89-91 - Polskie Stowarzyszenie Biomateriałów
89-91 - Polskie Stowarzyszenie Biomateriałów
89-91 - Polskie Stowarzyszenie Biomateriałów
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fIg.5. Stress distribution (von mieses theory) on<br />
surface of uhmWPE bushings [mPa].<br />
fIg.6. Stress distribution (von mieses theory) on<br />
surface of femoral component [mPa].<br />
Conclusions<br />
One of the most common reasons of joint endoprosthesis<br />
malfunction leading to a reoperation is a mechanical defect<br />
or an implant loosening (or their combination). Appropriate<br />
design of the implant can dramatically eliminate this risk.<br />
As a useful tool for endoprosthesis development, a finite<br />
element method can be used, providing that the anatomical<br />
relation or mechanical test standards are kept.<br />
A goal of this paper was to make up a computer simulation<br />
of oncology knee implant loading during the mechanical<br />
test defined by ISO 14243 [1-3]. The results pointed out the<br />
fIg.7. Stress distribution (von mieses theory) on<br />
surface of tibial stem [mPa].<br />
most critical areas of the endoprosthesis, i.e. UHMWPE<br />
bushings and femoral stem made of titanium alloy. The<br />
analyses made for four degrees of flexion (1.53 deg, 8.13<br />
deg, 15.31 deg and 26.33deg) can be used for simulation<br />
of various designs of the endoprosthesis. Since the oncology<br />
implants are produced as an individual replacement,<br />
finite element method represents a time and money saving<br />
method of the implant production.<br />
acknowledgements<br />
This research is supported by a grant of Ministry of Industry<br />
and Trade of the Czech Republic: MPO FI-IM4/125.<br />
References<br />
[1] ISO 14243-1. Implants for surgery - Wear of total knee-joint<br />
prostheses - Part 1: Loading and displacement parameters for<br />
wear-testing machines with load control and corresponding environmental<br />
conditions for test. 2002.<br />
[2] ISO 14243-2. Implants for surgery - Wear of total knee-joint<br />
prostheses - Part 2: Methods of measurement. 2000.<br />
[3] ISO 14243-3. Implants for surgery - Wear of total knee-joint<br />
prostheses - Part 3: Loading and displacement parameters for<br />
wear-testing machines with displacement control and corresponding<br />
environmental conditions for test. 2004.<br />
[4] Prospon, s.r.o., Jiriho Voskovce 3206, Kladno, 272 01, Czech<br />
Republic. On-line at:
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