Interobserver reliability is higher for assessments with 3D software-generated models than with conventional MRI images in the classification of trochlear dysplasia

Abstract Purpose Trochlear dysplasia is a significant risk factor for patellofemoral instability. The severity of trochlear dysplasia is commonly evaluated based on the Dejour classification in axial MRI slices. However, this often leads to heterogeneous assessments. A software to generate MRI-based 3D models of the knee was developed to ensure more standardized visualization of knee structures. The purpose of this study was to assess the intra- and interobserver agreements of 2D axial MRI slices and an MRI-based 3D software generated model in classification of trochlear dysplasia as described by Dejour. Methods Four investigators independently assessed 38 axial MRI scans for trochlear dysplasia. Analysis was made according to Dejour’s 4 grade classification as well as differentiating between 2 grades: low-grade (types A + B) and high-grade trochlear dysplasia (types C + D). Assessments were repeated following a one-week interval. The inter- and intraobserver agreement was determined using Cohen’s kappa (κ) and Fleiss kappa statistic (κ). In addition, the proportion of observed agreement (po) was calculated for assessment of intraobserver agreement. Results The assessment of the intraobserver reliability with regard to the Dejour-classification showed moderate agreement values both in the 2D (κ = 0.59 ± 0.08 SD) and in the 3D analysis (κ = 0.57 ± 0.08 SD). Considering the 2-grade classification, the 2D (κ = 0.62 ± 0.12 SD) and 3D analysis (κ = 0.61 ± 0.19 SD) each showed good intraobserver matches. The analysis of the interobserver reliability also showed moderate agreement values with differences in the subgroups (2D vs. 3D). The 2D evaluation showed correspondences of κ = 0.48 (Dejour) and κ = 0.46 (high / low). In the assessment based on the 3D models, correspondence values of κ = 0.53 (Dejour) and κ = 0.59 (high / low) were documented. Conclusion Overall, moderate-to-good agreement values were found in all groups. The analysis of the intraobserver reliability showed no relevant differences between 2 and 3D representation, but better agreement values were found in the 2-degree classification. In the analysis of interobserver reliability, better agreement values were found in the 3D compared to the 2D representation. The clinical relevance of this study lies in the superiority of the 3D representation in the assessment of trochlear dysplasia, which is relevant for future analytical procedures as well as surgical planning. Level of evidence Level II.

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Reliability of the Oswestry-Bristol Classification for trochlear dysplasia

Bone & Joint Open ◽

10.1302/2046-3758.17.bjo-2020-0048.r1 ◽

2020 ◽

Vol 1 (7) ◽

pp. 355-358

Author(s):

Christian Konrads ◽

Christoph Gonser ◽

Sufian S. Ahmad

Keyword(s):

Classification System ◽

Trochlear Dysplasia ◽

Kappa Statistic ◽

Daily Practice ◽

Intraobserver Reliability ◽

Grading System ◽

Intraobserver Agreement ◽

Mri Scans ◽

Classification Tool ◽

Dejour Classification

Aims The Oswestry-Bristol Classification (OBC) was recently described as an MRI-based classification tool for the femoral trochlear. The authors demonstrated better inter- and intraobserver agreement compared to the Dejour classification. As the OBC could potentially provide a very useful MRI-based grading system for trochlear dysplasia, it was the aim to determine the inter- and intraobserver reliability of the classification system from the perspective of the non-founder. Methods Two orthopaedic surgeons independently assessed 50 MRI scans for trochlear dysplasia and classified each according to the OBC. Both observers repeated the assessments after six weeks. The inter- and intraobserver agreement was determined using Cohen’s kappa statistic and S-statistic nominal and linear weights. Results The OBC with grading into four different trochlear forms showed excellent inter- and intraobserver agreement with a mean kappa of 0.78. Conclusion The OBC is a simple MRI-based classification system with high inter- and intraobserver reliability. It could present a useful tool for grading the severity of trochlear dysplasia in daily practice. Cite this article: Bone Joint Open 2020;1-7:355–358.

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Reliability of the Oswestry-Bristol Classification for trochlear dysplasia

Bone & Joint Open ◽

10.1302/2633-1462.17.bjo-2020-0048.r1 ◽

2020 ◽

Vol 1 (7) ◽

pp. 355-358

Author(s):

Christian Konrads ◽

Christoph Gonser ◽

Sufian S. Ahmad

Keyword(s):

Classification System ◽

Trochlear Dysplasia ◽

Kappa Statistic ◽

Daily Practice ◽

Intraobserver Reliability ◽

Grading System ◽

Intraobserver Agreement ◽

Mri Scans ◽

Classification Tool ◽

Dejour Classification

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The Evaluation of Trochlear Osseous Morphology: An Epidemiologic Study

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120s00441 ◽

2020 ◽

Vol 8 (7_suppl6) ◽

pp. 2325967120S0044

Author(s):

Sercan Yalçin ◽

Gabriel Onor ◽

Scott Kaar ◽

lee Pace ◽

Paolo Ferrua ◽

...

Keyword(s):

Correlation Coefficient ◽

Normal Population ◽

Trochlear Dysplasia ◽

Interobserver Reliability ◽

Intraclass Correlation ◽

Epidemiologic Study ◽

Intraobserver Reliability ◽

Severe Dysplasia ◽

Mild Dysplasia ◽

Study Population

Objectives: The purpose of this study is to investigate the prevalence of the trochlear dysplasia in our study population. Methods: We obtained 692 skeletally mature femoral specimens from the [Blinded Institution], [Blinded Collection]. Five observers were asked to evaluate each specimen for trochlear dysplasia on a scale between 0 and 3 (0 – normal/no dysplasia; 1 – mild dysplasia; 2 – moderate dysplasia; 3 – severe dysplasia). Each observer made initial evaluations for interobserver reliability. Each observer then re-evaluated each specimen one month later to determine intraobserver reliability. We evaluated inter and intraobserver reliability utilizing intraclass correlation coefficient (ICC). All statistics were performed with SPSS v.25 (IBM, USA). Results: The interobserver ICC of first and second evaluation of all observers were found to be 0.906 [0.894-0,916] and 0.904 [0.892-0.915], respectively. The intraobserver ICC of observers were as follows: Reviewer1: 0.799 [0.771-0.825]; Reviewer2: 0.686 [0.645-0.724]; Reviewer3: 0.808 [0.781-0.832]; Reviewer4: 0.787 [0.757-0.814]; Reviewer5: 0.778 [0.747-0.806]. These results show intra and interobserver correlation was good to excellent. The percentages of normal trochlea, mild dysplasia, moderate dysplasia and severe dysplasia for first evaluation, by reviewer, are as follows: Reviewer 1: 82.7%, 12.1%, 4.0%, 1.2%; Reviewer 2: 37.3%, 26.2%, 27.5%, 9.1%; Reviewer 3: 57.9%, 28.0%, 12.1%, 1.9%; Reviewer 4: 64.2%, 25.6%, 7.7%, 2.6%; Reviewer 5: 65.6%, 14.9%, 12.3%, 7.2%. The percentages of normal trochlea, mild dysplasia, moderate dysplasia and severe dysplasia for second evaluation, by reviewer, are as follows: Reviewer 1: 78.8%, 16.6%, 3.6%, 1.0%; Reviewer 2: 40.3%, 26.4%, 23.3%, 10.0%; Reviewer 3: 42.2%,35.1%, 18.8%, 3.9%; Reviewer 4: 57.4%, 31.9%, 8.2%, 2.5%; Reviewer 5: 73.7%, 8.2%, 9.7%, 8.4%. In total, the percentages of normal trochlea, mild dysplasia, moderate dysplasia and severe dysplasia were 60.00%, 22.51%, 12.72%, 4.77%; respectively. Conclusions: This study shows that although there was no absolute criteria to grade trochlear dysplasia, observers had similar opinions on the degree of dysplasia. Also, our cohort shows that moderate to severe dysplasia is not uncommon as it is present in around 17% of knees in our cohort. This is the first epidemiologic study evaluating the prevalence of trochlear dysplasia in the normal population.

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Intra and Inter-observer Concordance of a New Classification System for Myopic Maculopathy

10.21203/rs.3.rs-128390/v1 ◽

2020 ◽

Author(s):

Rong-rong Zhang ◽

Yan Yu ◽

Yin-fen Hou ◽

Chang-fan Wu

Keyword(s):

Classification System ◽

Clinical Decision Making ◽

Interobserver Reliability ◽

Type A ◽

Clinical Decision ◽

Intraobserver Agreement ◽

Intraobserver Reproducibility ◽

Fundus Photographs ◽

Myopic Maculopathy

Abstract Background: Myopic maculopathy (MM) is one of the major causes of visual impairment and irreversible blindness in eyes with PM. However, the classification of each type of lesion associated with MM has not been determined. Recently, a new MM classification system was proposed, known as the ATN grading and classification system, which was based on the fundus photographs and OCT images, including three variable components: atrophy (A), traction (T), and neovascularization (N). Hence, this study aimed to perform an independent interobserver and intraobserver agreement evaluation of the recently developed ATN grading system for MM. Methods: This was a retrospective study. Fundus photographs and the optical coherence tomography (OCT) images of 125 patients (226 eyes) with various of MM were evaluated and classified using the ATN grading of the new MM classification system by four evaluators (2 attending ophthalmologists and 2 ophthalmic residents). All cases were repeatedly evaluated by the same evaluators after an interval of 6 weeks. The Kappa coefficient (κ) and 95% confidence interval (CI) were used to determine the interobserver and intraobserver agreement.Results: The interobserver reliability was substantial when considering the maculopathy type (A, T, and N). The weighted Fleiss κ values for each MM type (A, T, and N) were 0.651 (95% CI: 0.602–0.700), 0.734 (95% CI: 0.689–0.779), and 0.702 (95% CI: 0.649–0.755), respectively. The interobserver agreement when considering the sub-types was good or excellent, except for stages A1, A2, and N1 which weighted κ value was less than 0.6, with a moderate agreement. The intraobserver reproducibility of types or sub-types was excellent, with κ>0.8. No significant differences were observed between attending ophthalmologists and residents in the interobserver reliability and intraobserver reproducibility.Conclusions: The ATN classification allows an adequate agreement among ophthalmologists with different qualifications and by the same observer on separate occasions. Future prospective studies should further evaluate whether this classification can be better implemented at clinical decision-making and disease progression assessment.

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A Classification-System Improves the Intra- and Interobserver Reliability of Radiographic Diagnosis of “Pistol-Grip-Deformity”

Hip International ◽

10.5301/hip.2011.8821 ◽

2011 ◽

Vol 21 (6) ◽

pp. 732-739 ◽

Cited By ~ 3

Author(s):

Ingmar Ipach ◽

Eva-Maria Arlt ◽

Falk Mittag ◽

Beate Kunze ◽

Petra Wolf ◽

...

Keyword(s):

Lower Limit ◽

Classification System ◽

Interobserver Reliability ◽

Alpha Angle ◽

Treatment Algorithm ◽

Kappa Coefficient ◽

Intraobserver Agreement ◽

Single Plane ◽

Upper Limit

Early detection of pistol-grip-deformity may be beneficial in optimising the outcome and the cost effectiveness of surgery. It is important to identify reliable radiographic parameters in assessing femoro-acetabular impingement (FAI) to develop a treatment algorithm. Radiographs of 47 patients ranging from “pistol grip deformity” to a normal head-neck-junction were measured for alpha angle and head ratio, and then classified by two different observers. The Bland-Altman plot was used for inter- and intraobserver agreement of alpha angle and head ratio. Inter- and intraobserver agreement for classification of “pistol grip deformity” was determined using weighted Cohen's kappa coefficient. Observer I achieved a kappa coefficient of 0.97. Observer II achieved a kappa coefficient of 0.92. An interobserver kappa coefficient between 0.87 and 0.92 was achieved by using a classification system. By testing for interobserver agreement, a bias of –0.004 with an upper limit of 0.461 and a lower limit of –0.47 was seen for the ratio and a bias of –3.7 with an upper limit of 17.2 and a lower limit of –24.6 for the alpha angle. Therefore, poor results were seen for intra- and interobserver reliability by using only a single plane for classification of “pistol grip deformity”. The strength of agreement could be improved by using a classification system (based on two planes).

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Conventional Radiographs and Magnetic Resonance Imaging for the Analysis of Trochlear Dysplasia: The Influence of Selected Levels on Magnetic Resonance Imaging

The American Journal of Sports Medicine ◽

10.1177/0363546516685054 ◽

2017 ◽

Vol 45 (5) ◽

pp. 1059-1065 ◽

Cited By ~ 22

Author(s):

Philippe Matthias Tscholl ◽

Florian Wanivenhaus ◽

Sandro F. Fucentese

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Distal Femur ◽

Trochlear Dysplasia ◽

Joint Line ◽

Low Grade ◽

Resonance Imaging ◽

Level Of Evidence ◽

Dejour Classification

Background: Trochlear dysplasia is one of the most important risk factors for recurrent patellar instability. It is defined on true lateral conventional radiographs (CR) and axial magnetic resonance imaging (MRI). The type of trochlear dysplasia is decisive for surgical treatment; however, low agreement between CR and MRI has been reported. Purpose: To compare the Dejour classification of trochlear dysplasia on CR and axial MRI using differing levels defined in the literature. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The 4-type classification of trochlear dysplasia by Dejour was used to analyze 228 knees with recurrent patellar dislocations on true lateral CR and axial MRI. The 2-type modification of the Dejour classification was also similarly analyzed. Measurements on axial MRI were performed at 3 different levels: MR1, the most proximal level where the intercondylar notch forms a “Roman arch”; MR2, 3 cm above the joint line; and MR3, the midpatellar height. Results: MR1 was measured at a mean distance of 29 ± 3.5 mm and MR3 at a mean of 38 ± 5.8 mm above the joint line. MR1 and MR2 were always measured on the cartilaginous trochlea, whereas 52% of MR3 was found more proximally. Overall agreement was fair between CR and MR1/MR2 (31.1%/25.4%, respectively) and highest for MR3 (45.2%; P < .01). The highest agreement (81.8%) was found for MR3 with the 2-type trochlear dysplasia classification (low-grade trochlear dysplasia: type A vs high-grade trochlear dysplasia: types B, C, and D) and lower for MR1 (67.5%) and MR2 (62.0%). Conclusion: Trochlear dysplasia measured on CR and MRI shows only fair agreement, especially when the supratrochlear region of the distal femur is not analyzed on axial MRI. MRI analysis that considers the cartilaginous trochlea only tends to underestimate the severity of dysplasia according to Dejour. For a more precise evaluation of trochlear dysplasia, the entire distal femur should be analyzed on axial MRI.

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Abstract 173: Coronary artery aneurysm measurement and z-score variability in Kawasaki Disease

Circulation ◽

10.1161/circ.131.suppl_2.173 ◽

2015 ◽

Vol 131 (suppl_2) ◽

Author(s):

Christina Ronai ◽

Akiko Hamaoka-Okamoto ◽

Christian Stopp ◽

Jane W Newburger ◽

Kevin Friedman

Keyword(s):

Coronary Artery ◽

Kawasaki Disease ◽

Interobserver Reliability ◽

Intraclass Correlation ◽

Management Strategies ◽

Artery Aneurysm ◽

Intraobserver Reliability ◽

Z Score ◽

Z Scores

Background: Coronary artery (CA) z-scores are commonly used for clinical decisions in Kawasaki disease (KD). We evaluated reliability in CA measurement, reproducibility of z-score calculation, and frequency with which different z-score formulas lead to divergent management strategies. Methods: We randomly selected 21 KD patients (pts) with ≥1 CA z-score 1.5-3 and all KD pts with ≥ 1 CA z-score 7-14 (n=20). Two echocardiographers measured LMCA, LAD and RCA. Inter- and intraobserver reliability were calculated. T-tests were used to compare CA z-score using 3 commonly used formulas (Boston, DC and Montreal). Results: Median age at KD echo was 1.2 y (0.2-11.5 y). Interobserver reliability was high for LAD (intraclass correlation [ICC] 0.970) and RCA (ICC 0.943) and lower for LMCA (ICC 0.725). Intraobserver reliability was also high for LAD and RCA (ICC 0.991 and 0.999) and lower for LMCA (ICC 0.946). Z-scores for the 3 formulas were similar at smaller CA size, i.e., z < 3, but varied markedly at larger CA dimensions (Figure). Z-scores for the same CA dimension calculated by each of the 3 formulas resulted in disparate classification of normal vs. mild dilation in 7/21 (22%) pts, and different guidance for anticoagulation based on CA z ≥10 in 10/20 (50%) pts. Conclusion: Although CA measurements have high inter- and intraobserver agreement, CA z-scores vary dramatically based on the z-score formula, particularly at larger CA dimensions. Discrepancies in CA z-score between calculators impacts not only the distinction between normal and mild dilatation, but most importantly, the recommendation of anticoagulation for pts with larger CA dimensions.

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Three-dimensional analysis of tooth movement after intrusion of a supraerupted molar using a mini-implant with partial-fixed orthodontic appliances

The Angle Orthodontist ◽

10.2319/060912-480.1 ◽

2012 ◽

Vol 83 (2) ◽

pp. 274-279 ◽

Cited By ~ 6

Author(s):

Shin-Jae Lee ◽

Sook-Yun Jang ◽

Youn-Sic Chun ◽

Won Hee Lim

Keyword(s):

Tooth Movement ◽

Treatment Time ◽

Three Dimensional ◽

3D Models ◽

Orthodontic Appliances ◽

Scanning System ◽

3D Analysis ◽

Fixed Orthodontic Appliances ◽

The Mean ◽

3D Software

ABSTRACT Objective: To evaluate three-dimensional (3D) positional changes of an intruded tooth, a neighboring tooth, and a tooth connected to a mini-implant following intrusion of a single supraerupted molar, using a mini-implant with partial-fixed orthodontic appliances. Materials and Methods: The study consisted of 14 adult patients (two males and 12 females, mean age 41.9 years) with a supraerupted molar due to loss of an antagonist. Intrusion was performed using a mini-implant with a partial strap-up. The mean treatment time was 11.9 months, and the mean retention time was 23.3 months. To quantify the positional changes of the teeth, 3D models using a laser-based, dental scanning system and 3D software at pretreatment, posttreatment, and retention were oriented in a coordinate system and superimposed using nonmoved teeth as references. The changes on the x-, y-, and z-axes were measured at the tip of each cusp in the involved teeth. Results: A supraerupted molar was intruded by a mean amount of 1.35 ± 0.48 mm and was well maintained during the retention period. The overall change in the neighboring tooth was insignificant, although it showed opposite movement compared to the intruded tooth during the intrusion. The tooth connected to a mini-implant exhibited a secure anchorage. Conclusion: 3D analysis showed the detailed positional changes of each tooth, and the involved molars were well maintained after intrusion.

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ISAKOS Classification of Meniscal Tears. Intra and Interobserver Reliability.

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967114s00239 ◽

2014 ◽

Vol 2 (12_suppl4) ◽

pp. 2325967114S0023

Author(s):

Mariano J. Fresneda ◽

Juan J. Dere ◽

Carlos H. Yacuzzi ◽

Matías Costa Paz

Keyword(s):

Correlation Coefficient ◽

Intraclass Correlation Coefficient ◽

Interobserver Reliability ◽

Intraclass Correlation ◽

Intraobserver Reliability ◽

Knee Surgery ◽

Meniscal Tears ◽

Meniscal Lesions ◽

Good Agreement

Objectives: To analyze the intra and interobserverreliability of the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) classification of meniscal tears. Methods: Thearthroscopic classification of meniscal lesions created by the ISAKOS was used. Thirty one arthroscopic videos, made between June and December 2013,with different meniscal tear characteristics were analyzedby three orthopedic surgeons (two specialists in knee surgery and a fellowship), twice at an interval of 30 days. The Kappa Coefficients (k) was used to assess the intraobserver reliability and intraclass correlation coefficient (ICC) for interobserverreliability. Results: The averageintraobserver reliability was for the first observer 51%, the second 65% and the third 58%, reaching moderate agreement according to the Kappa coefficient used by Landis and Koch. Regarding interobserver reliability, good agreement (ICC = 0.71) was obtained as the intraclass correlation coefficient. The whole results were significantlystatical (p <0.05). Conclusion: While this classification provides a detailed description of meniscal lesions, the intraobserver reliability did not reach the optimum values obtained despite having on average a moderate agreement. However interobserver reliability results showed on average 70% of agreement (good agreement), which can affirm that the agreement and interobserver reliability is acceptable.

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The Oswestry-Bristol Classification

The Bone & Joint Journal ◽

10.1302/0301-620x.102b1.bjj-2019-0366.r3 ◽

2020 ◽

Vol 102-B (1) ◽

pp. 102-107 ◽

Cited By ~ 3

Author(s):

Nikhil Sharma ◽

Ashley Brown ◽

Theodoros Bouras ◽

Jan H. Kuiper ◽

Jonathan Eldridge ◽

...

Keyword(s):

Classification System ◽

Interobserver Agreement ◽

Trochlear Dysplasia ◽

Significant Risk ◽

Patellofemoral Instability ◽

Kappa Statistic ◽

Significant Risk Factor ◽

Classification Systems ◽

Intraobserver Agreement ◽

Dejour Classification

Aims Trochlear dysplasia is a significant risk factor for patellofemoral instability. The Dejour classification is currently considered the standard for classifying trochlear dysplasia, but numerous studies have reported poor reliability on both plain radiography and MRI. The severity of trochlear dysplasia is important to establish in order to guide surgical management. We have developed an MRI-specific classification system to assess the severity of trochlear dysplasia, the Oswestry-Bristol Classification (OBC). This is a four-part classification system comprising normal, mild, moderate, and severe to represent a normal, shallow, flat, and convex trochlear, respectively. The purpose of this study was to assess the inter- and intraobserver reliability of the OBC and compare it with that of the Dejour classification. Methods Four observers (two senior and two junior orthopaedic surgeons) independently assessed 32 CT and axial MRI scans for trochlear dysplasia and classified each according to the OBC and the Dejour classification systems. Assessments were repeated following a four-week interval. The inter- and intraobserver agreement was determined by using Fleiss’ generalization of Cohen’s kappa statistic and S-statistic nominal and linear weights. Results The OBC showed fair-to-good interobserver agreement and good-to-excellent intraobserver agreement (mean kappa 0.68). The Dejour classification showed poor interobserver agreement and fair-to-good intraobserver agreement (mean kappa 0.52) Conclusion The OBC can be used to assess the severity of trochlear dysplasia. It can be applied in clinical practice to simplify and standardize surgical decision-making in patients with recurrent patella instability. Cite this article: Bone Joint J 2020;102-B(1):102–107

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