ABSTRACT
Disk-shaped implants of spinel, alumina, mullite, zircon, a cast Co-Cr-Mo alloy, and ultra-high molecular weight polyethylene (UHMWPE), were implanted in the paraspinalis muscle of 12 adult, male, white New Zealand rabbits. Prior to implantation the implants were characterized with respect to size and shape, weight and surface roughness. After periods of 1 month, 2 months, and 4 months, the rabbits were sacrificed and the tissue specimens were retrieved with the implants still intact. Histological examination of the tissues surrounding the implants along with changes in the size and shape, weight, and surface roughness of the implants were used as criteria for evaluating these materials for implant purposes. No surfaces degradation of any of the materials was detected using scanning electron microscopy. Fibrous tissue seemed to adhere to the UHMWPE implants more than any other material used in this study. Large amounts of fibrous tissue were also found to adhere to the cast Co-Cr-Mo alloy implants. The histological results indicated that within the limits of this investigation, the biocompatibility of the ceramic materials used in this study compared favorably with the clinically used Co-Cr-Mo alloy implants and the UHMWPE implants.
Subject(s)
Biocompatible Materials/pharmacology , Ceramics , Aluminum/pharmacology , Animals , Biocompatible Materials/analysis , Ceramics/analysis , Chromium Alloys/pharmacology , Magnesium/pharmacology , Male , Microscopy, Electron, Scanning , Muscles/anatomy & histology , Muscles/drug effects , Muscles/surgery , Polyethylenes/pharmacology , Rabbits , Silicon Dioxide/pharmacology , Surface Properties , Zirconium/pharmacologyABSTRACT
This investigation attempts to apply the concept of direct skeletal attachment via tissue ingrowth to the attachment of femoral head prostheses to the femur. Stainless steel (316L) canine femoral head prostheses with a ceramic coated stem were implanted into the femora of dogs and their results compared to those obtained by the impaction of stainless steel prostheses and acrylic-stabilized prostheses. The implants were tested in vivo for time periods ranging from 2 to 13 months, after which time the animals were sacrificed and the femora excised. The femora were sectioned with the implants in place and prepared for examination by light microscopy. Bone was in closer approximation to the ceramic coated implants than to the other two types of implantations. The uncoated and acrylic-stabilized implants were usually characterized by the presence of a relatively thick fibrous sequestering membrane.
