Radiologic Assessment of Knee Phenotypes Based on the Coronal Plane Alignment of the Knee Classification in a Korean Population.

Background: The Coronal Plane Alignment of the Knee (CPAK) classification system has been developed as a comprehensive system that describes 9 coronal plane phenotypes based on constitutional limb alignment and joint line obliquity (JLO). Due to the characteristics of Asian populations, which show more varus and wider distribution in lower limb alignment than other populations, modification of the boundaries of the arithmetic hip-knee-ankle angle (aHKA) and JLO should be considered. The purpose of this study was to determine the knee phenotype in a Korean population based on the original CPAK and modified CPAK classification systems. Methods: We reviewed prospectively collected data of 500 healthy and 500 osteoarthritic knees between 2021 and 2023 using radiographic analysis and divided them based on the modified CPAK classification system by widening the neutral boundaries of the aHKA to 0° ± 3° and using the actual JLO as a new variable. Using long-leg standing weight-bearing radiographs, 6 radiographic parameters were measured to evaluate the CPAK type: the mechanical HKA angle, medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), aHKA, JLO, and actual JLO. Results: From 2 cohorts of 1,000 knees, the frequency distribution representing all CPAK types was different between the healthy and arthritic groups. The most common categories were type II (38.2%) in the healthy group and type I (53.8%) in the arthritic group based on the original CPAK classification. The left and upward shift in the distribution of knee phenotypes in the original classification was corrected evenly after re-establishing the boundaries of a neutral aHKA and the actual JLO. According to the modified CPAK classification system, the most common categories were type II (35.2%) in the healthy group and type I (38.0%) in the arthritic group. Conclusions: Although the modified CPAK classification corrected the uneven distribution seen when applying the original classification system in a Korean population, the most common category was type I in Korean patients with osteoarthritic knees in both classification systems. Furthermore, there were different frequencies of knee phenotypes among healthy and arthritic knees.

Gait classification of knee osteoarthritis patients using shoe-embedded internal measurement units sensor.

BACKGROUND: Knee osteoarthritis negatively affects the gait of patients, especially that of elderly people. However, the assessment of wearable sensors in knee osteoarthritis patients has been under-researched. During clinical assessments, patients may change their gait patterns under the placebo effect, whereas wearable sensors can be used in any environment. METHODS: Sixty patients with knee osteoarthritis and 20 control subjects were included in the study. Wearing shoes with an IMU sensor embedded in the insoles, the participants were required to walk along a walkway. The sensor data were collected during the gait. To discriminate between healthy and knee osteoarthritis patients and to classify different subgroups of knee osteoarthritis patients (patients scheduled for surgery vs. patients not scheduled for surgery; bilateral knee osteoarthritis diagnosis vs. unilateral knee osteoarthritis diagnosis), we used a machine learning approach called the support vector machine. A total of 88 features were extracted and used for classification. FINDINGS: The patients vs. healthy participants were classified with 71% accuracy, 85% sensitivity, and 56% specificity. The "patients scheduled for surgery" vs. "patients not scheduled for surgery" were classified with 83% accuracy, 83% sensitivity, and 81% specificity. The bilateral knee osteoarthritis diagnosis vs. unilateral knee osteoarthritis diagnosis was classified with 81% accuracy, 75% sensitivity, and 79% specificity. INTERPRETATION: Gait analysis using wearable sensors and machine learning can discriminate between healthy and knee osteoarthritis patients and classify different subgroups with reasonable accuracy, sensitivity, and specificity. The proposed approach requires no complex gait factors and is not limited to controlled laboratory settings.

Validation of a second-generation appropriateness classification system for total knee arthroplasty: a prospective cohort study.

BACKGROUND: To test the validity of a second-generation appropriateness system in a cohort of patients undergoing total knee arthroplasty (TKA). METHODS: We applied the RAND/UCLA Appropriateness Method to derive our second-generation system and conducted a prospective study of patients diagnosed with knee osteoarthritis in eight public hospitals in Spain. Main outcome questionnaires were the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short-Form-12 (SF-12), and the Knee Society Score satisfaction scale (KSS), completed before and 6 months after TKA. Baseline, changes from baseline to 6 months (journey outcome), and 6-month scores (destination outcome) were compared according to appropriateness category. Percentage of patients attaining the minimal clinically important difference (MCID) and responders according to Outcome Measures in Rheumatology-Osteoarthritis Research Society (OMERACT-OARSI) criteria were also reported. RESULTS: A total of 282 patients completed baseline and 6-month questionnaires. Of these, 142 (50.4%) were classified as Appropriate, 90 (31.9%) as Uncertain, and 50 (17.7%) as Inappropriate. Patients classified as Appropriate had worse preoperative pain, function, and satisfaction (p < 0.001) and had greater improvements (i.e., journey scores) than those classified as Inappropriate (p < 0.001). At 6 months, destination scores for pain, function, or satisfaction were not significantly different across appropriateness categories. The percentage of patients meeting responder criteria (p < 0.001) and attaining MCID was statistically higher in Appropriate versus Inappropriate groups in pain (p = 0.04) and function (p = 0.004). CONCLUSIONS: The validity of our second-generation appropriateness system was generally supported. The findings highlight a critical issue in TKA healthcare: whether TKA appropriateness should be driven by the extent of improvement, by patient final state, or by both.

Patients with lateral compartment knee osteoarthritis during arthroscopy are at highest risk of subsequent knee arthroplasty.

BACKGROUND: Arthroscopic treatment of knee osteoarthritis has declined, in part due to concerns with conversion to arthroplasty. Some studies have investigated the demographic predictors for conversion to arthroplasty, few have assessed the risk factors within the knee itself. Our aim was to analyse the demographics and anatomical wear features of a large cohort of patients undergoing knee arthroscopy. METHODS: A retrospective analysis of 1760 cases spanning over 17 years undergoing knee arthroscopy was performed. Patients were 36 years or older at time of the index arthroscopy. Each patient received the International Cartilage Regeneration and Joint Preservation Society (ICRS) grade of all regions as well an estimate of the remaining meniscal percentage. Demographic factors as well as intraoperatively collected data were analysed as predictive variables for subsequent conversion to arthroplasty using a multi-step Cox regression analysis. RESULTS: A total of 102 patients (6.2%) were converted to arthroplasty. Age at arthroscopy (hazard ratio (HR) 1.073; 95% confidence interval (CI) 1.058-1.088) and ICRS grade of the lateral tibial plateau (HR 1.166; 95% CI 1.066-1.276) were statistically significant predicting variables for conversion to arthroplasty. CONCLUSIONS: The results of this study indicate that higher ICRS grade of the lateral tibial plateau at arthroscopy is the most significant predictor for conversion to knee arthroplasty, with a hazard equal to an increase in age. The absence of these factors does not justify arthroscopic treatment of patients with knee osteoarthritis. LEVEL OF EVIDENCE: III.

Validation of the Oxford Knee Score and Lower Extremity Functional Score questionnaires for use in Slovenia.

BACKGROUND: With the increasing prevalence of total knee replacement (TKR) due to knee osteoarthritis, the absence of patient-reported outcome measures in Slovenia must be addressed. QUESTIONS/PURPOSES: (1) We cross-culturally adapted Oxford Knee Score (OKS) and Lower Extremity Functional Scale (LEFS) questionnaires to the Slovenian-speaking community. (2) We evaluated OKS and LEFS psychometric characteristics. PATIENTS AND METHODS: In the first assessment (Time 1) Slovenian versions of both questionnaires (OKS-Slo and LEFS-Slo), knee pain, timed-up to go (TUG) and sit to stand (STS) tests were completed by 123 subjects (55% females), of which 78 were patients scheduled for TKR and 45 were healthy age-matched controls. The questionnaires were assessed one week apart (Time 2) to investigate the test-retest reliability, with 121 subjects (98.4%) completing second measurements. RESULTS: Significant differences were observed between the two groups. Where patients had greater body mass index, they were slower in TUG, weaker in STS, had greater knee pain in both knees and scored lower on both questionnaires. Additionally, correlation analysis showed that OKS-Slo and LEFS-Slo correlated almost perfectly (correlation coefficient [CC] = .968, p < 0.001). Excellent negative correlations were observed with TUG (OKS-Slo/CC = - 0.679, p < 0.001; LEFS-Slo/CC = - 0.692, p < 0.001) and STS (OKS-Slo/CC = 0.790, p < 0.001; LEFS-Slo/CC = 0.815, p < 0.001) tests, while knee pain of affected leg correlated the most (OKS-Slo/CC = - 0.923, p < 0.001; LEFS-Slo/CC = - 0.915, p < 0.001). The Cronbach's alpha coefficient for both the OKS-Slo and LEFS-Slo ranged between 0.87 and 0.99, while the interclass correlation coefficient was excellent; i.e., 0.99. Finally, both questionnaires proved to be unidimensional measures. CONCLUSION: The Slovenian version of both questionnaires is feasible, valid and reliable for use in clinical studies including the older adult population in Slovenia. LEVEL OF EVIDENCE: Level III, Diagnostic-case-control study.

Correlation between radiographic knee osteoarthritis and lifetime cigarette smoking amount in a Korean population: A cross-sectional study.

Although the inverse correlation between smoking and degenerative arthritis is controversial, quantitative analysis of the correlation between lifetime cigarette smoking amount and degenerative arthritis has not been performed. We investigated the correlation between knee radiographic osteoarthritis (ROA) and lifetime cigarette smoking amount in the general population.This cross-sectional study used the Fifth and Sixth Korean National Health and Nutrition Examination Survey (2010-2013) data. Subjects included 11,638 community-dwelling adults aged ≥50 years. Knee ROA was defined as a Kellgren/Lawrence grade ≥2 on plain radiography. Lifetime cigarette smoking amount was calculated in terms of pack-year and further divided into quartile groups. Independent correlation between smoking and knee ROA was determined using odds ratios (OR) adjusted for age, sex, obesity, physical activity, and household income on multivariate logistic regression analysis.Knee ROA prevalence was 37.3%; prevalence of lifetime cigarette smokers was 26.0%. Subjects with knee ROA had higher mean age, female sex ratio, and body mass index but lower physical activity level. The adjusted logistic regression model revealed that female sex (OR, 2.110; 95% confidence interval [CI], 1.895-2.349) was significantly associated with knee ROA. Older age, obesity, and lower household income were positively correlated with knee ROA. Second-and fourth-quartile groups of smokers had the lower ROA prevalence than never-smokers (OR, 0.800; 95% CI, 0.643-0.99; OR, 0.812; 95% CI, 0.684-0.965, respectively).An inverse correlation with knee ROA was confirmed in mid-light to heavy smokers. Prospective studies are needed to reveal whether knee ROA involves smoking.

MRI-based screening for structural definition of eligibility in clinical DMOAD trials: Rapid OsteoArthritis MRI Eligibility Score (ROAMES).

PURPOSE: Our aim was to introduce a simplified MRI instrument, Rapid OsteoArthritis MRI Eligibility Score (ROAMES), for defining structural eligibility of patients for inclusion in disease-modifying osteoarthritis drug trials using a tri-compartmental anatomic approach that enables stratification of knees into different structural phenotypes and includes diagnoses of exclusion. We also aimed to define overlap between phenotypes and determine reliability. METHODS: 50 knees from the Foundation for National Institutes of Health Osteoarthritis Biomarkers study, a nested case-control study within the Osteoarthritis Initiative, were selected within pre-defined definitions of phenotypes as either inflammatory, subchondral bone, meniscus/cartilage, atrophic or hypertrophic. A focused scoring instrument was developed covering cartilage, meniscal damage, inflammation and osteophytes. Diagnoses of exclusion were meniscal root tears, osteonecrosis, subchondral insufficiency fracture, tumors, malignant marrow infiltration and acute traumatic changes. Reliability was determined using weighted kappa statistics. Descriptive statistics were used for determining concordance between the a priori phenotypic definition and ROAMES and overlap between phenotypes. RESULTS: ROAMES identified 43 of 50 (86%) pre-defined phenotypes correctly. Of the 50 participants, 27 (54%) had no additional phenotypes other than the pre-defined phenotype. 18 (36%) had one and 5 (10%) had two additional phenotypes. None had three or four additional phenotypes. All features of ROAMES showed almost perfect agreement. One case with osteonecrosis and one with a tumor were detected. CONCLUSIONS: ROAMES is able to screen and stratify potentially eligible knees into different structural phenotypes and record relevant diagnoses of exclusion. Reliability of the instrument showed almost perfect agreement.

Automated detection & classification of knee arthroplasty using deep learning.

BACKGROUND: Preoperative identification of knee arthroplasty is important for planning revision surgery. However, up to 10% of implants are not identified prior to surgery. The purposes of this study were to develop and test the performance of a deep learning system (DLS) for the automated radiographic 1) identification of the presence or absence of a total knee arthroplasty (TKA); 2) classification of TKA vs. unicompartmental knee arthroplasty (UKA); and 3) differentiation between two different primary TKA models. METHOD: We collected 237 anteroposterior (AP) knee radiographs with equal proportions of native knees, TKA, and UKA and 274 AP knee radiographs with equal proportions of two TKA models. Data augmentation was used to increase the number of images for deep convolutional neural network (DCNN) training. A DLS based on DCNNs was trained on these images. Receiver operating characteristic (ROC) curves with area under the curve (AUC) were generated. Heatmaps were created using class activation mapping (CAM) to identify image features most important for DCNN decision-making. RESULTS: DCNNs trained to detect TKA and distinguish between TKA and UKA both achieved AUC of 1. Heatmaps demonstrated appropriate emphasis of arthroplasty components in decision-making. The DCNN trained to distinguish between the two TKA models achieved AUC of 1. Heatmaps showed emphasis of specific unique features of the TKA model designs, such as the femoral component anterior flange shape. CONCLUSIONS: DCNNs can accurately identify presence of TKA and distinguish between specific arthroplasty designs. This proof-of-concept could be applied towards identifying other prosthesis models and prosthesis-related complications.

Kellgren-Lawrence scoring system underestimates cartilage damage when indicating TKA: preoperative radiograph versus intraoperative photograph.

INTRODUCTION: The Kellgren-Lawrence score helps the orthopedic surgeon to classify the severity of knee osteoarthritis (OA) before total knee arthroplasty (TKA). There might be a discrepancy between subjective complaints of the patients and radiologically visible changes of the knee joint in many cases. In this context, we performed a prospective clinical study to compare the preoperative degree of knee OA using the Kellgren-Lawrence score with the intraoperative extent of cartilage damage during primary TKA. MATERIALS AND METHODS: A total of 251 primary TKA surgeries due to a primary knee OA were prospectively included. Preoperative Kellgren-Lawrence score was determined using standardized preoperative plain radiographs of three views; anteroposterior, lateral and skyline of the patella by a senior radiologist. Intraoperatively, in all cases, photographs of the medial, lateral, and patellofemoral joint compartments were taken. Using the International Cartilage Repair Society (ICRS) score, the degree of chondromalacia was assessed. Subsequently, correlation analysis was performed using the Pearson-Clopper 95% confidence interval (CI). RESULTS: There were higher intraoperative scores compared to the preoperative scores in 160 of all cases (63.7% of 251, 95% CI 57.5-69.7%). A mismatch of two score grade points was found in 8.4% (95% CI 5.3-12.5%). The most common mismatch was noted in patients with preoperative Kellgren-Lawrence score of 3 and an intraoperative score of 4 in 48.2% (95% CI 41.9-54.6%). CONCLUSIONS: The preoperative radiographs using Kellgren-Lawrence underestimate the severity of knee osteoarthritis. The true extent of articular cartilage damage can be better appreciated intraoperatively. In patients undergoing primary TKA, the correlation of clinical symptoms with radiological findings is crucial in deciding when to perform the surgery. Besides, other imaging modalities may be used as an adjunct when the clinical findings and plain radiographs do not correlate.

Effects of receptor activator nuclear factor κB gene polymorphisms on the susceptibility to knee osteoarthritis: A case-control study.

The present study aimed to explore genetic association of receptor activator nuclear factor κB (RANK) polymorphisms with individual susceptibility to knee osteoarthritis (OA) in different Kellgren-Lawrence (KL) grades.This case-control study included 138 knee OA patients and 145 healthy individuals. RANK rs1805034 and rs8086340 polymorphisms were genotyped through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The effects of RANK polymorphisms on knee OA risk were analyzed via χ test or Fisher exact test, and the results were expressed using odds ratios (ORs) with corresponding 95% confidence intervals (CIs).The C allele of rs1805034 polymorphism had significantly higher frequency in knee OA patients than in controls (P = .044), indicating that this allele could increase the risk of knee OA (OR = 1.424, 95% CI = 1.010-2.008). Besides, the CC genotype and C allele of the rs1805034 polymorphism were significantly associated with elevated risk of knee OA in moderate grade (CC vs TT: P = .018, OR = 3.071, 95% CI = 1.187-7.941; C vs T: P = .012, OR = 1.787, 95% CI = 1.131-2.823). However, rs8086340 polymorphism had no significant association with knee OA riskThe C allele of RANK rs1805034 polymorphism is closely correlated with increased risk of knee OA, especially for moderate grade.

Short-term pain reduction after low-dose radiotherapy in patients with severe osteoarthritis of the hip or knee joint: a cohort study and literature review.

BACKGROUND: Low-dose radiotherapy (LDRT) for pain reduction in osteoarthritis (OA) is a frequently used treatment in Germany and Eastern European countries. The evidence on the effects of LDRT on pain in patients with OA remains unclear. This study evaluated the effect of LDRT on pain in patients with severe OA of the hip or knee joint. METHODS: This prospective study included a total of 16 joints in 12 patients (4 hips and 12 knees). The inclusion criteria were: patients older than 50 years, severe OA (Kellgren-Lawrence grade III-IV) of the hip or knee joint, patients not responding to conservative treatment and patients who are inoperable or not willing to undergo surgery. The joint was irradiated with a total dose of 6.0 Gray. The Numeric Rating Scale for pain (NRS-pain) and patient-reported outcome measures were obtained at pre-, 6, 13, 26, 39 and 52 weeks post-radiation. A decrease of two points on the NRS-pain was defined as clinical relevant. RESULTS: The median age of the included patients was 74 years (range 58-89). In 50% of the joints (n = 8, 3 hip and 5 knee joints), a clinical relevant difference in pain at 6 weeks post-radiation was observed. This clinical relevant difference decreased to 25% at 52 weeks post-radiation. CONCLUSION: LDRT showed a clinical relevant pain relief at 6 weeks after radiotherapy. The long-term effect of LDRT, however, was limited. A randomized placebo-controlled trial is necessary to assess the effect of LDRT on pain in patients with OA of the hip or knee joint.

Validade dos critérios de classificação da osteoartrite de joelho: ELSA-Brasil Musculoesquelético (ELSA-Brasil ME) / Validity of the knee osteoarthritis classification criteria: ELSA-Brasil Musculoskeletal (ELSA-Brasil ME)

Introdução: Vários critérios de classificação de osteoartrite (OA) de joelhos estão disponíveis na literatura, geralmente divididos em clínicos, clínico-radiográficos e radiográficos. A existência de diferentes critérios de classificação de OA de joelhos dificulta uniformizar e comparar resultados em estudos epidemiológicos, assim como a investigação de fatores de risco e manifestações clínicas associados à OA de joelhos. O conhecimento sobre a capacidade desses diferentes critérios em discriminar indivíduos com e sem OA, assim como conhecer a força de associação de fatores de risco, da presença de dor e de limitação funcional com os diferentes critérios, é essencial para se compreender as vantagens e limitações do uso de cada um deles. Objetivo: avaliar a validade de diferentes critérios de classificação de OA de joelhos em uma amostra de servidores públicos acompanhados pelo Estudo Longitudinal de Saúde do Adulto, ELSA-Brasil Musculoesquelético (ELSA-Brasil ME). Método: trata-se de um estudo transversal de validação de diferentes critérios de classificação de OA de joelho, a saber: OA sintomática, OA radiográfica, OA pelo American College of Rheumatology (ACR clínico e clínico-radiográfico) e OA pela definição do National Institute for Health and Care Excellence (NICE). Os participantes do estudo foram provenientes da coorte ELSA-Brasil ME, um estudo ancilar ao Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil). O ELSA-Brasil ME acompanha 2901 servidores públicos, ativos e aposentados, em um dos seis centros de investigação do ELSA-Brasil, localizado no estado de Minas Gerais, Brasil. O presente estudo foi realizado em uma subamostra de conveniência com 250 participantes do ELSA-Brasil ME, de ambos os sexos, com idade entre 39 e 78 anos. A avaliação foi feita por uma reumatologista (RCCM) no período de fevereiro de 2014 a junho de 2015. Apenas um joelho por indivíduo foi incluído, aquele com OA pela reumatologista. Quando ambos ou nenhum dos joelhos apresentava OA, foi feita a seleção por sorteio aleatório simples. Avaliou-se o desempenho dos critérios de classificação de OA descritos anteriormente, tendo como padrão-referência a avaliação clínico-radiográfica da reumatologista. Foram apresentados dados de prevalência, sensibilidade, especificidade, valores preditivos positivo e negativo e acurácia (IC 95%;α=5%). Posteriormente, a validade de construto convergente desses critérios foi avaliada a partir da associação entre a presença de OA de joelho identificada pelos critérios e as seguintes variáveis explicativas: índice de massa corporal (IMC), dor atual e limitação funcional (subjetiva e objetiva). A presença da dor atual em joelhos e a limitação funcional subjetiva foram avaliadas pelo Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) e a limitação funcional objetiva pelo teste sentar e levantar repetido. Associações foram testadas por modelos de regressão logística binária e multinomial (IC 95%;α=5%). Resultados: a idade média foi de 56,1 anos (DP=8,7), 51,2% eram homens. A maior prevalência de OA ocorreu na avaliação da reumatologista (39,2%), seguido de OA pelo NICE (36,8%) e pelo critério OA radiográfica (22,0%). OA radiográfica demonstrou sensibilidade e especificidade de 51,0% e 96,7%, respectivamente. A definição pelo NICE apresentou sensibilidade de 57,0% e especificidade de 76,3%. Os demais critérios mostraram boa especificidade, mas sensibilidade menor que 30,0%. Na avaliação de validade de construto convergente, IMC, dor atual e limitação funcional subjetiva se associaram à OA de joelho identificada por todos os critérios, sendo a magnitude da associação particularmente forte entre dor atual e OA segundo o critério ACR clínico (OR 21,7; IC95% 7,12-66,12) e entre limitação funcional subjetiva e OA segundo o NICE (OR 32,5; IC95% 13,4-79,0). Limitação funcional objetiva apresentou associação com os critérios OA sintomática e ACR clínico e clínico-radiográfico. Conclusões: o presente estudo demonstrou que dentre os critérios avaliados a OA radiográfica demonstrou melhor desempenho quanto à sensibilidade e especificidade, seguido pela definição de OA pelo NICE. Os critérios OA sintomática e OA pelo ACR clínico e clínico-radiográfico não se mostraram adequados para estudos que objetivam avaliar prevalência, devido à baixa sensibilidade dos mesmos. Entretanto, podem ser uma alternativa em estudos longitudinais nos quais é favorável o uso de critérios com boa especificidade. Quanto à validade de construto convergente, de forma geral, os resultados encontrados oferecem suporte para todos os critérios investigados, já que houve associação de IMC, dor atual e limitação funcional subjetiva com todos os critérios e a limitação funcional objetiva apenas não se associou à OA radiográfica e ao NICE. É importante ressaltar que a escolha de qual critério utilizar em um estudo requer levar em conta qual combinação melhor atende aos objetivos preconizados pelo estudo.

Introduction: the classification criteria for knee osteoarthritis (OA) available in the literature are usually divided into three main groups; clinical, clinical-radiographic and radiographic. The existence of different knee OA classification criteria makes it difficult to standardize and compare results in epidemiological studies, and also to investigate risk factors and clinical manifestations associated with knee OA. It is essential to understand the extent to which these different criteria are able to discriminate between subjects with and without OA. It is also important to know the strength of association of the following items with the different criteria: risk factors, the presence of pain and the functionality Objective: To evaluate the validity of different knee osteoarthritis (OA) classification criteria: radiographic OA, symptomatic OA, clinical and clinical-radiographic criteria of the American College of Rheumatology (ACR) and the OA definition proposed by the National Institute for Health and Care Excellence (NICE). Method: A cross-sectional study of the validity of different knee OA classification criteria, radiographic OA, symptomatic OA, clinical and clinical-radiographic criteria of the American College of Rheumatology (ACR) and the OA definition proposed by the National Institute for Health and Care Excellence (NICE). The subjects were from the ELSA-Brasil Musculoskeletal cohort (ELSA-Brasil MSK), an ancillary investigation on musculoskeletal disorders of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). The ELSA- Brasil MSK follows 2901 active and retired civil servants at one of the six ELSA-Brasil investigations centers, located in the State of Minas Gerais, Brazil. The present study was carried out using a convenience subsample with 250 male and female subjects aged between 39 and 78 selected from ELSA-Brasil MSK. The assessment was made by a rheumatologist (RCCM) between February 2014 and June 2015. Only one knee per subject was included i.e., the one that had OA according to the rheumatologist and, when both or none of the knees were affected, one knee was randomly selected for analysis. The performance of the classification criteria of knee OA described before was evaluated, using as reference-standard the clinicalradiographic evaluation of the rheumatologist. OA prevalence, sensitivity, specificity, positive and negative predictive values and accuracy were presented (CI 95%; α = 5%). After that the construct validity of the criteria was evaluated by the relationship between the presence of knee OA identified by the criteria and the following explanatory variables: body mass index (BMI), pain and the functional limitation. The presence of current pain in knees and the subjective functional limitation were evaluated using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the objective functional limitation was evaluated by the five-times sitto-stand test (FTSTS). Associations were tested by bivariate and multinomial logistic regression models (CI 95% ;α=5%). Mean age was 56.1 years (SD=8.7); 51.2% were male. The highest knee OA prevalence was observed in OA according to the rheumatologist, followed by the NICE definition (36,8%) and radiographic OA (22.0%).The sensitivity and the specificity of radiographic OA were 51% and 96.7%, respectively, while the NICE definition showed 57.0% and 76.3%, respectively. The other OA criteria showed good levels of specificity, but the levels of sensitivity were below 30%. In the convergent construct validity evaluation, BMI, current pain and subjective functional limitation were associated with knee OA identified by all criteria. The magnitude of the estimates were particularly strong between current pain and OA according to the ACR clinical criteria (OR 21.7; 95%CI 7.12-66.12) and between subjective functional limitation and OA according to NICE (OR 32.5; 95%CI 13.4- 79.0). The objective functional limitation was associated with symptomatic OA and with clinical and clinical-radiographic ACR criteria. Conclusions: the present study demonstrated that among the evaluated criteria, radiographic OA showed the best performance, followed by the NICE OA definition. The other criteria, namely symptomatic OA, clinical ACR and clinical-radiographic ACR were not adequate for studies that aim to evaluate prevalence, due to the low sensitivity of these criteria. However, they may be an alternative in longitudinal studies in which it is appropriate to use criteria with good specificity. Regarding the convergent construct validity, overall, our results offer support for all of the investigated criteria, since there was an association of BMI, pain and subjective functional limitation with all the criteria and the objective functional limitation was not radiographic OA and NICE. It is important to emphasize that the choice of criteria for a study requires deciding which the combination best meets the study objectives.

Effect of Early Surgery vs Physical Therapy on Knee Function Among Patients With Nonobstructive Meniscal Tears: The ESCAPE Randomized Clinical Trial.

Importance: Despite recent studies suggesting arthroscopic partial meniscectomy (APM) is not more effective than physical therapy (PT), the procedure is still frequently performed in patients with meniscal tears. Objective: To assess whether PT is noninferior to APM for improving patient-reported knee function in patients with meniscal tears. Design, Setting, and Participants: Noninferiority, multicenter, randomized clinical trial conducted in 9 hospitals in the Netherlands. Participants were aged 45 to 70 years with nonobstructive meniscal tears (ie, no locking of the knee joint). Patients with knee instability, severe osteoarthritis, and body mass index greater than 35 were excluded. Recruitment took place between July 17, 2013, and November 4, 2015. Participants were followed up for 24 months (final participant follow-up, October 11, 2017). Interventions: Three hundred twenty-one participants were randomly assigned to APM (n = 159) or a predefined PT protocol (n = 162). The PT protocol consisted of 16 sessions of exercise therapy over 8 weeks focused on coordination and closed kinetic chain strength exercises. Main Outcomes and Measures: The primary outcome was change in patient-reported knee function on the International Knee Documentation Committee Subjective Knee Form (range, 0 to 100; from worse to best) from baseline over a 24-month follow-up period. The noninferiority margin was defined as a difference between treatment groups of 8 points and was assessed with a 1-sided α of .025. The primary analysis followed the intention-to-treat principle. Results: Among 321 patients who were randomized (mean [SD] age, 58 [6.6] years; 161 women [50%]), 289 (90%) completed the trial (161 women and 158 men). In the PT group, 47 participants (29%) had APM during the 24-month follow-up period, and 8 participants randomized to APM (5%) did not have APM. Over a 24-month follow-up period, knee function improved in the APM group by 26.2 points (from 44.8 to 71.5) and in the PT group by 20.4 points (from 46.5 to 67.7). The overall between-group difference was 3.6 points (97.5% CI, -∞ to 6.5; P value for noninferiority = .001). Adverse events occurred in 18 participants in the APM group and 12 in the PT group. Repeat surgery (3 in the APM group and 1 in the PT group) and additional outpatient visits for knee pain (6 in the APM group and 2 in the PT group) were the most frequent adverse events. Conclusions and Relevance: Among patients with nonobstructive meniscal tears, PT was noninferior to APM for improving patient-reported knee function over a 24-month follow-up period. Based on these results, PT may be considered an alternative to surgery for patients with nonobstructive meniscal tears. Trial Registration: ClinicalTrials.gov Identifier: NCT01850719.

Inter- and Intraobserver Reliabilities of Four Different Radiographic Grading Scales of Osteoarthritis of the Knee Joint.

The purpose of this study was to investigate the interobserver and intraobserver reliabilities of four different radiographic grading scale of osteoarthritis (OA) of the knee joint, namely, Kellgren-Lawrence (KL), Ahlback, Brandt, and OA Research Society International (OARSI). One consultant orthopaedic surgeon and one rheumatologist who were familiar with these OA grading scales participated in the study. Radiological assessments were performed in random order by each observer on two separate occasions, at least 2 weeks apart. K-statistics were used to establish a relative level of agreement between the observers for the two readings and between separate readings by the same observer. A total of 140 patients (53 males and 87 females) with a mean age of 61.2 years (range, 50-72 years) were included in the study. Intraobserver reliability for KL was substantial for observer A (κ: 0.753) and moderate for observer B (κ: 0.573). Interobserver reliability for KL was moderate for both observers (κ: 0.499 and 0.458, respectively). Intraobserver reliability for Ahlback was substantial for observer A (κ: 0.768) and moderate for observer B (κ: 0.561). Interobserver reliability for Ahlback was fair for both observers (κ: 0.365 and 0.204, respectively). Intraobserver reliability for Brandt was substantial for observer A (κ: 0.741) and moderate (κ: 0.425) for observer B. Interobserver reliability for Brandt was fair for both observers (κ: 0.308 and κ: 0.246, respectively). Intraobserver reliability for OARSI was substantial for observer A (κ: 0.792) and moderate for observer B (κ: 0.508). Interobserver reliability for OARSI was moderate for observer A (κ: 0.425) and slight for observer B (κ: 0.175). None of the studied OA grading scales showed acceptable reliability (κ > 0.80). The evaluation of patients with OA should not be dependent on radiographic findings alone; clinical findings should also guide the treatment and follow-up.

Association between the severity of symptomatic knee osteoarthritis and cumulative metabolic factors.

BACKGROUND: The association between cumulative metabolic syndrome (MS) factors and knee osteoarthritis (KOA) has been highlighted over the past two decades. AIMS: To clarify the relationship between cumulative MS factors and symptomatic KOA. METHODS: A cross-sectional survey involving 119 women aged 45-88 years who were scheduled to undergo knee surgery was conducted. They were stratified into tertiles of symptoms as assessed by the Japanese Orthopedic Association score for KOA. Multinomial logistic regressions were performed using the severity of symptomatic KOA as the dependent variable and each MS factor or the cumulative MS factors as the independent variables. RESULTS: Logistic regression analyses were performed with the upper tertile of stratified symptoms of subjects used as the reference group. After adjustment for confounders, KOA patients who had two (p = 0.004) or three or more (p < 0.0001) MS factors were significantly more likely to have severe symptoms compared to those who had no MS factors. MS factors excluding obesity were similarly analyzed. Even after additional adjustment for body mass index (BMI), KOA patients who had two or more (p = 0.005) MS factors were significantly more likely to have severe symptoms. CONCLUSION: Among KOA female patients diagnosed using radiographic definition, the severity of symptomatic KOA was significantly associated with hypertension, dyslipidemia, and the number of MS factors after adjustment for age, BMI, strength of the knee extensor, and Kellgren-Lawrence grade. The severity of radiographic KOA was not associated with any MS factor or cumulative MS factors.

Analysis and multiclass classification of pathological knee joints using vibroarthrographic signals.

BACKGROUND AND OBJECTIVE: Vibroarthrography (VAG) is a method developed for sensitive and objective assessment of articular function. Although the VAG method is still in development, it shows high accuracy, sensitivity and specificity when comparing results obtained from controls and the non-specific, knee-related disorder group. However, the multiclass classification remains practically unknown. Therefore the aim of this study was to extend the VAG method classification to 5 classes, according to different disorders of the patellofemoral joint. METHODS: We assessed 121 knees of patients (95 knees with grade I-III chondromalacia patellae, 26 with osteoarthritis) and 66 knees from 33 healthy controls. The vibroarthrographic signals were collected during knee flexion/extension motion using an acceleration sensor. The genetic search algorithm was chosen to select the most relevant features of the VAG signal for classification. Four different algorithms were used for classification of selected features: logistic regression with automatic attribute selection (SimpleLogistic in Weka), multilayer perceptron with sigmoid activation function (MultilayerPerceptron), John Platt's sequential minimal optimization algorithm implementation of support vector classifier (SMO) and random forest tree (RandomForest). The generalization error of classification algorithms was evaluated by stratified 10-fold cross-validation. RESULTS: We obtained levels of accuracy and AUC metrics over 90%, more than 93% sensitivity and more than 84% specificity for the logistic regression-based method (SimpleLogistic) for a 2-class classification. For the 5-class method, we obtained 69% and 90% accuracy and AUC respectively, and sensitivity and specificity over 91% and 69%. CONCLUSIONS: The results of this study confirm the high usefulness of quantitative analysis of VAG signals based on classification techniques into normal and pathological knees and as a promising tool in classifying signals of various knee joint disorders and their stages.

Indication Criteria for Total Knee Arthroplasty in Patients with Osteoarthritis - A Multi-perspective Consensus Study.

Background and Objectives Knee osteoarthritis (OA) is a significant public health burden. Rates of total knee arthroplasty (TKA) in OA vary substantially between geographical regions, most likely due to the lack of standardised indication criteria. We set out to define indication criteria for the German healthcare system for TKA in patients with knee OA, on the basis of best evidence and transparent multi-stakeholder consensus. Methods We undertook a complex mixed methods study, including an iterative process of systematic appraisal of existing evidence, Delphi consensus methods and stakeholder conferences. We established a consensus panel representing key German national societies of healthcare providers (orthopaedic surgeons, rheumatologists, pain physicians, psychologists, physiotherapists), payers, and patient representatives. A priori defined consensus criteria were at least 70% agreement and less than 20% disagreement among the consensus panel. Agreement was sought for (1) core indication criteria defined as criteria that must be met to consider TKA in a normal patient with knee OA, (2) additional (not obligatory) indication criteria, (3) absolute contraindication criteria that generally prohibit TKA, and (4) risk factors that do not prohibit TKA, but usually do not lead to a recommendation for TKA. Results The following 5 core indication criteria were agreed within the panel: 1. intermittent (several times per week) or constant knee pain for at least 3 - 6 months; 2. radiological confirmation of structural knee damage (osteoarthritis, osteonecrosis); 3. inadequate response to conservative treatment, including pharmacological and non-pharmacological treatment for at least 3 - 6 months; 4. adverse impact of knee disease on patient's quality of life for at least 3 - 6 months; 5. patient-reported suffering/impairment due to knee disease. Additional indication criteria, contraindication criteria, and risk factors for adverse outcome were also agreed by a large majority within the multi-perspective stakeholder panel. Conclusion The defined indication criteria constitute a prerequisite for appropriate provision of TKA in patients with knee OA in Germany. In eligible patients, shared-decision making should eventually determine if TKA is performed or not. The next important steps are the implementation of the defined indication criteria, and the prospective investigation of predictors of success or failure of TKA in the context of routine care provision in Germany.

Severe arthritis predicts greater improvements in function following total knee arthroplasty.

PURPOSE: Although excellent outcomes are routinely reported following total knee replacement, up to 20 % of patients remain dissatisfied. The aim of this study was to determine whether pre-operative radiographic classification was associated with functional outcomes following surgery. METHODS: A retrospective review of a prospective arthroplasty database identified 256 patients that fulfilled the inclusion criteria over an 18-month period. Baseline demographic data on all patients were collected prospectively. All pre-operative radiographs were assessed using the Kellgren and Lawrence (K&L) classification system. Patients were prospectively assessed using the American Knee Society Score pre-operatively and at 1, 3 and 5 years post-surgery. RESULTS: An association was found between the pre-operative radiographic severity of arthritis and the pre-operative American Knee Society Knee (AKSK) scores, with worsening radiographic grade corresponding to worsening AKSK scores (p = 0.020). There was an association between K&L classification and improvement in AKSK scores from pre-operative to 1 year (p = 0.003) and 3 years (p = 0.04), with K&L grades 3 and 4 demonstrating the most significant improvements. On multivariate regression analysis, K&L classification was the only significant predictor of improvement in AKSK at 1 year (p = 0.009). No correlation was found between K&L grade and the American Knee Society Functional Scores at any stage. CONCLUSIONS: The results of this study may help to improve satisfaction rates in total knee replacement by targeting treatment. Patients can be counselled that although radiographic severity of arthritic changes can predict knee-specific functional improvement, the extent of their global functional improvement cannot. LEVEL OF EVIDENCE: IV.

Clinical comparison of oral administration and viscosupplementation of hyaluronic acid (HA) in early knee osteoarthritis.

PURPOSE: Osteoarthritis (OA) is a progressive, chronic and degenerative joint disease characterized by a loss of articular cartilage. Treatment of OA is largely palliative based on nonsteroidal anti-inflammatory drugs, opioids and injections of steroids. Regarding conservative treatment, intra-articular injections of hyaluronic acid (HA) can play a role in early symptomatic knee OA. MATERIALS AND METHODS: Between August 2015 and September 2015, sixty patients (32 males and 28 females) between 40 and 70 years old were randomly allocated into two groups: Half were treated with three weekly intra-articular injections of hyaluronic acid 1.6 % (group A), while the others were treated with Syalox 300 Plus® (hyaluronic acid 300 mg + Boswellia serrata extract 100 mg) 1 tab/die for 20 days and afterward Syalox 150® (hyaluronic acid 150 mg) 1 tab/die for other 20 days (group B). All patients were evaluated clinically with American Knee Society Score (AKSS) and visual analogue scale (VAS) for the pain before the treatment and after 3 months. RESULTS: AKSS of the patients in both groups was significantly increased by the treatment, and VAS score was significantly reduced. In both groups, two subgroups were created with patients older than 60 years and patients younger than 60 years. Better results are reported in younger patients of group A and older subjects in group B. CONCLUSIONS: Despite several limitations, the results of the study have shown that HA injection and oral administration may have beneficial therapeutic effects on patients with early osteoarthritis. Different outcomes in younger and older subject suggested a combined therapy first with local infiltrations and then with oral composition.

The relationship between meniscal pathology and osteoarthritis depends on the type of meniscal damage visible on magnetic resonance images: data from the Osteoarthritis Initiative.

OBJECTIVE: To determine the association of different types of meniscal pathology with knee pain, bone marrow lesion (BML) volume, and end-stage knee osteoarthritis (esKOA). DESIGN: Participants were selected from an ancillary project to the Osteoarthritis Initiative (OAI) who had at least one knee with symptomatic osteoarthritis. Baseline magnetic resonance images (MRI) were evaluated for meniscal pathology using a modified International Society of Arthroscopy, Knee Surgery, and Orthopaedic Sports Medicine (ISAKOS) classification system. We collapsed 10 types of meniscal pathology into five categories: normal, intrameniscal signal, morphological deformity/extrusion (altered meniscal shape and/or extrusion but no apparent substance loss), tear, and maceration. Outcomes included Western Ontario and McMaster Universities osteoarthritis index (WOMAC) knee pain and BML volume at baseline and after 2 years. We defined the prevalence of esKOA based on a validated algorithm. We performed logistic regression and adjusted for age, sex, and body mass index (BMI). RESULTS: The 463 participants (53% male) included in the analysis had mean age 63 (9.2) years, BMI 29.6 (4.6) kg/m2, and 71% had Kellgren-Lawrence grade ≥2. Morphological deformity/extrusion and maceration, but no other types of meniscal pathology, were associated with BML volume (morphological deformity/extrusion odds ratio [OR] = 2.47, 95% CI: 1.49, 4.09, maceration OR = 5.85, 95% CI: 3.40, 10.06) and change in BML volume (morphological deformity/extrusion OR = 2.17, 95% CI: 1.37, 3.45, maceration OR = 3.12, 95% CI: 1.87, 5.19). Only maceration was associated with baseline WOMAC knee pain (OR = 2.82, 95% CI: 1.79, 4.43) and prevalence of esKOA (OR = 7.53, 95% CI: 4.25, 13.31). CONCLUSIONS: Based on MRI, morphologic deformity/extrusion and maceration rather than intrameniscal signal or tear were associated with osteoarthritis severity and progression, which highlights the importance of differentiating distinct types of meniscal pathology.