Comparison between two classifications of humeral head fractures: Neer and AO-ASIF

Our purpose was to verify if the Neer and AO-ASIF classifications for fractures of the proximal humerus satisfy the requisites of simplicity and reproducibility and if the parameters that they consider to establish the severity of the fracture are similar. Two of the authors classified the proximal humeral fractures of 227 patients based on plain radiographs, and they repeated the classification five years later. The reliability, reproducibility and coherence of the classifications were investigated. Inter-observer reliability was K = 0.77 (Neer) and K = 0.65 (AO-ASIF) while intra-observer reproducibility was K = 0.68 (examiner I) and K = 0.63 (examiner II). In 1/5 of the cases, disagreement led to a different classification of the same fracture. Furthermore, neither classification establishes a linear scale of gravity able to provide an indication for treatment. The Neer and AO-ASIF classifications have a low reproducibility and reliability when fractures, especially those with 3 or 4 parts, are assessed by means of plain radiographs. Therefore, patients with complex fractures should be submitted to CT to have a correct pre-operative diagnosis.     

A combined fracture of the greater and lesser tuberosity with head shaft continuity in the proximal humerus

We treated a combined fracture of the greater and lesser tuberosity with head shaft continuity in the proximal humerus. This case is impossible to classify in three of the classifications, the Neer classification, AO Müller classification, or Jakob classification. However, this case has been described as fracture types in two different categories in the Codman classification. Based on our experience with this case, we concluded that both the plain radiographs and the CT scans were necessary to make a correct diagnosis and classify the fractures of the proximal humerus.     

Reliability and reproducibility of dens fracture classification with use of plain radiography and reformatted computer-aided tomography

BACKGROUND: The classification system of dens fractures by Anderson and D'Alonzo has been widely used in clinical studies. Of the three types of fractures, Type II and Type III are of particular importance because the distinction between them may affect treatment decisions. The purposes of this study were to assess whether this classification is reliable and reproducible and to determine whether computed tomography can improve its reliability and reproducibility. METHODS: Plain radiographs and spiral computed tomography images of dens fractures in eleven patients were assessed, and the fractures were assigned a classification of Type II or Type III at two readings, separated by six months, by two spine surgeons and three neuroradiologists. Kappa coefficients of agreement between the raters as well as the reproducibility of the classifications made by the individual raters were calculated independently for the fracture classifications based on the plain radiographs and those based on the reformatted computed tomography scans. RESULTS: The kappa coefficient for classifications based on plain radiographs was 0.30 and 0.25 (fair agreement) at the first and second readings, respectively. For classifications based on computed tomography scans, the corresponding kappa coefficients were 0.46 (moderate agreement) and 0.67 (substantial agreement). The kappa coefficients for intrarater reliability among the five raters averaged 0.56 (moderate agreement) when computed tomography scans were used and 0.28 (fair agreement) when plain radiographs were used. CONCLUSIONS: Substantial variation with regard to the classification of dens fractures was found within our group of raters. Greater agreement occurred when reformatted computed tomography scans rather than plain radiographs were used as the basis for classification. When classifying dens fractures according to the system of Anderson and D'Alonzo, one should consider using reformatted computed tomography scans and reaching a consensus with multiple raters.     

Classification of intertrochanteric fractures with computed tomography: a study of intraobserver and interobserver variability and prognostic value

The purpose of this prospective study was to determine the level of interobserver and intraobserver agreement among orthopedic surgeons and radiologists when computed tomography (CT) scans are used with plain radiographs to evaluate intertrochanteric fractures. In addition, the prognostic value of current classifications systems concerning quality of life was evaluated. Sixty-one patients who presented with intertrochanteric fractures received open reduction and internal fixation with compression hip screw. Three orthopedic surgeons and 2 radiologists independently classified the fractures according to 2 systems: Evans-Jensen and AO (Arbeitsgemeinschaft für Osteo-synthesefragen). Fractures were initially graded with plain radiographs and then again in conjunction with CT. Results were analyzed using the (kappa) kappa coefficient. The 36-item Short-Form Health Survey was administered at baseline, 3 months, and 1 year, and results were correlated with fracture grade. Mean kappa coefficients when comparing radiography alone with radiography and CT scan were 0.63 for the AO system and 0.59 for the Evans-Jensen system. Both represent "fair" agreements. Mean overall interobserver kappa coefficients were 0.67 for radiologists and 0.57 for orthopedic surgeons. Radiologists also had higher intraobserver kappa coefficients. No significant relationships were found between follow-up Short Form Health Survey results and intraoperative grading of fractures. When these classification schemes are compared, interobserver agreement does not appear to change dramatically when information from CT scans is added. This may suggest that (1) more data have been provided by CT with greater possibilities for misinterpretation and (2) these classification schemes may not be comprehensive in describing fracture pattern and displacement. Finally, both systems failed to provide any prognostic value.     

Improved interobserver variation after training of doctors in the Neer system. A randomised trial

We investigated whether training doctors to classify proximal fractures of the humerus according to the Neer system could improve interobserver agreement. Fourteen doctors were randomised to two training sessions, or to no training, and asked to categorise 42 unselected pairs of plain radiographs of fractures of the proximal humerus according to the Neer system. The mean kappa difference between the training and control groups was 0.30 (95% CI 0.10 to 0.50, p = 0.006). In the training group the mean kappa value for interobserver variation improved from 0.27 (95% CI 0.24 to 0.31) to 0.62 (95% CI 0.57 to 0.67). The improvement was particularly notable for specialists in whom kappa increased from 0.30 (95% CI 0.23 to 0.37) to 0.79 (95% CI 0.70 to 0.88). These results suggest that formal training in the Neer system is a prerequisite for its use in clinical practice and research.     

Two and three-dimensional computed tomography for the classification and management of distal humeral fractures. Evaluation of reliability and diagnostic accuracy

BACKGROUND: Complex fractures of the distal part of the humerus can be difficult to characterize on plain radiographs and two-dimensional computed tomography scans. We tested the hypothesis that three-dimensional reconstructions of computed tomography scans improve the reliability and accuracy of fracture characterization, classification, and treatment decisions. METHODS: Five independent observers evaluated thirty consecutive intra-articular fractures of the distal part of the humerus for the presence of five fracture characteristics: a fracture line in the coronal plane; articular comminution; metaphyseal comminution; the presence of separate, entirely articular fragments; and impaction of the articular surface. Fractures were also classified according to the AO/ASIF Comprehensive Classification of Fractures and the classification system of Mehne and Matta. Two rounds of evaluation were performed and then compared. Initially, a combination of plain radiographs and two-dimensional computed tomography scans (2D) were evaluated, and then, two weeks later, a combination of radiographs, two-dimensional computed tomography scans, and three-dimensional reconstructions of computed tomography scans (3D) were assessed. RESULTS: Three-dimensional computed tomography improved both the intraobserver and the interobserver reliability of the AO classification system and the Mehne and Matta classification system. Three-dimensional computed tomography reconstructions also improved the intraobserver agreement for all fracture characteristics, from moderate (average kappa [kappa2D] = 0.554) to substantial agreement (kappa3D = 0.793). The addition of three-dimensional images had limited influence on the interobserver reliability and diagnostic characteristics (sensitivity, specificity, and accuracy) for the recognition of specific fracture characteristics. Three-dimensional computed tomography images improved intraobserver agreement (kappa2D = 0.62 compared with kappa3D = 0.75) but not interobserver agreement (kappa2D = 0.24 compared with kappa3D = 0.28) for treatment decisions. CONCLUSIONS: Three-dimensional reconstructions improve the reliability, but not the accuracy, of fracture classification and characterization. The influence of three-dimensional computed tomography was much more notable for intraobserver comparisons than for interobserver comparisons, suggesting that different observers see different things in the scans-most likely a reflection of the training, knowledge, and experience of the observer with regard to these relatively uncommon and complex injuries.     

Four distal radial fracture classification systems tested amongst a large panel of Dutch trauma surgeons

Five different radiographs of distal radial fractures were classified according to the AO/ASIF, Frykman, Fernandez and Older systems by 45 observers (trauma surgeons and residents). The same panel classified the same radiographs in a different order 4 months later. Mean interobserver correlation for all cases was fair to moderate according to the Spearman rank test. However, these classifications showed poor correlation with the gold standard as classified by the senior author. All intraobserver agreements demonstrated a moderate kappa agreement (K(w)=0.52) for the AO/ASIF classification and fair for the Frykman (K(w)=0.26), Fernandez (K(w)=0.24) and Older (K(w)=0.27) classifications. When the group was divided according to years of clinical experience (<6 years; >or=6 years), there was poor correlation between experience and consistency amongst all four classifications. In view of these findings, we do not recommend use of these classifications for clinical application because of their questionable reproducibility and reliability.     

Assessment of two thoracolumbar fracture classification systems as used by multiple surgeons

BACKGROUND: The reproducibility and repeatability of modern systems for classification of thoracolumbar injuries have not been sufficiently studied. We assessed the interobserver and intraobserver reproducibility of the AO (Arbeitsgemeinschaft für Osteosynthesefragen) classification and compared it with that of the Denis classification. Our purpose was to determine whether the newer, AO system had better reproducibility than the older, Denis classification. METHODS: Anteroposterior and lateral radiographs and computerized tomography scans (axial images and sagittal reconstructions) of thirty-one acute traumatic fractures of the thoracolumbar spine were presented to nineteen observers, all trained spine surgeons, who classified the fractures according to both the AO and the Denis classification systems. Three months later, the images of the thirty-one fractures were scrambled into a different order, and the observers repeated the classification. The Cohen kappa (kappa) test was used to determine interobserver and intraobserver agreement, which was measured with regard to the three basic classifications in the AO system (types A, B, and C) as well as the nine subtypes of that system. We also measured the agreement with regard to the four basic types in the Denis classification (compression, burst, seat-belt, and fracture-dislocation) and with regard to the sixteen subtypes of that system. RESULTS: The AO classification was fairly reproducible, with an average kappa of 0.475 (range, 0.389 to 0.598) for the agreement regarding the assignment of the three types and an average kappa of 0.537 for the agreement regarding the nine subtypes. The average kappa for the agreement regarding the assignment of the four Denis fracture types was 0.606 (range, 0.395 to 0.702), and it was 0.173 for agreement regarding the sixteen subtypes. The intraobserver agreement (repeatability) was 82% and 79% for the AO and Denis types, respectively, and 67% and 56%, for the AO and Denis subtypes, respectively. CONCLUSIONS: Both the Denis and the AO system for the classification of spine fractures had only moderate reliability and repeatability. The tendency for well-trained spine surgeons to classify the same fracture differently on repeat testing is a matter of some concern.     

Three-dimensional computed tomography imaging increases the reliability of classification systems for tibial plateau fractures

Objective

The purpose of this study was to determine whether three-dimensional reconstructed computed tomography (CT) images can improve intra-observer and inter-observer reliability for classification systems of tibial plateau fractures compared to plain radiographs and two-dimensional CT images.

Methods

Twenty-one tibial plateau fractures were classified independently by four attending orthopaedic trauma surgeons using the AO/ASIF and Schatzker classification systems. First, a combination of plain radiographs and two-dimensional (2D) CT images were evaluated. Second, 4 weeks later, plain radiographs and three-dimensional (3D) CT images were assessed. Then, 4 weeks later, these two rounds of evaluation were repeated. The intra-observer and inter-observer reliability were assessed using kappa statistics.

Results

Three-dimensional CT images can improve the inter-observer and intra-observer reliability regarding both AO/ASIF and Schatzker classification systems of tibial plateau fractures compared to 2D CT images. The degree of agreement of the inter-observer and intra-observer reliability among four surgeons increased from ‘substantial’ to ‘almost perfect’.

Conclusion

Three-dimensional CT is a more reliable radiographic modality than 2D CT in evaluation of fracture patterns in tibial plateau fractures. This finding seems to show that more sophisticated imaging techniques can improve the reliability of fracture classification systems.     

Diagnostik und Klassifikation von Schulterverletzungen

The diagnosis of shoulder injuries follows a standardized protocol regardless of the injury sustained. Imaging techniques are of decisive importance, and especially conventional radiographs including the trauma series (true a-p, y-view and axial views). Sonography and MRI are used to evaluate accompanying soft tissue injuries. The 3D CT reconstruction is a great help when decisions have to be made on the treatment of proximal humerus fractures, and particularly on whether the humeral head should be reconstructed or a primary arthroplasty performed. There is no universally applied classification system for proximal fractures of the humerus. The Neer classification seems to have emerged as the gold standard. For scapular fractures the Euler and Rüedi classification, which is based on the pathologic findings, has proved its worth.     

The comparison of two classifications for trochanteric femur fractures: The AO/ASIF classification and the Jensen classification

This study compares the reproducibility of two classifications for trochanteric femur fractures: the Jensen classification and the AO/ASIF classification. Furthermore we evaluated the agreement on fracture stability, choice of osteosynthesis, fracture reduction and the accuracy of implant positioning.In order to calculate the inter-, and intra-observer variability 10 observers classified 50 trochanteric fractures.The inter-observer agreement of the AO/ASIF classification and the Jensen classification was κ0.40 and κ0.48. The kappa coefficient of the intra-observer reliability of the AO/ASIF classification was κ0.43 and κ0.56 for the Jensen classification.Preoperative agreement on fracture stability and type of implant showed kappa values of κ0.39 and κ0.65. The postoperative agreement on choice of implant, fracture reduction and position of the implant was κ0.17, κ0.29 and κ0.22, respectively.Both classifications showed poor reproducibility. This study suggests that the definition of stability of trochanteric fractures remains controversial, which possibly complicates the choice of osteosynthesis.     

Impact of MRI on treatment plan and fracture classification of tibial plateau fractures

OBJECTIVE: To evaluate the interobserver agreement for both treatment plan and fracture classification of tibial plateau fractures using plain radiographs, computed tomography (CT) scan, and magnetic resonance imaging (MRI). DESIGN: Prospective study to assess the impact of an advanced radiographic study on the agreement of treatment plan and fracture classification of tibial plateau fractures among three orthopaedic surgeons. SETTING/PARTICIPANTS: Patients presenting with tibial plateau fractures to a level I trauma center were evaluated with plain knee radiographs (anteroposterior, lateral, two oblique views), CT scan, and MRI. Three experienced attending orthopaedic trauma surgeons were randomly presented three sets of studies for each injury: radiographs alone, radiographs with CT, and radiographs with MRI (including soft tissue injuries documented by an experienced MRI radiologist). The surgeons were asked to render fracture classification and treatment plan based upon the blind reading of each individual radiographic set. MAIN OUTCOME MEASURES: Agreement among the three surgeons was measured using kappa coefficients. RESULTS: For fracture classification, radiographs alone yielded a mean kappa coefficient of 0.68, which increased to 0.73 for radiographs with CT scan and 0.85 for radiographs with MRI. Fracture classification (Schatzker) was changed an average of 6% with the addition of the CT scan and 21% based on radiographs with MRI. For the fracture management plan, the mean interobserver kappa coefficient for radiographs alone was 0.72, which increased to 0.77 for radiographs with CT scan and 0.86 for radiographs with MRI. MRI changed treatment plan in 23% of the cases. CONCLUSION: Magnetic resonance imaging increases the interobserver agreement on fracture classification and operative management of tibial plateau fractures.     

Diagnosing displaced four-part fractures of the proximal humerus: a review of observer studies

Displaced four-part fractures comprise 2-10 % of all proximal humeral fractures. The optimal treatment is unclear and randomised trials are needed. The conduct and interpretation of such trials is facilitated by a reproducible fracture classification. We aimed at quantifying observer agreement on the classification of displaced four-part fractures according to the Neer system. Published and unpublished data from five observer studies were reviewed. Observers agreed less on displaced four-part fractures than on the overall Neer classification. Mean kappa values for interobserver agreement ranged from 0.16 to 0.48. Specialists agreed slightly more than fellows and residents. Advanced imaging modalities (CT and 3D CT) seemed to contribute more to classification of displaced four-part patterns than in less complex fracture patterns. Low observer agreement may challenge the clinical approach to displaced four-part fractures and poses a problem for the interpretation and generalisation of results from future randomised trials.     

Interobserver and intraobserver variation in classification systems for fractures of the distal humerus

We assessed the inter- and intraobserver variation in classification systems for fractures of the distal humerus. Three orthopaedic trauma consultants, three trauma registrars and three consultant musculoskeletal radiologists independently classified 33 sets of radiographs of such fractures on two occasions, each using three separate systems. For interobserver variation, the Riseborough and Radin system produced 'moderate' agreement (kappa = 0.513), but half of the fractures were not classifiable by this system. For the complete AO system, agreement was 'fair' (kappa = 0.343), but if only AO type and group or AO type alone was used, agreement improved to 'moderate' and 'substantial', respectively (kappa = 0.52 and 0.66). Agreement for the system of Jupiter and Mehne was 'fair' (kappa = 0.295). Similar levels of intraobserver variation were found. Systems of classification are useful in decision-making and evaluation of outcome only if there is agreement and consistency among observers. Our study casts doubt on these aspects of the systems currently available for fractures of the distal humerus.     

AO or Schatzker? How reliable is classification of tibial plateau fractures?

Introduction We compare the intra- and interobserver reproducibility of classifications of tibial plateau fractures most commonly used in our clinical practice. These were the AO and Schatzker classifications.Patients and methods Agreement was measured using kappa coefficients on the data obtained from three observers reviewing 30 fractures and these values were interpreted according to Landis and Koch.Results It was found that both classifications were substantially reliable with regards to intraobserver reliability but that the Schatzker system was only fairly reliable and the AO classification moderately reliable with regards to interobserver reliability. Breaking down the AO classification, with regards to intraobserver reliability, the AO group was substantially reliable and the type excellently reliable. For interobserver reliability, the AO group was moderately reliable while the AO type was substantially reliable.Conclusion For tibial plateau fractures seen on plain x-ray, the AO classification is more reliable between observers than the Schatzker classification.     

Surgical anatomy of multipart fractures of the proximal humerus

The gross fracture anatomy was recorded in a cohort of 22 consecutive patients who underwent open surgery for 3-part and 4-part fractures of the proximal humerus and was compared with preoperative radiographs in a blind manner. It was noted that 8 of the 22 fractures did not correspond to any category of the Neer or AO/Orthopaedic Trauma Association/Jakob classification. These fractures had 3 displaced segments in terms of surgical anatomy, but the humeral head was free of soft tissue. In addition, the soft-tissue attachments to the head were closely related to the articular surface orientation on radiographs (medially oriented or not), rather than to the number of displaced segments or to the grouping of the AO/Orthopaedic Trauma Association/Jakob classification. Thus, in our study population, the current classification systems were inaccurate for realizing the fracture anatomy, particularly humeral head status. They would be accurate if the articular surface orientation was taken into account.     

Reliability of the AO/ASIF classification for pertrochanteric femoral fractures

20 radiographs of pertrochanteric femoral fractures were classified as to fracture "group" and "sub-group" according to the AO/ASIF Fracture Classification (type 31A) by 15 observers. 3 months later, the same radiographs were reviewed by the same observers. Mean agreement of the observers with the final consensus ranged from 53% (with subgroup classification) to 81% (without subgroup). The mean kappa value for interobserver reliability was 0.33 and 0.34 for classification with subgroup in both observer sessions, respectively. Omission of the subgroup classification resulted in better mean kappa values (0.67 and 0.63, respectively). Mean intraobserver reliability was 0.48 in the fracture "subgroup" and 0.78 in the "group" classification. In conclusion, the results show that the AO/ASIF classification for pertrochanteric fractures is reliable for fracture subgroups 31A1, A2 or A3. The group classification should be used to compare scientific data and determine the best treatment. Further classification of fracture subgroups leads to poor reproducibility of results.     

经外侧三角肌入路应用肱骨近端锁定接骨板治疗肱骨近端骨折

目的 探讨经外侧三角肌入路应用肱骨近端锁定接骨板(LPHP)治疗肱骨近端骨折的方法.方法 自2003年2月～2007年6月经外侧三角肌入路应用LPHP治疗22例肱骨近端骨折,按Neer分型,其中二部分骨折5例,三部分骨折15例,四部分骨折2例.结果 随访时间6～48个月,骨折全部获得愈合,愈合时间6～12周,根据肩关节Neer功能百分评分标准:优12例,良8例,可2例,优良率91%.结论 经外侧三角肌入路应用LPHP治疗肱骨近端骨折,可降低对软组织和骨折残留血运的破坏,获得满意的复位和坚强的固定,减少关节周围瘢痕的形成,术后能进行早期功能锻炼,其是一种安全、微创、有效的治疗方法.     

Reliability of the AO/ASIF classification for pertrochanteric femoral fractures

20 radiographs of pertrochanteric femoral fractures were classified as to fracture "group" and "subgroup" according to the AO/ASIF Fracture Classification (type 31A) by 15 observers. 3 months later, the same radiographs were reviewed by the same observers. Mean agreement of the observers with the final consensus ranged from 53% (with subgroup classification) to 81% (without subgroup). The mean kappa value for interobserver reliability was 0.33 and 0.34 for classification with subgroup in both observer sessions, respectively. Omission of the subgroup classification resulted in better mean kappa values (0.67 and 0.63, respectively). Mean intraobserver reliability was 0.48 in the fracture "subgroup" and 0.78 in the "group" classification. In conclusion, the results show that the AO/ASIF classification for pertrochanteric fractures is reliable for fracture subgroups 31A1, A2 or A3. The group classification should be used to compare scientific data and determine the best treatment. Further classification of fracture subgroups leads to poor reproducibility of results.