A Device to Control Implant and Bone-Cement Temperatures in Cemented Arthroplasty

To increase the cement-implant interface strength and simultaneously prevent the possibility of bone thermal necrosis, an automated electronic control device was designed to be use in cemented arthroplasties. The device developed was specifically adapted for the knee arthroplasty, namely, for tibial-tray cementing. The device controls the heat flux direction between the tibial-tray and the atmosphere through the “Peltier effect,” using Peltier tablets. The device is placed on the upper surface of the tibial tray during the cementing phase, to heating the tibial-tray in a first phase, promoting the polymerization which starts at the warmer cement-implant interface. After the initiation of polymerization, the heat flux in the Peltier tablets is inverted (cooling) to extract the heat generated in bone-cement, avoiding bone thermal necrosis. The efficiency of the device was evaluated by cementing several tibial-trays in bovine fresh bone and by measuring the tray and cement temperatures. The results showed that the use of the device increases the implant temperature at the initial bone-cement polymerization phase and reduces the maximum temperature of the cement in the subsequent polymerization process, preventing the effect of bone thermal necrosis.