Gupta Vishal, Pandey Pulak M, Gupta Ravi K, Mridha Asit R
1 Department of Mechanical Engineering, Indian Institute of Technology Delhi, New Delhi, India.
2 Department of Orthopaedics, Government Medical College & Hospital, Chandigarh, India.
Proc Inst Mech Eng H. 2017 Mar;231(3):189-196. doi: 10.1177/0954411916688500. Epub 2017 Jan 24.
Bone drilling is common in orthopedic procedures and the heat produced during conventional experimental drilling often exceeds critical temperature of 47 °C and induces thermal osteonecrosis. The osteonecrosis may be the reason for impaired healing, early loosening and implant failure. This study was undertaken to control the temperature rise by interrupted cutting and reduced friction effects at the interface of drill tool and the bone surface. In this work, rotary ultrasonic drilling technique with diamond abrasive particles coated on the hollow drill tool without any internal or external cooling assistance was used. Experiments were performed at room temperature on the mid-diaphysis sections of fresh pig bones, which were harvested immediately after sacrifice of the animal. Both rotary ultrasonic drilling on bone and conventional surgical drilling on bone were performed in a five set of experiments on each process using identical constant process parameters. The maximum temperature of each trial was recorded by K-type thermocouple device. Ethylenediaminetetraacetic acid decalcification was done for microscopic examination of bone. In this comparative procedure, rotary ultrasonic drilling on bone produced much lower temperature, that is, 40.2 °C ± 0.4 °C and 40.3 °C ± 0.2 °C as compared to that of conventional surgical drilling on bone, that is, 74.9 °C ± 0.8 °C and 74.9 °C ± 0.6 °C with respect to thermocouples fixed at first and second position, respectively. The conventional surgical drilling on bone specimens revealed gross tissue burn, microscopic evidence of thermal osteonecrosis and tissue injury in the form of cracks due to the generated force during drilling. But our novel technique showed no such features. Rotary ultrasonic drilling on bone technique is robust and superior to other methods for drilling as it induces no thermal osteonecrosis and does not damage the bone by generating undue forces during drilling.
骨钻孔在骨科手术中很常见，传统实验钻孔过程中产生的热量往往超过47°C的临界温度，会引发热骨坏死。骨坏死可能是愈合受损、早期松动和植入物失败的原因。本研究旨在通过间断切割以及降低钻孔工具与骨表面界面处的摩擦效应来控制温度升高。在这项工作中，使用了空心钻孔工具上涂覆有金刚石磨料颗粒且无任何内部或外部冷却辅助的旋转超声钻孔技术。实验在室温下对新鲜猪骨的骨干中段进行，这些猪骨在动物处死后立即采集。在每个过程的五组实验中，分别对骨进行旋转超声钻孔和传统外科钻孔，使用相同的恒定工艺参数。每次试验的最高温度由K型热电偶装置记录。进行乙二胺四乙酸脱钙处理以对骨进行显微镜检查。在这个对比过程中，与传统外科钻孔相比，骨旋转超声钻孔产生的温度要低得多，对于固定在第一和第二位置的热电偶，分别为40.2°C±0.4°C和40.3°C±0.2°C，而传统外科钻孔分别为74.9°C±0.8°C和74.9°C±0.6°C。对骨标本进行的传统外科钻孔显示出明显的组织烧伤、热骨坏死的微观证据以及钻孔过程中产生的力导致的裂纹形式的组织损伤。但我们的新技术没有这些特征。骨旋转超声钻孔技术性能强大且优于其他钻孔方法，因为它不会引发热骨坏死，并且在钻孔过程中不会因产生过大的力而损伤骨。
