Survival of diced and block cartilage grafts in combination with injectable calcium hydroxylapatite.

OBJECTIVES/HYPOTHESIS Dorsal nasal irregularities after trauma, and various procedures such as excessive nasal hump resection, are major problems for patients who have undergone rhinoplasty. Many grafts have been described for the correction of dorsal nasal irregularities. In this study, we used an injectable implant, in combination with diced or block cartilage grafts, to test the efficacy of injectable calcium hydroxylapatite on the survival of diced or block cartilage grafts. STUDY DESIGN Prospective, controlled, parallel group animal study. METHODS Fourteen New Zealand white rabbits were used. Block cartilage and diced cartilage grafts, alone and in combination with injectable calcium hydroxylapatite, were placed subcutaneously in the rabbits' dorsal thoracolumbar region. On the 90th day following surgery, the graft areas were extracted immediately after the rabbits were sacrificed. Pathological examination was conducted on all specimens. RESULTS The pathologic and histochemical findings were compared between groups. There was chronic inflammation observed in all of the groups. However, none of the groups had metaplastic bone formation or calcification. The group that received diced cartilage in combination with the injectable implant received the highest scores for peripheral chondrocyte proliferation, matrix collagen, elastic fiber, and proteoglycan content (P < 0.05). A comparison of the block and diced cartilage grafts revealed that peripheral chondrocyte proliferation was more pronounced in the diced cartilage grafts (P < 0.05). CONCLUSION The use of calcium hydroxylapatite in combination with diced cartilage grafts does not have any long-term negative effects on chondrocyte viability.