Thermal evaluation of the injectable liquid metal bone cement in orthopedic treatment

Abstract

The thermophysical properties of bone cement are important parameters for its application in the orthopedic treatment. This article focused on the thermal evaluation of the low-melting-point metal (BiInSn alloy), which has been proved to be an excellent bone cement. Firstly, the basic thermophysical properties of BiInSn alloys with different melting points were measured. Secondly, 15 fresh porcine femurs placed in the saline bath, bone cements with different melting points and amounts were injected into the bone cavities, respectively. Thermocouples were used to measure the temperature changes of the bone-cement interface and peripheral bone tissue. The possibility of thermal necrosis was evaluated. Moreover, a three-dimensional human knee model was built to numerically assess the effects of thermal parameters, such as melting point and latent heat on tissue temperature distribution. All the experimental and numerical results implied the heat distribution in the tissue depended on the thermal performances of liquid metal bone cement (LMBC). For LMBC of the same melting point, with increased amounts, the damage to the bone tissue is more severe, while for the same amount of different melting point LMBCs, with the higher melting point, which will lead to more serious damage to the tissue. Also, higher latent heat of LMBC has distinct longer solidification process, which may cause irreversible damage to surrounding tissues. Therefore, in the future, for different clinical surgery needs, the appropriate liquid metal bone cement can be obtained by adjusting the thermal parameters.