Assessment of pure-phase β - tricalcium phosphate (β - TCP) cylindrical ceramic implant osseointegration used in critical segmental bone defects of the radius of rabbits
Garcia DC1, Mingrone LE2, Pinotti FE3, Seade L2, Melo R2, De Sá MJC1
1Federal University of Campina Grande (UFCG), Patos, Brazil, 2Animal Care Barueri Veterinary Clinic, Barueri, Brazil, 3State University of São Paulo (UNESP), Araraquara, Brazil.
Introduction
Although grafts show excellent skeletal incorporation, host's morbidity and graft acquisition and quantity limit their use. Alternatively, synthetic materials play an important role in reconstructive orthopedic surgery.
Objective
To assess the occurrence of osseointegration using a customized β-TCP implant.
Materials and Methods
Eighteen adult New Zealand rabbits were divided into 3 groups (n=6 per group). A defect was created in the mid-diaphysis of each left radius with a high-speed drill. In Group-A and Group-B, β-TCP and allogenous cortical bone grafts respectively were placed into the radial defect, while the defect remained empty in Group C. Pain, swelling, limb alignment, lameness, foreign body reactions, osseointegration and implant resorption were assessed through clinical examination and qualitative radiographic analysis immediately postoperatively and, 30, 60, 90, and 120 days postoperatively. All animals were euthanized on day 120, and μCT and histological assessments for calcified and uncalcified specimens were performed.
Results
No clinical alterations were observed in any rabbit after 120 days. On radiographic and µCT images, as well as upon histologic assessment, complete bone healing was observed in all rabbits in Group-B. Non-unions were observed in all rabbits in Group-A and Group-C. Implant resorption was not observed in Group-A.
Discussion
This study showed that β-TCP did not elicit any osteoconductivity and osseointegration. The lack of ceramic bioactivity and resorption observed with β-TCP was probably due to low implant porosity and/or other implant shape features. However, expected biocompatibility was present.
Conclusion
The customized β-TCP implant was not considered effective for bone healing.