Surgical grinding tool for minimally thermal invasive surgery during bone resection (Saline as irrigation)

Abstract

Bone grinding with miniature ball-end diamond wheels, called diamond burs by surgeons, is widely used for surgical resection of bones, especially in orthopedic surgery and neurosurgery. During bone resection, a considerable amount of grinding heat is generated, which can cause thermal injury to adjacent tissues, including nerves. To address this problem, several types of countermeasures such as irrigation, namely coolant supplying methods, have been developed; however, the existing measures cannot suppress the excessive heat generation. To solve this problem, our previous studies proposed surgical diamond grinding wheels with titanium dioxide (TiO₂) particles deposited surfaces for preventing strong loading of bone swarf on the wheel surfaces due to hydrophilicity of TiO₂ and found that such wheels reduced the grinding-induced temperature elevation. However, in the experiments, pure water was used as coolant instead of saline, which is typically used in surgery. Then the grinding performances of the wheels under a saline supply were investigated. The experimental results revealed that sodium ion in saline promoted the strong loading on the wheel surface through Maillard reaction and, as a result, the grinding-induced temperature increased rapidly and finally exceeded the threshold for thermal injury. Based on our findings, new grinding wheels with fluorine-treated surfaces were developed in the hopes of promptly shedding of the adhesion of bone swarf on the wheel surface. These wheels significantly and stably suppressed bone temperature elevation compared with commercial and previously developed wheels.