The development of lower limb musculoskeletal models with clinical relevance is dependent upon the fidelity of the mathematical description of the lower limb. Part 2: patient-specific geometry

2012 ◽  
Vol 226 (2) ◽  
pp. 133-145 ◽  
Author(s):  
Daniel J Cleather ◽  
Anthony MJ Bull
Keyword(s):  
Lower Limb ◽  
Mathematical Description ◽  
Clinical Relevance ◽  
Patient Specific ◽  
Musculoskeletal Models ◽  
Specific Geometry

Lower Limb Assistive Device Design Optimization Using Musculoskeletal Modeling: A Review

2019 ◽  
Vol 13 (4) ◽  
Author(s):  
Emerson Paul Grabke ◽  
Kei Masani ◽  
Jan Andrysek
Keyword(s):  
Design Optimization ◽  
Lower Limb ◽  
Musculoskeletal Model ◽  
Musculoskeletal Modeling ◽  
Model Complexity ◽  
Clinical Population ◽  
Assistive Device ◽  
Patient Specific ◽  
Device Design ◽  
Musculoskeletal Models

Abstract Many individuals with lower limb amputations or neuromuscular impairments face mobility challenges attributable to suboptimal assistive device design. Forward dynamic modeling and simulation of human walking using conventional biomechanical gait models offer an alternative to intuition-based assistive device design, providing insight into the biomechanics underlying pathological gait. Musculoskeletal models enable better understanding of prosthesis and/or exoskeleton contributions to the human musculoskeletal system, and device and user contributions to both body support and propulsion during gait. This paper reviews current literature that have used forward dynamic simulation of clinical population musculoskeletal models to perform assistive device design optimization using optimal control, optimal tracking, computed muscle control (CMC) and reflex-based control. Musculoskeletal model complexity and assumptions inhibit forward dynamic musculoskeletal modeling in its current state, hindering computational assistive device design optimization. Future recommendations include validating musculoskeletal models and resultant assistive device designs, developing less computationally expensive forward dynamic musculoskeletal modeling methods, and developing more efficient patient-specific musculoskeletal model generation methods to enable personalized assistive device optimization.

Applications of Musculoskeletal Modelling and Simulation for Lower-Limb Prosthesis Design Optimization

2018 ◽  
Author(s):  
Emerson Paul Grabke ◽  
Jan Andrysek
Keyword(s):  
Design Optimization ◽  
Lower Limb ◽  
Predictive Modelling ◽  
Musculoskeletal Model ◽  
Modelling And Simulation ◽  
Prosthesis Design ◽  
Model Complexity ◽  
Patient Specific ◽  
Musculoskeletal Modelling ◽  
Musculoskeletal Models

Lower-limb amputees can suffer from preventable pain and bone disorders attributable to suboptimal prosthesis design. Predictive modelling and simulation of human walking using conventional biomechanical gait models offer an alternative to intuition-based prosthesis design, providing insight into the biomechanics underlying pathological gait. Musculoskeletal models additionally enable understanding of prosthesis contributions to the human musculoskeletal system, and both prosthesis and individual muscle contributions to body support and propulsion during gait. Based on this review, forward dynamic simulation of amputee musculoskeletal models have been used to perform prosthesis design optimization using optimal control and reflex-based control. Musculoskeletal model complexity and assumptions inhibit fully predictive musculoskeletal modelling in its current state, hindering computational prosthesis design optimization. Future recommendations include validating musculoskeletal models and resultant optimized prosthesis designs, developing less computationally-expensive predictive musculoskeletal modelling methods, and developing more efficient patient-specific musculoskeletal model generation methods to enable personalized prosthesis optimization.

scholarly journals Automatic Generation of Personalised Skeletal Models of the Lower Limb from Three-Dimensional Bone Geometries

2020 ◽  
Author(s):  
Luca Modenese ◽  
Jean-Baptiste Renault
Keyword(s):  
Lower Limb ◽  
Subtalar Joint ◽  
Computational Models ◽  
Three Dimensional ◽  
Automatic Generation ◽  
Medical Image Segmentation ◽  
Biomechanical Analysis ◽  
Patient Specific ◽  
Musculoskeletal Models ◽  
Scripting Language

AbstractThe generation of personalised and patient-specific musculoskeletal models is currently a cumbersome and time-consuming task that normally requires several processing hours and trained operators. We believe that this aspect discourages the use of computational models even when appropriate data are available and personalised biomechanical analysis would be beneficial. In this paper we present a computational tool that enables the fully automatic generation of skeletal models of the lower limb from three-dimensional bone geometries, normally obtained by segmentation of medical images. This tool was evaluated against four manually created lower limb models finding remarkable agreement in the computed joint parameters, well within human operator repeatability. The coordinate systems origins were identified with maximum differences between 0.5 mm (hip joint) and 5.9 mm (subtalar joint), while the joint axes presented discrepancies between 1° (knee joint) to 11° (subtalar joint). To prove the robustness of the methodology, the models were built from four datasets including both genders, anatomies ranging from juvenile to elderly and bone geometries reconstructed from high-quality computed tomography as well as lower-quality magnetic resonance imaging scans. The entire workflow, implemented in MATLAB scripting language, executed in seconds and required no operator intervention, creating lower extremity models ready to use for kinematic and kinetic analysis or as baselines for more advanced musculoskeletal modelling approaches, of which we provide some practical examples. We auspicate that this technical advancement, together with upcoming progress in medical image segmentation techniques, will promote the use of personalised models in larger-scale studies than those hitherto undertaken.

scholarly journals Morphological Changes of the Hip Commonly Associated With Femoroacetabular Impingement Are Not Correlated With Rotational Range of Hip Motion in Elite Soccer Athletes

2021 ◽  
pp. 194173812097366
Author(s):  
André Orlandi Bento ◽  
Guilherme Falótico ◽  
Keelan Enseki ◽  
Ronaldo Alves Cunha ◽  
Benno Ejnisman ◽  
...  
Keyword(s):  
Femoroacetabular Impingement ◽  
Lower Limb ◽  
Clinical Relevance ◽  
Morphological Changes ◽  
Alpha Angle ◽  
Soccer Players ◽  
Level Of Evidence ◽  
Rotational Movement ◽  
Professional Soccer ◽  
Significant Difference

Background: Morphological changes characteristic of femoroacetabular impingement (FAI) are common in soccer players. However, the clinical relevance of such anatomical variations is still not well-defined. Hypothesis: We hypothesized that high alpha angle values and/or acetabular retroversion index (ARI) are correlated with rotational range of motion (ROM) of the hip and that there are clinical-radiological diferences between the dominant lower limb (DLL) and nondominant lower limb (NDLL) in professional soccer players. Study Design: Cross-sectional. Level of Evidence: Level 3. Methods: A total of 59 male professional soccer players (average age 25.5 years, range 18-38 years) were evaluated in the preseason. As main outcome measures, we evaluated the alpha angle and the ARI and hip IR and ER ROM with radiographic analysis. Results: The measurements taken on DLL and NDLL were compared and a significant difference was found between the sides in the ER ( P = 0.027), where the DLL measures were 1.54° (95% CI, 0.18-2.89) greater than the NDLL. There were no significant differences between the sides in the measures of IR ( P > 0.99), total ROM ( P = 0.07), alpha angle ( P = 0.250), and ARI ( P = 0.079). The correlations between the rotation measurements and the alpha angle in each limb were evaluated and the coefficient values showed no correlation; so also between the ARI and rotation measures. Conclusion: Morphological changes of the femur or acetabulum are not correlated with hip IR and ER ROM in male professional soccer players. ER on the dominant side was greater than on the nondominant side. There was no significant difference in the other measurements between sides. Clinical Relevance: In clinical practice, it is common to attribute loss of hip rotational movement to the presence of FAI. This study shows that anatomical FAI may not have a very strong influence on available hip rotational movement in professional soccer athletes.

scholarly journals Fully Data-Driven Pseudohealthy Synthesis for Planning Valve-Sparing Aortic Root Reconstruction using Conditional Variational Autoencoders

2020 ◽  
Vol 6 (3) ◽  
pp. 284-287
Author(s):  
Jannis Hagenah ◽  
Mohamad Mehdi ◽  
Floris Ernst
Keyword(s):  
Aortic Root ◽  
Similarity Index ◽  
Ground Truth ◽  
Representation Learning ◽  
Patient Specific ◽  
Ultrasound Images ◽  
Specific Geometry ◽  
The Individual ◽  
Native Root ◽  
Original Information

AbstractAortic root aneurysm is treated by replacing the dilated root by a grafted prosthesis which mimics the native root morphology of the individual patient. The challenge in predicting the optimal prosthesis size rises from the highly patient-specific geometry as well as the absence of the original information on the healthy root. Therefore, the estimation is only possible based on the available pathological data. In this paper, we show that representation learning with Conditional Variational Autoencoders is capable of turning the distorted geometry of the aortic root into smoother shapes while the information on the individual anatomy is preserved. We evaluated this method using ultrasound images of the porcine aortic root alongside their labels. The observed results show highly realistic resemblance in shape and size to the ground truth images. Furthermore, the similarity index has noticeably improved compared to the pathological images. This provides a promising technique in planning individual aortic root replacement.

scholarly journals A Protocol for Automated a-posteriori Adaptive Meshing with SimVascular

2019 ◽  
Author(s):  
Akash Gupta ◽  
Ethan O. Kung
Keyword(s):  
Mesh Size ◽  
Patient Specific ◽  
A Posteriori ◽  
Adaptive Meshing ◽  
Considerable Effort ◽  
Error Metrics ◽  
Scenario Modelling ◽  
Order Of Magnitude ◽  
Novice Users ◽  
Specific Geometry

Abstract Objective: Operational details regarding the use of the adaptive meshing (AM) algorithm available in the SimVascular package are scarce despite its application in several studies. Lacking these details, novice users of the AM algorithm may experience undesirable outcomes post-adaptation such as increases in mesh error metrics, unpredictable increases in mesh size, and losses in geometric fidelity. Here we propose an iterative protocol that will help prevent these undesirable outcomes and enhance the utility of the AM algorithm. We present three trials (conservative, aggressive and moderate settings) of our proposed protocol applied to a scenario modelling a Fontan junction with a patient-specific geometry and physiologically realistic boundary conditions. Results: In all three trials, an overall reduction in mesh error metrics is observed (range 47%-86%). The increase in the number of elements through each adaptation never exceeded the mesh size of the pre-adaptation mesh by one order of magnitude. In all three trials, the protocol resulted in consistent, repeatable improvements in mesh error metrics, no losses of geometric fidelity and steady increments in the number of elements in the mesh. Our proposed protocol prevented the aforementioned undesirable outcomes and can potentially save new users considerable effort and computing resources.

scholarly journals Mechanical and Anatomical Axis in Total Ankle Arthroplasty

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0008
Author(s):  
Ali-Asgar Najefi ◽  
Andrew Goldberg
Keyword(s):  
Lower Limb ◽  
Mechanical Axis ◽  
Normal Group ◽  
Total Ankle Arthroplasty ◽  
Coronal Plane ◽  
Patient Specific ◽  
Ankle Arthroplasty ◽  
Patient Specific Instrumentation ◽  
Significant Difference ◽  
Anatomical Axis

Category: Ankle Arthritis Introduction/Purpose: Inadequate correction of alignment in the coronal, sagittal or axial planes will inevitably lead to failure of the Total Ankle Arthroplasty (TAA). The mechanical axis of the lower limb (MAL), the mechanical axis of the tibia (MAT) and the anatomical axis of the tibia (AAT) are three recognized coronal plane measurements using plain radiography. The relationship between anatomical and mechanical axes depends on the presence of femoral or tibial deformities from trauma or inherited conditions, or previous corrective or replacement surgery. Ankle arthroplasty relies heavily on preoperative radiographs or CT scans and the purpose of this study was to assess whether MAL, MAT and AAT are the same in a cohort of patients upon which placement of TAA is considered. Methods: We analysed 75 patients operated on between 2015 and 2016 at a specialist tertiary centre for elective orthopaedic surgery. All patients had a pre-operative long leg radiograph. They were split into 2 groups. The first group had known deformity proximal to the ankle (such as previous tibial or femoral fracture, severe arthritis, or previous reconstructive surgery) and the second group had no clinically detectable deformity. The MAL, MAT and AAT were assessed and the difference between these values was calculated. Results: There were 54 patients in the normal group, and 21 patients in the deformity group. Overall, 25 patients(33%) had a difference between all three axes of less than 1 degree. In 33 patients(44%), there was a difference in one of the axes of ≥2 degrees. There was no significant difference between MAT and AAT in patients in the normal group(p=0.6). 95% of patients had a difference of <1 degree. There was a significant difference between the MAT and AAT in patients in the deformity group(p<0.01). In the normal group, 39 patients(73%) had a difference of <2 degrees between the AAT and MAL. In the deformity group, only 10 patients (48%) had a difference of <2 degrees.In fact, 24% of patients had a difference ≥3 degrees. Conclusion: Malalignment in the coronal plane in TAA may be an issue that we have not properly addressed. Up to 66% of patients without known deformity may have a TAA that is placed at least 1 degree incorrectly relative to the MAL. We recommend the use of full-length lower limb radiographs when planning a TAA in order to plan the placement of implants. The decision to perform extramedullary referencing, intramedullary referencing, or patient specific Instrumentation must be part of the pre-operative planning process.

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