Announcement

Collapse
No announcement yet.

summary: non magnetic bone pins

Collapse
This topic is closed.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • summary: non magnetic bone pins

    The original posting is below, followed by the responses





    biomech-l,



    Has anyone used, or have knowledge of types and suppliers of
    intracortical (bone) pins that are non-magnetic, such as perhaps
    titanium?



    This is for a project where a reflective marker triad set will be
    attached to bone pins for motion tracking and MRI's may potentially be
    taken.



    Thanks,

    Sarah Hummel

    Steadman Hawkins Sports Medicine Foundation



    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%







    Please visit www.amtbe.com for further information.



    Dr Dimitri ASLANIDIS

    AMS World Services

    rue de la Nethen 14, Beauvechain

    1320 Belgium

    tel +32 478 296969, fax +32 10 862134, e-mail to: metallurgy@skynet.be



    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

    Sarah,



    I am not aware of non-magnetic pins. However, in our studies of knee
    joint motion, we used 3.0 mm Apex self-drilling/self-tapping bone pins
    (Stryker Howmedica). These pins are generally used with the Hoffmann® II
    External Fixation System. Although our pins were stainless steel, it may
    be that Stryker Corporation may have non-magnetic pins but you will have
    to contact them for more information. For your information, the
    disadvantage of titanium is that this metal has an extremely low modulus
    of elasticity & low tensile strength. Therefore, pins have to be bulkier
    than stainless steel in order to provide same rigidity. Since you may be
    looking at static positions in the MRI chamber, this may not be an issue
    however it may become an issue if you will be investigating dynamic
    trials. Refer to Wheeless' Textbook of Orthopaedics, found at
    http://wheeless.orthoweb.be/o16/67.htm for more info.



    For references with respect to other pin research and Methodological
    Concerns Using Intra-cortical Pins, please refer to the following
    reference:





    Ramsey DK, Wretenberg PF, Benoit D, Lamontagne M, Németh G.
    Methodological Concerns Using Intra-cortical Pins to Measure
    Tibiofemoral Kinematics. Knee Surgery, Sports Traumatology, Arthroscopy,
    2003;11:344–349



    I am also aware that markers were placed in on a 160 mm long, 4/5 mm
    Schanz screw to measure vertebral motion.



    James P. Dickey,Michael R. Pierrynowskib, Drew A. Bednarc and Simon X.
    Yangd Relationship between pain and vertebral motion in chronic low-back
    pain Clinical Biomechanics, Volume 17, Issue 5 , June 2002, Pages
    345-352.



    Sincerely

    Dan



    Dan K. Ramsey PhD

    Post Doctoral Research Fellow

    University of Delaware,

    Department of Physical Therapy

    301 McKinly Lab

    Newark, DE 19716-2591



    Tel: +1 (302) 831-4646

    Fax: +1 (302) 831-4234

    Email: dramsey@udel.edu

    URL: http://www.udel.edu/PT/

    Profile: http://myprofile.cos.com/DRam



    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



    We use ORTHOFIX, Bussolengo, Italy. I don't know the material. Sandra



    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



    Sarah,



    I'm a little confused by your application. Are you planning to collect
    kinematic data while taking a MRI, do you want to leave bone pins in
    after collecting kinematic data or do you have a different purpose?



    If you're planning to take static MRI images and calculate the
    kinematics from scan to scan (with repositioning between) you might want
    to investigate the image processing system 3DVIEWNIX
    (http://mipgsun.mipg.upenn.edu/). This software allows you to segment a
    set of bones and calculates the geometric centroid and a principal axis
    system. The software is capable of calculating the angle of rotation
    and the centroidal translation from one bone relative to another (or
    relative to the scanner) or you can make them on your own based on the
    transformation matrices given from segmentation.



    If you have any questions about my suggestion, please don't hesitate to
    ask.



    Stacie

    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

    Hello Sarah



    I know a variety of bone pins that are non magnetic. How can I help you
    with getting the right kind for your project? If you wish you can call
    me at Alta Surgical 906-228-9682



    George J Iwanski



    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%





    Hi Sarah,

    I saw your request for non-magnetic bone pins and was wondering if you
    had any success locating some yet. I am an engineer with Orthofix and
    know that our bone bones have minimal magnetic properties. If you are
    interested in using them, please feel free to get back to me and I'll
    try to help you out. What type of research will you be using them for?
    You mentioned it was a motion analysis study, but could you give me a
    little more information about it?



    Thanks,



    Kristen Duchac



    Product Development Engineer

    Orthofix, Inc.

    Winston-Salem, NC

    336.726.2964










    -----------------------------------------------------------------
    To unsubscribe send SIGNOFF BIOMCH-L to LISTSERV@nic.surfnet.nl
    For information and archives: http://isb.ri.ccf.org/biomch-l
    Please consider posting your message to the Biomch-L Web-based
    Discussion Forum: http://movement-analysis.com/biomch_l
    -----------------------------------------------------------------
Working...
X