PMID- 18615463
OWN - NLM
STAT- MEDLINE
DCOM- 20091110
LR  - 20131121
IS  - 1552-4965 (Electronic)
IS  - 1549-3296 (Linking)
VI  - 90
IP  - 3
DP  - 2009 Sep 1
TI  - The influence of Young's modulus of loaded implants on bone remodeling: an 
      experimental and numerical study in the goat knee.
PG  - 792-803
LID - 10.1002/jbm.a.32145 [doi]
AB  - The aim of this study was to examine the influence of the Young's modulus of the 
      implant material on the bone remodeling in a loaded condition. A combined animal 
      experimental and computational study was set up. The animal experimental group 
      comprised of 16 Saanen goats, each receiving one titanium implant (Young's 
      modulus 110 GPa) and one high-density polyethylene (HDPE) implant (Young's 
      modulus 1 GPa) in the left femoral condyle. Both types of implants received a 
      titanium coating of 100 nm thickness. The implants protruded in the knee joint 
      space and were directly weight bearing. The first group of eight goats was 
      sacrificed after 6 weeks of loading and the second group of eight goats after 6 
      months of loading. The 16 femoral condyles with the 32 implants were prepared for 
      microfocus computed tomography (micro-CT) scanning and histological sectioning. 
      Three-dimensional trabecular bone parameters were calculated on the micro-CT 
      images for the zones neck, middle, and apex of the implant. The percent of bone 
      contact with the implant was measured on longitudinal histological sections. An 
      axisymmetric finite element (FE) model was created to compare peri-implant bone 
      strains and relative motion between a titanium and a HDPE implant for the 
      experimental loading condition, and to assess the influence of different 
      bone-implant interface (contact) conditions. From the statistical analysis of the 
      3D bone parameters, the difference between the titanium and HDPE implants was not 
      significantly different (p > 0.05) between the zones (neck, middle, and apex) for 
      both groups of goats. The implants could be considered in their entirety. After 6 
      weeks of loading, the PE implant presented lower connectivity and smaller marrow 
      spaces in the circular region of 0-500 microm. In the region 500-1500 microm more 
      bone volume was present for the PE implant. After 6 months, the PE implants 
      showed more bone volume and thicker trabeculae than the titanium implants for the 
      entire length of the implant. This effect was already present in the smallest 
      region of interest, 0-500 microm. After 6 months more fibrous encapsulation was 
      found around titanium implants. FE results demonstrated a substantial influence 
      of the interface conditions on peri-implant strains and relative motion. For 
      interface conditions that were representative for the early postoperative 
      situation (involving press-fit and friction), differences in peri-implant bone 
      strain distributions between titanium and HDPE could be related to the 
      experimentally observed differences in amounts of bone and fibrous encapsulation. 
      In contrast, differences in relative motion did not seem to play a role. Both the 
      experimental and computational results suggest that implant stiffness can affect 
      the peri-implant tissue response, which may be related to differences in 
      peri-implant strains.
FAU - Stoppie, Nele
AU  - Stoppie N
AD  - Department of Prosthetic Dentistry/BIOMAT Research Group, School of Dentistry, 
      Oral Pathology and Maxillofacial Surgery, Katholieke Universiteit Leuven, 
      Belgium.
FAU - Van Oosterwyck, Hans
AU  - Van Oosterwyck H
FAU - Jansen, John
AU  - Jansen J
FAU - Wolke, Joop
AU  - Wolke J
FAU - Wevers, Martine
AU  - Wevers M
FAU - Naert, Ignace
AU  - Naert I
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Biomed Mater Res A
JT  - Journal of biomedical materials research. Part A
JID - 101234237
RN  - 0 (Biocompatible Materials)
RN  - 9002-88-4 (Polyethylene)
RN  - D1JT611TNE (Titanium)
SB  - IM
MH  - Animals
MH  - Biocompatible Materials/*standards
MH  - *Bone Remodeling
MH  - Finite Element Analysis
MH  - Goats
MH  - Implants, Experimental/*standards
MH  - Knee Joint/*surgery
MH  - *Polyethylene
MH  - Stress, Mechanical
MH  - *Titanium
MH  - Weight-Bearing
EDAT- 2008/07/11 09:00
MHDA- 2009/11/11 06:00
CRDT- 2008/07/11 09:00
PHST- 2008/07/11 09:00 [pubmed]
PHST- 2009/11/11 06:00 [medline]
PHST- 2008/07/11 09:00 [entrez]
AID - 10.1002/jbm.a.32145 [doi]
PST - ppublish
SO  - J Biomed Mater Res A. 2009 Sep 1;90(3):792-803. doi: 10.1002/jbm.a.32145.