scholarly journals Measurement of the femoral neck angle in medium and large dog breeds using computed tomography

2019 ◽  
Vol 67 (1) ◽  
pp. 22-33
Author(s):  
Ahmad Al Aiyan ◽  
Kenneth Richardson ◽  
George Manchi ◽  
Johanna Plendl ◽  
Leo Brunnberg
Keyword(s):  
Computed Tomography ◽  
Femoral Neck ◽  
Hip Prosthesis ◽  
Three Dimensional ◽  
Image Data ◽  
Total Hip Prosthesis ◽  
Total Hip ◽  
Group I ◽  
Group Ii ◽  
Femoral Neck Angle

The aim of this study was to get precise normal values of the femoral neck angle (FNA) in support of developing an optimally functioning total hip prosthesis for medium and large dog breeds. Accordingly, two- and three-dimensional computed tomographic images of the anatomical structures of the proximal femora of 58, hip-dysplasia-free, mature dogs of medium and large breeds were studied. Based on the length of their femora the dogs were allocated to Group I (from 145 to 195 mm) and Group II (from 196 to 240 mm). The FNA was measured on each femur using multi-slice spiral computed tomography (CT). The two- and three-dimensional image data were processed as multi-planar and threedimensional reconstructions using Advantage Workstation software. The CT measurements revealed that Group I had an average femoral neck angle of 147.59° (min. 144.05°, max. 153.35°), while in Group II the average FNA was 147.46° (min. 141°, max. 154.35°). There was no significant correlation between the length of the femur and the FNA in either group. The optimal FNA for a total hip prosthesis is 147.5° for medium and large dog breeds.

scholarly journals Measurement of the Femoral Anteversion Angle in Medium and Large Dog Breeds Using Computed Tomography

2021 ◽  
Vol 8 ◽  
Author(s):  
Ahmad Al Aiyan ◽  
Ken Richardson ◽  
George Manchi ◽  
Mário Ginja ◽  
Leo Brunnberg
Keyword(s):  
Computed Tomography ◽  
Hip Prosthesis ◽  
Three Dimensional ◽  
Femoral Anteversion ◽  
Hip Joints ◽  
Anteversion Angle ◽  
Group I ◽  
Wide Range ◽  
Group Ii ◽  
Femoral Neck Angle

To promote the development of an optimally functional total hip prosthesis for medium and large dog breeds, accurate measurements of the normal anatomy of the proximal femur and acetabular retroversion are essential. The aim of the current study was to obtain precise normal values of the femoral anteversion angle using computed tomography on cadavers of mature dogs with normal hip joints of both medium and large breeds. Based on the length of their femora 58 dogs were allocated either to group I: ≤195 mm or group II: >195 mm. In the study the femoral anteversion angle (FAA) was measured on each femur using multi-slice spiral computed tomography (CT). The data were processed as multi-planar and three-dimensional reconstructions using Advantage Workstation software. The CT measurements showed that the mean ± standard deviation (SD) FAA of group I was 31.34 ± 5.47° and in group II it was 31.02 ± 4.95°. There were no significant mean difference associations between the length of the femur and the femoral neck angle in either group (P > 0.05). The data suggest that a prosthesis FAA of 31 degrees would be suitable for a wide range of dog sizes.

INDIVIDUALLY COMPUTED FINITE ELEMENT ANALYSIS OF THE NON-STEMMED ANATOMICAL TOTAL HIP PROSTHESIS

2005 ◽  
Vol 09 (01) ◽  
pp. 21-33
Author(s):  
Poon-Ung Chieng ◽  
Ching-I Chen ◽  
Chi-Chang Lin ◽  
Ching-Lin Tsai ◽  
Po-Quang Chen
Keyword(s):  
Finite Element ◽  
Femoral Neck ◽  
Stress Analysis ◽  
Hip Prosthesis ◽  
Element Model ◽  
Main Body ◽  
Total Hip Prosthesis ◽  
Level Of Evidence ◽  
Element Analysis ◽  
Total Hip

Background: Current total hip prosthesis lack an accurate individualized finite element model to assure an accurate fit, and further require amputation of a possibly healthy femoral neck. Methods: This research presents a new methodology for performing an automated three-dimensional finite element meshing for a new type of total hip prosthesis. The stress analysis for this new design, known as Non-stemmed Anatomical Total Hip Prosthesis, is based on the methodology proposed here. The merit of this method is that the automated meshing process can be produced by using ANSYS software alone, without the need for a complicated, self-developed meshing interface program. Results: This new methodology provides a smooth boundary around the contour of the femur and the interface between the femur and the Non-stemmed Anatomical Total Hip Prosthesis, as well as avoiding additional complications. This newly designed prosthesis involves minimal modification of the intact femoral neck alignment after total hip replacement, provided that the femoral neck is still healthy. The main body of this new prosthesis is a conical-shaped mask that tightly embraces the femoral neck. The bottom skirt of this mask contacts the greater and lesser trochanter in such a way that maintains the mask in the desired position using a screw through the axis of the femoral neck. Finite element stress analysis is performed to compare the stress distribution of the intact femur and the femur after implantation of the Non-stemmed Anatomical Total Hip Prosthesis. Conclusions: Hopefully, this new prosthesis will be the method of choice for patients who have healthy femoral necks, but sick femoral heads. Further research can focus on applying this new methodology to other bone structures. Level of Evidence: Therapeutic study, Level IV.

Comparison of Two- and Three-Dimensional Methods for Assessment of Orientation of the Total Hip Prosthesis

1988 ◽  
Vol 29 (3) ◽  
pp. 357-361 ◽  
Author(s):  
K. Herrlin ◽  
H. Pettersson ◽  
G. Selvik
Keyword(s):  
Hip Prosthesis ◽  
Three Dimensional ◽  
Total Hip Prosthesis ◽  
Hip Prostheses ◽  
Total Hip ◽  
Total Hip Prostheses ◽  
Prosthetic Component ◽  
High Degree ◽  
Made In

A comparison of two- and three-dimensional methods for the determination of the orientation of total hip prostheses was made in a group of 57 patients. The acetabular inclination and the collum-diaphyseal angle measured on a.p. projections (2-D) were adequate in most cases for assessing how vertically the prosthetic component was inserted, but in individual cases with a high degree of version these measurements could be misleading. Anteversion measured in the transverse plane (2-D) was more sensitive to errors than planar anteversion measured as a rotation around the longest diameter of the ellipsoid projection of the acetabular opening, but it gave a rough estimate of the relation of the prosthetic components. Determination of the spatial (3-D) orientation of the components provides a precise estimate of the component relations.

Metallosis Due to Impingement Between the Socket and the Femoral Neck in a Metal-on-Metal Bearing Total Hip Prosthesis. A Case Report*

1999 ◽  
Vol 81 (3) ◽  
pp. 400-3 ◽  
Author(s):  
HIROKAZU IIDA ◽  
EISHI KANEDA ◽  
HIDEAKI TAKADA ◽  
KANJI UCHIDA ◽  
KEIICHI KAWANABE ◽  
...  
Keyword(s):  
Case Report ◽  
Femoral Neck ◽  
Hip Prosthesis ◽  
Total Hip Prosthesis ◽  
Total Hip ◽  
Metal On Metal

scholarly journals Mechanical Behavior of Bone Cement under Dynamic Loading

2017 ◽  
Vol 61 (3) ◽  
pp. 204
Author(s):  
Mohammed Elnedhir Belgherras ◽  
Boualem Serier ◽  
Ali Benouis ◽  
Lalia Hachemi
Keyword(s):  
Bone Cement ◽  
Hip Replacement ◽  
Hip Prosthesis ◽  
Three Dimensional ◽  
Dynamic Loads ◽  
The Finite Element Method ◽  
Three Dimensional Model ◽  
Total Hip Prosthesis ◽  
Total Hip ◽  
Climbing Stairs

In orthopedic surgery and particularly in total hip arthroplasty, The fixation of the implant is generally made by the surgical cement, constituted essentially by polymer (PMMA), It is necessary to know the strengths applied to the prosthetic articulation during the current activities exercised by the patient in their life, to know the distribution of the constraints in the system (bone - cement - implant).This study aims to analyze numerically using the finite element method, the effect of activities (dynamic loads) of the patient on the level and distribution of stresses generated in the components of total hip prosthesis. Five activities, the most frequently performed by the patient such as normal walking, the up and down stairs, sitting and up from chair, were selected for this study. For this purpose, a three-dimensional model of the total hip prosthesis has been developed. The results obtained from this model show that the total hip replacement components and especially the bone cement are more highly stressed during the process of climbing stairs. These excessively high loads can lead to damage of the cement and thus the loosening of the prosthesis.

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