Repiphysis Expandable Technology“When MEs and MDs talk”

Presented By:

Jessica M. Lopez

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 1/2”at a time so it isn’t painful

Designed by French engineer Arnaud Soubeiran

First used in December 2002

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

How Does It Work?

The spring expands. When the electromagnetic field

is removed, the polymer hardens, locking the spring at its new length.

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

Titanium Alloy

Produced by hot forging 90 wt% Ti, 6 wt% Al, 4 wt% V Allows for better CT and MRI scanning Doesn’t interfere with the body’s chemistry Imitates density of real bone Tensile strength, and fatigue strength match, if not

exceed those of stainless steel More biocompatible

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.

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.macrumors.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/people/Jenkins_files/

smsEngineeringPolymers.pdf Material Science and Engineering, William D. Callister, Jr.,Von

Hoffman Press, 2003 DynoMed, Inc

http://www.wcortho.com/Patients/oncology/repiphysis.asp