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Cartilage is an avascular structure. It is composed of chondrocytes sitting within a chondromucoprotein matrix containing no blood vessels and surrounded by an avascular perichondrium. Chondrocytes are the living element in cartilage and are responsible for the production of the matrix. The survival of cartilage autografts has been thought by Gibson to be due to the persistence of live chondrocytes." Chondrocytes are the antigenic portion of cartilage; however, because chondrocytes are so well encased within the matrix, cartilage is weakly antigenic and is considered to he an immunologically privileged graftY. The matrix is composed of type II collagen and proteoglycans which combine to provide tensile strength and elasticity. Collagen fibers are modified into different alignments to serve a variety of functions.
The properties that make cartilage an ideal grafting material include its strength, elasticity, and its mild antigenic. As has been stated in this chapter, autografts do not have to be buried deeply and can he placed directly under the skin allowing for excellent con-touring, particularly under the thin skin of the nose.'"
The firmness and resiliency of cartilage obtained from portions of the nasal septum produce grafts which are excellent supporting structures. Elasticity of cartilage harvested from the concha of the ear and that obtained from the thinner portions of the nasal septum produce excellent contour grafts. Cartilage is easy to handle, and can be carved and beveled with a knife, or smoothed with a drill or an abrasive. When implanted, it does not have to be in contact with host cartilage, nor does it require a good blood supply for survival.' If removal is required, this can be easily accomplished since the cartilage graft is encapsulated and is not strongly attached to the surrounding host tissue. << previous page next page>> |
