Cartilage induction for reconstruction

Abstract

Objective. By ‘controlled engineering’ autologous cartilage could be produced in vivo. This cartilage was used as graft for septal reconstruction in children. The producer of cells was a pedicled perichondrium flap of the pinna, the inductor was demineralized bovine bone matrix (DBM). Two aspects were investigated (1) if cartilage production could be stimulated in a free perichondrial flap and (2) how the demineralized bone is resorbed. Methods. DBM was implanted subcutaneously in the ear, subcutaneously in the abdomen or intra-muscularly in the quadriceps both with and without a perichondrium envelope. Degradation of DBM and formation of cartilage were studied in a time series using (immuno)histochemistry. Results. Resorption of DBM was mediated by macrophages. Formation of new cartilage occurred only in the presence of perichondrium. The generated cartilage contained hyaline cartilage specific collagen and proteoglycans. In a less vascular environment this process of cartilage formation was slower and less predictable. Conclusions. (1) A free perichondrium flap is an excellent producer of cells for cartilage production. (2) The cartilage inductor (DMB) is completely resorbed by macrophages. (3) Even larger intramuscularly grafts can be generated. (4) The new formed autologous cartilage is less differentiated and seems to demonstrate better wound healing.