Osseointegration of a hydroxyapatite-coated multilayered mesh stem

Hiroshi Kusakabe, Toyonori Sakamaki, Kotaro Nihei, Yasuo Oyama, Shigeru Yanagimoto, Masaru Ichimiya, Jun Kimura, Yoshiaki Toyama

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Abstract

A new type of porous coating for hip prostheses called "multilayered mesh" was tested under weight-bearing conditions. The surface of the stem is constructed of titanium mesh produced by etching. The hip stems of hydroxyapatite (HA)-coated multilayered mesh and conventional beads were implanted into canine right hips, and animals were killed 3, 6 and 10 weeks and 6 and 12 months after implantation. Shear strength between the implant and the bone was evaluated by the push-out test. Bone ingrowth was calculated from backscattered electron imaging-scanning electron microscopy (BEI-SEM) images of transverse sections. Toluidine blue stained sections and the BEI-SEM images were evaluated histologically. The break sites of the specimens after the push-out test were evaluated on BEI-SEM images of longitudinal sections. The mean push-out strength of the HA-coated multilayered mesh samples was greater than that of the beads-coated samples every time tested, and the HA-coated multilayered mesh implants had significantly stronger push-out strength at 3 and 6 weeks (p<0.05). The strength of the HA-coated multilayered mesh implants was even greater at 6 and 12 months, whereas the strength of the beads-coated samples decreased. The HA-coated multilayered mesh implants showed significantly higher percentages of bone ingrowth than the beads-coated implants every time tested, except at 6 months (p<0.05). At 6 and 12 months, the bone ingrowth data for the HA-coated multilayered mesh implants increased, whereas it decreased for the beads-coated implants. The new bone formation had reached the bottom of the porous area of the HA-coated multilayered mesh surface by 3 weeks, but not had reached the bottom of the conventional beads surface. At 6 and 12 months, the smaller pores of the bead surface stopped the thickening of trabecular bone, and at 12 months, the break sites were at the bone-implant interface of the bead surface, whereas they were on the bone side of the HA-coated multilayered mesh surface. The difference between the break sites was significant at 12 months (p<0.05). The HA-coated multilayered mesh stem provided faster, stronger, and more durable osseointegration than the conventional bead stem.

Original languageEnglish
Pages (from-to)2957-2969
Number of pages13
JournalBiomaterials
Volume25
Issue number15
DOIs
Publication statusPublished - 2004 Jul

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Keywords

  • Cementless hip prosthesis
  • Hydroxyapatite coating
  • Multilayered mesh
  • Osseointegration
  • Weight-bearing model

ASJC Scopus subject areas

  • Bioengineering
  • Ceramics and Composites
  • Biophysics
  • Biomaterials
  • Mechanics of Materials

Cite this

Kusakabe, H., Sakamaki, T., Nihei, K., Oyama, Y., Yanagimoto, S., Ichimiya, M., Kimura, J., & Toyama, Y. (2004). Osseointegration of a hydroxyapatite-coated multilayered mesh stem. Biomaterials, 25(15), 2957-2969. https://doi.org/10.1016/j.biomaterials.2003.09.090