Provided herein is an adaptor for modifying the operation of a surgical bone-tool, comprising: a housing having a distal end and a proximal end coupled between a chuck and an operating bit of said tool, such that force generated by a motor of the tool is delivered to the operating bit through the adaptor； a clutch, contained in the housing, having an engaged and a disengaged configurations, respectively interconnecting and disconnecting the chuck to the operating bit； the clutch automatically disengages in response to an electric current, causing a cutoff of the force delivery； wherein the housing comprises a proximal fastener, sized and shaped to connect with the operating bit and a distal fastener, sized and shaped to connect with the chuck.
