The Laryngoscope VC 2013 The American Laryngological, Rhinological and Otological Society, Inc. Survival of Diced and Block Cartilage Grafts in Combination With Injectable Calcium Hydroxylapatite Nagehan Erdogmus¸, MD; Cemal Cingi, MD; Funda Canaz, MD; Mustafa Acikalin, MD; Melek Kezban Gurbuz, MD; Ercan Kaya, MD; Hamdi C¸akli, MD; Armagan Incesulu, MD; Erkan Ozudogru, MD 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 correc- tion 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 combi- nation 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 ex- amination 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. Key Words: Injectable calcium hydroxylapatite, diced cartilage, cartilage graft, rhinoplasty. Level of Evidence: N/A. Laryngoscope, 123:E17–E22, 2013 INTRODUCTION In rhinoplasty procedures, many types of graft materials have been used in the past, and are still being used today, to fix nasal dorsum irregularities and pro- vide support for the nasal dorsum. Autologous cartilage, temporoparietal fascial grafts, skin grafts, fat tissue, a submucosal aponeurotic system (SMAS), and alloplastic materials are used for this purpose because they some- times limitations. 1 The alloplastic options include gelatin film, 2 polytet- rafluoroethylene, 3 silicone, 4 proplast, 5 high-density porous polyethylene, 6 and acellular dermal matrix. 7 Although these methods do not cause donor-site morbid- ity, there are variable rates of failure in the usage of alloplastic material. Infections and foreign body reactions are the main complications. These factors limit the usage of alloplastic materials by surgeons. Today, autologous cartilage is the accepted first- choice material in rhinoplasty. However, there may be problems with its use in some situations. If the cartilage graft is insufficient or too close to the surface, particu- larly in patients with thin skin, it may be necessary to increase the volume of the cartilage graft with another material. Studies by Becker 8 and Lacerda and Zancanaro 9 used injectable calcium hydroxylapatite (CaHA) to repair nasal contour irregularities and dorsal irregularities in primary and secondary rhinoplasty. They published posi- tive and very appreciable results. Radiesse is a brand name material composed of CaHA (30%) suspended in a gel carrier (70%) consisting of sodium carboxymethylcellulose, glycerin, and high-pu- rity water. The CaHA microspheres range in size from 25 lm to 45 lm. 10,11 Injectable CaHA acts promptly as an elastic gel and facilitates skin regeneration via the stimulation of collagen production in fibroblasts. In vitro and in vivo studies have demonstrated that injectable CaHA does not cause immunologic reactions. In addi- tion, there is no new bone formation following its injec- tion; thus, its antigenicity is accepted as low. 12 In this study, we used an injectable implant, in combination with diced or block cartilage grafts, to test From the Department of Otorhinolaryngology (N.E., C.C., M.K.G., E.K., H.C., A.I., E.O.), Eskisehir Osmangazi University Medicine Faculty, Eskis¸ehir, Turkey, Department of Pathology (F.C., M.A.), Eskisehir Osman- gazi University Medicine Faculty, Eskis¸ehir, Turkey Editor’s Note: This Manuscript was accepted for publication on March 4, 2013. The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Cemal Cingi, MD, Eskisehir Osmangazi University, Medical Faculty, Department of Otorhinolaryngology, 26480, Eskisehir, Turkey. E-mail: ccingi@ogu.edu.tr DOI: 10.1002/lary.24116 Laryngoscope 123: November 2013 Erdogmus¸ et al.: Cartilage Graft With Calcium Hydroxylapatite E17