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Dear All,
Thankyou for your replies to the e-mail I posted recently, regarding
the geometry of the mid-proximal femur. The replies have given me
some indication as to where, it is hoped, I will be able to find some
useful information. The combined replies are given below along with
the original posting.
---------------------------- Original Posting -----------------------
> Dear All,
>
> I am writing to ask for help regarding the geometry of human femora.
> Of most interest to me is the mid-shaft of the femur (from above the
> condyles up to the lesser trochanter). This includes the outer
> femur as well as the medullar. I am generally interested in the
> cross-sectional shape, and the changes in geometry along the shaft.
> Cortical thickness and femoral curvature are parameters of interest,
> while it is of equal importance that any straight sections along
> the shaft should be detailed.
>
> Any help would be greatly appreciated. I will post a summary of all
> replies.
>
> Regards
>
> Paul.
>
> Paul Stephenson
> Research School of Medicine
> Leeds University
>
>
> ---------------------------Replies-----------------------
Paul,
One of my students did a project where she looked at some of these
parameters. If you have access to 1996 Advances in Bioengineering,
there is a summary of the paper in there. Otherwise, I could probably
find a copy of the report and mail it to you.
Beth Todd
Dr. Beth A. Todd
Assistant Professor
Mechanical Engineering
Box 870276
University of Alabama
Tuscaloosa, AL 35487-0276
btodd@coe.eng.ua.edu
(205)348-1623
fax: (205)348-6419
----------------------------------------------------
Paul-
Check out Phil Noble's master's thesis on the anatomy of the human
femur.
This is an oft-quoted work on the morphology of the femur. Good
luck. If
you cannot find it, let me know and I'll look up the reference for
you.
Also, if you need CT files, Hayes Medical in Sacramento can give you
files or normalized information on a population. They can also take
CT data through a proprietary Raster-to-Vector conversion if you are
so inclined. You can reach them at 916-646-5431.
Robert Enzerink
--------------------------------
Date sent: Thu, 15 May 1997 10:12:51 -0230 (NDT)
From: Paul M Smith
To: "P. STEPHENSON"
Subject: Re: Femoral Geometry.
My name is Paul Smith and I am an Engineering grad student at Memorial
University of Newfoundland. I am doing finite element work on the
human femur. I have CT data which I am using to construct my model. I
can e-mail you some scan slices or just give you some measurements,
whatever you want. Drop me a line with details.
Paul
-----------------------------
Date sent: Thu, 15 May 1997 06:33:48 -0500 (CDT)
From: Rick Sumner
To: mrpps@leeds.ac.uk
Subject: femur geometry
Take a look at these references:
1. CORDEY, J.; SCHNEIDER, M.; BELENDEZ, C.; ZIEGLER, W. J.; RAHN, B.
A.; AND PERREN, S. M. Effect of bone size, not density, on the
stiffness of the proximal part of normal and osteoporotic human
femora. J Bone Miner Res, 7: S437-S444, 1992.
2. ERICKSEN, M. F. Aging changes in the medullary cavity of the
proximal femur in american blacks and whites. Am. J. Phys. Anthrop.
51: 563-570, 1979.
3. FEIK, S. A.; THOMAS, C. D. L.; AND CLEMENT, J. G. Age trends in
remodeling of the femoral midshaft differ between the sexes. J Orthop
Res, 14: 590-597, 1996.
4. GERMAN, R. Z. AND MEYERS, L. L. The role of time and size in
ontogenetic allometry: II. An empirical study of human growth.
Growth, Development & Aging, 53: 107-115, 1989.
5. GOULDING, A.; GOLD, E.; CANNAN, R.; WILLIAMS, S.; AND LEWIS-BARNED,
N. J. Changing femoral geometry in growing girls: a cross-sectional
DEXA study. Bone, 19: 645-649, 1996.
6. HRDLICKA, A. The human femur: shape of shaft. Am J Phys Anthrop,
19: 477-479, 1934.
7. LAZENBY, R. Porosity-geometry interaction in the conservation of
bone strength. J Biomech, 19: 257-258, 1986.
8. MARTIN, R. B. AND ATKINSON, P. J. Age and sex-related changes in
the structure and strength of the human femoral shaft. J Biomech, 10:
223-231, 1977.
9. MILLER, G. J. AND PIOTROWSKI, G. Geometric properties of paired
human femurs. 73-74, 1977.(Abstract)
10. MORO, M.; VAN DER MEULEN, M. C. H.; KIRATLI, B. J.; MARCUS, R.;
BACHRACH, L. K.; AND CARTER, D. R. Body mass is the primary
determinant of midfemoral bone acquisition during adolescent growth.
Bone, 19: 519-526, 1996.
11. PIZIALI, R. L.; HIGHT, T. K.; AND NAGEL, D. A. Geometric
properties of human leg bones. J Biomech, 13: 881-885, 1980.
12. RHO, J. Y.; ASHMAN, R. B.; HOBATHO, M. C.; AND FORWOOD, M. R.
Geometric properties and shapes of human long bone using computed
tomography. In Advances in Bioengineering, pp. 83-86. Edited by M. W.
Bidez. The American Society of Mechanical Engineers, New York, 1992.
13. RUFF, C. Biomechanical analyses of archaeological human skeletal
samples. In Skeletal biology of past peoples: research methods, pp.
37-58. Edited by S. R. Saunders and A. Katzenburg. Wiley-Liss, Inc.
1992.
14. RUFF, C. B. Sexual dimorphism in human lower limb bone structure:
relationship to subsistence strategy and sexual division of labor.
Journal of Human Evolution, 16: 391-416, 1987.
15. RUFF, C. B.; SCOTT, W. W.; AND LIU, A. Y.-C. Articular and
diaphyseal remodeling of the proximal femur with changes in body mass
in adults. Am J Phys Anthrop, 86: 397-413, 1991.
16. SUMNER, D. R. AND ANDRIACCHI, T. P. Adaptation to differential
loading: comparison of growth-related changes in cross-sectional
properties of the human femur and humerus. Bone, 19: 121-126, 1996.
17. VAN DER MEULEN, M. C. H.; ASHFORD, M. W.; KIRATLI, B. J.;
BACHRACH, L. K.; AND CARTER, D. R. Determinants of femoral geometry
and structure during adolescent growth. J Orthop Res, 14: 22-29, 1996.
18. VAN GERVEN, D. P. The contribution of size and shape variation to
patterns of sexual dimorphism of the human femur. Am J Phys Anthrop,
37: 49-60, 1972.
************************************************** *********
Rick Sumner, Ph.D.
Associate Professor
Department of Orthopedic Surgery
Rush-Presbyterian-St. Luke's Medical Center
2242 West Harrison, Suite 103
Chicago, Illinois 60612
---------------------------------------
From: SAM EVANS
To: "P. STEPHENSON"
Date sent: Thu, 15 May 1997 11:01:29 GMT Subject: Re:
Femoral Geometry. Priority: normal
Dear Paul,
What you need is the standardized femur project. Details are on:
http://www.cineca.it/prometeo/stand_fem.htm
or you could email Marco Viceconti (viceconti@tecno.ior.it).
Best wishes,
Sam.
Dr. Sam Evans,
Medical Systems Engineering Research Unit,
UWC School of Engineering,
PO Box 688, The Parade,
Cardiff CF2 3TE, UK.
Tel. (01222) 874533 or (01222) 874000 x5926
Fax. (01222) 874533
-----------------------------------------
Date sent: Thu, 15 May 1997 10:40:19 +0100
To: "P. STEPHENSON"
From: viceconti@tecno.ior.it (Marco Viceconti) Subject:
Re: Femoral Geometry.
Here is the solution!!!!
This was originally posted to biomch-l on September 95.
Marco
To: BIOMCH-L
Dear Colleagues,
here enclosed is an announcement of the "Standardized Femur
Program" proposed by the Laboratory for Biomaterials Technology of the
Rizzoli Institute in the frame of the Prometeo project.
It is available on the market a bone analogue, hereinafter referred as
"composite femur", made of glass fibre reinforced epoxy and
polyurethane foam. Differently from many similar products for
surgical simulation, this bone replica was designed to mimic as close
as possible the mechanical behaviour of a human femoral bone (Beals,
1987; Szivek, 1990; Szivek, 1991; Cristofolini, 1995).
The advantages of using a standardized artificial analogue for in
vitro studies are obvious; in fact an increasing number of published
experimental works report the use of the composite femur in place of
cadaver bones (Bianco, 1989;McKellop, 1991; Otani, 1993a; Otani,
1993b; Cristofolini, 1994; Harman, 1995).
It is here proposed to use the three dimensional geometry of this
composite femur as a standardized reference for finite element models
of the human femur. These models are used in orthopaedic Biomechanics
to investigate the mechanical behaviour of the bone under load. This
would allow every researcher to use all the published experimental
measurements made on the composite femur as calibration data.
Furthermore, a common reference geometry would allow the
inter-laboratories replication of numerical studies. This
cross-calibration approach has already been used in our lab with good
results (McNamara, 1994; McNamara, 1995).
We used this particular commercial bone replica as reference geometry
because in our knowledge it is the only available on the market which
was designed to replicate the mechanical behaviour of a human bone
(Inquiry on BIOMCH-L, 15/5/1995). Nevertheless, this program will not
endorse in any way the company which produce the composite femur; on
the contrary the diffusion of this reference geometry could create
market opportunities for other commercial subjects.
To further support this proposal, we have made available at no cost
through Internet the solid model of the composite femur, converted in
formats which should be readable by most commercial CAD/CAE programs.
Although already useful the available models could be improved; if our
initiative will be approved by the community, more and better models
will be made available.
REFERENCES
- Beals, N. (1987) Evaluation of a composite Sawbones femur model.
Research Report ML-87-25. Richards Medical Company, Memphis,
Tennessee. - Bianco, P.T., Bechtold, J.E., Kyle, R.F., Gustilo, R.B.
(1989) Synthetic composite femurs for use in evaluation of torsional
stability of cementless femoral prosthesis. Proc. Biomechanics
Symposium (Edited by Torzilli, P.A., Friedman, M.H.), pp.297-300 ASME
AMD. - Cristofolini L., Cappello A., Toni A. (1994) "Experimental
errors in the application of photoelastic coatings on human femurs
with uncemented hip stems", Strain 30(3): 95-103. - Cristofolini L.,
Viceconti M., Cappello A., Toni A. (1995) "Structural validation of
commercially available composite femur models", J. Biomechanics, In
press. - Harman, M.K., Toni, A., Cristofolini, L., Viceconti, M.
(1995) Initial stability of uncemented hip stems: an in-vitro protocol
to measure torsional interface motion. Medical Engineering and Physics
17(3): 163-171. - McKellop, H., Ebramzdeh, E., Niederer, P.G.,
Sarmiento, A. (1991) Comparison of the stability of press-fit hip
prosthesis femoral stems using a synthetic model femur. J. Orthop.
Res. 9, 297-305. - Mcnamara B.P., Cristofolini L., Toni A., Taylor D.
(1994) "Effect of bone-prosthesis interface bonding on stress
shielding in cementless THA.", Advances in Bioengineering 1994, Askew
M.J. Ed., ASME-BED, New York publ.: vol. 28 201-202 - Mcnamara B.P.,
Cristofolini L., Toni A., Taylor D. (1995) "Evaluation of experimental
and finite element models of synthetic and cadaveric femora for
pre-clinical design-analysis", J. Clinical Materials, In press. -
Otani, T., Whiteside, L.A., White, S.E., McCarthy, D.S. (1993b).
Effect of femoral component material properties on cementless fixation
in total hip arthroplasty. J. Arthrop. 8, 67-74. - Otani, T.,
Whiteside, L.A., White, S.E.. (1993a) Strain distribution in the
proximal femur with flexible composite and metallic femoral components
under axial and torsional loads. J. Biomed. Materials Res. 27,
575-585. - Szivek, J.A., Gealer, R.L. (1991) Comparison of the
deformation response of synthetic and cadaveric femora during
simulated one-legged stance. J. Appl. Biomaterials 2, 277-280. -
Szivek, J.A., Weng, M., Karpman, R. (1990) Variability in the
torsional and bending response of a commercially available composite
femur. J. Appl. Biomaterials 1, 183-186.
Marco Viceconti 1
Massimiliano Casali 1
Luca Cristofolini 1 4
Aldo Toni 1 2
Barbara Massari 3
Sanzio Bassini 3
1 Laboratory for Biomaterials Technology, Rizzoli Institute
2 Orthopaedic Clinic, University of Bologna
3 C.I.N.E.C.A.
4 Engineering Faculty, University of Bologna
**************** THE STANDARDIZED FEMUR PROPOSAL ***************
- What is the "Standardized Femur"?
The standardized femur is the 3D computer model of a femoral bone
analogue produced by Pacific Research Labs (Vashon Island, Washington,
USA) which is becoming a de facto standard in experimental
orthopaedic Biomechanics.
- Why to use the "Standardized Femur"?
More and more experimental data based on this bone analogue are
becoming available in the literature; we propose to adopt this
geometry as a reference for finite element studies in orthopaedic
Biomechanics . This will produce two advantages: 1) because of the
common geometry, it will be easier to compare results from different
FEM studies. 2) Every researcher building FE models will be able to
use data from experimental tests available in literature to calibrate
his model.
- Where is the "Standardized Femur"?
Information on the femoral bone analogue and all of the geometry files
are available through a link available in the Biomechanics WWW pages
or directly at the following URL:
(http://www.cineca.it/prometeo/stand_fem.htm) Actually only data
referring to the smaller size adult femur are available. Together with
the CT scan images we used to generate the model (all converted in
TIFF format), you will find also files containing the inner and outer
contours of every slice. Lastly, an IGES model of the inner and outer
surface is available.
- How to obtain the "Standardized Femur"?
If you try to download a file, a dialog box will request your
username-password. The "Standardized Femur" files containing the
model are publicly available for research purposes to anyone who makes
an explicit request. However, we would like you to acknowledge the
source of the geometrical model every time you use it (we are looking
for fame!). Thus, we devised this mechanism: you download the
"Transfer Agreement Form" available on-line, fill it out, sign it, and
send it to us by regular mail. When we receive it, we shall send you
the password which allows you to download the files. Files download
will be possible only after September 15th, 1995.
************ END OF THE STANDARDIZED FEMUR PROPOSAL ************
>Dear All,
>
>I am writing to ask for help regarding the geometry of human femora.
>Of most interest to me is the mid-shaft of the femur (from above the
>condyles up to the lesser trochanter). This includes the outer femur
>as well as the medullar. I am generally interested in the
>cross-sectional shape, and the changes in geometry along the shaft.
>Cortical thickness and femoral curvature are parameters of interest,
>while it is of equal importance that any straight sections along the
>shaft should be detailed.
>
>Any help would be greatly appreciated. I will post a summary of all
>replies.
>
>Regards
>
>Paul.
>
>Paul Stephenson
>Research School of Medicine
>Leeds University
>
>
>-------------------------------------------------------------------
>To unsubscribe send UNSUBSCRIBE BIOMCH-L to LISTSERV@nic.surfnet.nl
>For more information: http://www.kin.ucalgary.ca/isb/biomch-l.html
>-------------------------------------------------------------------
--------------------------------------------------
MARCO VICECONTI
(viceconti@tecno.ior.it) Laboratorio di Tecnologia dei Materiali
tel. 39-51-6366865 Istituti Ortopedici Rizzoli
fax. 39-51-6366863 via di barbiano 1/10, 40136 -
Bologna, Italy
Tiger! Tiger! Burning bright in the forest of the night,
what immortal hand or eye could frame thy fearful symmetry?
--------------------------------------------------
Opinions expressed here do not necessarly reflect those of my employer
---------------------------------------------------------
Date sent: Thu, 15 May 1997 08:42:51 +0930
From: Tim Ferris
Subject: Re: Femoral Geometry.
To: "P. STEPHENSON"
Paul,
I have recently done some work for another purpose, related to the
knee joint, reported in the attachment (Word 6). A full text version
is currently under consideration. My interest has been analysis of
the knee joint, as would be evident, but the relevence is the
'straight' section identification technique used in our work. At
present ewe have only used one image because we have been developing
image processing techniques. I am also interested in related work
concerning condyle description, but you state you are not interested
in that geometry.
Tim FErris.
At 04:07 PM 14/05/97 GMT0BST, you wrote:
>Dear All,
>
>I am writing to ask for help regarding the geometry of human femora.
>Of most interest to me is the mid-shaft of the femur (from above the
>condyles up to the lesser trochanter). This includes the outer femur
>as well as the medullar. I am generally interested in the
>cross-sectional shape, and the changes in geometry along the shaft.
>Cortical thickness and femoral curvature are parameters of interest,
>while it is of equal importance that any straight sections along the
>shaft should be detailed.
>
>Any help would be greatly appreciated. I will post a summary of all
>replies.
>
>Regards
>
>Paul.
>
>Paul Stephenson
>Research School of Medicine
>Leeds University
>
>
>-------------------------------------------------------------------
>To unsubscribe send UNSUBSCRIBE BIOMCH-L to LISTSERV@nic.surfnet.nl
>For more information: http://www.kin.ucalgary.ca/isb/biomch-l.html
>-------------------------------------------------------------------
>
--------------------------End of Replies -----------------------------
Thankyou for your replies to the e-mail I posted recently, regarding
the geometry of the mid-proximal femur. The replies have given me
some indication as to where, it is hoped, I will be able to find some
useful information. The combined replies are given below along with
the original posting.
---------------------------- Original Posting -----------------------
> Dear All,
>
> I am writing to ask for help regarding the geometry of human femora.
> Of most interest to me is the mid-shaft of the femur (from above the
> condyles up to the lesser trochanter). This includes the outer
> femur as well as the medullar. I am generally interested in the
> cross-sectional shape, and the changes in geometry along the shaft.
> Cortical thickness and femoral curvature are parameters of interest,
> while it is of equal importance that any straight sections along
> the shaft should be detailed.
>
> Any help would be greatly appreciated. I will post a summary of all
> replies.
>
> Regards
>
> Paul.
>
> Paul Stephenson
> Research School of Medicine
> Leeds University
>
>
> ---------------------------Replies-----------------------
Paul,
One of my students did a project where she looked at some of these
parameters. If you have access to 1996 Advances in Bioengineering,
there is a summary of the paper in there. Otherwise, I could probably
find a copy of the report and mail it to you.
Beth Todd
Dr. Beth A. Todd
Assistant Professor
Mechanical Engineering
Box 870276
University of Alabama
Tuscaloosa, AL 35487-0276
btodd@coe.eng.ua.edu
(205)348-1623
fax: (205)348-6419
----------------------------------------------------
Paul-
Check out Phil Noble's master's thesis on the anatomy of the human
femur.
This is an oft-quoted work on the morphology of the femur. Good
luck. If
you cannot find it, let me know and I'll look up the reference for
you.
Also, if you need CT files, Hayes Medical in Sacramento can give you
files or normalized information on a population. They can also take
CT data through a proprietary Raster-to-Vector conversion if you are
so inclined. You can reach them at 916-646-5431.
Robert Enzerink
--------------------------------
Date sent: Thu, 15 May 1997 10:12:51 -0230 (NDT)
From: Paul M Smith
To: "P. STEPHENSON"
Subject: Re: Femoral Geometry.
My name is Paul Smith and I am an Engineering grad student at Memorial
University of Newfoundland. I am doing finite element work on the
human femur. I have CT data which I am using to construct my model. I
can e-mail you some scan slices or just give you some measurements,
whatever you want. Drop me a line with details.
Paul
-----------------------------
Date sent: Thu, 15 May 1997 06:33:48 -0500 (CDT)
From: Rick Sumner
To: mrpps@leeds.ac.uk
Subject: femur geometry
Take a look at these references:
1. CORDEY, J.; SCHNEIDER, M.; BELENDEZ, C.; ZIEGLER, W. J.; RAHN, B.
A.; AND PERREN, S. M. Effect of bone size, not density, on the
stiffness of the proximal part of normal and osteoporotic human
femora. J Bone Miner Res, 7: S437-S444, 1992.
2. ERICKSEN, M. F. Aging changes in the medullary cavity of the
proximal femur in american blacks and whites. Am. J. Phys. Anthrop.
51: 563-570, 1979.
3. FEIK, S. A.; THOMAS, C. D. L.; AND CLEMENT, J. G. Age trends in
remodeling of the femoral midshaft differ between the sexes. J Orthop
Res, 14: 590-597, 1996.
4. GERMAN, R. Z. AND MEYERS, L. L. The role of time and size in
ontogenetic allometry: II. An empirical study of human growth.
Growth, Development & Aging, 53: 107-115, 1989.
5. GOULDING, A.; GOLD, E.; CANNAN, R.; WILLIAMS, S.; AND LEWIS-BARNED,
N. J. Changing femoral geometry in growing girls: a cross-sectional
DEXA study. Bone, 19: 645-649, 1996.
6. HRDLICKA, A. The human femur: shape of shaft. Am J Phys Anthrop,
19: 477-479, 1934.
7. LAZENBY, R. Porosity-geometry interaction in the conservation of
bone strength. J Biomech, 19: 257-258, 1986.
8. MARTIN, R. B. AND ATKINSON, P. J. Age and sex-related changes in
the structure and strength of the human femoral shaft. J Biomech, 10:
223-231, 1977.
9. MILLER, G. J. AND PIOTROWSKI, G. Geometric properties of paired
human femurs. 73-74, 1977.(Abstract)
10. MORO, M.; VAN DER MEULEN, M. C. H.; KIRATLI, B. J.; MARCUS, R.;
BACHRACH, L. K.; AND CARTER, D. R. Body mass is the primary
determinant of midfemoral bone acquisition during adolescent growth.
Bone, 19: 519-526, 1996.
11. PIZIALI, R. L.; HIGHT, T. K.; AND NAGEL, D. A. Geometric
properties of human leg bones. J Biomech, 13: 881-885, 1980.
12. RHO, J. Y.; ASHMAN, R. B.; HOBATHO, M. C.; AND FORWOOD, M. R.
Geometric properties and shapes of human long bone using computed
tomography. In Advances in Bioengineering, pp. 83-86. Edited by M. W.
Bidez. The American Society of Mechanical Engineers, New York, 1992.
13. RUFF, C. Biomechanical analyses of archaeological human skeletal
samples. In Skeletal biology of past peoples: research methods, pp.
37-58. Edited by S. R. Saunders and A. Katzenburg. Wiley-Liss, Inc.
1992.
14. RUFF, C. B. Sexual dimorphism in human lower limb bone structure:
relationship to subsistence strategy and sexual division of labor.
Journal of Human Evolution, 16: 391-416, 1987.
15. RUFF, C. B.; SCOTT, W. W.; AND LIU, A. Y.-C. Articular and
diaphyseal remodeling of the proximal femur with changes in body mass
in adults. Am J Phys Anthrop, 86: 397-413, 1991.
16. SUMNER, D. R. AND ANDRIACCHI, T. P. Adaptation to differential
loading: comparison of growth-related changes in cross-sectional
properties of the human femur and humerus. Bone, 19: 121-126, 1996.
17. VAN DER MEULEN, M. C. H.; ASHFORD, M. W.; KIRATLI, B. J.;
BACHRACH, L. K.; AND CARTER, D. R. Determinants of femoral geometry
and structure during adolescent growth. J Orthop Res, 14: 22-29, 1996.
18. VAN GERVEN, D. P. The contribution of size and shape variation to
patterns of sexual dimorphism of the human femur. Am J Phys Anthrop,
37: 49-60, 1972.
************************************************** *********
Rick Sumner, Ph.D.
Associate Professor
Department of Orthopedic Surgery
Rush-Presbyterian-St. Luke's Medical Center
2242 West Harrison, Suite 103
Chicago, Illinois 60612
---------------------------------------
From: SAM EVANS
To: "P. STEPHENSON"
Date sent: Thu, 15 May 1997 11:01:29 GMT Subject: Re:
Femoral Geometry. Priority: normal
Dear Paul,
What you need is the standardized femur project. Details are on:
http://www.cineca.it/prometeo/stand_fem.htm
or you could email Marco Viceconti (viceconti@tecno.ior.it).
Best wishes,
Sam.
Dr. Sam Evans,
Medical Systems Engineering Research Unit,
UWC School of Engineering,
PO Box 688, The Parade,
Cardiff CF2 3TE, UK.
Tel. (01222) 874533 or (01222) 874000 x5926
Fax. (01222) 874533
-----------------------------------------
Date sent: Thu, 15 May 1997 10:40:19 +0100
To: "P. STEPHENSON"
From: viceconti@tecno.ior.it (Marco Viceconti) Subject:
Re: Femoral Geometry.
Here is the solution!!!!
This was originally posted to biomch-l on September 95.
Marco
To: BIOMCH-L
Dear Colleagues,
here enclosed is an announcement of the "Standardized Femur
Program" proposed by the Laboratory for Biomaterials Technology of the
Rizzoli Institute in the frame of the Prometeo project.
It is available on the market a bone analogue, hereinafter referred as
"composite femur", made of glass fibre reinforced epoxy and
polyurethane foam. Differently from many similar products for
surgical simulation, this bone replica was designed to mimic as close
as possible the mechanical behaviour of a human femoral bone (Beals,
1987; Szivek, 1990; Szivek, 1991; Cristofolini, 1995).
The advantages of using a standardized artificial analogue for in
vitro studies are obvious; in fact an increasing number of published
experimental works report the use of the composite femur in place of
cadaver bones (Bianco, 1989;McKellop, 1991; Otani, 1993a; Otani,
1993b; Cristofolini, 1994; Harman, 1995).
It is here proposed to use the three dimensional geometry of this
composite femur as a standardized reference for finite element models
of the human femur. These models are used in orthopaedic Biomechanics
to investigate the mechanical behaviour of the bone under load. This
would allow every researcher to use all the published experimental
measurements made on the composite femur as calibration data.
Furthermore, a common reference geometry would allow the
inter-laboratories replication of numerical studies. This
cross-calibration approach has already been used in our lab with good
results (McNamara, 1994; McNamara, 1995).
We used this particular commercial bone replica as reference geometry
because in our knowledge it is the only available on the market which
was designed to replicate the mechanical behaviour of a human bone
(Inquiry on BIOMCH-L, 15/5/1995). Nevertheless, this program will not
endorse in any way the company which produce the composite femur; on
the contrary the diffusion of this reference geometry could create
market opportunities for other commercial subjects.
To further support this proposal, we have made available at no cost
through Internet the solid model of the composite femur, converted in
formats which should be readable by most commercial CAD/CAE programs.
Although already useful the available models could be improved; if our
initiative will be approved by the community, more and better models
will be made available.
REFERENCES
- Beals, N. (1987) Evaluation of a composite Sawbones femur model.
Research Report ML-87-25. Richards Medical Company, Memphis,
Tennessee. - Bianco, P.T., Bechtold, J.E., Kyle, R.F., Gustilo, R.B.
(1989) Synthetic composite femurs for use in evaluation of torsional
stability of cementless femoral prosthesis. Proc. Biomechanics
Symposium (Edited by Torzilli, P.A., Friedman, M.H.), pp.297-300 ASME
AMD. - Cristofolini L., Cappello A., Toni A. (1994) "Experimental
errors in the application of photoelastic coatings on human femurs
with uncemented hip stems", Strain 30(3): 95-103. - Cristofolini L.,
Viceconti M., Cappello A., Toni A. (1995) "Structural validation of
commercially available composite femur models", J. Biomechanics, In
press. - Harman, M.K., Toni, A., Cristofolini, L., Viceconti, M.
(1995) Initial stability of uncemented hip stems: an in-vitro protocol
to measure torsional interface motion. Medical Engineering and Physics
17(3): 163-171. - McKellop, H., Ebramzdeh, E., Niederer, P.G.,
Sarmiento, A. (1991) Comparison of the stability of press-fit hip
prosthesis femoral stems using a synthetic model femur. J. Orthop.
Res. 9, 297-305. - Mcnamara B.P., Cristofolini L., Toni A., Taylor D.
(1994) "Effect of bone-prosthesis interface bonding on stress
shielding in cementless THA.", Advances in Bioengineering 1994, Askew
M.J. Ed., ASME-BED, New York publ.: vol. 28 201-202 - Mcnamara B.P.,
Cristofolini L., Toni A., Taylor D. (1995) "Evaluation of experimental
and finite element models of synthetic and cadaveric femora for
pre-clinical design-analysis", J. Clinical Materials, In press. -
Otani, T., Whiteside, L.A., White, S.E., McCarthy, D.S. (1993b).
Effect of femoral component material properties on cementless fixation
in total hip arthroplasty. J. Arthrop. 8, 67-74. - Otani, T.,
Whiteside, L.A., White, S.E.. (1993a) Strain distribution in the
proximal femur with flexible composite and metallic femoral components
under axial and torsional loads. J. Biomed. Materials Res. 27,
575-585. - Szivek, J.A., Gealer, R.L. (1991) Comparison of the
deformation response of synthetic and cadaveric femora during
simulated one-legged stance. J. Appl. Biomaterials 2, 277-280. -
Szivek, J.A., Weng, M., Karpman, R. (1990) Variability in the
torsional and bending response of a commercially available composite
femur. J. Appl. Biomaterials 1, 183-186.
Marco Viceconti 1
Massimiliano Casali 1
Luca Cristofolini 1 4
Aldo Toni 1 2
Barbara Massari 3
Sanzio Bassini 3
1 Laboratory for Biomaterials Technology, Rizzoli Institute
2 Orthopaedic Clinic, University of Bologna
3 C.I.N.E.C.A.
4 Engineering Faculty, University of Bologna
**************** THE STANDARDIZED FEMUR PROPOSAL ***************
- What is the "Standardized Femur"?
The standardized femur is the 3D computer model of a femoral bone
analogue produced by Pacific Research Labs (Vashon Island, Washington,
USA) which is becoming a de facto standard in experimental
orthopaedic Biomechanics.
- Why to use the "Standardized Femur"?
More and more experimental data based on this bone analogue are
becoming available in the literature; we propose to adopt this
geometry as a reference for finite element studies in orthopaedic
Biomechanics . This will produce two advantages: 1) because of the
common geometry, it will be easier to compare results from different
FEM studies. 2) Every researcher building FE models will be able to
use data from experimental tests available in literature to calibrate
his model.
- Where is the "Standardized Femur"?
Information on the femoral bone analogue and all of the geometry files
are available through a link available in the Biomechanics WWW pages
or directly at the following URL:
(http://www.cineca.it/prometeo/stand_fem.htm) Actually only data
referring to the smaller size adult femur are available. Together with
the CT scan images we used to generate the model (all converted in
TIFF format), you will find also files containing the inner and outer
contours of every slice. Lastly, an IGES model of the inner and outer
surface is available.
- How to obtain the "Standardized Femur"?
If you try to download a file, a dialog box will request your
username-password. The "Standardized Femur" files containing the
model are publicly available for research purposes to anyone who makes
an explicit request. However, we would like you to acknowledge the
source of the geometrical model every time you use it (we are looking
for fame!). Thus, we devised this mechanism: you download the
"Transfer Agreement Form" available on-line, fill it out, sign it, and
send it to us by regular mail. When we receive it, we shall send you
the password which allows you to download the files. Files download
will be possible only after September 15th, 1995.
************ END OF THE STANDARDIZED FEMUR PROPOSAL ************
>Dear All,
>
>I am writing to ask for help regarding the geometry of human femora.
>Of most interest to me is the mid-shaft of the femur (from above the
>condyles up to the lesser trochanter). This includes the outer femur
>as well as the medullar. I am generally interested in the
>cross-sectional shape, and the changes in geometry along the shaft.
>Cortical thickness and femoral curvature are parameters of interest,
>while it is of equal importance that any straight sections along the
>shaft should be detailed.
>
>Any help would be greatly appreciated. I will post a summary of all
>replies.
>
>Regards
>
>Paul.
>
>Paul Stephenson
>Research School of Medicine
>Leeds University
>
>
>-------------------------------------------------------------------
>To unsubscribe send UNSUBSCRIBE BIOMCH-L to LISTSERV@nic.surfnet.nl
>For more information: http://www.kin.ucalgary.ca/isb/biomch-l.html
>-------------------------------------------------------------------
--------------------------------------------------
MARCO VICECONTI
(viceconti@tecno.ior.it) Laboratorio di Tecnologia dei Materiali
tel. 39-51-6366865 Istituti Ortopedici Rizzoli
fax. 39-51-6366863 via di barbiano 1/10, 40136 -
Bologna, Italy
Tiger! Tiger! Burning bright in the forest of the night,
what immortal hand or eye could frame thy fearful symmetry?
--------------------------------------------------
Opinions expressed here do not necessarly reflect those of my employer
---------------------------------------------------------
Date sent: Thu, 15 May 1997 08:42:51 +0930
From: Tim Ferris
Subject: Re: Femoral Geometry.
To: "P. STEPHENSON"
Paul,
I have recently done some work for another purpose, related to the
knee joint, reported in the attachment (Word 6). A full text version
is currently under consideration. My interest has been analysis of
the knee joint, as would be evident, but the relevence is the
'straight' section identification technique used in our work. At
present ewe have only used one image because we have been developing
image processing techniques. I am also interested in related work
concerning condyle description, but you state you are not interested
in that geometry.
Tim FErris.
At 04:07 PM 14/05/97 GMT0BST, you wrote:
>Dear All,
>
>I am writing to ask for help regarding the geometry of human femora.
>Of most interest to me is the mid-shaft of the femur (from above the
>condyles up to the lesser trochanter). This includes the outer femur
>as well as the medullar. I am generally interested in the
>cross-sectional shape, and the changes in geometry along the shaft.
>Cortical thickness and femoral curvature are parameters of interest,
>while it is of equal importance that any straight sections along the
>shaft should be detailed.
>
>Any help would be greatly appreciated. I will post a summary of all
>replies.
>
>Regards
>
>Paul.
>
>Paul Stephenson
>Research School of Medicine
>Leeds University
>
>
>-------------------------------------------------------------------
>To unsubscribe send UNSUBSCRIBE BIOMCH-L to LISTSERV@nic.surfnet.nl
>For more information: http://www.kin.ucalgary.ca/isb/biomch-l.html
>-------------------------------------------------------------------
>
--------------------------End of Replies -----------------------------