EVALUATION OF FIBROCARTILAGE REGENERATION AND BONE RESPONSE AT FULL-THICKNESS CARTILAGE DEFECTS IN ARTICULATION WITH PYROLYTIC CARBON OR COBALT-CHROMIUM ALLOY HEMIARTHROPLASTIES
Js. Kawalec et al., EVALUATION OF FIBROCARTILAGE REGENERATION AND BONE RESPONSE AT FULL-THICKNESS CARTILAGE DEFECTS IN ARTICULATION WITH PYROLYTIC CARBON OR COBALT-CHROMIUM ALLOY HEMIARTHROPLASTIES, Journal of biomedical materials research, 41(4), 1998, pp. 534-540
Hemiarthroplasty is one method used to treat osteoarthritic joints. Of
ten, however, an adverse response of the articular cartilage to the me
tal implants occurs. The purpose of this study was to evaluate and com
pare the response of a surgically created defect to pyrolytic carbon a
nd cobalt-based alloy hemiarthroplasties. The cartilage on the lateral
side of the tibial plateau of a canine knee joint was abraded to crea
te a full-thickness defect. Two small holes were drilled into the expo
sed subchondral bone. Next, either a carbon or metal implant was place
d in the lateral femoral condyle. The implantation period was 1 year.
Histologic examination of the tibial defects revealed a smooth bony su
rface for both implant groups. In addition, there was no evidence of a
residual adverse inflammatory response nor of a significant increase
in subchondral bone formation for either group. Surface cracks resulti
ng from the presence of the implant were seen in 14% of the carbon imp
lant specimens and in 100% of the metal implants. Fibrocartilage regen
eration was seen in 86% of the carbon implants and in 25% of the metal
implants. Thus the carbon appears to be better tolerated mechanically
compared to wrought cobalt-chromium alloy. Pyrolytic carbon shows pro
mise for use in hemiarthroplasty. (C) 1998 John Wiley & Sons, Inc. J B
iomed Mater Res, 41, 534-540, 1998.