THE EFFECT OF ARTICULAR SURFACE SHAPE AND TENDON FORCES OF TOTAL WRIST ARTHROPLASTY SYSTEMS: A FINITE ELEMENT STUDY

2012 ◽  
Vol 15 (04) ◽  
pp. 1250021 ◽  
Author(s):  
Matthew B. A. McCullough ◽  
Brian D. Adams ◽  
Nicole M. Grosland
Keyword(s):  
Finite Element ◽  
Articular Surface ◽  
Surface Shape ◽  
Element Analysis ◽  
Future Directions ◽  
Ulnar Deviation ◽  
Articular Surfaces ◽  
Total Wrist Arthroplasty ◽  
Flexion Extension ◽  
Wrist Arthroplasty

In order to better understand the behavior of the total wrist implant systems, finite element analysis (FEA) was used to model the articular surfaces of two unconstrained total wrist arthroplasty (TWA) devices. After creating models based on manufacturer specifications, simulations of flexion, extension, radial deviation, ulnar deviation and circumduction were run with simulated moments from surrounding tendons under displacement control. In addition, simulations were run under positioning that represented a pronated and supinated forearm as well as unstable conditions. Understanding implant behavior and capabilities as related to the shape of the articular surfaces is important for proper prescription of implants as well as determining future directions for the design of arthroplasty devices.

scholarly journals Biomechanical Effects of Position-Loading During Cervical Rotatory Manipulation: A Finite Element Analysis

2020 ◽  
Author(s):  
Huihao Wang ◽  
Hongsheng Zhan ◽  
Kuan Wang ◽  
Zhen Deng ◽  
Xiaofei Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Neck Pain ◽  
Contact Pressure ◽  
Articular Surface ◽  
Angular Displacement ◽  
Element Model ◽  
Intervertebral Discs ◽  
Element Analysis ◽  
Articular Surfaces ◽  
The Right

Abstract Background: Cervical rotatory manipulation(CRM) is one of the most common treatments for neck pain in China. This study utilized a finite element method (FEM) to model the biomechanical effects of positioning during CRM in a normal sitting position. Methods: Passive head kinematics data, including angular displacement in six directions, were recorded. These data were then imported and a finite element model constructed, then validated. Relative angular displacements, and stress on the intervertebral discs and articular surfaces were calculated in a standard symmetry model (SSM) and compared with a pathological model (PM).Results: The results indicate that the intervertebral disc pressure (IDP) at the C2-C3, C3-C4 and C4-C5 discs subjected to CRM with position-loading were lower than the pressures experienced without position-loading. Furthermore, IDP on the target C5-C6 segment during CRM with position-loading in the PM was lower than that without position-loading, the former being close to the IDP of the C5-C6 segment during CRM without position-loading in the SSM. The left articular surface contact pressure of the target C5-C6 segment subjected to CRM towards the right without position-loading in the PM was slightly lower than that of the right articular surface experiencing leftward manipulation and lower than that predicted by the SSM. However, contact pressure of the C5-T1 segment in leftward CRM with position-loading in the PM and C6-T1 in rightward CRM with position-loading in the PM were significantly higher than the standard threshold, especially for contact pressure on the articular surfaces of C5-C6 in leftward CRM with position-loading in the PM. Conclusions: CRM should be considered a promising strategy to mitigate neck pain in patients.

Total Wrist Arthroplasty Alignment and Its Potential Association with Clinical Outcomes

2021 ◽  
Author(s):  
Bardiya Akhbari ◽  
Kalpit N. Shah ◽  
Amy M. Morton ◽  
Janine Molino ◽  
Douglas C. Moore ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Clinical Outcomes ◽  
Three Dimensional ◽  
Radial Component ◽  
Single Type ◽  
Radiographic Images ◽  
Computed Tomography Images ◽  
Total Wrist Arthroplasty ◽  
Flexion Extension ◽  
Wrist Arthroplasty

Abstract Purpose There is a lack of quantitative research that describes the alignment and, more importantly, the effects of malalignment on total wrist arthroplasty (TWA). The main goal of this pilot study was to assess the alignment of TWA components in radiographic images and compare them with measures computed by three-dimensional analysis. Using these measures, we then determined if malalignment is associated with range of motion (ROM) or clinical outcomes (PRWHE, PROMIS, QuickDash, and grip strength). Methods Six osteoarthritic patients with a single type of TWA were recruited. Radiographic images, computed tomography images, and clinical outcomes of the wrists were recorded. Using posteroanterior and lateral radiographs, alignment measurements were defined for the radial and carpal components. Radiographic measurements were validated with models reconstructed from computed tomography images using Bland–Altman analysis. Biplanar videoradiography (<1mm and <1 degree accuracy) was used to capture and compute ROM of the TWA components. Linear regression assessed the associations between alignment and outcomes. Results Radiographic measures had a 95% limit-of-agreement (mean difference ±  1.96 × SD) of 3 degrees and 3mm with three-dimensional values, except for the measures of the carpal component in the lateral view. In our small cohort, wrist flexion–extension and radial–ulnar deviation were correlated with volar–dorsal tilt and volar–dorsal offset of the radial component and demonstrated a ROM increase of 3.7 and 1.6 degrees per degree increase in volar tilt, and 10.8 and 4.2 degrees per every millimeter increase in volar offset. The carpal component's higher volar tilt was also associated with improvements in patient-reported pain. Conclusions We determined metrics describing the alignment of TWA, and found the volar tilt and volar offset of the radial component could potentially influence the replaced wrist's ROM. Clinical Relevance TWA component alignment can be measured reliably in radiographs, and may be associated with clinical outcomes. Future studies must evaluate its role in a larger cohort.

scholarly journals The biomechanical effect on the adjacent L4/L5 segment of S1 superior facet arthroplasty: a finite element analysis for the male spine

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Zewen Shi ◽  
Lin Shi ◽  
Xianjun Chen ◽  
Jiangtao Liu ◽  
Haihao Wu ◽  
...  
Keyword(s):  
Finite Element ◽  
Range Of Motion ◽  
Facet Joint ◽  
Adjacent Segment ◽  
Finite Element Models ◽  
Level Of Evidence ◽  
Element Analysis ◽  
Flexion Extension ◽  
Biomechanical Effect ◽  
Lumbar Range Of Motion

Abstract Background The superior facet arthroplasty is important for intervertebral foramen microscopy. To our knowledge, there is no study about the postoperative biomechanics of adjacent L4/L5 segments after different methods of S1 superior facet arthroplasty. To evaluate the effect of S1 superior facet arthroplasty on lumbar range of motion and disc stress of adjacent segment (L4/L5) under the intervertebral foraminoplasty. Methods Eight finite element models (FEMs) of lumbosacral vertebrae (L4/S) had been established and validated. The S1 superior facet arthroplasty was simulated with different methods. Then, the models were imported into Nastran software after optimization; 500 N preload was imposed on the L4 superior endplate, and 10 N⋅m was given to simulate flexion, extension, lateral flexion and rotation. The range of motion (ROM) and intervertebral disc stress of the L4-L5 spine were recorded. Results The ROM and disc stress of L4/L5 increased with the increasing of the proportions of S1 superior facet arthroplasty. Compared with the normal model, the ROM of L4/L5 significantly increased in most directions of motion when S1 superior facet formed greater than 3/5 from the ventral to the dorsal or 2/5 from the apex to the base. The disc stress of L4/L5 significantly increased in most directions of motion when S1 superior facet formed greater than 3/5 from the ventral to the dorsal or 1/5 from the apex to the base. Conclusion In this study, the ROM and disc stress of L4/L5 were affected by the unilateral S1 superior facet arthroplasty. It is suggested that the forming range from the ventral to the dorsal should be less than 3/5 of the S1 upper facet joint. It is not recommended to form from apex to base. Level of evidence Level IV

scholarly journals Proximal Row Carpectomy with Total Scapoidectomy vs. Conventional Carpal Resection for ReMotion Total Wrist Arthroplasty

2021 ◽  
Vol 10 (9) ◽  
pp. 1865
Author(s):  
Stefan M. Froschauer ◽  
Matthias Holzbauer ◽  
Dietmar Hager ◽  
Oskar Kwasny ◽  
Dominik Duscher
Keyword(s):  
Grip Strength ◽  
Clinical Assessment ◽  
Complication Rates ◽  
Proximal Row Carpectomy ◽  
Prosthesis Implantation ◽  
Total Wrist Arthroplasty ◽  
Significant Difference ◽  
Flexion Extension ◽  
Wrist Arthroplasty

High complication rates in total wrist arthroplasty (TWA) still lead to controversy in the medical literature, and novel methods for complication reduction are warranted. In the present retrospective cohort study, we compare the outcomes of the proximal row carpectomy (PRC) method including total scaphoidectomy (n = 22) to the manufacturer’s conventional carpal resection (CCR) technique, which retains the distal pole of the scaphoid (n = 25), for ReMotion prosthesis implantation in non-rheumatoid patients. Mean follow-up was 65.8 ± 19.8 and 80.0 ± 28.7 months, respectively. Pre- and postoperative clinical assessment included wrist flexion-extension and radial-ulnar deviation; Disability of Arm, Shoulder, and Hand scores; and pain via visual analogue scale. At final follow-up, grip strength and satisfaction were evaluated. All complications, re-operations, and revision surgeries were noted. Clinical complications were significantly lower in the PRC group (p = 0.010). Radial impaction was detected as the most frequent complication in the CCR group (n = 10), while no PRC patients suffered from this complication (p = 0.0008). Clinical assessment, grip strength measurements, and the log rank test evaluating the re-operation as well as revision function showed no significant difference. All functional parameters significantly improved compared to preoperative values in both cohorts. In conclusion, we strongly recommend PRC for ReMotion prosthesis implantation.

PHOTOGRAMMETRY MEASUREMENTS OF INITIAL IMPERFECTIONS FOR THE ULTIMATE STRENGTH ASSESSMENT OF PLATES

2021 ◽  
Vol 156 (A4) ◽  
Author(s):  
A Cubells ◽  
Y Garbatov ◽  
C Guedes Soares
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Compressive Load ◽  
Initial Imperfection ◽  
Maximum Load ◽  
Surface Shape ◽  
Element Analysis ◽  
Strength Assessment ◽  
Load Carrying ◽  
Geometrical Imperfections

The objective of the present study is to develop a new approach to model the initial geometrical imperfections of ship plates by using Photogrammetry. Based on images, Photogrammetry is able to take measurements of the distortions of plates and to catch the dominant surface shape, including the deformations of the edges. Having this data, it is possible to generate faithful models of plate surface based on third order polynomial functions. Finally, the maximum load- carrying capacity of the plates is analysed by performing a nonlinear finite element analysis using a commercial finite element code. Three un-stiffened and four stiffened plates have been modelled and analysed. For each plate, two initial imperfection models have been generated one, based on photogrammetric measurements and the other, based on the trigonometric Fourier functions. Both models are subjected to the same uniaxial compressive load and boundary conditions in order to study the ultimate strength.

Finite Element Analysis for Surface Shape Deformation of Photo-Electronic Theodolite Primary Mirror

2008 ◽  
Vol 28 (4) ◽  
pp. 756-763 ◽  
Author(s):  
谭凡教 Tan Fanjiao ◽  
乔彦峰 Qiao Yanfeng ◽  
李耀彬 Li Yaobin ◽  
高慧斌 Gao Huibin ◽  
刘旨春 Liu Zhichun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Surface Shape ◽  
Shape Deformation ◽  
Element Analysis ◽  
Primary Mirror

Biomechanical Study of Lumbar Spine (L2-L4) Using Hybrid Stabilization Device - A Finite Element Analysis

2020 ◽  
Vol 10 (1) ◽  
pp. 20-32 ◽  
Author(s):  
Pushpdant Jain ◽  
Mohammed Rajik Khan
Keyword(s):  
Finite Element ◽  
Compressive Force ◽  
Element Model ◽  
Biomechanical Study ◽  
Bottom Surface ◽  
Element Analysis ◽  
Axial Compressive Force ◽  
Hybrid Stabilization ◽  
Flexion Extension ◽  
Lumbar Segment

Spinal instrumentations have been designed to alleviate lower back pain and stabilize the spinal segments. The present work aims to evaluate the biomechanical effect of the proposed Hybrid Stabilization Device (HSD). Non-linear finite element model of lumbar segment L2-L4 were developed to compare the intact spine (IS) with rigid implant (RI) and hybrid stabilization device. To restrict all directional motion vertebra L4 bottom surface were kept fixed and axial compressive force of 500N with a moment of 10Nm were applied to the top surface of L2 vertebrae. The results of range of motion (ROM), intervertebral disc (IVD) pressure and strains for IVD-23 and IVD-34 were determined for flexion, extension, lateral bending and axial twist. Results demonstrated that ROM of HSD model is higher than RI and lower as compared to IS model. The predicted biomechanical parameters of the present work may be considered before clinical implementations of any implants.

Re-motion total wrist arthroplasty: 39 non-rheumatoid cases with a mean follow-up of 7 years

2019 ◽  
Vol 44 (9) ◽  
pp. 946-950 ◽  
Author(s):  
Stefan M. Froschauer ◽  
Maximilian Zaussinger ◽  
Dietmar Hager ◽  
Manfred Behawy ◽  
Oskar Kwasny ◽  
...  
Keyword(s):  
Radial Component ◽  
Visual Analogue Scale Pain ◽  
Wrist Flexion ◽  
Level Of Evidence ◽  
Pain Scores ◽  
Total Wrist Arthroplasty ◽  
Flexion Extension ◽  
Analogue Scale Pain ◽  
Wrist Arthroplasty

We evaluated the outcomes of the Re-motion total wrist arthroplasty in 39 non-rheumatoid patients. The mean follow-up was 7 years (range 3–12). Postoperative wrist flexion-extension and radial-ulnar deviation as well as the scores of the Disability of Arm Shoulder and Hand questionnaire and the visual analogue scale pain scores improved significantly. Complications occurred in 13 wrists, five of which required further surgery. The most frequent complication was impingement between the scaphoid and the radial implant (n = 5), which can be avoided by complete or almost complete scaphoid resection. Periprosthetic radiolucency developed around the radial component in three cases and three radial screws loosened. Despite the incidence of high implant survival in 38 of 39 wrists over 7 years (97%), the complication rate is not satisfying. Knowledge of the risk of complications and patient selection are essential when making the decision to choose wrist arthroplasty over arthrodesis. Level of evidence: IV

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