A surgical cutting instrument for use with a motor assembly including a motor housing and a motor driving a drive mechanism, the cutting instrument comprising: an elongate drive member 24 defining a proximal section and a distal section a cutting tip 26 secured to the distal section of the drive member a non-conductive coupling body 28 attached to the proximal section of the drive member and adapted for selective attachment to the motor assembly drive mechanism and a non-conductive housing 30 provided apart from the motor assembly housing, the non-conductive housing encompassing the coupling body and the proximal section of the drive member wherein the coupling body and the housing are configured to electrically isolate the cutting tip from the motor assembly upon mounting of the cutting instrument to the motor assembly.
