Upload
maximilian-singleton
View
219
Download
0
Tags:
Embed Size (px)
Citation preview
Orthopaedic implant components as a source of
nanoparticlesIngrid Milošev
Jožef Stefan Institute, Ljubljana, andJožef Stefan Institute, Ljubljana, andValdoltra Orthopaedic Hospital, Ankaran, SloveniaValdoltra Orthopaedic Hospital, Ankaran, Slovenia
Conference on Nano-Safety, Conference on Nano-Safety, Ljubljana, 22-24 April 2009Ljubljana, 22-24 April 2009
Number of implants and devices for USA (global numbers 2-3 times higher)
Type of implant Number
Intraocular implants
Intraocular lenses 2.500.000
Contact lenses 30.000.000
Cardiovascular implants
Pace makers 400.000
Vascular grafts 300.000
Stents 1.500.000
Heart valves 100.000
Orthopaedic implants
Total hip replacements
250.000
Total knee replacements
250.000
Dental implants 910.000
Biomaterial Science, B.D. Ratner, A.S. Hoffman, F.J. Schoen, J.E. Lemons, 2004Biomaterial Science, B.D. Ratner, A.S. Hoffman, F.J. Schoen, J.E. Lemons, 2004
Indications for total hip replacement: - osteoarthritis- osteoarthritis secondary to dysplasia- aseptic femoral head necrosis- rheumatoid arthritis- post-traumatic arthritis
Radigraph image of THR: (A) Post implantation (B) Prior revision surgery – aseptic loosening with
osteolytic zones along the stem and changed cup position
Animation: http://www.wmt.com/
Survivorship curve is a long-term indicator of the successfulness
of a particular prosthesis.
Data are created based in the Valdoltra
Register of hip and knee prostheses.
fu12,5010,007,505,002,500,00
Cum
Sur
viva
l
1,00
0,95
0,90
0,85
0,80
MP-censoredMM-censoredMPMM
proteza
Time in situ / yearsTime in situ / years
Cu
mu
lati
ve s
urv
ivors
hip
Cu
mu
lati
ve s
urv
ivors
hip
At 12 years post-op, 90% At 12 years post-op, 90% of prostheses still of prostheses still
implantedimplanted
826 hip revision operations in the period from 2002 to 2007
585
183
258
144
6748
30 26 23 8 19 20
0
100
200
300
400
500
600
700
Loosening Looseningof acetab.
part
Looseningof femoral
part
Looseningof bothparts
Deepinfection
Fracture ofthe femur
Dislocation Two-stagerevision
Osteolysisof femoral
part
Pain Fracture ofthe
prosthesis
Other
Reason for revision
Num
ber
of r
evis
ions
71%
Aseptic loosening related to the formation of wear debris and consequent osteolysis is reason for revision in >70%.
Origin of wearSurface wear damageWear particles
Polyethylene particles Metal particlesCement particles
Novel bearing combinationsMetal-on-metalCeramic-on-ceramic
Biological consideration of particulate debris
Introduction
Polyethylene particles
origin: acetabular cup,acetabular inlay
Wear debris
e f
Mode 1: two primary bearing surfaces (a,b)
Mode 2: primary surface moving against a
secondary surface (c, d)
Mode 3: primary surfaces including third particles
interposed (e, f)
d
ba
c
e f
Metal particlesFor SEM analysis – filtrate the bottom layer through 0.2 um polycarbonate filter paper and coat with gold
Polyethylene particles• For SEM analysis - filtrate the top layer through 0.2 um polycarbonate filter paper and coat with gold
Isolation procedureby NaOH digestion