scapula fracture classification system - Kreiskrankenhaus Mechernich

J Shoulder Elbow Surg (2013) 22, 512-520 

www.elsevier.com/locate/ymse 

The AO Foundation and Orthopaedic Trauma Association 

(AO/OTA) scapula fracture classification system: focus 

on glenoid fossa involvement 

Martin Jaeger, MD a , Simon Lambert, FRCSEd(Orth) b , Norbert P. S€udkamp, MD a , 

James F. Kellam, MD c , Jan Erik Madsen, MD d , Reto Babst, MD e , Jonas Andermahr, MD f , 

Wilson Li, MD g , Laurent Audige, PhD h, * 

a Department of Orthop€adie und Traumatologie, Universit€atsklinikum Freiburg, Albert-Ludwigs-Universit€at, Freiburg, 

Germany 

b Shoulder and Elbow Service, The Royal National Orthopaedic Hospital, Stanmore, UK 

c Department of Orthopaedic Surgery, Carolinas Medical Center, Charlotte, NC, USA 

d Orthopaedic Department, Oslo University Hospital, Ullevaal, Norway 

e Klinik f€ur Unfallchirurgie, Luzerner Kantonsspital, Luzern, Switzerland 

f Department for Orthopedic and Trauma Surgery, Hospital of the University of Bonn, Mechernich, Germany 

g Department of Orthopaedics & Traumatology, Queen Elizabeth Hospital, Kowloon, Hong Kong 

h AO Clinical Investigation and Documentation, D€ubendorf, Switzerland 

Background: Fractures of the glenoid frequently require surgical treatment. A comprehensive and reliable 

scapula classification system involving the glenoid fracture patterns is needed to describe the underlying 

pathology. The AO Scapula Classification Group introduces an appropriate novel system that is presented 

along with its inter-rater reliability and accuracy. 

Materials and methods: An iterative consensus process (involving a series of face-to-face meetings and 

agreement studies) with an international group of 7 experienced shoulder surgeons was used to specify 

and evaluate a scapular fracture classification system with a focus on fracture patterns of the glenoid 

fossa. The last evaluation was conducted on a consecutive collection of 120 scapular fractures documented 

by both plain radiographs and computed tomography scans including 3-dimensional surface 

rendering. Inter-rater reliability was analyzed with k statistics, and accuracy was estimated by latent 

class modeling. 

Results: Of 120 scapular fractures, 46 involved the glenoid (38%), with 38 classified as F1 articular rim 

fractures. The overall median sensitivity and specificity in identifying these fractures were 95% and 

93%, respectively. Surgeons’ accuracy in classifying F1 fractures ranged from 86% to 100% (median, 

94%). Subsequently, classification of simple F1 fractures resulted in a proportion of 36% of anterior 

rim fractures, 19% of posterior rim fractures, and 45% of short oblique fractures, with accuracies ranging 

from 85% to 98%. 

Institutional review board/ethics committee approval: not required. 

*Reprint requests: Laurent Audige, PhD, AO Clinical Investigation and 

Documentation, Stettbachstrasse 6, CH-8600 D€ubendorf, Switzerland. 

E-mail address: laurent.audige@aofoundation.org (L. Audige). 

1058-2746/$ - see front matter Ó 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. 

http://dx.doi.org/10.1016/j.jse.2012.08.003

Classification of glenoid fractures 513 

Conclusion: This new system for scapular glenoid fractures has proved to be sufficiently reliable and 

accurate when applied by experienced shoulder surgeons. Further validation of the most detailed system, 

as well as involvement of surgeons with different levels of training in the framework of clinical routine 

and research, however, should be considered. 

Level of evidence: Level II, Development of Diagnostic Criteria, Diagnostic Study. 

Ó 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. 

Keywords: Scapula fracture; glenoid fossa; fracture classification; diagnostic; reliability; accuracy 

Scapular fractures are rare and account for 1% of all fractures 

and 3% to 5% of all shoulder girdle fractures. 7 In the 

Swedish population, the annual incidence was estimated at 10 

per 10,000 inhabitants. 18 AccordingtoGoss, 13 the scapular 

body is involved in up to 45% of all scapula fractures, with the 

remainder involving the glenoid (approximately 10%), the 

scapular neck (25%), the processes (approximately 15%), and 

the spine (5%). Treatment modalities depend on the fracture 

location, pattern, and displacement on the one hand and the 

patient’s age, demands, and comorbidity on the other. In 

contrast to fractures of the scapular body, which are mostly 

treated conservatively, surgery is more often indicated for 80% 

of fractures involving the glenoid. 24 This is explained by the 

specific shape and function of the glenoid. Glenoid rim fractures 

can result in joint instability, where surface incongruity may 

increase the risk of post-traumatic arthrosis accompanied by 

pain and limited function. The surgical approach is influenced 

by the main pathology. Not all glenoid fractures can be sufficiently 

reduced and stabilized by an anterior approach. Posterior 

fracture patterns have to be managed through a posterior 

approach that is more complex and less frequently practiced. 

In the clinical environment, diagnosis of scapular fractures 

is based mainly on radiographic examination of the 

shoulder. Three plains comprising an anteroposterior view, 

outlet view, and axillary view are very helpful in gathering 

essential information. If the glenoid is involved, it is 

strongly recommended to obtain an additional computed 

tomography (CT) scan to precisely evaluate the glenoid 

surface. It is also crucial to analyze the fracture systematically 

with the help of a clinically relevant, reliable, and valid 

fracture classification system. 5,9,11,19 Until now, a number of 

glenoid fracture classifications have been in use 1,10,14-16,20 ; 

however, none of these are comprehensive and validated. 

A comprehensive scapula classification system has been 

developed as a collaborative effort between the AO Foundation 

and the Orthopaedic Trauma Association. 17 The 

purpose of this study was to create and validate a focused 

classification of the glenoid as an extension of this system. 

Materials and methods 

Scapula classification group and phase I consensus 

development 

The international Scapula Classification Group (SCCG) 

comprising 7 experienced shoulder specialist surgeons was 

established to propose a focused system for fractures of the glenoid 

fossa, along with definitions and illustrations. This system was to 

be descriptive, clinically relevant, sufficiently comprehensive, and 

intuitive for both inexperienced and experienced surgeons. Under 

coordination by a methodologist statistician, a phase 1 consensus 

development process was implemented in an iterative manner with 

a series of 3 agreement studies (classification sessions), followed 

by face-to-face review meetings to discuss disagreements and 

improve the system. Consensus was reached when the SCCG 

agreed that the system was well defined, clinically relevant, and 

reliable for its purpose. 4 This development process was the first of 

3 research phases that is required to be completed before the 

classification could be considered as validated. 

Fracture classification system 

The classification system for bony lesions of the scapula consists 

of separate codes, that is, one each for the involvement of the 

articular segment (glenoid fossa), the body, and any of the 

processes. In addition, each code comprises 2 levels, where level 1 

represents a basic system for rapid simplified documentation 17 and 

level 2 provides a focused system for detailed documentation. 

Classification of the scapula is divided into 3 regions: the 

articular segment, the processes, and the body. The articular 

segment includes the area involving the glenoid fossa and the 

articular rim, which is limited by a line joining the superior articular 

rim to the lateral border of the suprascapular notch and a line 

positioned medially and parallel to the plane of the glenoid fossa 

that starts cranially at the lateral border of the suprascapular notch. 

In the basic system, fractures of the articular segment (denoted 

F) are classified in 1 of 3 groups (Fig. 1): F0, fracture of the 

articular segment, not through the glenoid fossa, but resulting in 

the fossa being detached from any part of the scapula body; F1, 

fracture involving the glenoid fossa with a simple rim, transverse, 

or oblique fracture pattern; and F2, multifragmentary joint fracture 

involving the glenoid fossa with 3 or more articular fragments. 

The focused system is an extended classification of F1 or F2 

fractures according to their location in 4 quadrants within 

the glenoid fossa (Fig. 2). These quadrants are defined by the 

equatorial line and the intertubercular line running from the 

supraglenoid tubercle to the infraglenoid tubercle. There are 5 

subgroups, consisting of 3 for F1 fractures and 2 for F2 fractures: 

F1(1), simple anterior articular rim or oblique fracture; F1(2), 

simple posterior articular rim or oblique fracture; F1(3), simple 

transverse or short oblique fracture; F2(4), multifragmentary 

fracture with more than 1 fracture line exit point; and F2(5), 

central fracture-dislocation, with no exit line through the rim. 

Simple anterior (1) and posterior (2) articular rim or oblique 

fractures are further divided into 3 categories (Fig. 3): 1a/2a,

514 M. Jaeger et al. 

Figure 1 

Fractures of the articular segment. Ó 2012, Jaeger et al. 

Figure 2 

Four areas defined within the glenoid fossa. Ó 2012, Jaeger et al. 

infra-equatorial fracture located in 1 quadrant (same side as the 

maximum glenoid meridian); 1b/2b, rim fracture anterior/posterior 

to the maximum glenoid meridian with exits superior/inferior to 

the equatorial line; and 1c/2c, fracture oblique line exiting on 

the opposite side (posterior/anterior) to the maximum glenoid 

meridian. (Initial definitions used for the last evaluation session are 

presented in Appendix I, available on the journal’s website at www. 

jshoulderelbow.org. A revision and final proposal are presented in 

Fig. 3). 

Simple transverse or short oblique fractures (3) are also further 

divided into 3 categories (Fig. 4): 3a, infra-equatorial; 3b, equatorial; 

and 3c, supra-equatorial. 

For multifragmentary fractures with a combination of 2 

‘‘simple’’ fracture lines, the focused codes describing this 

combination may be added as an optional specification (Fig. 5); 

for example, in the case of a transverse and rim fracture, the 

classification would be F2(4/1c3c). 

Consecutive series and classification sessions 

The classification system was evaluated for reliability and accuracy 

using a consecutive series of scapula fractures documented 

with CT scans and conventional radiographs obtained from 

2 centers in Europe and North America. Cases were included


Figure 3 

Focused classification system of glenoid fossa rim fractures (F1). Ó 2012, Jaeger et al. 

Figure 4 

Focused classification system of simple transverse or short oblique fractures of the glenoid fossa (F1). Ó 2012, Jaeger et al. 

when diagnosed with a scapula fracture within 15 days after the 

injury in adult patients (mature skeleton). Whereas the first session 

used the 2-dimensional CT series visualized with a standard 

DICOM (Digital Imaging and Communications in Medicine) 

viewer, the last 2 sessions considered 3-dimensional (3D) reconstructions 

for all cases prepared by the primary author (M.J.) on 

video sequences (Fig. 6). All diagnostic images were collected in 

DICOM (Digital Imaging and Communications in Medicine)


Figure 5 

Focused classification system of multifragmentary joint fractures (F2). Ó 2012, Jaeger et al. 

Figure 6 

Example of a 3D CT reconstruction video used for the last classification session. Ó 2012, Jaeger et al. 

format, anonymized, and distributed on DVD format to SCCG 

members, who classified fractures independently ‘‘at home’’ 

within a 3-month period. Fracture codes were collected electronically 

using specifically designed Excel sheets (Microsoft, Redmond, 

WA, USA), which were centralized for the analyses. The 

results including reliability and accuracy data were reviewed 

during face-to-face meetings to identify the reasons for coding 

disagreements and improving the system. 

The final session included 120 cases documented with the 

2-dimensional CT series and 3D CT reconstruction videos, as well 

as additional radiographs available from 105 cases. Data were 

managed and analyzed by use of Intercooled Stata, version 11 

(StataCorp LP, College Station, TX, USA). The basic system was 

first analyzed to assess the likely distribution of articular segment 

(F0/F1/F2) fractures in the sample and identify them. The focused 

system was then applied to this fracture subset and separately 

analyzed for simple fracture patterns (F1) and multifragmentary 

joint fractures (F2). Interobserver reliability was evaluated by 

means of k coefficients. The k coefficient is commonly used as 

a chance-corrected measure of agreement, which ranges from þ1 

(complete agreement) to 0 (agreement by chance alone) to less 

than 0 (less agreement than expected by chance). The k coefficient 

is a useful indicator of reliability, and a value of 0.70 is considered 

an adequate sign of reliability. Classification accuracy was estimated 

by latent class modeling 22,23 using Latent GOLD software, 

version 3.0.1 (Statistical Innovations, Belmont, MA, USA). This 

technique aims at identifying the most likely ‘‘true’’ distribution of 

fracture classes in the population of scapula fractures based on the 

evaluated sample and the agreement data collected among the 

participating surgeons; for each class, the degree of classification 

accuracy for each surgeon is also estimated. 6 

Results 

When identifying cases using the basic system to classify 

a fracture of the articular segment (denoted F), the 

7 shoulder specialists were in agreement for 73% of the 120


cases. The overall k coefficient was 0.79, and the surgeons’ 

pair-wise k (21 pairs) ranged from 0.66 to 0.93. The sample 

identifying the most likely ‘‘true’’ distribution included 

46 cases (38%) with an F fracture, where the accuracy in 

identifying these fractures (diagnosis sensitivity) ranged 

from 91% to 99% (median, 95%). The surgeons’ accuracy 

in identifying the remaining 74 cases as non–articular 

segment fractures ranged from 86% to 98% (median, 93%). 

The 46 F fractures were further divided as follows: 1 F0 

fracture, 38 F1 fractures, and 7 F2 fractures. Surgeons 

agreed on this subclassification in 72% of these cases (33), 

with an overall k coefficient of 0.64. The surgeons’ 

pair-wise k (21 pairs) ranged from 0.43 to 0.92 (median, 

0.64). Surgeons were 86% to 100% accurate (median, 94%) 

in terms of classifying F1 fractures. The number of F2 

fractures was considered too small for estimation of the 

surgeons’ classification accuracy with an adequate degree 

of precision; nevertheless, 4 surgeons correctly classified 

6 of the 7 multifragmentary fractures, with a minimum of 

4 of these fractures correctly classified among the other 

3 surgeons. The only F0 fracture in the sample was 

correctly classified by 5 surgeons (Fig. 7), whereas the 

other 2 surgeons classified it as a simple fossa fracture (F1) 

or simple body fracture (B1). 

Surgeons attained full agreement in the classification of 

half of the 38 simple glenoid fossa (F1) fractures according 

to the higher level of the focused system (Figs. 3 and 4; 

Appendix I, available on the journal’s website at www. 

jshoulderelbow.org). The overall k coefficient was 0.66, 

with the surgeons’ pair-wise k ranging from 0.35 to 0.82 

(median, 0.67) (Table I). The estimated distribution of cases 

within the sample included 14 F1(1) fractures, 7 F1(2) 

fractures, and 17 F1(3) fractures with category-specific 

k coefficients of 0.70, 0.65, and 0.62, respectively. There 

was no central fracture-dislocation among the 7 multifragmentary 

joint fractures (Fig. 6), and all were classified 

as having more than 2 fracture line exit points [code F2(4)] 

with full agreement among the surgeons. 

Classification session data supported the distinction of 

simple fossa fractures into 3 classes with the following 

proportions: 36%, 19%, and 45% (Table II). The largest 

group, representing transverse or short oblique fractures 

(class 3), was classified with 87% to 93% accuracy by 

5 surgeons and 70% accuracy (median, 91%) for the other 

2. The second largest fracture group represented anterior 

rim or oblique fractures (class 1), showing the highest 

classification accuracies from 85% to 98% among the 

surgeons (median, 91%). The posterior rim or oblique 

fractures (class 2) were classified with 80% to 96% accuracy 

by 4 surgeons and 64% to 69% accuracy by the other 

3 (median, 80%). Incorrect classification of rim and oblique 

fractures as transverse and short oblique fracture types 

occurred more frequently, showing the higher ability to 

discern between anterior and posterior rim fractures. 

Further classification into the 3 subgroups of simple glenoid 

fossa fractures (ie, a, b, and c) showed a lower degree of 

interobserver reliability, with overall k coefficients of 0.46 

and 0.39 based on the combined group of anterior and 

posterior fractures (Fig. 3; Appendix I, available on the 

journal’s website at www.jshoulderelbow.org) and the group 

of transverse fractures, respectively (Fig. 4, Table I). 

Surgeons’ pair-wise k coefficients ranged from 0.07 to 0.89 

(median, 0.53) (anterior and posterior fractures) and from 

0.03 to 0.88 (median, 0.36) (transverse fractures). After 

reviewing these results, members of the SCCG unanimously 

agreed that a revision of categories 1c and 2c was required 

and a final proposal was made, as presented in Figure 3. 

Discussion 

The SCCG was established to develop and validate a clinically 

useful comprehensive scapula classification system. In 

a first phase, special interest was targeted at testing its 

reliability to allow its integration in a clinical setting. This 

study focuses on glenoid fractures. 

In our series of scapula fractures, the involvement of 

articular segment fractures was estimated for 38% of the 120 

cases. This incidence is much higher compared with data 

reported by Goss 15 suggesting that fractures of the glenoid 

cavity account for up to 10% of all scapula fractures. Ideberg 

et al 18 also reported involvement of the glenoid cavity in 

about 30% of scapula fractures, whichdsimilar to our own 

studydmight be due to the case selection process. Our 

scapular fracture cases were consecutively collected from 2 

major level I trauma centers in the United States and central 

Europe regardless of their treatments. To achieve a precise 

diagnosis, both plain radiographs and CT scans were obtained. 

Obtaining the latter, especially in combination with 

3D volume rendering, is believed to increase the accuracy in 

detecting glenoid fractures and, therefore, might also 

explain the higher proportion of glenoid fractures detected 

in our study compared with those from 3 more recent 

publications. 2,8,21 In an earlier evaluation session using only 

radiographs for 33 cases, 8 cases (24%) were diagnosed with 

glenoid involvement. The misdiagnosis of glenoid fractures 

may lead to either joint instability or joint incongruence, 

with the potential consequence of secondary arthrosis, so it 

is mandatory to identify these fractures precisely. We 

strongly recommend performing a CT scan routinely in all 

cases of scapular fractures. 

Using the entire scapula classification system provided 

by the SCCG, the involved shoulder surgeons were 

extremely accurate (>90%) in identifying all fractures 

involving the articular segment (code F). According to the 

focused classification system, the incidence of anterior rim 

fractures was 2 times higher compared with posterior 

fractures in our series. Single transverse or short oblique 

fractures were slightly more frequent compared with anterior 

rim fractures. Multifragmentary fractures with central 

fracture-dislocation were rare; this type of fracture pattern 

was not found in any of the 120 cases. The use of the


Figure 7 

Fracture of the articular segment not involving the glenoid fossa (F0). Ó 2012, Jaeger et al. 

Table I Coding agreement and reliability for glenoid fossa fractures according to focused system 

Fracture subsets Categories) No. of cases y Full agreement k Coefficient 

Overall Pair-wise (21 pairs) 

Minimum Median Maximum 

Simple fossa (F1) 50% 0.66 0.35 0.67 0.82 

1 14 0.70 

2 7 0.65 

3 17 0.62 

Multifragmentary fossa (F2) 4/5 7/0 100% 

F1(1) and F1(2) combined a/b/c 4/9/8 24% 0.46 0.07 0.53 0.89 

F1(3) a/b/c 3/8/6 29% 0.39 0.03 0.36 0.88 

) The categories of 1 to 5 represent the following: 1, anterior simple rim or oblique fracture; 2, posterior simple rim or oblique fracture; 3, simple 

transverse or short oblique fracture; 4, multifragmentary fossa with more than 2 fracture line exit points; and 5, multifragmentary fossa with central 

fracture-dislocation (no exit line through the rim). 

y Estimated by latent class analysis and the distribution of the surgeons’ codes. 

detailed subclassification seems to be reproducible with 

high accuracy (>80%) in all categories of F1 (1, 2, and 3). 

A more detailed description of rim fractures with respect to 

their location to the equator becomes less reliable and is 

most pronounced when differentiating short oblique fractures 

[F1(3)]. This cannot be done without a CT scan and 

was still not highly reliable with 3D volume rendering. One 

reason for this outcome might be the method used in this 

study. To provide the same data for all participating 

surgeons, 1 shoulder surgeon performed the volume 

rendering of all CT scans. The result was presented to the 

surgeons as a movie sequence in a 360 horizontal and 360 

vertical rotation; this setting was chosen based on common 

practice (usually of the radiologist) in presenting these 

types of data for further evaluation. Subsequently, the other 

shoulder surgeons did not perform their own 3D analysis, 

that is, they were unable to rotate or focus the 3D scans 

according to their own needs, and as such, their accuracy 

may have been limited. On the other hand, these results 

highlight the difficulty in distinguishing fractures bordering 

between 2 categories. Because the distribution of all glenoid 

fractures can be considered a continuum of possible 

patterns, any category is inherently associated with some 

level of imprecision for adjacent fracture pathologies. 

Former scapula classifications, especially of the glenoid, 

were conducted based on the assessment of plain radiographs. 

5,15,24 All of them were published without further 

reliability assessment. To our knowledge, this is the first 

study providing an evaluation of classification reliability 

and accuracy. Armitage et al 3 recently provided a frequency 

map of surgically treated scapula fractures. To our knowledge, 

this was the first article until now describing the use 

of 3D CT volume rendering to enhance the mapping of 

scapula fractures. In contrast to our study, Armitage et al


Table II Classification accuracy for patterns of simple fractures 

of glenoid fossa 

Surgeons and fracture categories Fracture classes 

1 2 3 

Class size 36% 19% 45% 

Surgeon 1 

1: Anterior rim or oblique 85%) 34% 29% 

2: Posterior rim or oblique 0% 64%) 0% 

3: Transverse or short oblique 15% 2% 71%) 

Surgeon 2 




Surgeon 3 




Surgeon 4 




Surgeon 5 




Surgeon 6 




Surgeon 7 




Classification accuracies 

Minimum 85% 64% 68% 

Median 91% 80% 91% 

Maximum 98% 96% 93% 

) Percentages indicate surgeon classification accuracies (percentages 

of correct classification). 

mainly focused on scapula body and neck fractures. 

Although they did not propose a classification system for 

glenoid fractures, they documented involvement of the 

glenoid in 17% of all scapula fractures. This incidence is 

surprisingly low considering the fact that these authors 

included fractures undergoing operative treatment. 

According to the current treatment decision process, 24 the 

fracture population of Armitage et al should have a bias 

toward including proportionally more glenoid fractures. On 

the other hand, Ada and Miller 1 reported glenoid fractures 

in 10% of their series based on assessments using plain 

radiographs. Such heterogeneity in the proportion of glenoid 

fractures may be a reflection that the distribution of 

fracture patterns is likely to differ between settings and, as 

such, a comparison between scapula fracture studies 

requires adequate classification and documentation. 

The combination of a glenoid fracture and scapula body 

fracture is frequent, so it is also important to have 

a combined classification considering both the glenoid and 

the rest of the scapula. This classification system should be 

descriptive and comprehensive, as well as aid in the 

decision-making process for individual therapy, especially 

if minimally invasive approaches are intended. 12 To our 

knowledge, the current scapula classification system is 

most comprehensive as well as highly reliable and accurate. 

Other existing scapula fracture classification systems lack 

a more focused description of glenoid fractures. The 

commonly used classification for glenoid fractures 

according to Ideberg et al 18 and Goss 15 does not consider 

the rest of the scapula; simple glenoid fracture lines 

between anterior and posterior rim fractures (types Ia and 

Ib) and transverse fractures (types II-V) are distinguished, 

and type VI fractures represent multifragmentary fractures. 

The classification of scapular fractures by Ada and Miller 1 

distinguishes among 4 types of fractures including type III 

glenoid fractures; however, further subclassifications of 

glenoid fractures do not exist. 

This evaluation is limited by its sample size, although it is 

one of the largest ever used in such a project. There is often 

a tradeoff between increasing the case collection and making 

the evaluation feasible when busy clinicians are involved. 

Results should be considered with caution when the number 

of cases in any category is low, such as in the more detailed a, 

b, and c category system. In addition, nothing can be said 

about the reliability of coding multifragmentary glenoid 

fossa fractures with central fracture-dislocation. Although 

classification of F1 simple fossa fractures according to 

anterior rim, posterior rim, or transverse patterns appears 

reasonably reliable and accurate, location of these fractures 

with regard to the 4 quadrants remains open for further 

clarification and evaluation. The wide range of surgeons’ 

pair-wise k coefficients shows that different applications of 

the definitions occurred among surgeons; thus, further 

clarification and specification of the system are required. 

Transverse or short oblique fractures typically separate 

a process (ie, coracoid 3c) or involve the body (3a and 3b). 

The 3a and 3b fractures are typically located near the 

equator. In contrast, 1c and 2c rim fractures are much smaller 

because they are located near the glenoid edge. 

The classification process and evaluation sessions were 

performed by experienced surgeons only, which may not 

reflect the validity of the system in general practice. As 

advocated by Audige et al, 4 a further study is required to 

assess the reliability and accuracy of this classification 

system when used by surgeons of varying education and 

experience. Such evaluation would also consider the final 

change made to the rim fracture categories. This study could 

also be influenced by the preparation of the 3D volume 

rendering datasets by only the main author. Furthermore, this 

report is not intended to make recommendations regarding 

any treatment modalities based on this classification 

system at this early stage; rather, our intent is to provide


a comprehensive, reliable, and accurate classification system 

as a base for further clinical examinations. 

Conclusion 

In summary, it was possible to create a comprehensive 

scapula classification system focusing also on fractures of 

the articular segment. This classification system is believed 

to be clinically relevant and appears reasonably reliable 

and accurate with respect to glenoid fractures at both the 

basic and more detailed levels. Further validation of the 

most detailed system in a larger case sample with surgeons 

of different training backgrounds should be considered. 

Acknowledgments 

The authors thank the following persons for their participation 

and support in the development of the basic scapula 

classification system: Edward Harvey (Montreal General 

Hospital, Montreal, Quebec, Canada), Dolfi Herscovici 

(Florida Orthopaedic Institute, Temple Terrace, FL, USA), 

and Julie Agel and Sean Nork (Harborview Medical Center, 

Seattle, WA, USA). The authors also thank M. Wilhelmi, 

PhD (AO Clinical Investigation and Documentation), for 

the preparation and copy editing of this manuscript. 

Disclaimer 

The authors, their immediate families, and any research 

foundations with which they are affiliated have not 

received any financial payments or other benefits from 

any commercial entity related to the subject of this article. 

The surgeons who participated in the successive faceto-face 

meetings were supported with regard to their travel 

expenses and received a small per-diem payment. Support 

for this study was provided by the AO Foundation. 

Supplementary data 

Supplementary data related to this article can be found 

online at http://dx.doi.org/10.1016/j.jse.2012.08.003. 

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scapula fracture classification system - Kreiskrankenhaus Mechernich

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