scholarly journals The Comprehensive AO CMF Classification System for Mandibular Fractures: A Multicenter Validation Study

2019 ◽  
Vol 12 (4) ◽  
pp. 254-265 ◽  
Author(s):  
Paul A. Mittermiller ◽  
Serena S. Bidwell ◽  
Florian M. Thieringer ◽  
Carl-Peter Cornelius ◽  
Amber W. Trickey ◽  
...  
Keyword(s):  
Classification System ◽  
Interobserver Reliability ◽  
Fracture Morphology ◽  
Mandibular Fractures ◽  
Condylar Process ◽  
Accuracy Study ◽  
Level 3 ◽  
Comprehensive Classification ◽  
Level 2 ◽  
Condylar Neck

The AO CMF has recently launched the first comprehensive classification system for craniomaxillofacial (CMF) fractures. The AO CMF classification system uses a hierarchical framework with three levels of growing complexity (levels 1, 2, and 3). Level 1 of the system identifies the presence of fractures in four anatomic areas (mandible, midface, skull base, and cranial vault). Level 2 variables describe the location of the fractures within those defined areas. Level 3 variables describe details of fracture morphology such as fragmentation, displacement, and dislocation. This multiplanar radiographic image-based AO CMF trauma classification system is constantly evolving and beginning to enter worldwide application. A validation of the system is mandatory prior to a reliable communication and data processing in clinical and research environments. This interobserver reliability and accuracy study is aiming to validate the three current modules of the AO CMF classification system for mandible trauma in adults. To assess the performance of the system at the different precision levels, it focuses on the fracture location within the mandibular regions and condylar process subregions as core components giving only secondary attention to morphologic variables. A total of 15 subjects individually assigned the location and features of mandibular fractures in 200 CT scans using the AO CMF classification system. The results of these ratings were then statistically evaluated for interobserver reliability by Fleiss’ kappa and accuracy by percentage agreement with an experienced reference assessor. The scores were used to determine if the variables of levels 2 and 3 were appropriate tools for valid classification. Interobserver reliability and accuracy were compared by hierarchy of variables (level 2 vs. level 3), by anatomical region and subregion, and by assessor experience level using Kruskal-Wallis and Wilcoxon's rank-sum tests. The AO CMF classification system was determined to be reliable and accurate for classifying mandibular fractures for most levels 2 and 3 variables. Level 2 variables had significantly higher interobserver reliability than level 3 variables (median kappa: 0.69 vs. 0.59, p < 0.001) as well as higher accuracy (median agreement: 94 vs. 91%, p < 0.001). Accuracy was adequate for most variables, but lower reliability was observed for condylar head fractures, fragmentation of condylar neck fractures, displacement types and direction of the condylar process overall, as well as the condylar neck and base fractures. Assessors with more clinical experience demonstrated higher reliability (median kappa high experience 0.66 vs. medium 0.59 vs. low 0.48, p < 0.001). Assessors with experience using the classification software also had higher reliability than their less experienced counterparts (median kappa: 0.76 vs. 0.57, p < 0.001). At present, the AO CMF classification system for mandibular fractures is suited for both clinical and research settings for level 2 variables. Accuracy and reliability decrease for level 3 variables specifically concerning fractures and displacement of condylar process fractures. This will require further investigation into why these fractures were characterized unreliably, which would guide modifications of the system and future instructions for its usage.

scholarly journals The Comprehensive AOCMF Classification: Skull Base and Cranial Vault Fractures — Level 2 and 3 Tutorial

2014 ◽  
Vol 7 (1_suppl) ◽  
pp. 103-113 ◽  
Author(s):  
Antonio Di Ieva ◽  
Laurent Audigé ◽  
Robert M. Kellman ◽  
Kevin A. Shumrick ◽  
Helmut Ringl ◽  
...  
Keyword(s):  
Skull Base ◽  
Classification System ◽  
Fracture Morphology ◽  
Cranial Vault ◽  
Diagnostic Features ◽  
Base Surface ◽  
Case Examples ◽  
Fracture Location ◽  
Level 3 ◽  
Level 2

The AOCMF Classification Group developed a hierarchical three-level craniomaxillofacial classification system with increasing level of complexity and details. The highest level 1 system distinguish four major anatomical units, including the mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94). This tutorial presents the level 2 and more detailed level 3 systems for the skull base and cranial vault units. The level 2 system describes fracture location outlining the topographic boundaries of the anatomic regions, considering in particular the endocranial and exocranial skull base surfaces. The endocranial skull base is divided into nine regions; a central skull base adjoining a left and right side are divided into the anterior, middle, and posterior skull base. The exocranial skull base surface and cranial vault are divided in regions defined by the names of the bones involved: frontal, parietal, temporal, sphenoid, and occipital bones. The level 3 system allows assessing fracture morphology described by the presence of fracture fragmentation, displacement, and bone loss. A documentation of associated intracranial diagnostic features is proposed. This tutorial is organized in a sequence of sections dealing with the description of the classification system with illustrations of the topographical skull base and cranial vault regions along with rules for fracture location and coding, a series of case examples with clinical imaging and a general discussion on the design of this classification.

scholarly journals The Comprehensive AOCMF Classification System: Classification and Documentation within AOCOIAC Software

2014 ◽  
Vol 7 (1_suppl) ◽  
pp. 114-122 ◽  
Author(s):  
Laurent Audigé ◽  
Carl-Peter Cornelius ◽  
Christoph Kunz ◽  
Carlos H. Buitrago-Téllez ◽  
Joachim Prein
Keyword(s):  
Classification System ◽  
Fracture Morphology ◽  
Illustrative Case ◽  
Clinical Documentation ◽  
Fracture Classification ◽  
Anatomical Structures ◽  
Case Examples ◽  
Level 3 ◽  
Level 1 ◽  
Level 2

The AOCMF Classification Group developed a hierarchical three-level craniomaxillofacial (CMF) fracture classification system. The fundamental level 1 distinguishes four major anatomical units including the mandible (code 91), midface (code 92), skull base (code 93) and cranial vault (code 94); level 2 relates to the location of the fractures within defined topographical regions within each units; level 3 relates to fracture morphology in these regions regarding fragmentation, displacement, and bone defects, as well as the involvement of specific anatomical structures. The resulting CMF classification system has been implemented into AO comprehensive injury automatic classifier (AOCOIAC) software allowing for fracture classification as well as clinical documentation of individual cases including a selected sample of diagnostic images. This tutorial highlights the main features of the software. In addition, a series of illustrative case examples is made available electronically for viewing and editing.

scholarly journals The Comprehensive AOCMF Classification System: Condylar Process Fractures - Level 3 Tutorial

2014 ◽  
Vol 7 (1_suppl) ◽  
pp. 44-58 ◽  
Author(s):  
Andreas Neff ◽  
Carl-Peter Cornelius ◽  
Michael Rasse ◽  
DanielDalla Torre ◽  
Laurent Audigé
Keyword(s):  
Classification System ◽  
Fracture Pattern ◽  
Fracture Site ◽  
Classification Systems ◽  
Head Region ◽  
Condylar Process ◽  
Level 3 ◽  
Condylar Head ◽  
Ramus Height ◽  
Condylar Neck

This tutorial outlines the detailed system for fractures of the condylar process at the precision level 3 and is organized in a sequence of sections dealing with the description of the classification system within topographical subdivisions along with rules for fracture coding and a series of case examples with clinical imaging. Basically, the condylar process comprises three fracture levels and is subdivided into the head region, the condylar neck, and the condylar base. Fractures of the condylar head show typical fracture lines either within the lateral pole zone, which may lead to loss of vertical height, or medially to the pole zone, with the latter ones usually not compromising the vertical condyle to fossa relation. In condylar head fractures, the morphology is further described by the presence of minor or major fragmentation, the vertical apposition of fragments at the plane of the head fracture, the displacement of the condylar head with regard to the fossa including a potential distortion of the condylar head congruency resulting in dystopic condyle to fossa relations and the presence or absence of a loss of vertical ramus height. A specific vertical fracture pattern extending from the head to the neck or base subregion is considered. Fractures of the condylar neck and base can be differentiated according to a newly introduced one-third to two-thirds rule with regard to the proportion of the fracture line above and below the level of the sigmoid notch, which is presented in the classification article, and are basically subdivided according to the presence or absence of displacement or dislocation. In both condylar neck and base fractures, the classification is again based on the above mentioned parameters such as fragmentation, displacement of the condylar head with regard to the fossa, including dystopic condyle to fossa relations and loss of vertical ramus height, that is, according to the measurement of the condylar process. In addition, the classification assesses a sideward displacement including the respective displacement sector at the neck or base fracture site as well as the angulation of the superior main fragment and also considers a potential displacement of the caudal fragment with regard to the fossa, which may occur in fractures affecting additional fracture locations in the mandible. The design of this classification is discussed along with a review of existing classification systems. The condylar process for fracture location was defined according to the level 2 system presented in a previous tutorial in this special issue.

scholarly journals The Comprehensive AOCMF Classification System: Midface Fractures - Level 2 Tutorial

2014 ◽  
Vol 7 (1_suppl) ◽  
pp. 59-67 ◽  
Author(s):  
Christoph Kunz ◽  
Laurent Audigé ◽  
Carl-Peter Cornelius ◽  
Carlos H. Buitrago-Téllez ◽  
John Frodel ◽  
...  
Keyword(s):  
Classification System ◽  
En Bloc ◽  
Case Examples ◽  
Fracture Location ◽  
Midface Fracture ◽  
Level 3 ◽  
The Common ◽  
Fracture Mapping ◽  
Le Fort Classification ◽  
Level 2

The AOCMF Classification Group developed a hierarchical three-level craniomaxillofacial classification system with increasing level of complexity and details. The highest level 1 system distinguish four major anatomical units including the mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94). This tutorial presents the level 2 system for the midface unit that concentrates on the location of the fractures within defined regions in the central (upper, intermediate, and lower) and lateral (zygoma, pterygoid) midface, as well as the internal orbit and palate. The level 2 midface fracture location outlines the topographic boundaries of the anatomical regions. The common nasoorbitoethmoidal and zygoma en bloc fracture patterns, as well as the time-honored Le Fort classification are taken into account. This tutorial is organized in a sequence of sections dealing with the description of the classification system with illustrations of the topographical cranial midface regions along with rules for fracture location and coding, a series of case examples with clinical imaging and a general discussion on the design of this classification. Individual fracture mapping in these regions regarding severity, fragmentation, displacement of the fragment or bone defect is addressed in a more detailed level 3 system in the subsequent articles.

Comprehensive classification system for multirod constructs across three-column osteotomies: a reliability study

2021 ◽  
Vol 34 (1) ◽  
pp. 103-109
Author(s):  
Mostafa H. El Dafrawy ◽  
Owoicho Adogwa ◽  
Adam M. Wegner ◽  
Nicholas A. Pallotta ◽  
Michael P. Kelly ◽  
...  
Keyword(s):  
Classification System ◽  
Interobserver Reliability ◽  
Kappa Coefficient ◽  
Intraobserver Reliability ◽  
Osteotomy Site ◽  
New Classification ◽  
Good Reliability ◽  
Kappa Value ◽  
Comprehensive Classification ◽  
High Degree

OBJECTIVEIn this study, the authors’ goal was to determine the intra- and interobserver reliability of a new classification system that allows the description of all possible constructs used across three-column osteotomies (3COs) in terms of rod configuration and density.METHODSThirty-five patients with multirod constructs (MRCs) across a 3CO were classified by two spinal surgery fellows according to the new system, and then were reclassified 2 weeks later. Constructs were classified as follows: the number of rods across the osteotomy site followed by a letter corresponding to the type of rod configuration: “M” is for a main rod configuration, defined as a single rod spanning the osteotomy. “L” is for linked rod configurations, defined as 2 rods directly connected to each other at the osteotomy site. “S” is for satellite rod configurations, which were defined as a short rod independent of the main rod with anchors above and below the 3CO. “A” is for accessory rods, defined as an additional rod across the 3CO attached to main rods but not attached to any anchors across the osteotomy site. “I” is for intercalary rod configurations, defined as a rod connecting 2 separate constructs across the 3CO, without the intercalary rod itself attached to any anchors across the osteotomy site. The intra- and interobserver reliability of this classification system was determined.RESULTSA sample estimation for validation assuming two readers and 35 subjects results in a two-sided 95% confidence interval with a width of 0.19 and a kappa value of 0.8 (SD 0.3). The Fleiss kappa coefficient (κ) was used to calculate the degree of agreement between interrater and intraobserver reliability. The interrater kappa coefficient was 0.3, and the intrarater kappa coefficient was 0.63 (good reliability). This scenario represents a high degree of agreement despite a low kappa coefficient. Correct observations by both observers were 34 of 35 and 33 of 35 at both time points. Misclassification was related to difficulty in determining connectors versus anchors.CONCLUSIONSMRCs across 3COs have variable rod configurations. Currently, no classification system or agreement on nomenclature exists to define the configuration of rods across 3COs. The authors present a new, comprehensive MRC classification system with good inter- and intraobserver reliability and a high degree of agreement that allows for a standardized description of MRCs across 3COs.

Reliability and application of the new morphological classification system for chronic symptomatic osteoporotic thoracolumbar fracture

2020 ◽  
Author(s):  
Ding-Jun Hao ◽  
Jun-Song Yang ◽  
Yuan Tuo ◽  
Chao-Yuan Ge ◽  
Bao-Rong He ◽  
...  
Keyword(s):  
Classification System ◽  
Dynamic Instability ◽  
Interobserver Reliability ◽  
Fracture Morphology ◽  
Thoracolumbar Fracture ◽  
Initial Assessment ◽  
Imaging Data ◽  
New Classification ◽  
Wide Clinical Application ◽  
Standard Classification

Abstract ObjectiveThis study proposed a new classification system for Chronic Symptomatic Osteoporotic Thoracolumbar Fracture (CSOTF) based on fracture morphology. Research on CSOTF has increased in recent years. However, the lack of a standard classification system has resulted in inconveniences regarding communication, research and treatment. Previous studies of CSOTF classification exhibit different defects, and none of these studies are widely accepted.MethodsWe collected 368 cases of CSOTF in our hospital from January 2010 to June 2017 and systematically analyzed the imaging data of all patients to develop a classification system. Imaging examinations included dynamic radiography, computed tomography scans and magnetic resonance imaging. Ten investigators systematically studied and fully understood the classification system grading 40 cases on two occasions, examined 1 month apart. Kappa coefficients (κ) were calculated to determine intraobserver and interobserver reliability.ResultsThe new classification system for CSOTF was divided into types I-V according to whether the CSOTF exhibited dynamic instability, spinal stenosis or kyphosis deformity. Intra- and interobserver reliability were excellent for all types (κ = 0.83 and 0.85, respectively).ConclusionsThe new classification system for CSOTF demonstrated excellent reliability in this initial assessment. The system is convenient for communication and research, but wide clinical application are needed to confirm its effectiveness and guide clinical treatment.

scholarly journals The Comprehensive AOCMF Classification System: Mandible Fractures- Level 2 Tutorial

2014 ◽  
Vol 7 (1_suppl) ◽  
pp. 15-30 ◽  
Author(s):  
Carl-Peter Cornelius ◽  
Laurent Audigté ◽  
Christoph Kunz ◽  
Randal Rudderman ◽  
Carlos H. Buitrago-Téllez ◽  
...  
Keyword(s):  
Classification System ◽  
Lateral Side ◽  
Mandibular Fractures ◽  
Daily Routine ◽  
Case Examples ◽  
Body Regions ◽  
Topographical Distribution ◽  
Definition Of ◽  
Mandible Fractures ◽  
Level 2

This tutorial outlines the details of the AOCMF image-based classification system for fractures of the mandible at the precision level 2 allowing description of their topographical distribution. A short introduction about the anatomy is made. Mandibular fractures are classified by the anatomic regions involved. For this purpose, the mandible is delineated into an array of nine regions identified by letters: the symphysis/parasymphysis region anteriorly, two body regions on each lateral side, combined angle and ascending ramus regions, and finally the condylar and coronoid processes. A precise definition of the demarcation lines between these regions is given for the unambiguous allocation of fractures. Four transition zones allow an accurate topographic assignment if fractures end up in or run across the borders of anatomic regions. These zones are defined between angle/ramus and body, and between body and symphysis/parasymphysis. A fracture is classified as “confined” as long as it is located within a region, in contrast to a fracture being “nonconfined” when it extents to an adjoining region. Illustrations and case examples of mandible fractures are presented to become familiar with the classification procedure in daily routine.

scholarly journals The Influence of Regional Differences on the Reliability of the AO Spine Sacral Injury Classification System

2022 ◽  
pp. 219256822110684
Author(s):  
Brian A. Karamian ◽  
Gregory D. Schroeder ◽  
Mark J. Lambrechts ◽  
Jose A. Canseco ◽  
Emiliano N. Vialle ◽  
...  
Keyword(s):  
North America ◽  
South America ◽  
Classification System ◽  
Interobserver Reliability ◽  
Fracture Morphology ◽  
Geographic Region ◽  
Cross Sectional Survey ◽  
Standard Type ◽  
Cross Sectional ◽  
Type C

Study Design Global cross-sectional survey. Objective To explore the influence of geographic region on the AO Spine Sacral Classification System. Methods A total of 158 AO Spine and AO Trauma members from 6 AO world regions (Africa, Asia, Europe, Latin and South America, Middle East, and North America) participated in a live webinar to assess the reliability, reproducibility, and accuracy of classifying sacral fractures using the AO Spine Sacral Classification System. This evaluation was performed with 26 cases presented in randomized order on 2 occasions 3 weeks apart. Results A total of 8320 case assessments were performed. All regions demonstrated excellent intraobserver reproducibility for fracture morphology. Respondents from Europe (k = .80) and North America (k = .86) achieved excellent reproducibility for fracture subtype while respondents from all other regions displayed substantial reproducibility. All regions demonstrated at minimum substantial interobserver reliability for fracture morphology and subtype. Each region demonstrated >90% accuracy in classifying fracture morphology and >80% accuracy in fracture subtype compared to the gold standard. Type C morphology (p2 = .0000) and A3 (p1 = .0280), B2 (p1 = .0015), C0 (p1 = .0085), and C2 (p1 =.0016, p2 =.0000) subtypes showed significant regional disparity in classification accuracy (p1 = Assessment 1, p2 = Assessment 2). Respondents from Asia (except in A3) and the combined group of North, Latin, and South America had accuracy percentages below the combined mean, whereas respondents from Europe consistently scored above the mean. Conclusions In a global validation study of the AO Spine Sacral Classification System, substantial reliability of both fracture morphology and subtype classification was found across all geographic regions.

scholarly journals The Comprehensive AOCMF Classification System: Midface Fractures - Level 3 Tutorial

2014 ◽  
Vol 7 (1_suppl) ◽  
pp. 68-91 ◽  
Author(s):  
Carl-Peter Cornelius ◽  
Laurent Audigé ◽  
Christoph Kunz ◽  
Carlos H. Buitrago-Téllez ◽  
Randal Rudderman ◽  
...  
Keyword(s):  
Classification System ◽  
Critical Appraisal ◽  
Structural Layout ◽  
Midface Fractures ◽  
Precision Level ◽  
Level 3 ◽  
Set Up ◽  
Fracture Types ◽  
Coding Rules ◽  
Level 2

This tutorial outlines the details of the AOCMF image-based classification system for fractures of the midface at the precision level 3. The topography of the different midface regions (central midface—upper central midface, intermediate central midface, lower central midface—incorporating the naso-orbito-ethmoid region; lateral midface—zygoma and zygomatic arch, palate) is subdivided in much greater detail than in level 2 going beyond the Le Fort fracture types and its analogs. The level 3 midface classification system is presented along with guidelines to precisely delineate the fracture patterns in these specific subregions. It is easy to plot common fracture entities, such as nasal and naso-orbito-ethmoid, and their variants due to the refined structural layout of the subregions. As a key attribute, this focused approach permits to document the occurrence of fragmentation (i.e., single vs. multiple fracture lines), displacement, and bone loss. Moreover, the preinjury dental state and the degree of alveolar atrophy in edentulous maxillary regions can be recorded. On the basis of these individual features, tooth injuries, periodontal trauma, and fracture involvement of the alveolar process can be assessed. Coding rules are given to set up a distinctive formula for typical midface fractures and their combinations. The instructions and illustrations are elucidated by a series of radiographic imaging examples. A critical appraisal of the design of this level 3 midface classification is made.

scholarly journals The Comprehensive AOCMF Classification System: Orbital Fractures - Level 3 Tutorial

2014 ◽  
Vol 7 (1_suppl) ◽  
pp. 92-102 ◽  
Author(s):  
Christoph Kunz ◽  
Laurent Audigé ◽  
Carl-Peter Cornelius ◽  
Carlos H. Buitrago-Téllez ◽  
Randal Rudderman ◽  
...  
Keyword(s):  
Classification System ◽  
Orbital Fractures ◽  
Superior Orbital Fissure ◽  
Case Examples ◽  
Detailed Classification ◽  
Level 3 ◽  
Lacrimal Bone ◽  
Level 1 ◽  
Level 2 ◽  
Inferior Orbital Fissure

The AOCMF Classification Group developed a hierarchical three-level craniomaxillofacial classification system with increasing level of complexity and details. Within the midface (level 1 code 92), the level 2 system describes the location of the fractures within defined regions in the central and lateral midface including the internal orbit. This tutorial outlines the level 3 detailed classification system for fractures of the orbit. It depicts the orbital fractures according to the subregions defined as orbital rims, anterior orbital walls, midorbit, and apex. The system allows documentation of the involvement of specific orbital structures such as inferior orbital fissure, internal orbital buttress, the greater wing of sphenoid, lacrimal bone, superior orbital fissure, and optic canal. The classification system is presented along with rules for fracture location and coding, a series of case examples with clinical imaging and a general discussion on the design of this classification.

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