1. Poster ID: 384 RADIOGRAPHIC EVALUATION OF BONE HEALING IN CRITICAL SIZE BONE DEFECTS IMPLANTED WITH OSTEOPASTE – PRELIMINARY RESULTS IIUM Research, Invention and Innovation Exhibition 2014 INTRODUCTION Bone healing continues to pose challenges for researchers and clinicians working in the field of orthopaedics. Autogenous and allogenous bone graft is widely used as bone graft material in orthopaedics but each has serious limitations by material availability and by the possible risks of infection or donor site morbidity. As an alternative, calcium phosphate (CaP) cements is used as a bone graft material because their calcium/phosphorus ratios are close to that of natural bone and they are relatively stable in physiological environment. In fact, the mineral component of calcium phosphate containing calcium ions (Ca 2+ ), orthophosphates (PO 4 3 ), metaphosphates or pyrophosphates (P 2 O 7 4 ) and occasionally hydrogen or hydroxide ions which is similar to the mineral component of bone. “Osteopaste” is a locally produced product and developed from limestone that has been converted to a combination of tetra-calcium phosphate (TTCP) and tri-calcium phosphate (TCP) powders simultaneously. Thus, in this study, injectable calcium phosphate bone cement – “Osteopaste” has been designed as bone cement to conduct pre-clinical evaluations (in vivo) in critical size defect (CSD) of New Zealand White rabbits. This injectable Osteopaste is hoped to have an edge to be used as bone graft substitutes to enhance and hasten repair of critical size bone defects. OBJECTIVE To determine the effectiveness of injectable Calcium Phosphate bone cement – “Osteopaste” for bone formation and healing of CSD. METHODS This study was approved by the Ethics Committee, Kulliyyah of Medicine, IIUM. Animal surgery was performed at Orthopaedic Research Laboratory (ORL), Jalan Hospital Campus according to ISO standards 17025. Sixty-one NZW rabbits weighing between 2.50 to 3.50 kg were used in this study. A CSD of approximately 4.5 mm (width) X 9.0 mm (length) were created at proximal tibial metaphysis of rabbit’s right leg and then, implanted with either Osteopaste, Jectos (positive control) or MIIG – X3 (positive control). CSD without treatment served as negative control. The defects were assessed using plain radiograph (lateral view) at day 1, 6, 12 and 24 weeks. RESULTS & DISCUSSION Radiographic observation of implantation with Osteopaste Che Nor Zarida CS 1, Mohamed Azril MA 1*, Mohd Shukrimi A 1, Zamzuri Z 1, Nazri MY 1, Aminudin CA 1, Zunariah B 2, Nur Zafirah MK 1 1 Department of Orthopaedics, Traumatology and Rehabilitation, Kulliyyah of Medicine, IIUM 2 Department of Basic Medical Sciences, Kulliyyah of Medicine, IIUM Phone:+609-5706000, Fax: +609-5144451, E-mail: drazril@yahoo.com Radiographic observation of implantation with MIIG-X3 (+ve control) 1 day6 weeks12 weeks24 weeks Radiographic observation of implantation with Jectos (+ve control)Radiographic observation of no implantation with biomaterial (-ve control) 1 day 6 weeks 12 weeks 24 weeks 12 weeks Figure 1: The resorption of osteopaste was minimal in the bone. There was direct contact between osteopaste material and host bone. The new bone was seen bridging the defect. Figure 2: MIIG-X3 was resorbed too fast. A decrease in properties was found from 6 to 24 weeks where implant resorption was nearly achieved while remodelling of the anteromedial cortex had yet to be completed. CONCLUSION Osteopaste material has potential to enhance new bone formation. ACKNOWLEDGEMENT This work was supported by TechnoFund Research Grant (Project no: TF001D160) from Ministry of Higher Education Malaysia. We gratefully acknowledge SIRIM Berhad and GranuLab (M) Sdn Bhd for this research collaboration. Figure 3:The radiographs show very minimal resorption of Jectos material in proximal tibial metaphysis. There was quite clear direct contract. The new bone was seen bridging the defect. Figure 4: The cavity of critical sized defect was almost healed but still incomplete bridging the defect.