The Replacing Behaviour of Tetra-Calciumphosphate (TeCP) - Alteration to Bone Tissue In Vivo

Oonishi, Hironobu; Kushitani, S.; Aono, M; Minami, Kazufumi; Watanabe, Ayako; Ogino, Atsuhiro; Fujisawa, Naoki; Tsuji, Eiji; Mizukoshi, Takanori

doi:10.1016/b978-0-7506-0269-3.50030-x

Cited by 9 publications

(9 citation statements)

References 4 publications

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“…Clinically, Oonishi et al (28,29) implanted hip prostheses with ultra high molecular weight polyethylene acetabular cups that had been subjected to 100 Mrad of gamma radiation in air with either cobalt-chrome Chemically crosslinked cups were gamma-irradiated in air to 3.1 Mrad ( I Mrad = 10 kGy) to model a worst-casc sterilization condition. Radiation-crosslinked cups were machined from the irradiated and remeltcd extruded bars and sterilized with ethylene oxide.…”

mentioning

confidence: 99%

Development of an extremely wear‐resistant ultra high molecular weight polythylene for total hip replacements

McKellop

Shen

Lü

et al. 1999

Journal Orthopaedic Research

694

429

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Summary:Ostcolysis induced by ultra high molecular weight polyethylene wear debris is one ol thc primary factors limiting the lifespan of total hip replacements. Crossliiiking polyethylcne is known to improve its wear resistance in certain industrial applications. and crosslinked polyethylene acetabular cups have shown improved wear resistance in two clinical studies. In the present study, crosslinked polyethylene cups wcre produced by two methods. Chemically crosslinked cups were produced by mixing a pcroxide with ultra high molecular weight polyethylene powder and then molding the cups directly to shape. Radiation-crosslinked cups were produced by exposing conventional extruded ultra high molecular weight polycthylene bar stock to gamma radiation at various doses from 3.3 to 100 Mrad (1 Mrad = 10 kGy), remelting the bars to extinguish residual free radicals (i.e., to minimize long-term oxidation), and then machining the cups by conventional techniques. In hip-joint simulator tests lasting as long as 5 million cycles. both types of crosslinked cups exhibited dramatically improved resistance to wear. Artificial aging of the cups by heating for 30 days in air at 80°C induced oxidation of the chemically crosslinked cups. However, a chemically crosslinkcd cup that was aged 2.7 years at room temperature had very little oxidation. Thus, whether substantial oxidation of chemically crosslinked polyethylene would occur at body temperature remains unclear. The radiationcrosslinked remelted cups exhibited excellent resistance to oxidation. Becausc crosslinking can reduce the ultimate tensile strength, fatigue strength, and elongation to failure of ultra high molecular weigh1 polyethylene, the optimal crosslinking dose provides a balancc between these physical properties and the wear resistance of the implant and might substantially reduce the incidence of wear-induced osteolysis with total hip replacements.

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mentioning

confidence: 99%

Development of an extremely wear‐resistant ultra high molecular weight polythylene for total hip replacements

McKellop

Shen

Lü

et al. 1999

Journal Orthopaedic Research

694

429

View full text Add to dashboard Cite

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“…We have previously shown in vivo that TeCP was replaced by new bone. The gradual replacement of the TeCP microcrystals by bone minerals was demonstrated by SEM and backscattered electron imaging (Oonishi et al 1991). TeCP is gradually transformed until replaced as shown in Fig.…”

Section: Controls and Discussionmentioning

confidence: 97%

“…In this study, bone reaction to fi ne granules of several sizes of several kinds of bioceramics were compared in the same animal modes, a 6 mm hole in rabbit femur (Oonishi 1991a(Oonishi , 1992Oonishi et al 1991Oonishi et al , 1992Oonishi et al , 1997a.…”

Section: Comparative Bone Growth Behavior In Granules Of Ha and Othermentioning

confidence: 99%

Clinical application of hydroxyapatite

Oonishi

Kim

Hench

et al. 2008

Bioceramics and Their Clinical Applications

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“…However, wear debris from the ultra-high molecular weight polyethylene (UHMWPE) insert in TKPs can induce aseptic loosening of the TKPs, which remains the prime cause for a majority of the revisions. In order to reduce polyethylene wear, the use of a combination of alumina ceramic (polycrystalline alumina with 99.5% or higher purity) and UHMWPE for TKPs began in the late 1970s based on good clinical results in total hip prostheses [1][2][3]. In this study, we observed the worn surfaces of retrieved TKPs that were implanted for long periods and evaluated their in vivo wear.…”

Section: Introductionmentioning

confidence: 99%

Ceramic Total Knee Prosthesis with Smooth Surface Keeps High Wear Resistance in Long Clinical Use

Kim

Oonishi

Kyomoto³

et al. 2007

KEM

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In the late 1970s, based on good clinical results in total hip prostheses, the use of a combination of alumina ceramics and ultra-high molecular weight polyethylene (UHMWPE) was begun for total knee prostheses (TKPs) in order to reduce UHMWPE wear. In this study, to examine the in vivo efficacy of the alumina ceramic bearing surfaces of TKPs, we compared retrieved alumina ceramic TKPs with cobalt-chrome (Co-Cr) alloy TKPs by surface observations and linear wear measurements. In scanning electron microscopic observations, many scratches due to clinical use were observed only on the retrieved Co-Cr alloy femoral components. The damage in the form of scratches on the articulating surface was linear and was produced by rubbing against the Co-Cr alloy surface. The linear wear rate of the retrieved Co-Cr alloy TKPs was 0.027–0.358 mm/year. In contrast, the wear of the retrieved alumina ceramic TKPs was stably low and linear; the linear wear rate was estimated to be 0.026 mm/year. The lower wear rate and milder nature of wear observed in the TKPs with the combination of UHMWPE inserts and alumina ceramic femoral components suggest the possibility of the retention of high performance even during prolonged clinical use.

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The Replacing Behaviour of Tetra-Calciumphosphate (TeCP) - Alteration to Bone Tissue In Vivo

Cited by 9 publications

References 4 publications

Development of an extremely wear‐resistant ultra high molecular weight polythylene for total hip replacements

Development of an extremely wear‐resistant ultra high molecular weight polythylene for total hip replacements

Clinical application of hydroxyapatite

Ceramic Total Knee Prosthesis with Smooth Surface Keeps High Wear Resistance in Long Clinical Use

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