IN-VIVO COMPATIBILITY OF HYDROXYAPATITE AND TRICALCIUM CERAMIC COMPOSITES USED IN SEGMENTAL BONE DEFECT HEALING
Cenk BALÇIK1, Alpaslan ŞENKÖYLÜ2, Nurşen KOÇ3, Muharrem TİMUÇİN4, Petek KORKUSUZ5, Feza KORKUSUZ2
1Başkent Üniversitesi Mühendislik Fakültesi, Biyomedikal Mühendisliği Bölümü, Ankara
2Orta Doğu Teknik Üniversitesi, Sağlık ve Rehberlik Merkezi, Ankara
3Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Metalurji ve Malzeme Mühendisliği Bölümü, Ankara
4Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Metalurji ve Malzeme Mühendisliği Bölümü, Ankara
5Hacettepe Üniversitesi Tıp Fakültesi, Histoloji ve Embriyoloji Anabilim Dalı, Sıhhiye Ankara
Keywords: Segmental Defect, Hydroxyapatite, Tricalcium Phosphate, Biocompatibility.
Purpose: Segmental bone loss is frequently seen after high energy trauma. In such cases, atrophic non-union occurs and there is a need for mechanical and biological restoration of the defect location. Bone implants composed of hydroxyapatite (HA) and tricalcium phosphate (TCP) have good osteoconductive properties and their use in segmental defect healing is under investigation. The aim of this study was to search the biocompatibility of porous ceramic implants of HA and TCP in segmental defect healing. Material and
Methods: Composite ceramics implants of 60 %HA and 40 %TCP consisting of interconnected porous structure were produced in cylindrical shapes to be used in the rabbit tibiae. Same-structured pure HA implants were also produced as for control. Prepared ceramic implants were placed into a 1.0 cm long segmental defect created in the mid 1/3 of the rabbit tibia. Fixation was provided by an intramedullary K-wire only. Compatibility of implants was histologically evaluated through ceramic samples collected at the end of one and two months.
Results: Fibrous encapsulation was observed in both composite and HA ceramics. In one month, connective tissue ingrowth into the pores of the implants was observed. At the end of the second month, the connective tissue was completely replaced with woven bone tissue. Phagocytes were not observed in any time point.
Discussion: In the early stages of the in vivo experiments, HA and TCP ceramics presented excellent biocompatibility. In conclusion, both types of implants were observed to have great potential for the healing of segmental defects in long bones.