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1.
PLoS One ; 15(10): e0238785, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33052931

RESUMO

A human cadaveric specimen-specific knee model with appropriate soft tissue constraints was developed to appropriately simulate the biomechanical environment in the human knee, in order to pre-clinically evaluate the biomechanical and tribological performance of soft tissue interventions. Four human cadaveric knees were studied in a natural knee simulator under force control conditions in the anterior posterior (AP) and tibial rotation (TR) axes, using virtual springs to replicate the function of soft tissues. The most appropriate spring constraints for each knee were determined by comparing the kinematic outputs in terms of AP displacement and TR angle of the human knee with all the soft tissues intact, to the same knee with all the soft tissues resected and replaced with virtual spring constraints (spring rate and free length/degree). The virtual spring conditions that showed the least difference in the AP displacement and TR angle outputs compared to the intact knee were considered to be the most appropriate spring conditions for each knee. The resulting AP displacement and TR angle profiles under the appropriate virtual spring conditions all showed similar shapes to the individual intact knee for each donor. This indicated that the application of the combination of virtual AP and TR springs with appropriate free lengths/degrees was successful in simulating the natural human knee soft tissue function. Each human knee joint had different kinematics as a result of variations in anatomy and soft tissue laxity. The most appropriate AP spring rate for the four human knees varied from 20 to 55 N/mm and the TR spring rate varied from 0.3 to 1.0 Nm/°. Consequently, the most appropriate spring condition for each knee was unique and required specific combinations of spring rate and free length/degree in each of the two axes.


Assuntos
Joelho/fisiologia , Modelos Biológicos , Idoso , Fenômenos Biomecânicos , Cadáver , Simulação por Computador , Tecido Conjuntivo/anatomia & histologia , Tecido Conjuntivo/fisiologia , Feminino , Humanos , Joelho/anatomia & histologia , Articulação do Joelho/anatomia & histologia , Articulação do Joelho/fisiologia , Masculino , Pessoa de Meia-Idade , Amplitude de Movimento Articular , Rotação , Tíbia/anatomia & histologia , Tíbia/fisiologia , Torque
2.
PLoS One ; 15(8): e0237042, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32813735

RESUMO

The largest dinosaurs were enormous animals whose body mass placed massive gravitational loads on their skeleton. Previous studies investigated dinosaurian bone strength and biomechanics, but the relationships between dinosaurian trabecular bone architecture and mechanical behavior has not been studied. In this study, trabecular bone samples from the distal femur and proximal tibia of dinosaurs ranging in body mass from 23-8,000 kg were investigated. The trabecular architecture was quantified from micro-computed tomography scans and allometric scaling relationships were used to determine how the trabecular bone architectural indices changed with body mass. Trabecular bone mechanical behavior was investigated by finite element modeling. It was found that dinosaurian trabecular bone volume fraction is positively correlated with body mass similar to what is observed for extant mammalian species, while trabecular spacing, number, and connectivity density in dinosaurs is negatively correlated with body mass, exhibiting opposite behavior from extant mammals. Furthermore, it was found that trabecular bone apparent modulus is positively correlated with body mass in dinosaurian species, while no correlation was observed for mammalian species. Additionally, trabecular bone tensile and compressive principal strains were not correlated with body mass in mammalian or dinosaurian species. Trabecular bone apparent modulus was positively correlated with trabecular spacing in mammals and positively correlated with connectivity density in dinosaurs, but these differential architectural effects on trabecular bone apparent modulus limit average trabecular bone tissue strains to below 3,000 microstrain for estimated high levels of physiological loading in both mammals and dinosaurs.


Assuntos
Osso Esponjoso/anatomia & histologia , Osso Esponjoso/fisiologia , Dinossauros/anatomia & histologia , Animais , Anisotropia , Fenômenos Biomecânicos , Densidade Óssea/fisiologia , Osso e Ossos/anatomia & histologia , Força Compressiva/fisiologia , Simulação por Computador , Fêmur/anatomia & histologia , Análise de Elementos Finitos , Fósseis , Processamento de Imagem Assistida por Computador/métodos , Mamíferos/anatomia & histologia , Estresse Mecânico , Tíbia/anatomia & histologia , Microtomografia por Raio-X/métodos
3.
Am J Sports Med ; 48(9): 2205-2212, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32667272

RESUMO

BACKGROUND: Several anatomic features of the knee have been shown to affect joint and anterior cruciate ligament (ACL) loading and the risk of subsequent injuries. While several studies have highlighted sex differences between these anatomic features, little is known on how these differences develop during skeletal growth and maturation. HYPOTHESES: (A) Anatomic features linked to an ACL injury will significantly change during skeletal growth and maturation. (B) The age-related changes in anatomic features linked to an ACL injury are different between male and female patients. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: After institutional review board approval, magnetic resonance imaging data from 269 unique knees (patient age 3-18 years; 51% female), free from any injuries, were used to measure femoral notch width, posterior slope of the lateral tibial plateau (lateral tibial slope), medial tibial depth, tibial spine height, and posterior lateral meniscal bone angle. Linear regression was used to test the associations between age and quantified anatomic indices. Patients were then divided into 4 age groups: preschool (3-6 years), prepubertal (7-10 years), early adolescent (11-14 years), and late adolescent (15-18 years). Also, 2-way analysis of variance with the Holm-Sidak post hoc test was used to compare morphology between male and female patients in each age group. RESULTS: The femoral notch width, medial tibial depth, and tibial spine height significantly increased with age (P < .001). The lateral tibial slope decreased with age only in male patients (P < .001). Except for the posterior lateral meniscal bone angle, the age-related changes in anatomy were different between male and female patients (P < .05). On average, early and late adolescent female patients had smaller femoral notches, steeper lateral tibial slopes, flatter medial tibial plateaus, and shorter tibial spines compared with age-matched male patients (P < .01). CONCLUSION: Overall, the findings supported our hypotheses, showing sex-specific changes in anatomic features linked to an ACL injury during skeletal growth and maturation. These observations help to better explain the reported age and sex differences in the prevalence of ACL injuries. The fact that most of these anatomic features undergo substantial changes during skeletal growth and maturation introduces the hypothesis that prophylactic interventions (ie, activity modification) would have the potential to reshape a maturing knee in a manner that lowers the risk of noncontact ACL injuries.


Assuntos
Lesões do Ligamento Cruzado Anterior/diagnóstico por imagem , Articulação do Joelho/anatomia & histologia , Caracteres Sexuais , Tíbia/anatomia & histologia , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Articulação do Joelho/diagnóstico por imagem , Imagem por Ressonância Magnética , Masculino , Fatores de Risco
4.
Bone Joint J ; 102-B(7): 861-867, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32600131

RESUMO

AIMS: Cementless unicompartmental knee arthroplasty (UKA) has advantages over cemented UKA, including improved fixation, but has a higher risk of tibial plateau fracture, particularly in Japanese patients. The aim of this multicentre study was to determine when cementless tibial components could safely be used in Japanese patients based on the size and shape of the tibia. METHODS: The study involved 212 cementless Oxford UKAs which were undertaken in 174 patients in six hospitals. The medial eminence line (MEL), which is a line parallel to the tibial axis passing through the tip of medial intercondylar eminence, was drawn on preoperative radiographs. Knees were classified as having a very overhanging medial tibial condyle if this line passed medial to the medial tibial cortex. They were also classified as very small if a size A/AA tibial component was used. RESULTS: The overall rate of fracture was 8% (17 out of 212 knees). The rate was higher in knees with very overhanging condyles (Odds ratio (OR) 13; p < 0.001) and with very small components (OR 7; p < 0.001). The OR was 21 (p < 0.001) in those with both very overhanging condyles and very small components. In all, 69% of knees (147) had neither very overhanging nor very small components, and the fracture rate in these patients was 1.4% (2 out of 147 knees). Males had a significantly reduced risk of fracture (OR 0.13; p = 0.002), probably because no males required very small components and females were more likely to have very overhanging condyles (OR 3; p = 0.013). 31% of knees (66) were in males and in these the rate of fracture was 1.5% (1 out of 66 knees). CONCLUSION: The rate of tibial plateau fracture in Japanese patients undergoing cementless UKA is high. We recommend that cemented tibial fixation should be used in Japanese patients who require very small components or have very overhanging condyles, as identified from preoperative radiographs. In the remaining 69% of knees cementless fixation can be used. This approach should result in a low rate of fracture. Cite this article: Bone Joint J 2020;102-B(7):861-867.


Assuntos
Artroplastia do Joelho/métodos , Prótese do Joelho , Complicações Pós-Operatórias/etiologia , Tíbia/anatomia & histologia , Fraturas da Tíbia/etiologia , Idoso , Idoso de 80 Anos ou mais , Artroplastia do Joelho/instrumentação , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Estudos Retrospectivos , Fatores de Risco
5.
Niger J Clin Pract ; 23(7): 1013-1021, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32620734

RESUMO

Background: In spite of its consideration as a very successful procedure nearly all total knee replacement (TKR) prostheses were designed based on the parameters of male 4,Western, and primarily white native knees. Mismatch between prosthesis and bone surface or malposition can lead to poor outcome of TKR. Aim: To determine the parameters of the native knee of the ethnic Igbos of South East Nigeria, determine any correlations amongst them ,compare the values with that of other populations and discuss its implication in total knee replacement. Materials and Method: The study was carried out on male adult cadavers with normal knees found at the museum of the Department of Anatomy University of Nigeria and all cadavers whose knees were deformed or had any pathological condition were excluded from the study. There were 60 knees from 30 male cadavers. Measurements were taken independently from the distal femur and proximal tibia with a method with the aid of a Vernier sliding calipers. Results: The determined values of the parameters of the cadaveric knees in centimeters are as follows: FLAP: M=7.10,SD=.44, FMAP: M=6.83,SD=.42, FML:M=7.78,SD=.40, FAR: M=1.10,SD=.06, TLAP:M=4.65,SD=.23, TMAP:M=5.17,SD=.27, TML: M=7.88,SD=.29, TAR:M=1.53. SD=.06. Conclusion: The normal values of the knee parameters of the native knee of the ethnic Igbos of the South Eastern Nigeria has been established and these should be taken into consideration by medical engineers during component design and arthroplasty surgeon during total knee replacement. There are correlations between these parameters that could be useful as a decision making tool during TKR and finally, the differences between these parameters and that of ethnic Western and Asian populations should be noted by implant manufacturers and arthroplasty surgeons.


Assuntos
Artroplastia do Joelho , Articulação do Joelho/anatomia & histologia , Joelho/anatomia & histologia , Adulto , Idoso , Antropometria , Cadáver , Grupos Étnicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nigéria , Desenho de Prótese , Tíbia/anatomia & histologia
6.
Am J Sports Med ; 48(8): 1893-1899, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32515986

RESUMO

BACKGROUND: Some cadaveric studies have indicated that the anterior cruciate ligament (ACL) consists of anteromedial and posterolateral bundles that display reciprocal function with regard to knee flexion. However, several in vivo imaging studies have suggested that these bundles elongate in parallel with regard to flexion. Furthermore, the most appropriate description of the functional anatomy of the ACL is still debated, with the ACL being described as consisting of 2 or 3 bundles or as a continuum of fibers. HYPOTHESIS: As long as their origination and termination locations are defined within the ACL attachment site footprints, ACL bundles elongate in parallel with knee extension during gait. STUDY DESIGN: Descriptive laboratory study. METHODS: High-speed biplanar radiographs of the right knee joint were obtained during gait in 6 healthy male participants (mean ± SD: body mass index, 25.5 ± 1.2 kg/m2; age, 29.2 ± 3.8 years) with no history of lower extremity injury or surgery. Three-dimensional models of the right femur, tibia, and ACL attachment sites were created from magnetic resonance images. The bone models were registered to the biplanar radiographs, thereby reproducing the in vivo positions of the knee joint. For each knee position, the distances between the centroids of the ACL attachment sites were used to represent ACL length. The lengths of 1000 virtual bundles were measured for each participant by randomly sampling locations on the attachment site surfaces and measuring the distances between each pair of locations. Spearman rho rank correlations were performed between the virtual bundle lengths and ACL length. RESULTS: The virtual bundle lengths were highly correlated with the length of the ACL, defined as the distance between the centroids of the attachment sites (rho = 0.91 ± 0.1, across participants; P < 5 × 10-5). The lengths of the bundles that originated and terminated in the anterior and medial aspects of the ACL were positively correlated (rho = 0.81 ± 0.1; P < 5 × 10-5) with the lengths of the bundles that originated and terminated in the posterior and lateral aspects of the ACL. CONCLUSION: As long as their origination and termination points are specified within the footprint of the attachment sites, ACL bundles elongate in parallel as the knee is extended. CLINICAL RELEVANCE: These data elucidate ACL functional anatomy and may help guide ACL reconstruction techniques.


Assuntos
Ligamento Cruzado Anterior/diagnóstico por imagem , Marcha , Articulação do Joelho/diagnóstico por imagem , Adulto , Ligamento Cruzado Anterior/anatomia & histologia , Fenômenos Biomecânicos , Fêmur/anatomia & histologia , Fêmur/diagnóstico por imagem , Humanos , Articulação do Joelho/anatomia & histologia , Masculino , Amplitude de Movimento Articular , Tíbia/anatomia & histologia , Tíbia/diagnóstico por imagem
7.
Anat Sci Int ; 95(4): 470-477, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32347456

RESUMO

The anterolateral ligament (ALL) has recently received considerable attention as a key structure maintaining the rotational stability of the tibia. However, the morphology of the ALL, particularly the proximal attachment, is controversial. This study aimed to elucidate the morphological relationship between the ALL and its adjacent structures. A total of 25 knees from 22 cadavers were used in the current study. One knee was set at 30°, 60° and 90° of flexion. Stretched or winkled fibrous tissues were then observed with internal and external rotations of the tibia at each angle. In 22 knees, fibrous tissues that were attached to the lateroposterior area to the Gerdy's tubercle were macroscopically observed. In the other 2 knees, the fibrous tissues were histologically investigated and analyzed using computer-assisted three-dimensional reconstruction. A taut fibrous tissue was observed between the lateroposterior area to the Gerdy's tubercle and the posterosuperior area to the lateral epicondyle during an internal rotation of the tibia. A complex of fibrous tissues that were attached to the lateroposterior area to the Gerdy's tubercle spread to the anterolateral aspect of the knee as a sheet-like structure. This complex tissue was composed of the fascia lata and fibrous tissues continuous from the fabellofibular ligament, intermuscular septum, and tendon of the gastrocnemius. Three-dimensional reconstruction showed that each fibrous tissue formed a sheet. The structure recognized as the ALL could not be detected; therefore, the ALL that has been reported to date is considered to be a complex of fibrous tissues with a sheet-like structure.


Assuntos
Articulação do Joelho/anatomia & histologia , Ligamentos Articulares/anatomia & histologia , Músculo Esquelético/anatomia & histologia , Humanos , Articulação do Joelho/fisiologia , Amplitude de Movimento Articular , Tíbia/anatomia & histologia
8.
Knee ; 27(3): 934-939, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32295725

RESUMO

BACKGROUND: Studies have shown that Q angle measurements were unreliable. Imaging studies have largely replaced the Q angle for measuring tibial tubercle lateralization. Creating a standardized protocol to measure the Q angle, with normative values, would provide a reliable reference without expensive imaging techniques. METHODS: Thirty men and 27 women without history of knee problems or family history of dislocating kneecaps were subjects. Exclusion criteria were: patellofemoral abnormalities upon examination. We measured the Q angles of both knees using a standardized protocol and a long-armed goniometer. These data were analyzed to calculate normative values. RESULTS: For all subjects, the mean was 14.8° (≈15°), 95% confidence interval (CI): ±5.4°. The male mean was 13.5°, 95% CI: ±5.2°. The female mean was 15.9°, 95% CI: ±4.8°. There was no significant difference between the right and left knees of the males (p = 0.52), nor of the females (p = 0.62), Beta = 0.14. The 2.4° difference between male and female means was due to the average height difference between the men and women. CONCLUSIONS: This study provides a standardized Q angle measurement protocol to assess tibial tubercle lateralization at a patient's first encounter (and intra-operatively) without resorting to expensive imaging studies. These values provide a reliable reference for clinical comparison, and will allow all clinicians and sports medicine personnel to assess tubercle lateralization with reliability and validity. When using this protocol, the term "Standard Q Angle" (SQA) should be used, to avoid confusion with other measurement protocols.


Assuntos
Artrometria Articular/normas , Protocolos Clínicos/normas , Joelho/anatomia & histologia , Joelho/fisiologia , Exame Físico/normas , Adulto , Fenômenos Biomecânicos , Feminino , Voluntários Saudáveis , Humanos , Articulação do Joelho/anatomia & histologia , Articulação do Joelho/fisiologia , Masculino , Pessoa de Meia-Idade , Patela/anatomia & histologia , Patela/fisiologia , Músculo Quadríceps/anatomia & histologia , Músculo Quadríceps/fisiologia , Valores de Referência , Reprodutibilidade dos Testes , Tíbia/anatomia & histologia , Tíbia/fisiologia , Adulto Jovem
9.
Int. j. morphol ; 38(2): 472-476, abr. 2020. graf
Artigo em Espanhol | LILACS | ID: biblio-1056464

RESUMO

El ligamento tibiofibular anterior suele presentar un fascículo distal independiente de la banda principal, denominado fascículo distal del ligamento tibiofibular anterior (FD-LTFA). Este discurre oblicuamente, cubriendo sus fibras más inferiores la zona anterolateral de la articulación talocrural. Su presencia se asocia a pellizcamiento del tobillo en esta zona, el cual puede producir un desgaste cartilaginoso de la cara anterolateral de la tróclea talar. El propósito de este estudio fue determinar la presencia y biometría del FD-LTFA, y su relación con la troclea talar en tobillos de un grupo de individuos Chilenos. En este estudio se utilizaron 30 miembros inferiores de cadáveres de individuos adultos. Se evaluó en el fascículo distal: Ancho en la inserción tibial, ancho en la inserción fibular, longitud del margen superior, longitud del margen inferior y el espesor. Se determinó si había contacto talar por parte del FD-LTFA y se observó desgaste articular en la superficie del domo talar, a nivel de la región de contacto del mencionado ligamento. El FD-LTFA fue encontrado en un 76,7 % de los casos, su anchura a nivel del sitio de fijación tibial fue de 5,30 mm (± 1,4) y a nivel fibular 4,43 mm (± 0,85). En cuanto a su longitud en el margen superior fue de 14,26 mm (± 3,66) y a nivel del margen inferior fue de 16,74 mm (± 2,91). Su espesor fue de 2,1 mm (± 0,36). En las 23 muestras de tobillo con presencia del FD-LTFA, hubo contacto talar en el 100 % de los casos y desgaste articular en esta zona en 3 de ellas (13,04 %). Los datos biométricos aportados por este estudio complementarán el conocimiento anatómico del FD-LTFA en la población Chilena.


The anterior tibiofibular ligament usually presents an independent distal fascicle of the main band, denominated distal fascicle of the anterior tibiofibular ligament (DF-ATiFL). Which obliquely passes, covering its most inferior fiber to the anterolateral corner of the talocrural articulation. Its presence is associated with the anterolateral impingement of the ankle in this area, which can produce cartilage wear of the anterolateral surface of the talar trochlea. The purpose of this study was to determine the presence and biometry of DF-ATiFL and its relation with the talar trochlea on the ankles of a group of Chilean individuals. Thirty inferior members were used in this study, all from adult individuals. It was evaluated: Width of the tibial insertion, width of the fibular insertion, length of the top margin, length of the bottom margin, and the thickness. It was determined whether there was talar contact by the distal fascicle of the anterior tibiofibular ligament. Also, it was observed the articular wear on the surface of the talar dome, at the level of the contact region of the distal fascicle of the anterior tibiofibular ligament. The DFATiFL was found in 76.7 % of the cases, its width at the level of the place of tibial fixation was 5.30 mm (± 1.40), and at the fibular level 4.43 mm (± 0.85). Regarding its length on the top margin was 14.26 mm (± 3.66), and at the bottom, the margin level was 16.74 mm (± 2.91). Its thickness was 2.1 mm (± 0.36). In the 23 ankles samples with the presence of DF-ATiFL, there was talar contact in 100 % of the cases and articular wear in this area in 3 of them (13.04 %). The biometric data contributed by this study will supplement the anatomical knowledge of the distal fascicle of the anterior tibiofibular ligament on the Chilean population.


Assuntos
Humanos , Tíbia/anatomia & histologia , Fíbula/anatomia & histologia , Ligamentos/anatomia & histologia , Tornozelo/anatomia & histologia , Tálus/anatomia & histologia
10.
Medicine (Baltimore) ; 99(9): e19328, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32118764

RESUMO

We assessed factors associated with premature physeal closure (PPC) and outcomes after closed reduction of Salter-Harris type II (SH-II) fractures of the distal tibia. We reviewed patients with SH-II fractures of the distal tibia treated at our center from 2010 to 2015 with closed reduction and a non-weightbearing long-leg cast. Patients were categorized by immediate postreduction displacement: minimal, <2 mm; moderate, 2 to 4 mm; or severe, >4 mm. Demographic data, radiographic data, and Lower Extremity Functional Scale (LEFS) scores were recorded.Fifty-nine patients (27 girls, 31 right ankles, 26 concomitant fibula fractures) were included, with a mean (±SD) age at injury of 12.0 ±â€Š2.2 years. Mean maximum fracture displacements were 6.6 ±â€Š6.5 mm initially, 2.7 ±â€Š2.0 mm postreduction, and 0.4 ±â€Š0.7 mm at final follow-up. After reduction, displacement was minimal in 23 patients, moderate in 21, and severe in 15. Fourteen patients developed PPC, with no significant differences between postreduction displacement groups. Patients with high-grade injury mechanisms and/or initial displacement ≥4 mm had 12-fold and 14-fold greater odds, respectively, of PPC. Eighteen patients responded to the LEFS survey (mean 4.0 ±â€Š2.1 years after injury). LEFS scores did not differ significantly between postreduction displacement groups (P = .61).The PPC rate in this series of SH-II distal tibia fractures was 24% and did not differ by postreduction displacement. Initial fracture displacement and high-grade mechanisms of injury were associated with PPC. LEFS scores did not differ significantly by postreduction displacement.Level of Evidence: Level IV, case series.


Assuntos
Fixação de Fratura/normas , Fraturas Salter-Harris/terapia , Adolescente , Criança , Feminino , Fixação de Fratura/métodos , Fixação de Fratura/estatística & dados numéricos , Humanos , Masculino , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/diagnóstico por imagem , Estudos Retrospectivos , Tíbia/anatomia & histologia , Tíbia/lesões , Tíbia/fisiopatologia , Resultado do Tratamento
11.
Anthropol Anz ; 77(2): 147-159, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32080704

RESUMO

The estimation of maximum bone length from its fragments is important in forensic anthropology as these length estimates can be used to estimate the total skeletal height (TSH), and thereby stature, of unknown skeletal remains. This is known as the indirect method of stature estimation. Alternatively, TSH can be estimated directly from bone fragments without first estimating maximum bone length. While regression equations for estimating maximum bone length from its fragments exist for long bones of the upper and lower limbs, these equations are population- and sex-specific and their use on populations other than the one they were derived from is not recommended. The aim of this study was therefore to develop formulae for estimating maximum tibial length from its fragments in black South Africans, which previously did not exist, and to compare the accuracies of the direct and indirect methods of estimating TSH from tibial fragments. Several measurements representing fragments were measured on the tibiae of 99 male and 99 female black South Africans, and equations estimating tibial length from these measurements were derived. Correlation coefficients of each equation were significant, and all equations estimated tibial length with moderate to high accuracy. A comparison of the standard errors of estimate (SEEs) between the direct and indirect methods of stature estimation indicate that the direct method is more accurate and should be used to estimate stature from tibial fragments when such equations exist.


Assuntos
Estatura , Antropologia Forense , Caracteres Sexuais , Tíbia , Grupo com Ancestrais do Continente Africano , Feminino , Humanos , Masculino , Análise de Regressão , Tíbia/anatomia & histologia
12.
Gait Posture ; 77: 269-275, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32092603

RESUMO

BACKGROUND: Bone shapes strongly influence force and moment predictions of kinematic and musculoskeletal models used in motion analysis. The precise determination of joint reference frames is essential for accurate predictions. Since clinical motion analysis typically does not include medical imaging, from which bone shapes may be obtained, scaling methods using reference subjects to create subject-specific bone geometries are widely used. RESEARCH QUESTION: This study investigated if lower limb bone shape predictions from skin-based measurements, utilising an underlying statistical shape model (SSM) that corrects for soft tissue artefacts in digitisation, can be used to improve conventional linear scaling methods of bone geometries. METHODS: SSMs created from 35 healthy adult femurs and tibiae/fibulae were used to reconstruct bone shapes by minimising the distance between anatomical landmarks on the models and those digitised in the motion laboratory or on medical images. Soft tissue artefacts were quantified from magnetic resonance images and then used to predict distances between landmarks digitised on the skin surface and bone. Reconstruction results were compared to linearly scaled models by measuring root mean squared distances to segmented surfaces, calculating differences of commonly used anatomical measures and the errors in the prediction of the hip joint centre. RESULTS: SSM reconstructed surface predictions from varying landmark sets from skin and bone landmarks were more accurate compared to linear scaling methods (2.60-2.95 mm vs. 3.66-3.87 mm median error; p < 0.05). No significant differences were found between SSM reconstructions from bony landmarks and SSM reconstructions from digitised landmarks obtained in the motion lab and therefore reconstructions using skin landmarks are as accurate as reconstructions from landmarks obtained from medical images. SIGNIFICANCE: These results indicate that SSM reconstructions can be used to increase the accuracy in obtaining bone shapes from surface digitised experimental data acquired in motion lab environments.


Assuntos
Pontos de Referência Anatômicos , Fêmur/anatomia & histologia , Modelos Biológicos , Modelos Estatísticos , Tíbia/anatomia & histologia , Adulto , Idoso , Fenômenos Biomecânicos , Feminino , Fêmur/diagnóstico por imagem , Voluntários Saudáveis , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Movimento , Projetos de Pesquisa , Tíbia/diagnóstico por imagem
13.
Niger J Clin Pract ; 23(1): 7-11, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31929200

RESUMO

Background: Angular deformities of the lower limbs are commonly encountered deformities in pediatric orthopedic clinics. The values of the tibiofemoral angle undergoes changes as the child grows and these changes are self-limiting. The aim of the study is to establish the normal variation of knee angles of children between 2 and 12 years of age in Enugu metropolis and to establish any correlation between the knee angles and the intermalleolar distances (IMDs). Subjects and Methods: This study was done on 630 school children in Enugu metropolis between the age groups of 2 and 12 years. Multistage sampling was used in the study. The tibiofemoral angles and intermalleolar/intercondylar distances were measured. Results: The maximum tibiofemoral angle from this study was 7.6° ± 2.4° and the age corresponding to this value was 4 years. Only 23 subjects (3.5%) had varus knee angle. The values of the mean tibiofemoral angle and IMDs plateaued from 8 to 12 years. There was a significant positive correlation between average knee angle and IMD (r = 0.785, P < 0.001). Conclusion: The physiological changes in the knee angle (tibiofemoral) follow a similar pattern as established in the literature and there was positive correlation between IMD and the tibiofemoral angle.


Assuntos
Fêmur/anatomia & histologia , Geno Valgo/fisiopatologia , Genu Varum/fisiopatologia , Articulação do Joelho/anatomia & histologia , Tíbia/anatomia & histologia , Antropometria , Criança , Pré-Escolar , Feminino , Humanos , Joelho , Masculino , Nigéria
14.
Lasers Med Sci ; 35(8): 1703-1709, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31953737

RESUMO

Studies reported the harmful effects of 2,4-D on body tissues, provoking changes in the anatomy and physiology of the kidneys, liver, and testicles. Thus, the objective was to evaluate if there were alterations in the bone quality of the tibia of rats submitted to feed consumption that were exposed to three different 2,4-D doses. Male Wistar rats were divided into four groups: oral control group (C: feed consumption without 2,4-D contamination); low oral concentration group (G3: contaminated feed with low concentration of 2,4-D); medium concentration group (G6: contaminated feed with medium concentration of 2,4-D); and high concentration group (G9: contaminated feed with high concentration of 2,4-D). The results demonstrated alterations of the mechanical properties and Raman ratios of the tibias of the contaminated groups. The maximum load, maximum stress, elastic modulus, and the cortical area were lower in the G6 and G9 compared to C group. The mineral-to-matrix ratio (relative mineral to organic content) was lower in the G6 and G9 groups compared to C group, but carbonate-to-matrix ratio (indicator of bone turnover) was higher in both groups. Thus, it is possible to suggest that the 2,4-D herbicide performed deleterious effects on the bone quality of male Wistar rats.


Assuntos
Ácido 2,4-Diclorofenoxiacético/análise , Ração Animal/análise , Comportamento Alimentar , Análise Espectral Raman , Tíbia/diagnóstico por imagem , Animais , Fenômenos Biomecânicos , Herbicidas/análise , Masculino , Ratos Wistar , Tíbia/anatomia & histologia
15.
J Bone Joint Surg Am ; 102(7): 582-591, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31977824

RESUMO

BACKGROUND: Intramedullary (IM) nailing is the treatment of choice for most tibial shaft fractures. However, an iatrogenic pitfall may be rotational malalignment. The aims of this retrospective analysis were to determine (1) the prevalence of rotational malalignment using postoperative computed tomography (CT) as the reference standard; (2) the average baseline tibial torsion of uninjured limbs; and (3) based on that normal torsion, whether the contralateral, uninjured limb can be reliably used as the reference standard. METHODS: The study included 154 patients (71% male and 29% female) with a median age of 37 years. All patients were treated for a unilateral tibial shaft fracture with an IM nail and underwent low-dose bilateral postoperative CT to assess rotational malalignment. RESULTS: More than one-third of the patients (n = 55; 36%) had postoperative rotational malalignment of ≥10°. Right-sided tibial shaft fractures were significantly more likely to display external rotational malalignment whereas left-sided fractures were predisposed to internal rotational malalignment. The uninjured right tibiae were an average of 4° more externally rotated than the left (mean rotation and standard deviation, 41.1° ± 8.0° [right] versus 37.0° ± 8.2° [left]; p < 0.01). Applying this 4° correction to our cohort not only reduced the prevalence of rotational malalignment (n = 45; 29%), it also equalized the distribution of internal and external rotational malalignment between the left and right tibiae. CONCLUSIONS: This study confirms a high prevalence of rotational malalignment following IM nailing of tibial shaft fractures (36%). There was a preexisting 4° left-right difference in tibial torsion, which sheds a different light on previous studies and current clinical practice and could have important implications for the diagnosis and management of tibial rotational malalignment. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.


Assuntos
Mau Alinhamento Ósseo/epidemiologia , Fixação Intramedular de Fraturas , Complicações Pós-Operatórias/epidemiologia , Fraturas da Tíbia/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Mau Alinhamento Ósseo/diagnóstico por imagem , Mau Alinhamento Ósseo/etiologia , Feminino , Fixação Intramedular de Fraturas/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico por imagem , Prevalência , Valores de Referência , Estudos Retrospectivos , Tíbia/anatomia & histologia , Tomografia Computadorizada por Raios X , Adulto Jovem
16.
J Pediatr Orthop ; 40(2): e96-e102, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31107711

RESUMO

BACKGROUND: Despite the critical role the trochlea plays in patellofemoral (PF) pathology, the development of the trochlea is poorly understood. The purpose of this study was 2-fold: (1) Describe quantitative osseous and soft tissue anatomy of the patella and trochlea in skeletally immature cadaveric specimens utilizing known measurements used in PF instability, and (2) evaluate additional measurement techniques in the sagittal plane as they relate to PF morphologic development. METHODS: Thirty-one skeletally immature fresh frozen cadaveric knees between the ages of 2 and 11 years old were evaluated using 0.625 mm computed tomography scans. In the axial plane, measurements included condylar height asymmetry, trochlear facet asymmetry, trochlear depth, osseous sulcus angle, cartilaginous sulcus angle, patella sulcus angle, and tibial tubercle-trochlear groove distance. In the sagittal plane, measurements included previously undescribed measurements of trochlear length and condylar height asymmetry which are based on the anterior femoral cortex. RESULTS: Analysis of trochlear morphology using condylar height asymmetry (both axial and sagittal), trochlear facet asymmetry, and trochlear depth and length demonstrated an increase in the size of the medial and lateral trochlea as age increased. There was more variability in the change of size of the medial trochlea (height, length, and facet length) than the lateral trochlea. The osseous sulcus angle, cartilaginous sulcus angle, and patella sulcus angle decreased (became deeper) with age until after 8 years and then plateaued. CONCLUSIONS: This cadaveric analysis demonstrated that there is an increase in the medial and lateral trochlear height as age increased by all measurements analyzed. The findings also demonstrate that the shape of the patella and trochlea change concurrently, which suggests that there may be interplay between the 2 during development. These new sagittal measurement techniques evaluating the medial, central, and lateral trochlear height and length with respect to age may help guide clinicians when investigating patellar instability in skeletally immature patients. LEVELS OF EVIDENCE: Level IV.


Assuntos
Fêmur/anatomia & histologia , Patela/anatomia & histologia , Articulação Patelofemoral/anatomia & histologia , Cadáver , Criança , Pré-Escolar , Epífises/anatomia & histologia , Epífises/diagnóstico por imagem , Epífises/crescimento & desenvolvimento , Feminino , Fêmur/diagnóstico por imagem , Fêmur/crescimento & desenvolvimento , Humanos , Masculino , Patela/diagnóstico por imagem , Patela/crescimento & desenvolvimento , Articulação Patelofemoral/diagnóstico por imagem , Articulação Patelofemoral/crescimento & desenvolvimento , Tíbia/anatomia & histologia , Tíbia/diagnóstico por imagem , Tomografia Computadorizada por Raios X
17.
Knee Surg Sports Traumatol Arthrosc ; 28(3): 888-896, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31111185

RESUMO

PURPOSE: The study purpose is to characterize the sizes of the anterior cruciate ligament (ACL) insertion site and intercondylar notch in Chinese patients undergoing ACL surgery. The findings will provide a reference for individualized clinical treatment of ACL rupture. METHODS: For this study, 137 patients (102 males, 35 females) with an average age of 30.3 ± 9.5 years (range 14-52 years) undergoing ACL reconstruction were included. The tibial ACL insertion site length and width and the intercondylar notch width were measured on MRI and arthroscopically using a ruler. Descriptive statistics of the patients, the distribution of the measurements and the differences between males and females were calculated. RESULTS: The ACL tibial insertion size and intercondylar notch width in Chinese patients with ACL injuries, as obtained by MRI and intra-operatively, exhibited significant individual variability. The tibial ACL insertion site had a mean length of 13.5 ± 2.1 mm and width of 10.9 ± 1.5 mm as measured on MRI and a mean length of 13.3 ± 2.1 mm and width of 11.0 ± 1.6 mm as measured intra-operatively. The mean intercondylar notch width was 15.2 ± 2.4 mm on MRI and the mean length was 15.0 ± 2.5 mm intra-operatively. The inter-rater reliability between MRI and intra-operative measurements confirmed that the two methods were consistent. In 65.7% of individuals, the ACL tibial insertion length was < 14 mm. CONCLUSION: The distribution of tibial footprint size in Chinese patients is different from that in Western populations. There is a higher proportion of subjects with a tibial footprint size < 14 mm among Chinese patients with ACL injury. Therefore, great care should be taken when treating this population with the double-bundle technique or larger graft options. Level of evidence IV.


Assuntos
Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior/métodos , Grupo com Ancestrais do Continente Asiático , Tíbia/anatomia & histologia , Tíbia/cirurgia , Adolescente , Adulto , Lesões do Ligamento Cruzado Anterior/diagnóstico por imagem , Lesões do Ligamento Cruzado Anterior/etnologia , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Tíbia/diagnóstico por imagem , Adulto Jovem
18.
Knee Surg Sports Traumatol Arthrosc ; 28(5): 1465-1472, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31123794

RESUMO

PURPOSE: This study aims to evaluate whether different tibial-femoral conformities for patient-specific mobile-bearing unicompartmental knee arthroplasties (UKAs) preserve natural knee kinematics, using computational simulations. METHODS: Different designs for patient-specific mobile-bearing UKAs were evaluated using finite element analysis. Three designs for the identical femoral component were considered: flat (non-conforming design), anatomy-mimetic, and conforming for the tibial insert. RESULTS: The conforming design for the patient-specific mobile-bearing UKAs exhibited a 1.2 mm and 0.7° decrease in the translation and rotation, respectively, in the swing phase compared with those of the natural knee. In addition, the femoral rollback and internal rotation were 2.6 mm and 1.2° lower, respectively, than those of the natural knee, for the conforming design under the deep-knee-bend condition. The flat design for the patient-specific mobile-bearing UKAs exhibited a 2.2 mm and 1.4° increase in the femoral rollback and rotation compared with the natural knee under the deep-knee-bend condition. The anatomy-mimetic patient-specific mobile-bearing UKAs best preserved the natural knee kinematics under the gait and deep-knee-bend loading conditions. CONCLUSIONS: The kinematics of the loading conditions in patient-specific mobile-bearing UKAs was determined to closely resemble those of a native knee. In additional, by replacing the anatomy-mimetic design with a mobile-bearing, natural knee kinematics during gait and deep-knee-bend motions is preserved. These results confirm the importance of tibiofemoral conformity in preserving native knee kinematics in patient-specific mobile-bearing UKA.


Assuntos
Artroplastia do Joelho/métodos , Articulação do Joelho/fisiopatologia , Articulação do Joelho/cirurgia , Prótese do Joelho , Artroplastia do Joelho/instrumentação , Fenômenos Biomecânicos , Simulação por Computador , Fêmur/diagnóstico por imagem , Fêmur/fisiopatologia , Fêmur/cirurgia , Análise de Elementos Finitos , Marcha/fisiologia , Humanos , Articulação do Joelho/anatomia & histologia , Articulação do Joelho/diagnóstico por imagem , Modelagem Computacional Específica para o Paciente , Postura/fisiologia , Desenho de Prótese , Amplitude de Movimento Articular , Tíbia/anatomia & histologia , Tíbia/diagnóstico por imagem , Tíbia/fisiopatologia , Tíbia/cirurgia
19.
Acta Radiol ; 61(6): 760-767, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31569946

RESUMO

BACKGROUND: Short T2 tissues can be directly visualized by dual-echo ultrashort echo time imaging with weighted subtraction. As a type of post-processing method, exponential subtraction of ultrashort echo time images with an optimal exponential factor is expected to provide improved positive short T2 contrast. PURPOSE: To test the feasibility and effectiveness of exponential subtraction in three-dimensional ultrashort echo time imaging and to determine the optimal exponential factor. MATERIAL AND METHODS: A dual-echo three-dimensional ultrashort echo time sequence was implemented on a 3-T MRI system. Exponential subtraction was performed on dual three-dimensional ultrashort echo time images of the tibia of seven healthy volunteers with exponential factors in the range of 1.00-3.00 in increments of 0.01. The regions of interest, including cortical bone, marrow, and muscle, were depicted on subtracted images of different exponential factors. Contrast-to-noise ratio values were calculated from these regions of interest and then used to assess the optimal exponential factor. To determine intra-observer agreement regarding region of interest selection, paired intra-observer measurements of regions of interest in all direct subtraction images were conducted with a one-week interval and the paired measurements were assessed using Bland-Altman analysis and paired-samples t-test. RESULTS: Cortical bone can be better visualized by using exponential subtraction in three-dimensional ultrashort echo time imaging; the suggested optimal exponential factor is 1.99-2.03 in the tibia. Paired measurements showed excellent intra-observer agreement. CONCLUSION: It is feasible to visualize cortical bone of the tibia using exponential subtraction in three-dimensional ultrashort echo time imaging. Compared with weighted subtraction images, exponential subtraction images with an optimal exponential factor provide enhanced visualization of short T2 tissues.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imagem por Ressonância Magnética/métodos , Tíbia/anatomia & histologia , Adulto , Estudos de Viabilidade , Feminino , Humanos , Masculino , Valores de Referência
20.
Eur J Orthop Surg Traumatol ; 30(2): 291-296, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31552484

RESUMO

INTRODUCTION: One of the final goals of anatomical anterior cruciate ligament (ACL) reconstruction is the restoration of native anatomy. It is essential to obtain more accurate predictors of mid-substance ACL size before surgery. However, to the best of our knowledge, no study has reported correlation between the mid-substance cross-sectional ACL size and the knee osseous morphology. The purpose of this study was to reveal correlation between the mid-substance cross-sectional ACL size and the knee osseous morphology. MATERIALS AND METHODS: We used 39 non-paired formalin fixed Japanese cadaveric knees. All surrounding muscles, ligaments and soft tissues in the knee were resected. After soft tissue resection, the knee was flexed at 90°, and a tangential plane of the femoral posterior condyles was marked and cut the ACL. Femoral ACL footprint size, Blumensaat's line length, lateral wall of the femoral intercondylar notch size, lateral wall of the femoral intercondylar notch height, tibial ACL footprint size, tibia plateau size, the whole anterior-posterior (AP) length, the medial and the lateral AP length of the tibia plateau, and the medial-lateral (ML) length of the tibia plateau were measured. The Pearson's product movement correlation was calculated to reveal correlation between the mid-substance cross-sectional ACL size and the measured parameters of the knee osseous morphology. RESULTS: The measured mid-substance cross-sectional ACL size was 49.9 ± 16.3 mm2. The tibial ACL footprint size, the tibia plateau size, the whole AP length of the tibia plateau, the lateral AP length of the tibia plateau and the ML length of the tibia plateau were significantly correlated with the mid-substance cross-sectional ACL size. CONCLUSIONS: For clinical relevance, some tibial sides of the knee osseous morphology were significantly correlated with the mid-substance cross-sectional ACL size. It might be possible to predict the mid-substance ACL size measuring these parameters.


Assuntos
Ligamento Cruzado Anterior/anatomia & histologia , Fêmur/anatomia & histologia , Articulação do Joelho/anatomia & histologia , Tíbia/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Cadáver , Epífises/anatomia & histologia , Feminino , Humanos , Masculino , Tamanho do Órgão
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