Pilot Study of a 3-Dimensional Method for Analysis of Pronation of the First Metatarsal of Hallux Valgus Patients

2018 ◽  
Vol 39 (12) ◽  
pp. 1449-1456 ◽  
Author(s):  
Bradley Campbell ◽  
Mark Carl Miller ◽  
Lance Williams ◽  
Stephen F. Conti
Keyword(s):  
Hallux Valgus ◽  
Computer Aided Design ◽  
Proximal Phalanx ◽  
Three Dimensional ◽  
Great Toe ◽  
3 Dimensional ◽  
First Metatarsal ◽  
Second Metatarsal ◽  
Three Dimensional Models ◽  
Aided Design

Background: The current work sought to quantify pronation of the first metatarsal relative to the second metatarsal and of the proximal phalanx of the great toe relative to the first metatarsal. Methods: Three-dimensional models were reconstructed from weightbearing computed tomography (CT) images (10 hallux valgus, 10 normal). The orientations of bones related to hallux valgus (HV) (ie, the phalanx, first and second metatarsals) were determined from coordinate systems established by selecting landmarks. After determining the hallux valgus and intermetatarsal angles, additional calculations geometrically determined the 3-dimensional (3D) angles using the aeronautical system of yaw-pitch-roll. The 3D geometrically determined angles were compared to the conventional plain radiographic angles. Results: HV measurements taken with CT and 3D computer-aided design (3DCAD) geometric methods were the same as measurements taken from plain radiographs (P > .05). The average pronation of the first metatarsal relative to the second metatarsal was 8.2 degrees greater in the hallux valgus group (27.3 degrees) than in the normal group (19.1 degrees) (P = .044). A regression analysis of pronation vs intermetatarsal angle (IMA) was not found to be significant. There was also no correlation between pronation of the great toe and first metatarsal in the HV group. Conclusions: The pronation angle of the first metatarsal relative to the second metatarsal between normal and hallux valgus patients was larger in HV patients but was not well correlated with the IMA. Clinical Relevance: The findings of this study indicate that pronation may need to be considered in the operative correction of hallux valgus for restoration of normal anatomy.

Correlation of Different Methods of Measuring Pronation of the First Metatarsal on Weightbearing CT Scans

2021 ◽  
pp. 107110072110030
Author(s):  
Matthew S. Conti ◽  
Tamanna J. Patel ◽  
Kristin C. Caolo ◽  
Joseph M. Amadio ◽  
Mark C. Miller ◽  
...  
Keyword(s):  
Hallux Valgus ◽  
Computer Aided Design ◽  
Foot And Ankle ◽  
Level Of Evidence ◽  
3 Dimensional ◽  
3D Cad ◽  
First Metatarsal ◽  
Hallux Valgus Deformity ◽  
Second Metatarsal ◽  
Α Angle

Background: There is no consensus in the foot and ankle literature regarding how to measure pronation of the first metatarsal in patients with hallux valgus. The primary purpose of this study was to compare 2 previously published methods for measuring pronation of the first metatarsal and a novel 3-dimensional measurement of pronation to determine if different measurements of pronation are associated with each other. Methods: Thirty patients who underwent a modified Lapidus procedure for their hallux valgus deformity were included in this study. Pronation of the first metatarsal was measured on weightbearing computed tomography (WBCT) scans using the α angle with reference to the floor, a 3-dimensional computer-aided design (3D CAD) calculation with reference to the second metatarsal, and a novel method, called the triplanar angle of pronation (TAP), that included references to both the floor (floor TAP) and base of the second metatarsal (second TAP). Pearson’s correlation coefficients were used to determine if the 3 calculated angles of pronation correlated to each other. Results: Preoperative and postoperative α angle and 3D CAD had no correlation with each other ( r = 0.094, P = .626 and r = 0.076, P = .694, respectively). Preoperative and postoperative second TAP and 3D CAD also had no correlation ( r = 0.095, P = .624 and r = 0.320, P = .09, respectively). However, preoperative and postoperative floor TAP and α angle were found to have moderate correlations ( r = 0.595, P = .001 and r = 0.501, P = .005, respectively). Conclusion: The calculation of first metatarsal pronation is affected by the reference and technique used, and further work is needed to establish a consistent measurement for the foot and ankle community. Level of Evidence: Level III, retrospective cohort study.

scholarly journals HV Patients Show Greater Pronation of the First Metatarsal than Normals

2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0000
Author(s):  
Bradley Campbell ◽  
Stephen Conti
Keyword(s):  
Regression Analysis ◽  
Hallux Valgus ◽  
Three Dimensional ◽  
Basic Sciences ◽  
Weak Correlation ◽  
Intermetatarsal Angle ◽  
First Metatarsal ◽  
Second Metatarsal ◽  
Three Dimensional Models ◽  
Standard Radiographs

Category: Basic Sciences/Biologics, Bunion, Midfoot/Forefoot Introduction/Purpose: The progression of the hallux valgus (HV) deformity demonstrates dorsiflexion and abduction; concomitant pronation has not received adequate documentation and the extent of pronation in the pathology is unknown even though correction of the deformity may need to address all three angles. To overcome the inability of standard radiographs to capture pronation, we have developed a means to assess the three dimensional deformity using CT scans. Our goal was to document the extent of pronation/supination both of the first phalanx with respect to the first metatarsal and of the first metatarsal with respect to the second metatarsal. Furthermore, we wanted to regress pronation against the intermetatarsal (IMA) angle of hallux valgus patients. Methods: Three-dimensional models were reconstructed from loaded and unloaded CT files of patients (10 HV, 10 normal). The orientations of specific bones, in anatomic directions, were determined by selecting landmarks on the surface of the phalanx and of the first and second metatarsals. The resulting calculations output a set of angles to determine the pronation/supination of the first metatarsal relative to the second and of the first phalanx relative to the first metatarsal. A regression analysis was conducted to extrapolate any relationship between adduction and pronation (known intermetatarsal and pronation). Results: The average pronation of the first metatarsal relative to the second metatarsal was 19.8 ± 7.1 and 28.3 ± 10.8 in the normal and HV groups respectively (p < 0.05). The influence of weightbearing demonstrated pronation angle differences that were greater in the normal group than in the HV group for both the IM pronation and the HV pronation (p < 0.05) (Figure 1). The differences in HV angles and IM angles between normal and HV patients were 22° and 7° respectively. The regression analysis of the pronation and intermetatarsal angle was not found to be significant, with a weak correlation (r2 = 0.26). Conclusion: The pronation of the first metatarsal relative to the second metatarsal between normal and HV patients is significantly different. While the first metatarsal had measurable pronation in patients with hallux valgus but that value was not predicted by the IMA. The findings of this study indicate pronation should be considered in any surgical technique that seeks to restore native configurations.

Effect of the Modified Lapidus Procedure on Pronation of the First Ray in Hallux Valgus

2019 ◽  
Vol 41 (2) ◽  
pp. 125-132 ◽  
Author(s):  
Matthew S. Conti ◽  
Joseph F. Willett ◽  
Jonathan H. Garfinkel ◽  
Mark C. Miller ◽  
Stephen V. Costigliola ◽  
...  
Keyword(s):  
Hallux Valgus ◽  
Computer Aided Design ◽  
Case Series ◽  
Ct Scans ◽  
Level Of Evidence ◽  
3 Dimensional ◽  
Computed Tomographic ◽  
First Metatarsal ◽  
Signed Rank ◽  
First Ray

Background: Hallux valgus (HV) is a triplanar deformity of the first ray including pronation of the first metatarsal with subluxation of the sesamoids. The purpose of this study was to investigate if a first tarsometatarsal fusion (modified Lapidus technique), without preoperative knowledge of pronation measured on weightbearing computed tomographic (CT) scans, changed pronation of the first metatarsal and determine if reduction of the sesamoids was correlated with changes in first metatarsal pronation. Methods: Thirty-one feet in 31 patients with HV who underwent a modified Lapidus procedure had preoperative and at least 5-month postoperative weightbearing CT scans and radiographs. Differences in preoperative and postoperative pronation of the first metatarsal using a 3-dimensional computer-aided design, HV angle, and intermetatarsal angle (IMA) were calculated using Wilcoxon signed-rank tests. After dividing patients into groups based on sesamoid station, Kruskal-Wallis H tests were used to compare first metatarsal pronation between the groups. Results: The mean preoperative and postoperative pronation of the first metatarsal was 29.0 degrees (range 15.8-51.1, SD 8.7) and 20.2 degrees (range 10.4-32.6, SD 5.4), respectively, which was a mean change in pronation of the first ray of −8.8 degrees ( P < .001). There was no difference in pronation of the first ray when stratified by postoperative sesamoid position ( P > .250). The average preoperative and postoperative IMA was 16.7 degrees (SD 3.2) and 8.8 degrees (SD 2.8), which demonstrated a significant change ( P < .001). Conclusions: The modified Lapidus procedure was an effective tool to change pronation of the first ray. Reduction of the sesamoids was not associated with postoperative first metatarsal pronation. Level of Evidence: Level IV, case series.

scholarly journals FEM and Von Mises Analysis on Prosthetic Crowns Structural Elements: Evaluation of Different Applied Materials

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Ennio Bramanti ◽  
Gabriele Cervino ◽  
Floriana Lauritano ◽  
Luca Fiorillo ◽  
Cesare D’Amico ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Engineering Systems ◽  
Dental Resin ◽  
Dental Crowns ◽  
Single Crown ◽  
Three Dimensional Models ◽  
Von Mises ◽  
Aided Design

The aim of this paper is to underline the mechanical properties of dental single crown prosthodontics materials in order to differentiate the possibility of using each material for typical clinical condition and masticatory load. Objective of the investigation is to highlight the stress distribution over different common dental crowns by using computer-aided design software and a three-dimensional virtual model. By using engineering systems of analyses like FEM and Von Mises investigations it has been highlighted the strength over simulated lower first premolar crowns made by chrome cobalt alloy, golden alloy, dental resin, and zirconia. The prosthodontics crown models have been created and put on simulated chewing stresses. The three-dimensional models were subjected to axial and oblique forces and both guaranteed expected results over simulated masticatory cycle. Dental resin presented the low value of fracture while high values have been recorded for the metal alloy and zirconia. Clinicians should choose the better prosthetic solution for the teeth they want to restore and replace. Both prosthetic dental crowns offer long-term success if applied following the manufacture guide limitations and suggestions.

scholarly journals Development of personalized molds for neovagina creation by 3D printer

2020 ◽  
Vol 66 (11) ◽  
pp. 1498-1502
Author(s):  
Thyeres Teixeira Bueno Chrispin ◽  
Marina Silva Fernandez ◽  
Claudia Cristina Takano Novoa ◽  
Marair Gracio Ferreira Sartori
Keyword(s):  
Health Professionals ◽  
Computer Aided Design ◽  
Surgical Planning ◽  
Three Dimensional ◽  
Physical Object ◽  
3D Printer ◽  
Vaginal Agenesis ◽  
Production Technologies ◽  
Three Dimensional Models ◽  
Aided Design

SUMMARY Additive Manufacturing (AM), also known as Rapid Prototyping, is a set of production technologies used in the synthesis of a particular physical object by adding layers to form a part based on data generated by Computer-Aided Design (CAD) systems. These technologies are widely used to quickly create prototypes of products and tools for commercial purposes. Over time, it has also been integrated with other areas, such as healthcare, since these tools have allowed health professionals to assist in diagnoses, surgical planning, and synthesis of orthoses and prostheses for patient rehabilitation. OBJECTIVE: To develop models for the construction of dilators for the treatment of vaginal agenesis. METHODS: Use CAD software and create a physical model using AM to analyze the viability of its production in the elaboration of customized dilators for each patient. RESULTS: The production through AM provides an advantage in the development, facilitating physical alterations just by adjusting the three-dimensional models made by the software in a quick way, thus making the customization process viable. CONCLUSION: The proposed procedure for the manufacture of dilators presented good results and technological feasibility, indicating that it can be a good solution for the production and customization of gynecological devices.

scholarly journals Computer aided design and manufacturing of dental restorations - “computerized impression” technology

2006 ◽  
Vol 53 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Aleksandar Todorovic ◽  
Vojkan Lazic
Keyword(s):  
Computer Aided Design ◽  
Dental Treatment ◽  
Three Dimensional ◽  
3D Measurement ◽  
Dental Restorations ◽  
Computer Aided ◽  
Cad Cam ◽  
Three Dimensional Models ◽  
Aided Design ◽  
Cam Systems

CAD/CAM technology (Computer Aided Design / Computer Aided Manufacturing) in the matter of fact helps in design and development of two-dimensional or three-dimensional models and their realization on numerical controlled machines. The key to direct or indirect CAD/CAM dental restorations is the measurement of dental preparation in the mouth or on the plaster die. The aim of this paper is to describe the possibilities and the way of function of different computer aided inspection (CAI) systems as a first part of CAD/CAM systems. Different researchers have presented several approaches of methods for three dimensional (3D) measurement. Today, for chairside dental treatment, only the optical method of measurement has lead to satisfactory results in practice. Laboratory CAD/CAM systems use mechanical and optical technologies for 3D measurement. Optical impression grows as a leader of CAI segment of almost every new CAD/CAM system. The most important properties of 3D scanners are: accuracy, volume and speed of measurement and ergonomy of instrument. .

Right ventricular function and three-dimensional modeling using computer-aided design

1990 ◽  
Vol 68 (4) ◽  
pp. 1707-1716 ◽  
Author(s):  
F. G. Spinale ◽  
B. A. Carabello ◽  
F. A. Crawford
Keyword(s):  
Right Ventricular ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Three Dimensional Modeling ◽  
Computer Aided ◽  
Dimensional Reconstruction ◽  
Three Dimensional Models ◽  
New Perspective ◽  
Highly Correlated ◽  
Aided Design

Right ventricular (RV) volumetric and morphological analysis is complicated by the trabeculations and geometric configuration of the RV chamber. To improve RV analysis, custom computer-aided design programs were employed to obtain RV volumes and three-dimensional models from biplane ventriculograms. Biplane RV ventriculograms were analyzed from 14 anesthetized dogs and 22 RV casts. Computed volumes were highly correlated with reference RV volumes (r = 0.98, n = 36, P less than 0.01) with a range of 5-73 ml. Three-dimensional wire-frame and solid models constructed from the ventriculographic images provided excellent detail and a new perspective in chamber shape. This modeling technique was then used to examine RV volumes, geometric conformation, and regional shortening in 10 pigs during inotropic stimulation and preload reduction. Changes in RV volumes, ejection fraction, and regional motion were detected as well as alterations in chamber conformation. In summary 1) computer-aided design offers an accurate and simplified means to compute RV volumes using basic microcomputer equipment, and 2) three-dimensional reconstruction provided a unique view of RV geometry and a means to examine regional RV function.

Development and Research of PVT Modules in Computer-Aided Design and Finite Element Analysis Systems

2020 ◽  
pp. 314-342 ◽  
Author(s):  
Vladimir Panchenko ◽  
Valeriy Kharchenko
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Computer Aided ◽  
Three Dimensional Models ◽  
Analysis System ◽  
Aided Design

This chapter discusses the simulation of solar photovoltaic thermal modules of planar and concentrator structures in computer-aided design systems KOMPAS 3D and finite element analysis ANSYS. To create photovoltaic thermal modules, a method for designing their three-dimensional models in the computer-aided design system has been developed. To study the thermal regimes of the created three-dimensional models of modules, a method has been developed for visualizing thermal processes, coolant velocity, and flow lines of a cooling agent in a finite element analysis system. As a result of calculations in the finite element analysis system using the developed method, conclusions can be drawn about the feasibility of the design created with its further editing, visualization of thermal fields, and current lines of the radiator cooling agent. As an illustration of the simulation results, a three-dimensional model of a photovoltaic thermal planar roofing panel and an optimized three-dimensional model of a photodetector of a solar concentrator photovoltaic thermal module are presented.

Computer-Aided Design and Simulated-Mechanical Study of Individualized Femoral Prosthesis

2012 ◽  
Vol 152-154 ◽  
pp. 1347-1352
Author(s):  
Dong Song Li ◽  
Shu Qiang Li ◽  
Bo Cai ◽  
Wei Feng ◽  
Jian Guo Liu
Keyword(s):  
Bone Cement ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Femoral Prosthesis ◽  
Pulp Cavity ◽  
Mechanical Study ◽  
Computer Aided ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
Aided Design

Objective To construct three-dimensional models of individualized femoral prosthesis by using computer-aided design and to verify whether individualized femoral prosthesis is superior to popular femoral prosthesis via simulating and contrasting mechanical study. Methods Two-dimensional images of fresh femurs were obtained by using total-length CT scanning and processed with computer edge recognition and three-dimensional contour extraction software to identify outer and inner contour of pulp cavity, extract contour data of pulp cavity and prosthesis, and construct three-dimensional models of femur and individualized femoral prosthesis. SolidWorks software was used to establish three-dimensional prosthetic models in common biological and bone cement types; moreover, bone-cement, biological, and individualized femoral prosthesis were replaced via simulating clinical surgery. Results Edge extracting was replaced by Canny operator, characterizing by stable running, credible outcome, and consistent with the primary request. Stress, femoral stress, interface stress, and primary micro-motion of individualized femoral prosthesis were significantly lower than biological and bone-cement femoral prosthesis (P Conclusion The computer-aided design is reliable to perform the assistant design of prosthesis; furthermore, biomechanical properties of the individualized femoral prosthesis are superior to those of popular femoral prosthesis.

Geometrical characterization of canted coil springs

2006 ◽  
Vol 220 (12) ◽  
pp. 1831-1841
Author(s):  
J M Soler ◽  
R H Rangel
Keyword(s):  
Computer Aided Design ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Helical Spring ◽  
Element Analysis ◽  
Geometrical Characterization ◽  
Three Dimensional Models ◽  
Curvature And Torsion ◽  
Aided Design

This article presents a geometrical description of canted coil springs as a particular type of space curve. The influence of the canted angle on the geometrical curvature and torsion is investigated in order to characterize the three-dimensional geometry of the springs. Geometrical descriptions of helical spring rings generated by joining together the two ends of a rectilinear-axis spring as well as several types of spring rings, obtained from rectilinear-axis canted coil springs, are proposed. To create such ring geometries, conservation of length of wire is assumed and approximate relations are derived in order to simplify computations. These geometrical descriptions are then applied to generate appropriate three-dimensional models. Such models can be further imported to computer-aided design and finite-element analysis programmes in order to estimate the mechanical response of such springs.

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