Parametric effect of vibrational drilling on osteonecrosis and comparative histopathology study with conventional drilling of cortical bone.

Abstract

Drilling to the bones is required to re-fix them at their appropriate location using the implants. During drilling some thermal and mechanical losses may be faced by the bone and surrounding tissues which may lead to the serious issue in terms of osteonecrosis. Osteonecrosis is one of the reasons for impaired healing process for the fractured bone and causes further complications like low pullout strength of cortical screws and bone crush. In order to maintain the low temperature during bone drilling, this study focused the thermal damages observed by the bone and its surrounding during bone drilling and compared the results of conventional and vibrational drilling techniques. Parametric optimization under the influence of vibrations was also studied. Drilling has been done with the both drilling technique, and results were recorded in terms of temperature raise. Optimal solution for drilling the bone has been accessed using Taguchi optimization technique. The morphological comparison has been done for conventional and vibrational drilled holes using histopathology of drilled bones sections. From Taguchi optimization, it was observed that R1F1A1 is the parametric combination which gives minimum thermal injury to the bone in case of vibrational bone drilling. Analysis of variance cleared that the all parameters involved significantly affect the results (P ≤ 0.05). Rotational speed was found to be the most influential factor among the all with 80.53%. Histopathology studies of bone specimens help to understand how heat generation affects the bone morphology during drilling. The specimens drilled with vibrational drilling show less damage in terms of osteonecrosis near the drill site which shows the significance of vibrational drilling in case of orthopedic surgeries. The raise in temperature during drilling is collective result of different drilling parameters. Vibrational drilling was observed a helping tool to control the thermal damage in bone drilling.