Abstract
OBJECTIVES: This study aims to evaluate the impact of tetracalcium phosphate (TTCP) applied directly to the fracture line in a rat femur fracture model. MATERIALS AND METHODS: Thirty-three male Sprague-Dawley rats weighing 350 to 400 g were randomly and equally divided into three groups: normal control (NC), fracture control (PC), and TTCP treatment group. Standardized femur fractures were created in the PC and TTCP groups and fixed using intramedullary Kirschner wires. In the TTCP group, TTCP dissolved in distilled water was applied directly to the fracture line. All rats were sacrificed on postoperative Day 28. Radiological, histopathological, and biochemical analyses were performed to assess fracture healing. RESULTS: Radiological scoring revealed significantly higher fracture healing in the TTCP group compared to the PC group on Days 14 and 28 (p<0.05). Histopathological analyses showed reduced inflammation and fibrosis, and increased chondrocyte activity and neovascularization in the TTCP group. On Day 28, serum tumor necrosis factor-alpha (TNF-α) levels were significantly higher in the PC group compared to TTCP and NC, while TTCP values were comparable to NC. No adverse tissue reactions were observed in any group. CONCLUSION: The TTCP enhances fracture healing when applied directly to the fracture line, without causing soft tissue irritation or histologically detectable adverse reactions. Its biological activity and ease of application suggest that TTCP may be a promising adjunct in the treatment of complex fractures.