, duct and an often complex intermediate part. Four subtypes are recognised within type III. Type I is found only in Hydarinae and type II only in Pseudophloeinae. Type III is found in both Coreinae and Meropachyinae. Subtype IIIA (“Coreus-group”) unites many tribes from the Eastern Hemisphere and only one (Spartocerini) from the Western Hemisphere. Subtypes IIIB (“Nematopus-group”) and IIID (“Anisoscelis-group”) are confined to taxa from the Western Hemisphere and subtype IIIC (“Chariesterus-group”) is found in tribes from both hemispheres. The polarity of several characters of the intermediate part and some of the spermathecal duct is evaluated, suggesting autapomorphies or apomorphies potentially relevant to the classification of Coreidae at the sufamilial and tribal levels. Characters of the intermediate part strongly indicate that the separation of Meropachyinae and Coreinae as currently constituted cannot be substantiated. The tribes Anisoscelini, Colpurini, Daladerini and Hyselonotini are heterogeneous, each exhibiting two subtypes of spermatheca, and probably polyphyletic. Two tribes, Cloresmini and Colpurini, requiring further investigation remain unplaced. This study demonstrates the great importance of characters of the spermatheca, in particular its intermediate part, for research into the phylogeny and taxonomy of Pentatomomorpha. 


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