Comparison of Structure and Viability of Block Cartilage Grafts With Ultrafine Diced Cartilage Grafts in Rabbits

Background: Autologous block cartilage grafts are traditional and commonly used but have an incidence of warping of 39%. Autologous diced cartilage does not warp or require a long learning curve and can be made from a combination of cartilage sources. Ultrafine diced cartilage (UFDC) (<0.5 mm³) facilitates cartilage nutrition owing to its increased surface area and reduced diffusion distance. An ultrafine size reduces the risk of irregular graft contours. Methods: Randomized pre- and posttest experimental studies on rabbits (Oryctolagus cuniculus). The fixed variables were block and ultrafine diced cartilage grafts. The dependent variables were structure, viability, and collagen content 1 month after implantation. Results: There was significant warping of the block cartilage postimplantation (P value 0.000<0.05). Twenty-five percent of UFDC grafts showed completely dense consistency, and 50% displayed dense edges with a soft and easily dispersed center. Weight of block cartilage increased from 1.14 to 3.73 g (0.000<0.05), whereas UFDC increased from 1.13 to 2.13 g (0.002<0.05). Block cartilage had 17.2 blood vessels, whereas UFDC had 24.3 (0.040<0.05). The block cartilage had an average of 235.8 cells with intact nuclei, whereas UFDC had an average of 394.15 cells (0.000<0.05). The collagen content of the block cartilage was 33.16%, whereas that of the UFDC was 40.97% (0.000<0.05). Conclusions: UFDC displayed better microscopic viability and higher collagen content than the block cartilage. The structural and functional integrity of the UFDC presents great potential for use in the plastic surgery armamentarium.