title: Rotary ultrasonic bone drilling: Improved pullout strength and reduced damage.
abstract: Bone drilling is one of the most common operations used to repair fractured parts of bones. During a bone drilling process, microcracks are generated on the inner surface of the drilled holes that can detrimentally affect osteosynthesis and healing. This study focuses on the investigation of microcracks and pullout strength of cortical-bone screws in drilled holes. It compares conventional surgical bone drilling (CSBD) with rotary ultrasonic bone drilling (RUBD), a novel approach employing ultrasonic vibration with a diamond-coated hollow tool. Both techniques were used to drill holes in porcine bones in an in-vitro study. Scanning electron microscopy was used to observe microcracks and surface morphology. The results obtained showed a significant decrease in the number and dimensions of microcracks generated on the inner surface of drilled holes with the RUBD process in comparison to CSBD. It was also observed that a higher rotational speed and a lower feed rate resulted in lower damage, i.e. fewer microcracks. Biomechanical axial pullout strength of a cortical bone screw inserted into a hole drilled with RUBD was found to be much higher (55-385%) than that for CSBD.
authors.affiliation: Mechanical Engineering Department, Indian Institute of Technology, Delhi, New Delhi 110016, India. Electronic address: vishaltayal86@gmail.com.
authors.forename: Vishal
authors.initials: V
authors.lastname: Gupta
authors.affiliation: Mechanical Engineering Department, Indian Institute of Technology, Delhi, New Delhi 110016, India. Electronic address: pmpandey@mech.iitd.ac.in.
authors.forename: Pulak M
authors.initials: PM
authors.lastname: Pandey
authors.affiliation: Wolfson School of Mechanical, Electrical and Manufacturing Engineering Loughborough University, Loughborough LE11 3TU, UK. Electronic address: V.Silberschmidt@lboro.ac.uk.
authors.forename: Vadim V
authors.initials: VV
authors.lastname: Silberschmidt
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001863:Bone Screws; D000071538:Cortical Bone / Q000293:injuries / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000009:adverse effects* / Q000295:instrumentation*; D055595:Mechanical Phenomena; D013552:Swine; D014465:Ultrasonics
keywords: Conventional surgical bone drilling; Microcracks; Pullout force; Rotary ultrasonic bone drilling; SEM