View Full Version : Spine modeling summary.

Sam Julian
12-04-1997, 10:12 PM
Here is a summary of the replies that I got to the following message:

Date sent: Tue, 11 Nov 1997 10:37:31

Dear All,

At present I am involved with a project to generate a 3D computer
model of the spine to use it to investigate:
1. the effects of surgical intervention of the function of the
spine, for example as a result of disc fusion.
2. to simulate the movement of the spine during surgical operations

The reason I am writing is to ask if anyone knows of a suitable
computer package that I could use to to simulate the movement and
interaction of the vertebrae and discs (and eventually muscles and
ligaments). The solid model data will be obtained from CT scans.

Also I looking for any papers, or authors of papers, that have been
written on this subject.

Your help is appreciated.

Yours sincerely

Sam Julian

Take a look at http://www.musculographics.com they have the softaware
SIMM that simulate what you are looking for. For the spine model, you
can take a look at http://www.zygote.com or http://www.viewpoint.com
they've got both nurbs model of the human spine. To obtain solid model
from CT scans, take a look at http://www.materialise.com

Hope this helps

Good luck !

I'm sorry I can't supply any names, but I know that the Bioengineering
Department at Aberdeen University have a computer model of a spine, or
at least that they were working on one.

I hope this is of some help.

Best wishes,

Rhona Leadbetter
Leadbetter Rhona From: Sam Julian

Musculographics, Inc. in the Biomechanic Yellow Pages

Daniel India
Vice President
Motion Analysis Corporation
World Sales: Dan.India@motionanalysis.com
Web Site: www.motionanalysis.com
European Sales: barry.oflynn@motionanalysis.com
North American Sales: Rebecca.Stine@motionanalysis.com

We use AVS from Advanced Visualization Systems, Waltham, Massachusetts
(www.avs.com) for doing similar work. AVS is a graphical programming
environment. A large visual library of modules are available. You drag
the modules down to your workspace, connect them using graphical
tools, then run the network. The network can then be saved and re-used
as needed. They also have software to package the final application
with a simple interface and then sell the final product. We use a
combination of commercial software and freeware to get CT and MRI data
into AVS, although there is a DICOM reader available.

AVS allows you to reconstruct (marching cube isosurfaces, ray tracing,
etc) the data to 3D models. You can then use a virtual probe to get
coordinates of points on the surface. You can also edit the data to
isolate individual vertebrae and move them. We have been able to use
markers digitized with an articulated arm digitizer to get coordiantes
of points on vertebrae, determine 3D transformation matrices
describing vertebral motions, and then pass the transformation
matrices to AVS to precisely control animated motions. We have an
example on our WEB site (www.spines.com). We also have several papers
in press using these methods. AVS also has modules for 2D image
processing, and you can get modules that others have written from an
International Web site (www.iavsc.org). You can also write your own
modules if you get stuck. We have done that to calculate contact
pressures in the hip joint and plan acetabular osteotomies.

The user interface can be somewhat intimidating to some at first, but
once over the learning curve, you can accomplish lots.

Hope this helps.

John A. Hipp, PhD
Director, Spine Research Laboratory
Department of Orthopedic Surgery
Baylor College of Medicine
Houston, TX
"John A. Hipp"

I have recently come across two references that might help you:

Oliver, S., McMillan, D., Taylor, R., Garbutt, G., A model of a
human spine segment for analysing loading, 4th European Congress
on Research in Rehabilitation, University of Newcastle, UK, July

Dietrich, Kedzior and Zagrajek, A. A biomechanical model of the
human spinal system. Journal of Engineering Medicine 1991; 205:

Also I would be very interested in your solid model data if you
might wish to share.

Kind regards,
Andy Bernhardt
Wright Medical Technology, Inc.


We have developed a 3D model of the neck musculature which
incorporates vertebral anatomy and kinematics along with the lines of
action and morphometry of 19 neck muscles. However, presently the
model does not include discs or ligaments.

In case you are interested, the paper is entitled "Influence of muscle
morphometry and moment arms on the moment-generating capacity of human
neck muscles", Vasavada, AN, Li, S, and Delp, SL. It will be
published in the Feb 15, 1998 edition of Spine.

Good luck with your modeling,
Anita Vasavada

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If you can get your CT scans into a solid modeling format that
can be read by Pro/ENGINEER, then you can use the multi-body dynamics
capability of Pro/MECHANICA MOTION to do dynamic simulations. There is
also functionality which lets you write your own C or Fortran code to
appy loads to your model, which you could use for modeling complex
muscle forces (e.g., with activation and contraction dynamics). For
simple muscle models, you can create the forces right in MOTION.

Both Pro/ENGINEER and Pro/MECHANICA MOTION are industrial-grade
mechanical design and functional simulation packages, though they have
not been used much in biomechanics research (yet).

B.J. Fregly

Benjamin J. Fregly, Ph.D.

E-mail: bj@sj.ptc.com
You may contact Jean Dansereau of Ecole Polytechnique, dept of
mechanical engineering, in Montreal. They work precisely in this area.
Paul Bourassa Paul Bourassa

Dear Sam Julian,

We are also developing biomechanical models of the spine and rib cage
to simulate spinal instrumentation manoeuvres. These models are
personalized to the geometry of scoliotic patients using multi-view
radiographic reconstruction techniques [1].

A first model utilizes the finite element method (ANSYS package) and
was developed by Stokes et al [2,3,4]. The surgical manoeuvres (CDI)
are simulated by means of 4 steps : 1. Approximate the hooks to the
concave side rod; 2. Distract the hooks; 3. Rotate the concave side
rod; 4. Lock the hooks to the rod, and relax the applied torque.

A second model is under development, using a different approach (on
ADAMS mechanical system simulation package).

If you need more informations, please contact us.

Carl-Eric Aubin, Ph.D.
Assistant Professor
Ecole Polytechnique, Department of Mechanical Engineering
C.P. 6079, Succ. "Centre-Ville", Montreal, Quebec, H3C3A7 (CANADA)
Tel: 1 (514) 340-4711 ext. 4437 Fax: 1 (514) 340-5867
EMAIL: aubin@grbb.polymtl.ca

[1]- Aubin C.É., Descrimes J.-L., Dansereau J., Skalli W., Lavaste F.
and Labelle H., Geometrical modeling of the spine and the thorax
for the biomechanical analysis of scoliotic deformities using the
finite element method, Ann Chir, 1995, 49 :8, 749-761.
[2]- Gardner-Morse M, Stokes IAF: Three-dimensional simulations of
scoliosis derotation by Cotrel-Dubousset instrumentation. J
Biomech. 27: 177-181, 1993.
[3]- Stokes IAF, Gardner-Morse M: Three-dimensional simulation of
Harrington distraction instrumentation for surgical correction of
scoliosis. Spine 18:2457-2464, 1993.
[4]- Aubin C.É., Stokes IAF. and Gardner-Morse M., Biomechanical
simulations of Cotrel-Dubousset instrumentation manoeuvres,
Canadian Orthopaedic Research Society, Hamilton, May 1997, #10,

Sam Julian:
I am conducting 3-D intravital investigation of the lumbar spine
through combined use of reconstructed CT scans and multiple camera
motion analysis. We have done 6 subjects in the process of "working
out the bugs" and are now planning a series to collect data for
modeling use, both for intervertebral kinematics and for disc (which
in a way is defined by the intervertebral kinematics and loads). This
work is for "normal" lumbar spines at the moment. I would like to
collaborate if there is interest. Let me know. By the way, my
philospophy is that the most important data is intravital data,
cadaveric data is of little use. Nic

************************************************** ****
Clarence L. "Nic" Nicodemus, PhD, ND


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Hy Sam
You may try to get in contact with the following Laboratory in Paris.
They're working since a couple of years on models of the spine:
Laboratoir biomecanique (LBM)
Ecole National Superieure des Arts et Metiers
Tel. : 0033144246364
Email: LBM@paris.ensam.fr

Good luck

Jörg Smolenski


Try to get in touch with Alison Sinclair and ask her about Voxar
package. It could be what you are looking for. Tel: 0131-4724792.

Good Luck.
Yours sincerely,

Dr Rami J Abboud, BEng, MSc, PhD
Lecturer in Orthopaedics & Trauma Surgery
Consultant Clinical BioEngineer

Hello Sam

Here in Loughborough, UK we are looking at different aspects of
computer and mathematical modelling of human spine. We produced our
own 3D geometric model to investigate the mathematical model(s). You
might be interested in the following papers:


Serpil Acar

Stepney P.D., Acar, B.S., Case K, Porter M (1996) "Computer Aided
Parametric Solid Modelling of the Spine". Eurographics UK Chapter,
14th Annual Conference (Eds:H jones, R Raby, D Vicars). Imperial
College, London, UK, 26-28 March 1996, V2, pp 235-244. ISBN 0 952 1097
3 5.

Grilli S.,L., Acar, B.S., (1996) "Human Spine Modeling Using
Engineering Design Tools" 7th International Machine Design and
Production Conference, METU, Ankara, Turkey, 11-13 September 1996, pp
915-926. ISBN 475-429-099-7.

Case K.,Porter J.M., Xiao D., Acar B S , (1997) "Modeling the Human
Body for Ergonomic CAD" Proceedings of International Conference on
Manufacturing Automation, Hong Kong April 1997.

Grilli S.,L., Acar, B.S., (1997) "Investigating the Role of Dynamic
Curvature of the Human Spine Using A Computer Based Model" 3rd
International Symposium on Computer Methods in Biomechanics and
Biomechanical Engineering, Barcelona, 7-10 May, 1997.

Xiao D.,Case K., Acar B S , Porter J.M., (1997) "Internal Forces in
the Spine Modelled as an Arch" Biomechanics Seminar, Vol 10, pp
106-113, ISSN 1100-2247.

Xiao D., Case K., Acar B S, Porter J.M., (1997) "Biomechanical Model
Of The Human Spine As An Arch" Proceedings of the Twenty-First Annual
Meeting of the American Society of Biomechanics (Abs), Clemson
University, South Carolina, September 24-27, 1997.

Acar, B.S., (1997) "Advancement in Science and Technology and
Designing for Women" Recently submitted to Journal of Women in Science
and Engineering'.

Grilli S.,L., Acar, B.S., (1997) "A Distributed Loading Pattern for
Body Weight and Muscle Forces for the Whole Spine" Recently submitted
to Journal of Computer Methods in Biomechanics and Biomedical

Grilli S.,L., Acar, B.S., (1997) "A Critical Review of Mathematical
Models of Human Spine" Recently submitted to Journal of Engineering in

************************************************** *******************

Dr B Serpil Acar

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Hi Sam !

You should have a look to the PubMed Web site
(http://www.ncbi.nlm.nih.gov select Medline).
You will find interesting papers on your specific topic (Which is not
so far of mine actually : I'm doing a PhD thesis on lumbar spinal
implants evaluation, and I'm using a 3D FEA model of Lumbar Spine
which have been developped in our Lab :

Lavaste et al.(1992) . Tridimensionnal geometrical and mechanical
modelling of the lumbar spine. J. of Biomechanics 25 (10) pp 1153-1164

Robin et al.(1994) . The influence of geometrical factors on the
behavior of lumbar spine segments. European Spine Journal Vol.3 pp

Skalli et al.(1993) . A biomechanical analysis of short segment spinal
fixation using a 3D geometrical and mechanical model. Spine 18 (5) pp

I would be glad to discuss about this topic with you ... (could you
send me a summary of replies ?)

Alexandre TEMPLIER

"Alexandre TEMPLIER"