View Full Version : Announcement: Hip-Op(c) 1.4.1 free Surgical Planning Systemreleased

Riccardo Lattanzi
04-02-2002, 08:01 PM
Hip-Op(c) 1.4.1 free Surgical Planning System released

The new release of the Hip-Op(c) software for Window NT 4.0 and Windows 2000
is now available at http://www.ior.it/hipop/
Two analysis modules are available in the new version. Four commercial
have been added to the implant database.

The first two analysis modules released are the Density Map and the
Distance Map.
The first provides a complete map of the apparent density (expressed in HU)
of the
tissue touching each point of the implant surface. The second computes the
between each point of the implant surface and the endosteal cortical
surface defined with
a settable density threshold.

However the previous version has been downloaded by many users, we did not
receive many
comments. We recommend all users to subscribe the mailing list and to use
it for bug reporting,
help, suggestions and critics. In that way software future releases will
be always better.
Hip-Op(c) 1.4.1 has been tested on Windows NT 4.0 and on Windows 2000, but
we are confident
that it would work also on Windows XP.

Next release, due before the end of June 2002, will fix all bugs reported
by the early users and will
provide two additional analysis modules, one for implant autofitting and
another for range of motion simulation.

Announcement: Hip-Op(c) 1.4.1 free Surgical Planning System released

Sorry for cross-posting:

** Hip-Op: a software system to plan total hip replacement surgery **
Hip-Op(c) is program originally conceived at the Istituti Ortopedici
Rizzoli and currently developed by the Bio-Computing Competence
Centre. Hip-Op(c) reads a CT dataset of the hip region and allow the
surgeon to plan the type, the size and the position of the hip prosthesis
that best fits into the patient anatomy. Scientists can also use the
program to study bones morphometry or to develop computer models of intact
and virtually operated bones. Registered users can use the program free of
charge on an "as-is" basis and under the limitations defined by the license


Hip-Op(c) may be useful not only to orthopaedic surgeons but also to
biomedical researchers, biomedical educators and to medical devices designers.

** Disclaim **
Hip-Op(c) has not been certified for clinical use, yet. Currently it is
intended for educational and investigational purposes only. Please read
carefully the license agreement for more information.

** More information for Researchers **
The Hip-Op(c) planning system is used in our institution not only for
surgical planning, but also for a variety of research-related
activities. While some of these activities rely on the access we have to
the Hip-Op(c) source code, others can be carried out just using the
executable version available to the general public. Here we shall describe
some of the ways we devised to use Hip-Op(c) for research
purposes. Probably many others exist, which we do not even imagine.

-- Anthropometry --
Many studies require the measurement of the human skeletal anatomy. Using
the 2D measurement tools available in Hip-Op(c) to take measurements in
multiple orthogonal windows, it is possible to obtain 3D measurements in an
easy and intuitive way. By using the elementary solids (a sphere, a
cylinder and a cone) that compose the Basic_Shapes databases distributed
with Hip-Op(c) it is possible to identify the shape best fitting the local
anatomy of interest.
A combination of the two methods is to place small spheres on anatomical
landmarks (whose correct location can be checked with the 3D view) and then
to use the 2D measurement tools to establish the distance between spheres.

Hip-Op(c) can be used to assess which type of size of implant best fit a
given population. While Hip-Op(c) is focused on total hip replacement,
elements of the Basic_Shapes library can be used to evaluate the fitting of
other devices, such as endo-medullary nails. On request we may create
special libraries containing the 3D models of any collection of shapes may
be necessary to carry out a particular research.

-- CT Datasets editing --
Using the capabilities of Hip-Op(c) it is possible to digitally manipulate
the CT data of a patient in order to simulate the anatomical changes
induced by the operation. At the current stage only neck resection and
femoral canal reaming can be simulated, but it should not be too difficult
to develop a more general tool to create synthetic bone defects, lesions,
screw holes, etc.
At the Istituti Ortopedici Rizzoli we use these tools to create
patient-specific finite element models of the intact and of the
synthetically operated femur. This is achieved by combining Hip-Op(c) with
some other in house programs, and by directly accessing the Hip-Op(c) data
structures. We may consider to incorporate many of these functions in
Hip-Op(c) and to provide them with a User accessible interface. However,
this would involve a significant effort and probably a collaborative
project with other research groups.

-- Analysis module --
Probably the most important feature for researchers is the analysis modules
library. These additional functions compute relevant biomechanical
indicators that may be extremely relevant in many research contexts.
The first two analysis modules released are the Density Map and the
Distance Map. The first provides a complete map of the apparent density
(expressed in HU) of the tissue touching each point of the implant
surface. The second computes the distance between each point of the
implant surface and the endosteal cortical surface defined with a settable
density threshold. Other more complex modules will appear in the
future. Suggestions are very welcome from all users.

-- Custom solutions --
The Hip-Op software can be extended to solve special research needs. In
one case, special software based on Hip-Op(c) was developed to perform 3D
measurements directly on the CT data. The tool was used to assess how
growth and remodelling changed the morphology of the transplanted fibula
used to reconstruct the proximal femur of a five years-old child affected
by a Ewing's sarcoma, during the first three years of follow-up.

** More information for Educators **
With Hip-Op(c) it is possible to set up a very simple but very effective
training tool for residents in orthopaedics who should learn the correct
position and size of a prosthetic implant. The senior surgeon can plan a
certain number of cases, and save position and implant size for later
reference. Then the residents are asked to perform the same task. The
surgical plans can be compared with that of the senior surgeon and if
necessary discussed in front of the computer screen. Other possible
educational application is the location of anatomical landmarks on X-ray
images and verification on the 3D view.

** More information for medical devices designers **

The Hip-Op(c) software is not only useful to visually assess the anatomical
fit of particular implantable device. A set of analysis modules is
available to quantitatively evaluate the design. For who designs
orthopaedic devices a specific Hip-Op(c) add-on, called Joint Prosthesis
Design (JPD) is currently under development. A beta users program will
start soon. If you are interested please check:


There are other fields (i.e. dental implants, maxillo-facial surgery, etc.)
that probably may use Hip-Op(c) for design purposes. If you have any idea
please contact us through the Hipop_L mailing list.


** More information for Orthopaedic surgeons **
Hip-Op(c) is a free program you can easily download and install on your
personal computer. It allows a fully three dimensional pre-operative
planning of total hip replacement, by means of a graphic user interface
specifically designed by a team of programmers, bioengineers and
orthopaedic surgeons and improved during a two-years clinical trial at the
Istituti Ortopedici Rizzoli.
Launch the program and load the CT data of your patient directly in the
DICOM3 format they are saved from your hospital computed tomography. You
will find yourself in a very familiar environment made of radiographs,
computed tomography sections and other visual representations aimed to
simulate the imaging modalities commonly used in the clinical practice.
Then you will be able to select the hip prosthesis you prefer from a
library of conceptual and commercial components. Adding another prosthesis
is quite simple; if the prosthesis you use is not included please let us
know and we shall provide as soon as possible.
Using intuitive commands you shall be able to "navigate" the prosthesis
within the patient body to the best anatomical position. Hip-Op(c) fully
supports modular implants. You can select a different size for each
component of the implant at any time during the planning, with just one
click. You can separately move the socket and the stem and the program
continuously visualises the distance between the centre of the ball head
and the centre of the socket. This will help to estimate the resulting
changes in limb length.
Once you have achieved the best anatomical fit an array of analysis modules
give you detailed indications on the functional and biomechanical
outcomes. Of course if any of these indicators does not satisfy you, you
can modify the type, size or position of the implant and see in real time
how this changes such indicator. This way it will be easy to find the best
compromise between opposite requirements.
Happy of the plan you achieved? OK, now you can save all relevant data in
a report that you can print and take with you in the operating room. Or, if
your hospital provides you with an intra-operative navigation system or a
surgical robot, you can save your surgical planning in a format your system
can read. If you system is not supported, please let us know and we shall
provide as soon as possible.

** Project Status **
This is the second public release of the Hip-Op. Version 1.0 and 1.1 were
aimed to internal research purposes only. Version 1.2 was used to perform
a large part of the validation studies and the clinical trial at the
Istituti Ortopedici Rizzoli. Version 1.3 was released on September 2001
and it ran only on Windows NT.
This release contains most of the functions we had in mind when we started
and the most evident bugs have been fixed, although we still experience
some occasional crashes. However, only a small number of users so far has
used the program, and on a limited number of computers.
Next release, due before the end of June 2002, will fix all bugs reported
by the early users and will provide a module for range of motion simulation.

Laboratorio di Tecnologia Medica
Istituti Ortopedici Rizzoli
Via di Barbiano 1/10, 40136 - Bologna, Italy
tel: +39 051 6366554
fax: +39 051 6366863
e-mail: lattanzi@tecno.ior.it
web: http://www.tecno.ior.it


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