Repiphysis Expandable Technology

1
Repiphysis Expandable TechnologyWhen MEs and
MDs talk

• Presented By
• Jessica M. Lopez

2
What is it?

• Prosthesis designed for children with cancer who
  are in danger of amputation
• Grows up to three inches without surgery
• Expands about 1/8 to 1/2at a time so it isnt
  painful
• Designed by French engineer Arnaud Soubeiran
• First used in December 2002

3
How Does It Work?

• A spring mechanism is buried in the larger of two
  polymer sleeves
• An electromagnetic field is delivered to an
  internal antennae, softening the polyetheylene

4
How Does It Work?

• The spring expands.
• When the electromagnetic field is removed, the
  polymer hardens, locking the spring at its new
  length.

5
Limb Salvage

• Non invasive after initial surgery
• No anesthetics needed (saves )
• Can be used for various cancers such as
  osteosarcoma and Ewing's sarcoma
• Reduces the need for amputation

6
Titanium Alloy

• Produced by hot forging
• 90 wt Ti, 6 wt Al, 4 wt V
• Allows for better CT and MRI scanning
• Doesnt interfere with the bodys chemistry
• Imitates density of real bone
• Tensile strength, and fatigue strength match, if
  not exceed those of stainless steel
• More biocompatible

7
Polyetherether Ketones

• Resistance to moisture
• Satisfactory resistance to degradation by various
  environments. Pg 595, Table 17.4 of your text
  book.
• Inherent toughness
• Does not allow tissue to scar onto it, easing the
  pain of elongation.

8
Reference

• ABC13 news http//abclocal.go.com/ktrk/news/63003_
  health_bonecancer.html
• Institute for Limb Preservation
  http//www.limbpres.com/TechList.asp
• Jelsoft Enterprises Limited http//forums.macrumor
  s.com/archive/topic/55820-1.html
• Mechanical Engineering, Vol.126/No.2 February
  2004, ASME, New York, NY
• Dr Mike Jenkins www.eng.bham.ac.uk/metallurgy/peop
  le/Jenkins_files/ smsEngineeringPolymers.pdf
• Material Science and Engineering, William D.
  Callister, Jr.,Von Hoffman Press, 2003
• DynoMed, Inc http//www.wcortho.com/Patients/oncol
  ogy/repiphysis.asp