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Showing 3 results for Bone Drilling
Ehsan Shakouri, Hossein Haghighi Hassanali Deh, Seifollah Gholampour,
Volume 17, Issue 3 (5-2017)
Abstract
Bone fracture occurs as a result of accident, old age and disease. Generally bone fracture treatment consists of stabilizing the fractured bone in the right position. In complex fractures, stabilizing internal and external tools and equipment is used to stabilize the fractured bone in position. Bone drilling is required in order to connect fixating devices. The forces required for chip formation, increase the temperature during bone drilling. The phenomenon of thermal necrosis of the bone occurs if the temperature exceeds 47 degrees Celsius. Thermal necrosis inhibit bone fixation and causes the wrong bone healing. The current study has been trying to examine the effect of the cooling gas on the reduction of temperature rise on drilling site as well as statistical analysis of the process. Tests have been carried out using direct injection of nitrogen gas using internal coolant drill bits. Using cooling gas reduced the increase in drilling temperature to 15 degrees Celsius and prevented the thermal necrosis. The maximum increase in temperature in conventional drilling was 56 degrees Celsius, while using cooling gas the increase in temperature of 43 degrees Celsius was achieved. This reduces the risk of thermal necrosis. Statistical analysis also indicates that in the drilling with direct cooling with nitrogen gas the temperature changes are almost independent of the rotational speed.
A. Pak, H. Yaghooti, V. Tahmasbi,
Volume 20, Issue 5 (5-2020)
Abstract
The use of ultrasonic vibrations to reduce the temperature in bone drilling is one of the most important advanced processes that has attracted the attention of bone surgeons. Therefore, the study of temperature behavior in the ultrasonic-assisted drilling process and the prediction of temperature behavior have an important effect on improving the use of this method in orthopedic surgery. In this research, the influence of process parameters on change in the temperature was studied using response surface methodology and data analysis. Data analysis was carried out to find the effect of process factors such as rotational speed, feed speed, and ultrasonic vibrational amplitude and their interaction on the temperature. Moreover, using the statistical method of Sobol sensitivity, the effect, and sensitivity of each input factor on temperature were studied. The results show that the use of ultrasonic vibrations reduces the temperature, and rotational speed (%48), vibrational amplitude (%33) and feed speed (%19) had the greatest effect on temperature in ultrasonic-assisted bone drilling, respectively. As a result, the use of ultrasonic vibration can reduce the dependency of process temperature on the feed speed, and thus make it possible to perform surgery in a shorter time. The minimum temperature is 37°C at the rotational speed of 500rpm and the feed speed of 20mm/min and the vibration amplitude of 15μm.
Fatemeh Negahdari, Behnam Akhoundi,
Volume 22, Issue 10 (10-2022)
Abstract
In orthopedic surgery, the drilling process is used to internally fix the fracture zone. During bone drilling, if the temperature exceeds the limit of 47 °C, it results in altered bone alkaline phosphatase nature, occurrence of thermal necrosis, non-fixation and inadequate bone fusion In order to investigate the effective parameters of the drilling process, after three-dimensional modeling of the femur bone in Mimics software and determination of bone coefficients based on the Johnson-Cook model, numerical simulation of the cortical and trabecular bone oblique drilling process have been performed. The drilling process was performed in both normal and high speed modes based on reverse heat transfer theory using DEFORM-3D software. The results of numerical simulation after validation with experimental results showed that this theory is capable of estimating the temperature and heat flux in this process and the occurrence of necrosis in both processes (normal and high speed) is imminent. The temperature in the drilling area of the trabecular bone is higher than the cortical bone at all speeds and feed rates and the axial force of the trabecular bone is less than the cortical bone at all speeds and feed rates. The optimum point leading to the minimum temperature in normal drilling of trabecular and cortical bone is the feed rate of 150 mm/min and the rotational speed of 2000 rpm. This optimum point is obtained in the high-speed drilling of trabecular and cortical bone at the feed rate of 150 mm/min and rotational speed of 4,000 rpm and 7,000 rpm.
