The Journal of Bone and Joint Surgery, Vol 71, Issue 2 264-272, Copyright © 1989 by Journal of Bone and Joint Surgery, Inc
Bonding behavior of a glass-ceramic containing apatite and wollastonite in segmental replacement of the rabbit tibia under load-bearing conditions
T Kitsugi, T Yamamuro and T Kokubo
Department of Orthopaedic Surgery, Faculty of Medicine, Kyoto University, Japan.
Glass-ceramic implants containing apatite and wollastonite were studied
under load-bearing conditions in a segmental replacement model in the tibia
of the rabbit. Alumina-ceramic implants were used as a control. A
sixteen-millimeter segment of the middle of the shaft of the tibia was
resected at a point distal to the junction of the tibia and the fibula. The
defect was replaced by a fifteen-millimeter-long hollow, cylindrical
implant that was fixed by intramedullary nailing using a Kirschner wire.
Two groups of eight rabbits each (one group with a glass-ceramic implant
and the other with an alumina implant) were killed twelve weeks after
implantation. Two similar groups were killed twenty-five weeks after
implantation. The segment of the tibia that contained the implant was
excised and tension-tested. The load to failure of glass-ceramic implants
containing apatite and wollastonite increased with time. The loads to
failure of the glass-ceramic and alumina implants at twelve weeks after
implantation were 19.8 +/- 7.06 and zero newtons, respectively. The loads
to failure of glass-ceramic and alumina implants at twenty-five weeks after
implantation were 126.4 +/- 32.54 and 19.6 +/- 13.92 newtons, respectively.
No glass-ceramic implants broke. A calcium-phosphorus layer at the
interface of the glass-ceramic and the bone was observed by scanning
electron microscopy and electron-probe microanalysis. There was no
interposition of soft tissue between the glass-ceramic and the bone, as
observed by Giemsa surface staining.