Three-dimensional Joint Research Articles

Interaction of loading and ligament injuries in subtalar joint instability quantified by 3D weightbearing computed tomography.

Despite decades of research since its first description, subtalar joint instability remains a diagnostic enigma within the concept of hindfoot instability. This could be attributed to current imaging techniques, which are impeded by two-dimensional measurements. Therefore, we used weightbearing computed tomography imaging to quantify three-dimensional displacement associated with subtalar joint instability. Three-dimensional models were generated in seven paired cadaver specimens to compute talocalcaneal displacement after different patterns of axial load (85 kg) combined with torque in internal and external rotation (10 Nm). Sequential imaging was repeated in the subtalar joint containing intact ligaments to determine reference displacement. Afterward, the interosseus talocalcaneal ligament (ITCL) or calcaneofibular ligament (CFL) was sectioned, then the ITCL with CFL and after the ITCL, CFL with the deltoid ligament (DL). The highest translation could be detected in the dorsal direction and the highest rotation occurred in the internal direction when external torque was applied to the foot without load. These displacements differed significantly from the condition containing intact ligaments, with a mean difference of 1.6 mm (95% CI, 1.3 to 1.9) for dorsal translation and a mean of 12.4° (95% CI, 10.1 to 14.8) for internal rotation. Clinical relevance: Our study provides a novel and noninvasive analysis to quantify subtalar joint instability based on three-dimensional WBCT imaging. This approach overcomes former studies using trans-osseous fixation to determine three-dimensional subtalar joint displacement and implements an imaging device and software modalities that are readily available. Based on our findings, we recommend applying torque in external rotation to the foot to optimize the detection of subtalar joint instability.

Real-time conversion of inertial measurement unit data to ankle joint angles using deep neural networks

Joint angle quantification from inertial measurement units (IMUs) is commonly performed using kinematic modelling, which depends on anatomical sensor placement and/or functional joint calibration; however, accurate three-dimensional joint motion measurement remains challenging to achieve. The aims of this study were firstly to employ deep neural networks to convert IMU data to ankle joint angles that are indistinguishable from those derived from motion capture-based inverse kinematics (IK) - the reference standard; and secondly, to validate the robustness of this approach across contrasting walking speeds in healthy individuals. Kinematics data were simultaneously calculated using IMUs and IK from 9 subjects during walking on a treadmill at 0.5 m/s, 1.0 m/s and 1.5 m/s. A generative adversarial network was trained using gait data at two of the walking speeds to predict ankle kinematics from IMU data alone for the third walking speed. There were significant differences between IK and IMU joint angle predictions for ankle eversion and internal rotation during walking at 0.5 m/s and 1.0 m/s (p < 0.001); however, no significant differences in joint angles were observed between the generative adversarial network prediction and IK at any speed or plane of joint motion (p < 0.05). The RMS difference in ankle joint kinematics between the generative adversarial network and IK for walking at 1.0 m/s was 3.8°, 2.1° and 3.5° for dorsiflexion, inversion and axial rotation, respectively. The modeling approach presented for real-time IMU to ankle joint angle conversion, which can be readily expanded to other joints, may provide enhanced IMU capability in applications such as telemedicine, remote monitoring and rehabilitation.

Test-retest reliability of entire time-series data from hip, knee and ankle kinematics and kinetics during one-leg hops for distance: Analyses using integrated pointwise indices

Motion capture systems enable in-depth interpretations of human movements based on data from three-dimensional joint angles and moments. Such analyses carry important bearings for evaluation of movement control during for instance hop landings among sports-active individuals from a performance perspective but also in rehabilitation. Recent statistical development allows analysis of entire time-series of angle and moment during hops using functional data analysis, but the reliability of such multifaceted data is not established. We used integrated pointwise indices (intra-class correlation, ICC; standard error of measurement, SEM) to establish the test–retest reliability of three-dimensional hip, knee and ankle angle and moment curves during landings of one-leg hop for distance (OLHD) in 23 asymptomatic individuals aged 18–28. We contrasted these findings to reliability of discrete variables extracted at specific events (initial contact, peak value). We extended the calculations of ICC and SEM to handle unbalanced situations (varying number of repetitions) to include all available data. Hip and knee angle curves proved reliable with stable ICC curves throughout the landing, with integrated ICCs ≥ 0.71 for all planes except for knee internal/external rotation (ICC = 0.57). Hip and knee moment curves and ankle angle and moments were less reliable and less stable, particularly in the first ~ 10–25% of the landing (integrated ICCs 0.44–0.57). Curve data were generally not in agreement with the results for discrete event data, thus advocating analysis of curve data which contains more information. To conclude, hip and knee angle curve data during OLHD landings can reliably be evaluated, while moment curves necessitate careful consideration.

Comparison of the Effect of Insole Correction on Three-Dimensional Knee Joint Moments during Gait in Standing Workers with Leg Length Discrepancy

Background Few studies have been performed to investigate the correction of leg length discrepancy (LLD) on the kinetic characteristics of the knee joint using a shoe insole during gait among those who must stand while working. Purpose To verify three-dimensional (3D) knee joint moments using a 3D motion capture system and force platforms with and without insoles during gait in standing workers with LLD. Study design This was a repeated-measures design. Methods Twenty-seven standing workers with LLD participated in this study. Kinetic data of the knee joint were collected using a motion analysis system and two force platforms. The participants were asked to walk freely along a 6-m walkway wearing a standard pair of shoes or standard shoes with an LLD-corrected insole. Repeated-measures analysis of variance (ANOVA) was used to compare the knee joint moments according to shoe conditions and limb sides. Results There were significant differences in most moment variables related to the knee joint in participants with LLD-corrected insoles worn on the short limb except for the knee moments of adduction, abduction, and internal rotation (<italic>p</italic>&lt;0.05). Significant differences were shown in the maximal moment of knee adduction, abduction, internal rotation, and external rotation between the long and short legs when the participants wore standard shoes only during gait (<italic>p</italic>&lt;0.05). Conclusions The results demonstrated a significant association between the imbalance of the knee moments and LLD among retail staff who must stand while working. Therefore, the results of this study will be useful in explaining the incidence and biomechanical characteristics of knee osteoarthritis in standing workers with LLD.

Dynamic response analysis for multi-degrees-of-freedom parallel mechanisms with various types of three-dimensional clearance joints

For spatial multibody systems, the dynamic equations of multibody systems with compound clearance joints have a high level of nonlinearity. The coupling between different types of clearance joints may lead to abundant dynamic behavior. At present, the dynamic response analysis of the spatial parallel mechanism considering the three-dimensional (3D) compound clearance joint has not been reported. This work proposes a modeling method to investigate the influence of the 3D compound clearance joint on the dynamics characteristics of the spatial parallel mechanism. For this purpose, 3D kinematic models of spherical clearance joint and revolute joint with radial and axial clearances are derived. Contact force is described as normal contact and tangential friction and later introduced into the nonlinear dynamics model, which is established by the Lagrange multiplier technique and Jacobian of constraint matrix. The influences of compound clearance joint and initial misalignment of bearing axes on the system are analyzed. Furthermore, validation of dynamics model is evaluated by ADAMS and Newton–Euler method. This work provides an essential theoretical basis for studying the influences of 3D clearance joints on dynamic responses and nonlinear behavior of parallel mechanisms.

A Biomechanical Comparison Shows No Difference Between Two Knee Braces used for Medial Collateral Ligament Injuries

PurposeThe purpose of this study was to assess the ability of 2 commonly used knee braces to control knee valgus motion and subsequent strain on the medial collateral ligament (MCL) in a laboratory-controlled environment.MethodsTwenty healthy individuals (6 male, 14 female; mean age, 23 ± 3 years) with no history of knee injury or brace use performed a jump landing task while wearing either no brace or 1 of 2 braces: the Playmaker and Total Range of Motion . Three-dimensional joint kinematics and kinetics were measured in our biomechanics laboratory.ResultsSignificantly less knee dynamic valgus angulation was noted when using either brace (−0.51° ± 3.9° and −1.3° ± 3.2°) compared no brace (4.8° ± 3.0°). Dynamic valgus angulation did not differ significantly between the 2 braces tested, which were both not statistically different from baseline alignment. There were significant differences seen in peak knee flexion angle between each brace (77.9° ± 8.8°and 83.1° ± 8.4°), as well as between both braces and no brace (90.6° ± 11.1°). There was no significant difference in knee frontal plane moment or peak vertical ground reaction force loading among all 3 testing conditions.ConclusionsCompared to no brace, both braces allowed significantly less dynamic valgus angulation of the knee under physiological vertical loads but were not significantly different from one another.Clinical RelevanceKnee braces are commonly used to protect the MCL when placed under physiological loads. It is important to know which braces effectively reduce valgus stress to provide the best outcomes.

Weight-bearing CT for Knee Osteoarthritis Assessment: A Story Unfolds

Weight-bearing CT for Knee Osteoarthritis Assessment: A Story Unfolds

Quantitative Three-dimensional Assessment of Knee Joint Space Width from Weight-bearing CT.

Background Imaging of structural disease in osteoarthritis has traditionally relied on MRI and radiography. Joint space mapping (JSM) can be used to quantitatively map joint space width (JSW) in three dimensions from CT images. Purpose To demonstrate the reproducibility, repeatability, and feasibility of JSM of the knee using weight-bearing CT images. Materials and Methods Two convenience samples of weight-bearing CT images of left and right knees with radiographic Kellgren-Lawrence grades (KLGs) less than or equal to 2 were acquired from 2014 to 2018 and were analyzed retrospectively with JSM to deliver three-dimensional JSW maps. For reproducibility, images of three sets of knees were used for novice training, and then the JSM output was compared against an expert's assessment. JSM was also performed on 2-week follow-up images in the second cohort, yielding three-dimensional JSW difference maps for repeatability. Statistical parametric mapping was performed on all knee imaging data (KLG, 0-4) to show the feasibility of a surface-based analysis in three dimensions. Results Reproducibility (in 20 individuals; mean age, 58 years ± 7 [standard deviation]; mean body mass index, 28 kg/m2 ± 6; 14 women) and repeatability (in nine individuals; mean age, 53 years ± 6; mean body mass index, 26 kg/m2 ± 4; seven women) reached their lowest performance at a smallest detectable difference less than ±0.1 mm in the central medial tibiofemoral joint space for individuals without radiographically demonstrated disease. The average root mean square coefficient of variation was less than 5% across all groups. Statistical parametric mapping (33 individuals; mean age, 57 years ± 7; mean body mass index, 27 kg/m2 ± 6; 23 women) showed that the central-to-posterior medial joint space was significantly narrower by 0.5 mm for each incremental increase in the KLG (threshold P < .05). One knee (KLG, 2) demonstrated a baseline versus 24-month change in its three-dimensional JSW distribution that was beyond the smallest detectable difference across the lateral joint space. Conclusion Joint space mapping of the knee using weight-bearing CT images is feasible, demonstrating a relationship between the three-dimensional joint space width distribution and structural joint disease. It is reliably learned by novice users, can be personalized for disease phenotypes, and can be used to achieve a smallest detectable difference that is at least 50% smaller than that reported to be achieved at the highest performance level in radiography. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Roemer in this issue.

Depth-to-basement study for the western Polish Outer Carpathians from three-dimensional joint inversion of gravity and magnetic data

Depth-to-basement study for the western Polish Outer Carpathians from three-dimensional joint inversion of gravity and magnetic data

Three-Dimensional Evaluation Of The Temporomandibular Joint After Using Facemask Appliance; A Clinical Prospective Study.

Aim of the study This study was conducted to evaluate the three dimensional changes in the TMJ after the maxillary protraction using face mask therapy. Material and Methods Eighteen growing patients (ages ranged from 8-11 years) were included in the current study. All patients manifested features of skeletal class III due to maxillary deficiency. A Petit-type facemask was used for all patients and was attached intraorally to a fixed labiolingual appliance through extraoral elastics . A cone-beam CT scan had been applied for each patient before the start of the treatment and after 10 months. The three-dimensional (3D) temporomandibular joint measurements included: 1) anterior fossa line inclination, 2) posterior fossa line inclination, 3) anterior joint space, 4)posterior joint space,5) medial joint space, and 6) superior joint space. Results Regarding Anterior Joint space : measurements after using a facemask appliance were significantly higher than before (as P<0.05) ,while regarding Posterior and superior Joint spaces : measurements after using a facemask appliance were significantly lower than before (as P<0.05) Conclusion Facemask therapy for maxillary protraction in management of skeletal class III produced: 1- Decrease in both posterior and superior joint spaces ,while increase in the anterior joint spaces. 2- Bone remodeling in the glenoid fossa causes upward and backward displacement of the condyle.

Optical motion capture accuracy is task-dependent in assessing wrist motion

Optical motion capture (OMC) systems are commonly used to capture in-vivo three-dimensional joint kinematics. However, the skin-based markers may not reflect the underlying bone movement, a source of error known as soft tissue artifact (STA). This study examined STA during wrist motion by evaluating the agreement between OMC and biplanar videoradiography (BVR). Nine subjects completed 7 different wrist motion tasks: doorknob rotation to capture supination and pronation, radial-ulnar deviation, flexion–extension, circumduction, hammering, and pitcher pouring. BVR and OMC captured the motion simultaneously. Wrist kinematics were quantified using helical motion parameters of rotation and translation, and Bland-Altman analysis quantified the mean difference (bias) and 95% limit of agreement (LOA). The rotational bias of doorknob pronation, a median bias of −4.9°, was significantly larger than the flexion–extension (0.7°, p < 0.05) and radial-ulnar deviation (1.8°, p < 0.01) tasks. The rotational LOA range was significantly smaller in the flexion–extension task (5.9°) compared to pitcher (11.6°, p < 0.05) and doorknob pronation (17.9°, p < 0.05) tasks. The translation bias did not differ between tasks. The translation LOA range was significantly larger in circumduction (9.8°) compared to the radial-ulnar deviation (6.3°, p < 0.05) and pitcher (3.4°, p < 0.05) tasks. While OMC technology has a wide-range of successful applications, we demonstrated it has relatively poor agreement with BVR in tracking wrist motion, and that the agreement depends on the nature and direction of wrist motion.

Joint and constrained inversion of magnetic and gravity data: A case history from the McArthur River area, Canada

Magnetic and gravity data are used in the early stages of exploration for uranium deposits in the Athabasca Basin of Canada, just as for many other mineral exploration scenarios. Uranium mineralization in the Athabasca Basin is located where faults in the basement intersect the unconformity between the basement and the overlying sandstones. The gravity and magnetic data are dominated by signatures from the basement and an overburden of glacial sediments. The gravity and magnetic data are effective at mapping the basement geology. Any subtle gravity signal from the mineralization related to the formation of the uranium deposits is masked by the signal from the variable-thickness overburden. Three-dimensional joint inversion of gravity and magnetic data, first without and then with constraints, is evaluated as a means of better determining the structure of the three main lithologies (overburden, sandstones, and basement) in the Athabasca Basin. A significant amount of physical property information is available for the main rock units (and overburden), which makes the use of the compositional approach to joint inversion appropriate. For the joint inversion, the fuzzy c-means clustering method is used. Results from representative synthetic examples indicate that the joint inversions can construct the overburden and basement structures better than the independent inversions of gravity and magnetic data. Furthermore, constrained joint inversion allows delineation of all three major layers in the area. The same inversion strategies then are applied to real airborne gravity and magnetic data from the McArthur River area in the eastern Athabasca Basin. The results we obtain demonstrate the capabilities of joint inversion for real-life situations.

Явный вид распределения избранных двумерных и трехмерных статистик (0,1)-последовательности

Рассмотрены совместимые распределения заданного числа 2-цепочек и заданного числа 3-цепочек фиксированного вида случайной битовой последовательности, позволяющие осуществлять статистический анализ локальных участков этой последовательности. В качестве 2-цепочек выступают все конфигурации, состоящие из двух подряд или нулей, или единиц битовой последовательности заданной длины. В свою очередь, 3-цепочками являются все конфигурации, состоящие из трех подряд или единиц (при условии, что 2-цепочки являются нулевыми), или нулей (при условии, что 2-цепочки единичны), а также в качестве 3 -цепочек рассматриваются все конфигурации, состоящие либо из трех подряд цифр: один, ноль и один (при условии, что 2-цепочки нулевые), либо из трех подряд цифр: ноль, один и ноль (при условии, что 2-цепочки единичные). Установлены явные выражения двумерных и трехмерных совместимых распределений событий, отражающих количество некоторых комбинаций указанных цепочек в конечной случайной битовой последовательности. Одно из основных предположений состоит в том, что нули и единицы в битовой последовательности — независимые одинаково распределенные случайные величины. Доказательства формул для распределений указанных событий построены на подсчете числа ответных благоприятных событий при условии, что битовая последовательность содержит фиксированное количество нулей и единиц. В качестве примеров использования явных выражений совместимых распределений приведены таблицы, в которых размещены значения вероятностей вышеперечисленных событий для случайной битовой последовательности длины 40 (табл. 1–3) и длины 24 (табл. 4) для некоторых фиксированных значений числа 2-цепочек и числа 3-цепочек в предположении, что нули и единицы появляются независимо и равновероятно. табл. 1–3 проиллюстрированы пузырьковыми диаграммами. Найденные формулы могут представлять интерес для задач тестирования локальных участков, формируемых на выходе генераторов псевдослучайных чисел, для некоторых задач защиты информации от несанкционированного доступа, а также в других сферах, где возникает необходимость в анализе битовых последовательностей.

Fabrication of a three-dimensional temporomandibular joint model for arthrocentesis and arthroscopy simulation

Arthrocentesis and arthroscopy are relatively safe treatments for arthrogenic temporomandibular disorders. Hands-on training in both procedures is essential for surgeons to become competent. In this study, a three-dimensional (3D) temporomandibular joint (TMJ) prototype was developed at a relatively low cost, and arthrocentesis and arthroscopy were performed successfully on the model. Despite its limitations, this model is a viable adjunct to TMJ surgical training and can be fabricated easily by any training centre with a 3D printer.

Accurate and Automatic 3D Segmentation of Femur and Pelvis from CT Images of the Hip based on Deep Learning

Background: Prosthesis design of hip joint and computer-assisted surgical planning can benefit from segmentation-based computed tomography (CT). Purpose: To automatically segment the three-dimensional (3D) hip joint images, the authors developed a deep learning-based segmentation algorithm and verified its feasibility with CT image of hip joint. Methods: Conventional image augmentation strategies and specific image augmentation strategies, which were designed to mimic the deformed shape and blurring boundaries of the diseased hips, were applied to obtain a large number of training samples of diseased hips to avoid overfitting. A 3D segmentation algorithm named light 3D U-net, which segmented images from coarse to fine, was developed to improve the segmentation accuracy and reduce the computation time in 3D hip joint image with multiple targets. Results and Discussion: The test results showed that the proposed method would exceed 0.9 in the aspects of Dice score, Specificity, and Sensitivity. Comparing with traditional method, the proposed method is more efficient, accurate, and robust. The proposed method has shown great potential to be applied in prosthesis design and computer-assisted surgical planning.

Establishment of a human three-dimensional chip-based chondro-synovial coculture joint model for reciprocal cross talk studies in arthritis research.

Rheumatoid arthritis is characterised by a progressive, intermittent inflammation at the synovial membrane, which ultimately leads to the destruction of the synovial joint. The synovial membrane as the joint capsule's inner layer is lined with fibroblast-like synoviocytes that are the key player supporting persistent arthritis leading to bone erosion and cartilage destruction. While microfluidic models that model molecular aspects of bone erosion between bone-derived cells and synoviocytes have been established, RA's synovial-chondral axis has not yet been realised using a microfluidic 3D model based on human patient in vitro cultures. Consequently, we established a chip-based three-dimensional tissue coculture model that simulates the reciprocal cross talk between individual synovial and chondral organoids. When co-cultivated with synovial organoids, we could demonstrate that chondral organoids induce a higher degree of cartilage physiology and architecture and show differential cytokine response compared to their respective monocultures highlighting the importance of reciprocal tissue-level cross talk in the modelling of arthritic diseases.

Energy Catastrophe of Jointed Rock Slope Considering Spatiotemporal Variability of Strength

The spatiotemporal variability of rock mass strength for jointed rock mass is crucial for the stability of open-pit mine slopes. The Dagushan Open-pit Iron Mine was taken as the background to systematically study the unloading damage and energy evolution of high slope jointed rock mass. Through a field survey of mixed rock slope and fuzzy C-means clustering optimization analysis, the random distribution parameters of two dominant joint sets of rock mass were determined, and a three-dimensional joint network of rock mass was reconstructed. Additionally, a numerical analysis method is proposed for the energy evolution of jointed rock mass considering the spatiotemporal variation of strength, and the variation trends of gravity potential energy, elastic strain energy, and dissipation energy of jointed rock slope were analyzed. Moreover, based on the cusp catastrophe theory, an energy criterion was established for jointed rock mass slope instability. Furthermore, the energy evolution mechanism of deformation and failure of jointed rock slope under mining was elucidated. The slope safety factor obtained from the energy cusp catastrophe dissipation energy cusp catastrophe is the same as that obtained from the limit equilibrium Janbu method.

Statistics of polarization speckle produced by a constant polarization phasor plus a random polarization phasor sum.

The statistical properties of the polarization speckle produced by a random polarization phasor sum plus a constant polarization phasor are studied. Based on the Gaussian assumption for the random electric field, the three-dimensional joint probability density functions of the Stokes parameters and the parameters characterizing the polarization ellipse for the produced random polarization fields are obtained. Subsequently, the statistics of an isotropic polarization speckle with a coherent polarization background have been investigated. The joint and marginal probability densities of these random variables are given to study the effect of the constant polarization background on the statistics of random polarization fields.

Modelling and simulation of sprinters’ health promotion strategy based on sports biomechanics

With the rapid development of the new edge discipline sports biomechanics, modelling and simulation of human motion as one of the cutting-edge research topics in sports biomechanics is receiving more and more attention. Based on the establishment of the three-dimensional simulation system model of human knee joint and the analysis of buckling motion, this paper uses the three-dimensional image registration knee joint motion analysis method to carry out the research on knee flexion movement to solve the knee joint injury problem of sprinters. The results showed that medial collateral ligament injury and meniscus injury were more common in all types of knee joint injuries, accounting for 24% respectively 7% and 22.4%. The incidence of lateral collateral ligament injury was relatively small, accounting for only 5.6%. And the research shows that the foot strength curve recognition method based on biomechanics sprinters knee joint simulation model is an advanced and complete strategy to reduce sprinters knee joint injury, and it can achieve better results in sprinters knee joint nursing.

A Clipless Pedal-Sensor System for Three Dimensional Kinetic Analysis During Cycling

A Clipless Pedal-Sensor System for three-dimensional kinetic analysis of the lower limb during cycling exercise has been designed and validated. This system is designed for measuring three-dimensional propulsion forces during cycling when wearing a shoe cleat. To compare the dynamic measured forces from the system and the applied forces from the material testing machine, the system has a high linearity and little offset (coefficient of determination, r2 > 0.99). The three-dimensional propulsion forces, ankle and knee joint loading during cycling by a subject in the university team were demonstrated. During cycling, the ankle and knee compression forces were around 5 N/kg for each joint. The ankle plantar-flexor and knee flexor moments were 0.6 N-m/kg for both joints. In future studies, the lower limb kinetics during cycling can be analyzed throughout this clipless pedal-sensor system and the parameters of the bike setup, such as seat height or crank length, can be further investigated when cyclists wear the shoes cleat.