The effects of drainage tube on pain and functional recovery after unicompartmental knee arthroplasty / Efeitos do tubo de drenagem na dor e recuperação funcional após artroplastia unicompartimental do joelho

ABSTRACT Objective: The objective of this study was to evaluate the impact of drainage tube placement on postoperative pain, recovery, and opioid consumption within a 72-hour period following unicompartmental knee arthroplasty (UKA). Methods: Patients with medial knee osteoarthritis who underwent UKA from January 2019 to August 2020 were enrolled in the study and divided into two groups based on whether they received a drain postoperatively. Results: The drainage group had significantly lower VAS scores on day 1, day 2, and day 3, in addition to significantly smaller changes in the circumference of the knee joint within 3 days postoperatively (P <0.05). The ROM in the drainage group significantly increased at 3 days and 1 month post-surgery, with a statistically significant difference in morphine consumption between the two groups at 3 days (P<0.05). The incidence of postoperative nausea and vomiting (5 cases) and wound bleeding (1 case) was lower in the drainage group compared to the non-drainage group (P<0.05). Conclusions: The placement of a drainage tube in UKA may reduce the swelling of knee joint and pain, which not only reduces the use of Opioid but also facilitates early functional activities of the knee joint. Level of Evidence III; Retrospective Comparative Study.

RESUMO Objetivo: O objetivo deste estudo foi avaliar o impacto da implantação do tubo de drenagem na dor pós-operatória, na recuperação e no consumo de opioides em um período de 72 horas após a artroplastia unicompartimental do joelho (UKA). Métodos: Pacientes com osteoartrite medial do joelho submetidos à UKA de janeiro de 2019 a agosto de 2020 foram incluídos no estudo e divididos em dois grupos com base no fato de terem ou não recebido um dreno no pós-operatório. Resultados: O grupo de drenagem apresentou escores EVA significativamente menores no dia 1, no dia 2 e no dia 3, além de alterações significativamente menores na circunferência da articulação do joelho em 3 dias de pós-operatório (P <0,05). A ADM no grupo de drenagem aumentou significativamente em 3 dias e 1 mês após a cirurgia, com uma diferença estatisticamente significativa no consumo de morfina entre os dois grupos em 3 dias (P<0,05). A incidência de náuseas e vômitos no pós-operatório(5 casos) e sangramento da ferida (1 caso) foi menor no grupo de drenagem em comparação com o grupo sem drenagem (P<0,05). Conclusão: A utilização de tubo de drenagem na UKA pode reduzir o edema articular do joelho e a dor, reduzindo o uso de opioides e facilitando as atividades funcionais iniciais da articulação do joelho. Nível de Evidência III; Estudo Comparativo Retrospectivo.

Knee osteoarthritis and aging: evaluation of the different muscles of thigh / Artrosis de rodilla y envejecimiento: investigación de los diferentes músculos del muslo / Osteoartrite de joelho e envelhecimento: investigação de diferentes músculos da coxa

ABSTRACT Introduction: Osteoarthritis (OA) is a chronic inflammatory degenerative disease, characterized by progressive degeneration of the articular cartilage, affecting mostly the knee joint. The elderly population is the most affected, intensifying the aging process. The concentration of intramuscular adipose tissue in the thigh muscles and knee OA at different ages remains under investigation. Objective: Investigate the cross-sectional area of thigh muscles at different ages with the relationship of the presence of intramuscular fat and knee OA. Methods: 80 participants were paired into 4 groups: Young Osteoarthritis Group and Old Osteoarthritis Group, both sedentary with knee OA diagnosis II or III; Healthy Young Group and Healthy Old Group, both healthy and sedentary. The groups were paired according to gender and body mass index, submitted to physiotherapeutic evaluation, WOMAC questionnaire, knee X-ray and thigh CT scans. Morphometric analysis was performed manually with ITK-SNAP software (version 3.6), by a single evaluator. Statistical analysis used the one-way ANOVA test followed by Bonferroni post-hoc for dependent variables (p≤0.05). Results: Comparison of the cross-sectional area of the rectus femoris, vastus lateralis, semitendinosus, sartorius and gracilis muscles between the groups indicated no significant differences (p>0.05). The study of attenuation for muscle adipose tissue indicated no significant difference in the values of between the OA-Young and Aged-S groups for all the muscles evaluated. Conclusion: Young individuals with knee OA present muscle morphological characteristics similar to those found during the aging process, characterizing early aging of the thigh muscles. Level of Evidence III; Retrospective cross-sectional and observational study.

RESUMEN Introducción: La artrosis (OA) es una enfermedad inflamatoria degenerativa crónica, caracterizada por la degeneración progresiva del cartílago articular, que afecta principalmente a la articulación de la rodilla. La población anciana es la más afectada, intensificándose el proceso de envejecimiento. La concentración de tejido adiposo intramuscular en los músculos del muslo y la OA de rodilla a diferentes edades sigue siendo objeto de investigación. Objetivo: Investigar el área transversal de los músculos del muslo a diferentes edades con la relación de la presencia de grasa intramuscular y la OA de rodilla. Métodos: Se emparejó a 80 participantes en 4 grupos: Grupo de jóvenes con osteoartritis y Grupo de mayores con osteoartritis, ambos sedentarios y con diagnóstico de OA de rodilla II o III; Grupo de jóvenes sanos y Grupo de mayores sanos, ambos sanos y sedentarios. Los grupos fueron emparejados según sexo e índice de masa corporal, sometidos a evaluación fisioterapéutica, cuestionario WOMAC, exámenes radiográficos de las rodillas y tomografía computarizada del muslo. El análisis morfométrico se realizó manualmente con el software ITK-SNAP (versión 3.6), por un único evaluador. En el análisis estadístico se utilizó la prueba ANOVA unidireccional seguida del post-hoc de Bonferroni para las variables dependientes (p≤0,05). Resultados: La comparación del área transversal de los músculos recto femoral, vasto lateral, semitendinoso, sartorio y gracilis entre los grupos no indicó diferencias significativas (p>0,05). El estudio de la atenuación para el tejido adiposo muscular no indicó diferencias significativas en los valores de entre los grupos OA-Young y Aged-S para todos los músculos evaluados. Conclusión: Individuos jóvenes con OA de rodilla presentan características morfológicas musculares similares a las encontradas durante el proceso de envejecimiento, caracterizando el envejecimiento precoz de los músculos del muslo. Nivel de Evidencia III; Estudio transversal y observacional retrospectivo.

RESUMO Introdução: A osteoartrite (OA) é uma doença inflamatória crônico-degenerativa, caracterizada pela degeneração progressiva da cartilagem articular, acometendo em maior parte a articulação do joelho. A população idosa é a mais atingida, intensificando o processo de envelhecimento. A concentração de tecido adiposo intramuscular nos músculos da coxa e a OA de joelho em diferentes idades permanece em investigação. Objetivo: Investigar a área de secção transversa dos músculos da coxa em diferentes idades com a relação da presença de gordura intramuscular e OA de joelho. Métodos: 80 participantes foram pareados em 4 grupos: Grupo Osteoartrite Jovem e Grupo Osteoartrite Idoso, ambos sedentários com diagnóstico de OA de joelho II ou III; Grupo Jovem Saudável e Grupo Idoso Saudável, ambos saudáveis e sedentários. Os grupos foram pareados de acordo com sexo e índice de massa corporal, submetidos à avaliação fisioterapêutica, questionário WOMAC, exames de raio-x dos joelhos e tomografia computadorizada da coxa. A análise morfométrica foi realizada manualmente com software ITK-SNAP (versão 3.6), por um único avaliador. Análise estatística utilizou o teste ANOVA one-way seguido pelo post-hoc de Bonferroni, para variáveis dependentes (p≤0,05). Resultados: A comparação da área de secção transversa dos músculos reto femoral, vasto lateral, semitendinoso, sartório e grácil, entre os grupos, não indicou diferenças significativas (p>0,05). O estudo da atenuação para o tecido adiposo muscular não indicou diferença significativa nos valores de entre os grupos OA-Jovem e Idoso-S para todos os músculos avaliados. Conclusão: Indivíduos jovens com OA de joelho apresentam características morfológicas musculares semelhantes às encontradas durante o processo de envelhecimento, caracterizando um envelhecimento precoce dos músculos da coxa.Nível de Evidência III; Estudo retrospectivo transversal e observacional.

Medial condyle hypoplasia in adolescent and young adult patients with trochlear dysplasia: a retrospective study / Hipoplasia do côndilo medial em pacientes adolescentes e adultos jovens com displasia troclear: estudo retrospectivo

Abstract Objective: To determine the association between medial femoral condyle hypoplasia and trochlear dysplasia by analyzing the knee magnetic resonance imaging scans of young patients with or without trochlear dysplasia. Materials and Methods: This was a retrospective analysis of magnetic resonance imaging scans of the knees of young individuals (16-35 years of age): 30 patients with trochlear dysplasia and 30 individuals with no signs of patellofemoral instability. The ratios between the depth, width, and height of the medial and lateral femoral condyles (dLC/dMC, wLC/wMC, and hLC/hMC, respectively) were calculated, as was the ratio between the width of the medial condyle and the total width of the femur (wMC/FW). All of the values were determined in consensus by two radiologists. Results: We evaluated 60 patients: 30 with trochlear dysplasia and 30 without. The mean dLC/dMC, wLC/wMC, and hLC/hMC ratios were higher in the patients than in the controls (p < 0.05), whereas the mean wMC/FW ratio was lower in the patients (p < 0.05). The optimal cutoff values, obtained by calculating the areas under the receiver operating characteristic curves, were 1.0465 for the dLC/dMC ratio (76% sensitivity and 63.3% specificity), 0.958 for the wLC/wMC ratio (80% sensitivity and 73.3% specificity), and 1.080 for the hLC/hMC ratio (93.3% sensitivity and 93.3% specificity). Conclusion: Our findings confirm our hypothesis that trochlear dysplasia is associated with medial condyle hypoplasia.

Resumo Objetivo: Determinar a associação entre hipoplasia do côndilo femoral medial e displasia troclear mediante análise de ressonância magnética do joelho de pacientes jovens com displasia troclear e sem displasia troclear. Materiais e Métodos: Análise retrospectiva de exames de ressonância magnética de joelhos de indivíduos jovens (16 a 35 anos de idade), sendo 30 pacientes com displasia troclear e 30 indivíduos sem sinais de instabilidade femoropatelar. As razões entre a profundidade, largura e altura dos côndilos femorais mediais e laterais (dLC/dMC, wLC/wMC e hLC/hMC, respectivamente) foram calculadas, assim como a razão entre a largura do côndilo medial e a largura total do fêmur (wMC/FW). Todos os valores foram determinados em consenso por dois radiologistas Resultados: Foram incluídos no estudo 60 adolescentes e adultos jovens, 30 com displasia troclear e 30 sem displasia troclear. A média das razões dLC/dMC, wLC/wMC, hLC/hMC foi maior nos pacientes do que nos controles (p < 0,05), enquanto a média da razão wMC/FW foi menor nos pacientes (p < 0,05). Os valores de corte ótimos obtidos da área sob a curva característica de operação do receptor foram 1,0465 para dLC/dMC (sensibilidade de 76% e especificidade de 63,3%), 0,958 para wLC/wMC (sensibilidade de 80% e especificidade de 73,3%) e 1,080 para hLC/hMC (sensibilidade de 93,3% e especificidade de 93,3%). Conclusão: Nossos resultados confirmam nossa hipótese de que a displasia troclear está associada a hipoplasia do côndilo medial.

Assessment of the relationship between smoking and meniscal injury / Avaliação da relação entre tabagismo e lesão meniscal

Abstract Objective: To determine whether being a smoker and the years of smoking correlate with the presence and degree of meniscal injury. Materials and Methods: Individuals who underwent magnetic resonance imaging of the knee were divided into two groups: smokers and nonsmokers. For each smoker, the total smoking history was calculated by multiplying the daily consumption (packs/day) by the years of smoking, and the result is expressed as pack-years. In the evaluation of meniscal injury, the grade of injury was recorded. The thickness of the subcutaneous adipose tissue, as an indicator of obesity, was measured at the medial knee on axial plane images. The relationships that smoking and obesity had with meniscal injury were analyzed statistically. Results: A total of 156 individuals were included in the study. The smoker group consisted of 48 individuals (30.8%), and the nonsmoker group consisted of 108 (69.2%). The meniscus was normal in one (2.1%) of the smokers and in 32 (29.6%) of the nonsmokers (p < 0.0001). The median subcutaneous adipose tissue thickness was 23 mm and 24 mm in the smokers and nonsmokers, respectively (p = 0.900). A moderate but statistically significant correlation was observed between packs/day and injury grade, as well as between pack-years and injury grade (r = 0.462, p = 0.001 and r = 0.523, p = 0.001, respectively). Smoking and age significantly increased the risk of meniscal injury, by 31.221 times (p = 0.001) and 1.076 times (p < 0.001), respectively. Conclusion: Our findings indicate that current smoking and smoking history correlate significantly with meniscal injury grade.

Resumo Objetivo: Determinar a correlação do tabagismo e do tempo de tabagismo com a presença e o grau de lesão do menisco. Materiais e Métodos: Foram incluídos pacientes submetidos a ressonância magnética do joelho e divididos em dois grupos: fumantes e não fumantes. O consumo total de cigarros dos pacientes foi calculado multiplicando-se a quantidade diária de cigarros (maços/dia) pelo tempo de tabagismo (anos). O grau mais alto de lesão foi registrado na avaliação da lesão meniscal. A espessura do tecido adiposo subcutâneo foi medida com base em imagem do joelho em plano axial, como indicador de obesidade. A relação entre tabagismo, obesidade e lesão meniscal foi analisada estatisticamente. Resultados: Foram incluídos no estudo 156 indivíduos. O grupo de fumantes consistiu de 48 (30,8%) indivíduos e o grupo de não fumantes, de 108 (69,2%) indivíduos. O menisco estava normal em um (2,1%) fumante e em 32 (29,6%) não fumantes (p < 0,0001). A espessura média do tecido adiposo subcutâneo em fumantes foi 23 mm e nos não fumantes foi 24 mm, com valor de p = 0,900. Foi observada correlação moderada e estatisticamente significante entre o grau de lesão por pacote/dia (r = 0,462, p = 0,001) e o grau de lesão por pacote × ano (r = 0,523, p = 0,001). O tabagismo e a idade afetaram significativamente o risco de lesão do menisco (31,221 vezes, p = 0,001 e 1,076 vez, p < 0,001, respectivamente). Conclusão: Foi encontrada correlação significativa entre tabagismo/dia e grau de lesão do menisco e pacote de tabagismo × ano e grau de lesão do menisco.

An Unusual Cause of Posterior Knee Pain: Mucoid Degeneration of the Anterior Cruciate Ligament - Case Report / Uma causa incomum de dor posterior no joelho: degeneração mucóide do ligamento cruzado anterior - Relato de caso

Abstract Mucoid degeneration of the anterior cruciate ligament (ACL) is an uncommon cause of pain in the posterior region of the knee, of unknown pathophysiology and underdiagnosed. The best treatment modality is still under discussion. Resection of the lesion with partial ACL debridement has shown good results without the occurrence of instability. The authors present a case of mucoid degeneration of the ACL treated with resection of the mucoid degeneration and partial debridement of the ACL by arthroscopy.

Resumo A degeneração mucoide do ligamento cruzado anterior (LCA) é uma causa pouco frequente de dor na região posterior do joelho, de patofisiologia desconhecida e subdiagnosticada. A melhor modalidade de tratamento ainda está em discussão. A ressecção da lesão com desbridamento parcial do LCA tem apresentado bons resultados, sem a ocorrência de instabilidade. Os autores apresentam um caso de degeneração mucoide do LCA tratado com ressecção da degeneração mucoide e desbridamento parcial do LCA por artroscopia.

Risk Factors for Symptomatic Cyclops Lesion Formation after Anterior Cruciate Ligament Reconstruction / Fatores de risco para formação de lesão cyclops sintomática após a reconstrução do ligamento cruzado anterior

Abstract Objective To evaluate the incidence of symptomatic cyclops lesions requiring surgical treatment after anterior cruciate ligament (ACL) reconstruction and to establish possible intraoperative risk factors related to it. Methods Three hundred and eighty-nine patients aged between 18 and 50 years who underwent primary ACL reconstruction were retrospectively evaluated. Patients were divided into groups according to the presence or absence of symptomatic cyclops lesions, and their characteristics were compared. Patients with associated lesions that required additional surgical procedures (except anterolateral extra-articular procedures) were not included. The rate of symptomatic cyclops lesions was recorded and the following parameters were evaluated: age, gender, time from injury to surgery, graft type and diameter, femoral tunnel perforation technique, fixation type, presence of knee hyperextension, preservation of the ACL remnant, associated anterolateral extra-articular procedure, associated meniscal injury and participation in sports. Results 389 patients were evaluated and 26 (6.7%) patients developed cyclops. The patients with and without cyclops lesions did not differ in age, time from injury to surgery, graft type or diameter, surgical technique, femoral fixation method, presence of knee hyperextension, remnant preservation and associated meniscal injury. The group with cyclops lesion had a higher proportion of females (10 (38.4%) vs 68 (18.7%); OR = 2.7; p= 0.015), higher proportion of extra-articular reconstruction (18 (11.8%) vs 8 (3.4%); OR = 3.8; p= 0.001) and higher proportion of sports practice (23 (8.6%) vs 3 (2.5%); OR = 3.6; p= 0.026). Conclusion In our series, 6.7% of the patients required arthroscopic removal of cyclops lesions. Female gender, associated extra-articular reconstruction and sports practice were factors related to this lesion. Remnant preservation had no relationship with cyclops lesion formation.

Resumo Objetivo Avaliar a incidência de lesões cyclops sintomáticas que precisam de tratamento cirúrgico após a reconstrução do ligamento cruzado anterior (LCA) e estabelecer os possíveis fatores de risco intraoperatórios relacionados a elas. Métodos Trezentos e oitenta e nove pacientes com idades entre 18 e 50 anos submetidos à reconstrução primária do LCA foram avaliados de forma retrospectiva. Os pacientes foram divididos em grupos de acordo com a presença ou ausência de lesões cyclops sintomáticas e suas características foram comparadas. Não foram incluídos pacientes com lesões associadas que necessitassem de outros procedimentos cirúrgicos (à exceção de procedimentos extra-articulares ântero-laterais). A taxa de lesões cyclops sintomáticas foi registrada e os seguintes parâmetros foram avaliados: idade, sexo, tempo da lesão à cirurgia, tipo e diâmetro do enxerto, técnica de perfuração do túnel femoral, tipo de fixação, presença de hiperextensão do joelho, preservação do LCA remanescente, associação a procedimento extra-articular ântero-lateral, lesão de menisco associada e participação em esportes. Resultados Dos 389 pacientes avaliados, 26 (6,7%) desenvolveram lesão cyclops. Os pacientes com e sem lesão cyclops não diferiram quanto à idade, tempo da lesão à cirurgia, tipo ou diâmetro do enxerto, técnica cirúrgica, método de fixação femoral, presença de hiperextensão do joelho, preservação do LCA remanescente e lesão de menisco associada. O grupo com lesão cyclops apresentou mais mulheres (10 [38,4%] vs. 68 [18,7%]; razão de probabilidades [OR] = 2,7; p= 0,015), maior proporção de reconstrução extra-articular (18 [11,8%] vs. 8 [3,4 %]; OR = 3,8; p= 0,001) e maior proporção de prática esportiva (23 [8,6%] vs. 3 [2,5%]; OR = 3,6; p= 0,026). Conclusão Em nossa série, 6,7% dos pacientes necessitaram de remoção artroscópica das lesões cyclops. O sexo feminino, a reconstrução extra-articular associada e a prática esportiva foram fatores relacionados a essa lesão. A preservação do menisco remanescente não foi associada à formação de lesões cyclops.

Where is tibial edema located in cases of osteomeniscal impingement? / Onde está o edema ósseo tibial em casos de impacto osteomeniscal?

Abstract Objective: To characterize the location of tibial edema related to meniscal degeneration with a flap displaced into the meniscotibial recess (osteomeniscal impingement) on magnetic resonance imaging (MRI). Materials and Methods: We evaluated 40 MRI examinations of patients submitted to surgery due to inferior displacement of a meniscal flap tear into the meniscotibial recess and peripheral bone edema. Tibial edema was quantified in the coronal and axial planes. Results: On coronal MRI sequences, edema started in the tibial periphery and extended for a mean of 5.6 ± 1.4 mm, or 7.4 ± 2.1% of the tibial plateau. In the craniocaudal direction, the mean extension was 8.8 ± 2.9 mm. The mean ratio between the extent of craniocaudal and mediolateral edema was 1.6 ± 0.6. In the axial plane, the edema started in the medial periphery and extended for a mean of 6.2 ± 2.0 mm, or 8.2 ± 2.9% of the tibial plateau. In the anteroposterior measurement, the mean start and end of the edema was 21.4 ± 5.4 mm and 35.7 ± 5.7 mm, respectively, or 43.4 ± 10.2% and 72.8 ± 11.1% of the tibial plateau. Conclusion: Apparently, tibial edema resulting from osteomeniscal impingement always starts in the periphery of the meniscus. In the coronal plane, it appears to be more extensive in the craniocaudal direction than in the mediolateral direction. In the axial plane, we found it to extend, on average, approximately 6.2 mm in the mediolateral direction and to be most commonly located from the center to the posterior region of the medial tibial plateau.

Resumo Objetivo: Caracterizar a localização do edema ósseo tibial relacionado a lesão meniscal degenerativa com fragmento deslocado no recesso meniscotibial (impacto osteomeniscal) por meio de ressonância magnética (RM). Materiais e Métodos: Quarenta RMs de pacientes submetidos a cirurgia por fragmento deslocado do menisco medial no recesso meniscotibial e edema ósseo periférico foram avaliadas. Edema ósseo tibial foi quantificado nos planos coronal e axial. Resultados: No plano coronal, o edema iniciou-se na periferia tibial e estendeu-se por 5,6 ± 1,4 mm, ou 7,4 ± 2,1% do platô. Na direção craniocaudal, o edema estendeu-se em média 8,8 ± 2,9 mm. A média entre a extensão do edema craniocaudal e mediolateral foi 1,6 ± 0,6. No plano axial, o edema iniciou-se na periferia medial e estendeu-se por 6,2 ± 2,0 mm, ou 8,2 ± 2,9% da medida da tíbia. Na medida anteroposterior, o edema iniciou-se em 21,4 ± 5,4 mm e terminou em 35,7 ± 5,7 mm ou iniciou-se em 43,4 ± 10,2% e terminou em 72,8 ± 11,1% do platô tibial. Conclusão: O edema ósseo tibial relacionado aos casos de impacto osteomeniscal sempre se inicia na periferia do menisco. Ele é mais extenso na direção craniocaudal do que mediolateral no plano coronal. No plano axial, ele estende-se por 6,2 mm de medial a lateral e é mais frequentemente localizado no centro da região posterior do platô medial.

Calculation of the Minimal Important Clinical Difference of the Lysholm and IKDC Scores After Anterior Cruciate Ligament Reconstruction / Cálculo da mínima diferença clínica importante dos escores Lysholm e IKDC após reconstrução do ligamento cruzado anterior

Abstract Objective To calculate the minimal important clinical difference (MICD) value for the Lysholm and International Knee Documentation Committee (IKDC) scores in a sample of patients submitted to anterior cruciate ligament reconstruction. Methods Primary, observational, retrospective, analytical study of participants submitted to anterior cruciate ligament reconstruction from March 2019 to December 2020 by the same surgeon, with a minimum follow-up of 6 months, analysis of knee function in the pre- and postoperative period by the Lysholm and IKDC scores, and answer to an anchor question at 6 months postoperatively for the calculation of the MICD of each score. Results A total of 59 patients participated in the study, with a mean age of 27.1 ± 5.7 years old. In the comparison between pre- and postoperative scores of all groups, there was an increase in values with statistical significance after intervention. The MICD was 5.5 for the Lysholm score, and the MICD value for the IKDC score could not be determined. Conclusion For the Lysholm score, the calculation of the MICD value by the anchor question method in the sample evaluated was 5.5. It was not possible to determine the value of the MICD for the IKDC score.

Resumo Objetivo Calcular o valor da mínima diferença clinicamente importante (MDCI) para os escores de Lysholm e International Knee Documentation Commitee (IKDC) na amostra de pacientes submetidos a reconstrução de ligamento cruzado anterior. Métodos Estudo primário, observacional, retrospectivo, analítico, de participantes submetidos a reconstrução do ligamento cruzado anterior no período de março de 2019 a dezembro de 2020, pelo mesmo cirurgião, com seguimento mínimo de 6 meses, análise da função do joelho no período pré e pós-operatório pelos escores de Lysholm e IKDC, e resposta a uma pergunta âncora aos 6 meses de seguimento pós-operatório, para o MDCI de cada escore. Resultados Participaram do estudo 59 pacientes, com média de idade de 27,1 ± 5,7 anos. Na comparação dos escores pré- e pós-operatórios de todos os grupos, observa-se aumento dos valores com significância estatística após a intervenção. A MDCI foi de 5,5 para o escore de Lysholm, não tendo sido possível determinar o valor para o IKDC. Conclusão O cálculo do valor da MDCI pelo método da pergunta âncora, na amostra avaliada, foi de 5,5 para o escore de Lysholm. Não foi possível determinar o valor da MDCI para o IKDC.

Monoaxial Mechanical Tests on Porcino Knee Ligaments / Ensaios mecânicos monoaxiais nos ligamentos do joelho porcino

Abstract The failure of ligament reconstruction has different risk factors, among which we can highlight the period before its incorporation, which is a mechanically vulnerable period. Loss of resistance over time is a characteristic of living tissues. Dissection with bone insertions of the cruciate ligaments of animal models is not described; however, it is essential for monoaxial assays to extract information from tests such as relaxation. The present work describes the dissection used for the generation of a test body for the performance of nondestructive tests to evaluate the mechanical behavior. We performed dissection of four porcino knee ligaments, proposing a dissection technique for the cruciate ligaments with bone inserts for comparison with collateral ligaments. The ligaments were submitted to relaxation tests and had strain gauges placed during the tests. The results showed viscoelastic behavior, validated by strain gauges and with a loss over time; with some ligaments presenting with losses of up to 20%, a factor to be considered in future studies. The present work dissected the four main ligaments of the knee demonstrating the posterior approach that allows maintaining their bone insertions and described the fixation for the monotonic uniaxial trials, besides being able to extract the viscoelastic behavior of the four ligaments of the knee, within the physiological limits of the knee.

Resumo A falha da reconstrução ligamentar tem diferentes fatores de risco, dentre os quais podemos destacar o período antes da sua incorporação, o qual configura um período mecânico vulnerável. A perda de resistência ao longo do tempo é uma característica dos tecidos vivos. A dissecção com as inserções ósseas dos ligamentos cruzados de modelos animais não é descrita; todavia, para os ensaios monoaxiais, é fundamental extrair as informações de ensaios como os de relaxação. O presente trabalho realiza a descrição da dissecção utilizada para a geração de corpo de prova para a realização de ensaios não destrutivos para avaliar o comportamento mecânico. Realizamos dissecção de quatro ligamentos de joelho porcino, propondo uma técnica de dissecção para os ligamentos cruzados com as inserções ósseas para comparação com os colaterais. Os ligamentos foram submetidos a testes de relaxação e foram colocadas strain gauges durante os testes. Os resultados mostraram comportamento viscoelástico, validado pelas strain gauges e com uma perda ao longo do tempo, sendo que, em alguns ligamentos, as perdas chegaram a até 20%, fator este a ser considerado em trabalhos futuros. O presente trabalho dissecou os quatro principais ligamentos do joelho, demonstrando a abordagem posterior que permite manter as suas inserções ósseas e descrevendo a fixação para os ensaios uniaxiais monotônicos, além de ter conseguido extrair o comportamento viscoelástico dos quatro ligamentos do joelho dentro dos limites fisiológicos do joelho.

Application of knee joint imaging in bone age assement in adolescent children / 国际儿科学杂志

Bone age is a quantitative representation of the skeletal development pattern.X-ray imaging of the wrist with the Greulich-Pyle method is commonly used to assess bone age in clinic.In adolescent children, the sensitivity and specificity of the the Greulich-Pyle method are not sufficient because the bones of the wrist are already mature.In contrast, epiphyseal morphological changes in the knee joint throughout adolescence can provide information for the assessment of bone age in adolescent children, and the feasibility of knee joint bone age assessment has been verified.With the application of artificial intelligence (AI) in the medical field, the accuracy of AI interpretation of bone age is also recognized.One of the important uses of bone age assessment in adolescent children is to predict the remaining growth potential.Based on knee images, exploring the use of AI to build a model for predicting residual growth potential is a more meaningful research direction for clinical purposes.This paper reviews the anatomical characteristics of the knee joint, the application of knee joint imaging and the research progress of AI in bone age assessment.

Effects of Transcranial Direct Current Stimulation on Endurance Performance of Lower Limbs:A Systematic Review / 医用生物力学

Sports fatigue of the lower limbs is one of the important factors affecting sports performance. How to improve the anti-fatigue ability of the lower limbs during endurance exercise is the focus of the research field of human sports biomechanics. This study systematically reviewed the relevant literature on transcranial direct current stimulation (tDCS) intervention on lower limb endurance performance, summarized the effect of tDCS on lower limb endurance performance, and analyzed the influencing factors and potential mechanisms. The results showed that: tDCS intervention has a significant effect on the endurance performance of the whole lower limbs, but there is no unified conclusion on the effect on the endurance performance of the knee joint. The researchers deem that tDCS can increase the excitability of the primary motor cortex and reduce the activation of the supplementary motor area and the premotor area to producing a lower rating of perceived exertion, but cannot affect the perception of exercise-induced pain, and stimulation protocols varied across studies, which may be partly responsible. This study can provide a theoretical basis for exploring the central mechanism of tDCS to improve endurance performance, formulating rehabilitation and sports training programsfor different groups of people, and developing new stimulation equipment to enhance the human body’s anti fatigue ability.

Mid-term clinical outcome of arthroscopic surgery on early knee osteoarthritis in middle-old aged patients / 中国骨伤

OBJECTIVE@#To compare the mid-term clinical effect of arthroscopic surgery versus conservative treatment on the middle aged early knee osteoarthritis (EKOA) patients, with the hope to provide clinical evidence for their individual therapy.@*METHODS@#A total of 145 middle aged EKOA patients(182 knees) who received arthroscopic surgery or conservative treatment from January 2015 to December 2016 were retrospectively enrolled, including 35 males and 110 females, aged from 47 to 79 years old with an average of (57.6±6.9) years old, and the duration of disease ranged from 6 to 48 months with an average of(14.6±8.9) months. According to treatment method, patients were divided into arthroscopic surgery group (47 patients, 58 knees) and conservative treatment group(98 patients, 124 knees). Before treatment, patients presented with symptoms of knee joint, such as pain, swelling, locking, limited flexion and extension, and weakness, as well as abnormal findings in knee X-ray (without or suspicious joint space narrow, and a few of osteophyte formation) or in knee MRI (injury or degeneration of articular cartilage or meniscus, loose body in the joint cavity and synovial hyperemia edema, etc). Related data were collected, including duration of knee symptoms, presence of meniscus injury, loose body in the joint cavity or mechanical symptoms such as locking, and visual analogue scale (VAS) and Lysholm knee function score before treatment and at the latest follow-up. Statistical analysis was performed to compare the differences in VAS or Lyshilm score before or after treatment between the low groups and within each group.@*RESULTS@#Patients in the two groups were followed up from 60 to 76 months. In the arthroscopic surgery group, the incision healing was good and no surgical complications occurred. There were no significant differences in age, gender, BMI and follow-up time between the two groups(P>0.05). Before treatment, compared with conservative group, duration of symptoms in the arthroscopic group was longer (P<0.001), comorbidity rates of meniscus injury (P<0.001), free body (P=0.001) and mechanical symptoms (P<0.001) were higher, VAS (P<0.001) and Lysholm score (P<0.001) were worse. At the final follow-up, VAS and Lysholm score in either the conservative group or the arthroscopic group were significantly better than before treatment (P<0.05), while no significant differences between the two groups were found. The VAS was (1.5±1.2) scores in the arthroscopic group and (1.6±1.0)scores in the conservative group(P=0.549), and the Lysholm score was (84.9±12.5) scores in the arthroscopic group and (84.2±9.9) scores in the conservative group (P=0.676).@*CONCLUSION@#Both arthroscopic surgery and conservative treatment have satisfactory intermediate clinical effect middle- aged patients with EKOA, without statistically differences. However, most of the patients before surgery in the arthroscopic treatment group had mechanical locking symptoms caused by meniscus injury or loose body. Therefore, for the middle-aged EKOA patients with mechanical locking symptoms or without obtaining satisfactory outcome after conservative treatment, arthroscopic surgery may be considered.

Value of personalized osteotomy in primary total knee arthroplasty for severe varus knee osteoarthritis / 中国骨伤

OBJECTIVE@#To explore application value and efficacy of personalized osteotomy in primary total knee arthroplasty (TKA) for severe varus knee osteoarthritis.@*METHODS@#From June 2018 to January 2020, 36 patients (49 knees) with severe varus knee osteoarthritis were treated, including 15 males (21 knees) and 21 females (28 knees), aged from 59 to 82 years old with an average of (67.6 ± 6.5) years old;the course of disease ranged from 9.5 to 20.5 years with an average of (15.0 ± 5.0) years;11 patients (15 knees) with Kellgren-Lawrence grade Ⅲ and 25 patients (34 knees) with grade Ⅳ according to Kellgren-Lawrence grading. According to AORI clsssification of tibial bone defects, 8 patients (15 knees) were typeⅠTa and 16 patients (18 knees) were typeⅡ T2a. All patients' femor-tibial angle (FTA) was above 15°, and received primary TKA with personalized osteotomy. Thirty-three patients (45 knees) were treated with posterior-stabilized (PS) prostheses, 13 patients (15 knees) with PS prostheses combined with a metal pad and extension rod on the tibial side, and 3 patients (4 knees) with legacy constrained condylar knee (LCCK) prostheses. FTA, posterior condylar angle (PCA), medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA) before and after operation at 1 month were measured and compared by using picture archiving and communication systems (PACS). Recovery of lower limbs before and after operation at 12 months was evaluated by American Knee Society Score(KSS), and complications were observed and recorded.@*RESULTS@#All 36 patients (49 knees) were followed up from 15 to 40 months with an average of (23.46±7.65) months. FTA, MPTA were corrected from preoperative (18.65±4.28)° and (83.75±3.65)° to postoperative (2.35±1.46)° and (88.85±2.25)° at 1 month, respectively (P<0.001). PCA was decreased from (2.42±2.16)° before operation to (1.65±1.35)° at 1 month after operation, LDFA improved from (89.56 ± 3.55)° before operation to (91.63±3.38)° at 1 month after operation (P<0.05). KSS increased from (67.58±24.16) before opertion to(171.31±15.24) at 12 months after operation, 14 patients (19 knees) got excellent result, 19 (26 knees) good, and 3 (4 knees) fair.@*CONCLUSION@#Personalized osteotomy is helpful for recovery of axial alignment of lower limbs and correct placement of prosthesis, could effectively relieve pain of knee joint, recover knee joint function.

Correlation between spatial inclination of Blumensaat line and anterior cruciate ligament injury based on EOS biplanar 3D imaging system / 中国骨伤

OBJECTIVE@#To explore correlation between femoral mechanical axis and Blumensaat line (FMBL) angle of knee joint (angle between Blumensaat line and femoral mechanical axis), α angle (angle between Blumensaat line and axis of distal femur in sagittal plane) on EOS biplane imaging and non-contact anterior cruciate ligament(ACL) injury, and evaluate angle for its accuracy in predicting the populations prone to non-contact ACL injury.@*METHODS@#From February 2018 to October 2020, EOS imaging and clinical data from 88 patients (176 knees) with unilateral non-contact ACL injury were retrospectively analyzed, including 53 males and 35 females, aged from 18 to 45 years old with an average of (30.3±6.2) years old, 48 patients on the left side and 40 patients on the right side. The patients were divided into ACL-affected group and ACL-health group according to side of ACL injuries, and 51 patients (51 knees) with non-ACL identified from EOS database were included in normal control group, including 28 males and 23 females, aged from 20 to 44 years old with an average of (31.6±5.5) years old, 26 patients on the left side and 25 patients on the right side. Full-length EOS imaging of skeleton extremitatis inferioris among three groups were reconstructed to 3D images of skeletal system with EOS software, and then FMBL angle and α angle were measured on the images. Univariate binary Logistic regression analysis was performed to determine the influence of the univariate(FMBL angle or α angle) on ACL status(normal or torn). And the angle cutoff value for univariate was selected based on receiver operating characteristics curve (ROC) to got the best accuracy.@*RESULTS@#There was no statistically significant difference in age, gender and side distribution between ACL-injured group and normal control group(P>0.05). Statistical analyses (one-way ANOVA) indicated no significant difference in FMBL angle between ACL-injured knee group (32.8±2.3)° and ACL-injured contralateral knee group(32.5±2.3)°(P>0.05), but the values between two groups were significantly lower than that in normal control group (37.0±2.0)°(P<0.001). There was no statistically significant difference in α angle among three groups (P>0.05). Univariate binary Logistic regression analysis demonstrated that FMBL angle was risk factor for non-contact ACL injury[OR=0.433, 95%CI(0.330, 0.569), P<0.001]. The area under ROC curve for FMBL angle was 0.909[95%CI(0.861, 0.958), P<0.001], and the sensitivity and specificity were 70.5% and 98.0% respectively, cut-off value was 33.7°.@*CONCLUSION@#FMBL angle formed by Blumensaat line and femoral mechanical axis is one of the risk factors for non-contact ACL injury and has good predictive accuracy. The general population with FMBL angle below 33.7° may be increased risk for ACL injury.

Effectiveness of anterior cruciate ligament reconstruction with personalized femoral locator based on apex of deep cartilage / 中国修复重建外科杂志

OBJECTIVE@#To investigate the effectiveness of anterior cruciate ligament (ACL) reconstruction assisted by personalized femoral locator based on the apex of deep cartilage (ADC) combined with patient imaging data.@*METHODS@#Between January 2021 and January 2022, a total of 40 patients with primary ACL rupture were selected and randomly divided into study group (ACL reconstruction assisted by personalized femoral locator based on ADC) and control group (ACL reconstruction assisted by intraoperative fluoroscopy and traditional femoral locator), with 20 cases in each group. There was no significant difference in gender, age, body mass index, affected side, cause of injury, and preoperative International Knee Documentation Committee (IKDC) score, Lyshlom score, and Tegner score between the two groups ( P>0.05). IKDC score, Lyshlom score, and Tegner score were used to evaluate the functional recovery of the affected knee before operation and at 3, 6, and 12 months after operation. CT scan and three-dimensional reconstruction were performed before and after operation to measure the horizontal distance from ADC to the anterior cartilage margin (L) and the horizontal distance from ADC to the center of the femoral canal (I), and the anteroposterior position of the bone canal (R) was calculated by I/L; the distance from the center to the distal cartilage margin (D) was measured on the two-dimensional cross section; the R value and D value were compared between the two groups.@*RESULTS@#The operation time of the study group was significantly less than that of the control group [ MD=-6.90 (-8.78, -5.03), P<0.001]. The incisions of the two groups healed by first intention, and no complication such as intra-articular infection, nerve injury, and deep vein thrombosis of lower limbs occurred. There was no significant difference in the R value and D value between the preoperative simulated positioning and the actual intraoperative positioning in the study group [ MD=0.52 (-2.85, 3.88), P=0.758; MD=0.36 (-0.39, 1.11), P=0.351]. There was no significant difference in the actual intraoperative positioning R value and D value between the study group and the control group [ MD=1.01 (-2.57, 4.58), P=0.573; MD=0.24 (-0.34, 0.82), P=0.411]. The patients in both groups were followed up 12-13 months (mean, 12.4 months). The IKDC score, Lysholm score, and Tegner score of the two groups increased gradually with time, and there were significant differences between pre- and post-operation ( P<0.05). There was no significant difference in the scores between the two groups at each time point after operation ( P>0.05).@*CONCLUSION@#The personalized femoral locator based on ADC can accurately assist the femoral tunnel positioning in ACL reconstruction, which can shorten the operation time when compared with traditional surgical methods, and achieve satisfactory early effectiveness.

Three-dimensional kinematic analysis of knee joint after anterior cruciate ligament reconstruction with personalized femoral positioner based on apex of deep cartilage / 中国修复重建外科杂志

OBJECTIVE@#To investigate the changes of knee joint kinematics after anterior cruciate ligament (ACL) reconstruction assisted by personalized femoral positioner based on the apex of deep cartilage (ADC).@*METHODS@#Between January 2021 and January 2022, a total of 40 patients with initial ACL rupture who met the selection criteria were randomly divided into the study group (using the personalized femoral positioner based on ADC design to assist ACL reconstruction) and the control group (not using the personalized femoral positioner to assist ACL reconstruction), with 20 patients in each group. Another 20 volunteers with normal knee were collected as a healthy group. There was no significant difference in gender, age, body mass index, and affected side between groups ( P>0.05). Gait analysis was performed at 3, 6, and 12 months after operation using Opti _ Knee three-dimensional knee joint motion measurement and analysis system, and the 6 degrees of freedom (flexion and extension angle, varus and valgus angle, internal and external rotation angle, anteroposterior displacement, superior and inferior displacement, internal and external displacement) and motion cycle (maximum step length, minimum step length, and step frequency) of the knee joint were recorded. The patients' data was compared to the data of healthy group.@*RESULTS@#In the healthy group, the flexion and extension angle was (57.80±3.45)°, the varus and valgus angle was (10.54±1.05)°, the internal and external rotation angle was (13.02±1.66)°, and the anteroposterior displacement was (1.44±0.39) cm, the superior and inferior displacement was (0.86±0.20) cm, and the internal and external displacement was (1.38±0.39) cm. The maximum step length was (51.24±1.29) cm, the minimum step length was (45.69±2.28) cm, and the step frequency was (12.45±0.47) step/minute. Compared with the healthy group, the flexion and extension angles and internal and external rotation angles of the patients in the study group and the control group decreased at 3 months after operation, and the flexion and extension angles of the patients in the control group decreased at 6 months after operation, and the differences were significant ( P<0.05); there was no significant difference in the other time points and other indicators when compared with healthy group ( P>0.05). In the study group, the flexion and extension angles and internal and external rotation angles at 6 and 12 months after operation were significantly greater than those at 3 months after operation ( P<0.05), while there was no significant difference in the other indicators at other time points ( P>0.05). There was a significant difference in flexion and extension angle between the study group and the control group at 6 months after operation ( P<0.05), but there was no significant difference of the indicators between the two groups at other time points ( P>0.05).@*CONCLUSION@#Compared with conventional surgery, ACL reconstruction assisted by personalized femoral positioner based on ADC design can help patients achieve more satisfactory early postoperative kinematic results, and three-dimensional kinematic analysis can more objectively and dynamically evaluate the postoperative recovery of knee joint.

Study on the correlation between early three-dimensional gait analysis and clinical efficacy after robot-assisted total knee arthroplasty / 中华创伤杂志(英文版)

PURPOSE@#Robot-assisted technology is a forefront of surgical innovation that improves the accuracy of total knee arthroplasty (TKA). But whether the accuracy of surgery can improve the clinical efficacy still needs further research. The purpose of this study is to perform three-dimensional (3D) analysis in the early postoperative period of patients who received robot-assisted total knee arthroplasty (RATKA), and to study the trend of changes in gait parameters after RATKA and the correlation with the early clinical efficacy.@*METHODS@#Patients who received RATKA in the Center of Joint Surgery, the First Hospital Affiliated to Army Military Medical University from October 2020 to January 2021 were included. The imaging parameters, i.e., hip-knee-ankle angle, lateral distal femoral angle, medial proximal tibial angle, posterior condylar angle were measured 3 months post-TKA. The 3D gait analysis and clinical efficacy by Western Ontario Mac Master University Index (WOMAC) score were performed pre-TKA, 3 and 6 months post-TKA. The differences in spatiotemporal parameters of gait, kinetic parameters, and kinematic parameters of the operated limb and the contralateral limb were compared. The correlation between gait parameters and WOMAC scores was analyzed. Paired sample t-test and Wilcoxon rank-sum test were used to analyze the difference between groups, and Spearman correlation coefficient was used to analyze the correlation.@*RESULTS@#There were 31 patients included in this study, and the imaging indexes showed that all of them returned to normal post-TKA. The WOMAC score at 3 months post-TKA was significantly lower than that pre-TKA, and there was no significant difference between at 3 and 6 months. The 3D gait analysis results showed that the double support time of the operated limb reduced at 3 and 6 months (all p < 0.05), the maximum extension and maximum external rotation of the knee joint increased at stance phase, and the maximum flexion angle, the range of motion and the maximum external rotation increased at swing phase. Compared with the preoperative data, there were significant improvements (all p < 0.05). Compared with the contralateral knee joint, the maximum external rotation of the knee joint at swing phase was smaller than that of the contralateral side, and the maximum flexion and extension moment was greater than that of the contralateral knee. The maximum external rotation moment of the joint was greater than that of the contralateral knee joint (p < 0.05). There was a negative correlation between the single support time pre-TKA and the WOMAC score at 3 months (p = 0.017), and the single support time at 3 months was negatively correlated with the WOMAC score at 6 months (p = 0.043). The cadence at 6 months was negatively correlated with the WOMAC score at 6 months (p = 0.031). The maximum knee extension at stance phase at 6 months was negatively correlated with the WOMAC score at 6 month (p = 0.048). The maximum external rotation at stance phase at 6 months was negatively correlated with the WOMAC score at 6 months (p = 0.024).@*CONCLUSION@#The 3D gait analysis of RATKA patients is more sensitive than WOMAC score in evaluating the clinical efficacy. Trend of changes in gait parameters shows that the knee joint support, flexion and extension function, range of motion, external rotation and varus deformity moment of the patient were significantly improved at 3 months after surgery, and continued to 6 months after surgery. Compared with the contralateral knee, the gait parameters of the operated limb still has significant gaps in functionality, such as the external rotation and flexion and extension. The single support time, cadence, knee extension, and knee external rotation of the operated limb have a greater correlation with the postoperative WOMAC score. Postoperative rehabilitation exercises should be emphasized, which is of great value for improving the early efficacy of RATKA.

Propensity score-matched study of uni-condylar arthroplasty in elderly patients with knee osteoarthritis / 中国骨伤

OBJECTIVE@#To investigate the clinical efficacy of unicompartmental knee arthroplasty (UKA) in the treatment of knee osteoarthritis in patients over 75 years old.@*METHODS@#The clinical efficacy of primary fixed platform UKA in patients with osteoarthritis, was retrospectively analyzed from October 2014 to November 2020. Age, body mass index (BMI), range of motion (ROM), preoperative joint function score, the quality of life score and other preoperative indicators were measured by propensity score matching (PSM). The patients were divided into elderly group (≥75 years old) and control group (<75 years old). Oxford knee score(OKS), Western Ontario McMaster Universities osteoarthritis index(WOMAC), Short Form-12 including physical component summary (PCS), mental component summary(MCS), minimal clinically important difference(MCID ) and clinical complications were evaluated preoperatively and postoperatively.@*RESULTS@#A total of 514 patients were analyzed, 428 patients fulfilled the inclusion criteria. A propensity-score matching study was conducted to eliminate confounding factors. After 1∶2 propensity match, there were 84 patients in elderly group (≥75 years), age ranged from 75 to 88 years old, with an average of (78.79±3.08) years old, and 168 patients in control group (<75 years), age ranged from 47 to 74 years old, with an average of (64.10±5.96)years old. The follow-up duration of two groups ranged from 12 to 84 months with an average of (29.35±16.52) months in elderly group, and 12 to 85 months with an average of (31.83±17.34) months in control group. There was only significant difference in age between the elderly and control groups preoperatively (P<0.01). Postoperatively, the elderly group showed significantly higher WOMAC (P<0.01) and lower SF-12 PCS scores (P<0.01) as compared to the control group. There was no significant difference between the elderly group and the control group in knee range of motion, OKS and the proportion of each scoring system reaching the minimum clinical difference value (P>0.05). In the aspect of preperative complications, the elderly group exhibited more surgical site complications and postoperative delirium compared to control group(P<0.05). The differences in other indicators including deep vein thrombosis, acute urinary retention, cardiovascular events, cerebrovascular events and radiolucent lines around prothesis were not statistically significant(P>0.05).@*CONCLUSION@#UKA in the treatment of elderly patients over 75 years old with knee osteoarthritis was safe and feasible, and could obtain satisfactory short-term efficacy.

Research on performance optimization method of human-machine physical interaction system considering exoskeleton wearing comfort / 生物医学工程学杂志

In order to improve the wearing comfort and bearing effectiveness of the exoskeleton, based on the prototype and working mechanism analysis of a relaxation wearable system for knee exoskeleton robot, the static optimization synthesis and its method are studied. Firstly, based on the construction of the virtual prototype model of the system, a comprehensive wearable comfort evaluation index considering the factors such as stress, deformation and the proportion of stress nodes was constructed. Secondly, based on the static simulation and evaluation index of system virtual prototype, multi-objective genetic optimization and local optimization synthesis of armor layer topology were carried out. Finally, the model reconstruction simulation data confirmed that the system had good wearing comfort. Our study provides a theoretical basis for the bearing performance and prototype construction of the subsequent wearable system.

Research Progress of Age Estimation in the Living by Knee Joint MRI / 法医学杂志

Bone development shows certain regularity with age. The regularity can be used to infer age and serve many fields such as justice, medicine, archaeology, etc. As a non-invasive evaluation method of the epiphyseal development stage, MRI is widely used in living age estimation. In recent years, the rapid development of machine learning has significantly improved the effectiveness and reliability of living age estimation, which is one of the main development directions of current research. This paper summarizes the analysis methods of age estimation by knee joint MRI, introduces the current research trends, and future application trend.