Abstract: A device includes a tubular element, and a cutter spring-biased relative to the tubular element. In an unloaded configuration the cutter is displaced relative to the tubular element by a displacement distance, and when the cutter is in a loaded configuration the displacement distance is reduced. A first structure is longitudinally fixed relative to the cutter and rotationally engaged relative to the tubular element. A length of the first structure extends proximally in the unloaded configuration. A second structure is longitudinally displaceable relative to the first structure. In the loaded configuration, a driver engages and rotates both the first and second structures, and thus the tubular element and cutter together. Once the cutter breaks through the bone, the cutter spring-biased into the unloaded configuration, resulting in disengagement of the first structure from the driver to prevent rotation of either the tubular element or the cutter.

Abstract: A device includes a tubular element, and a cutter spring-biased relative to the tubular element. In an unloaded configuration the cutter is displaced relative to the tubular element by a displacement distance, and when the cutter is in a loaded configuration the displacement distance is reduced. A first structure is longitudinally fixed relative to the cutter and rotationally engaged relative to the tubular element. A length of the first structure extends proximally in the unloaded configuration. A second structure is longitudinally displaceable relative to the first structure. In the loaded configuration, a driver engages and rotates both the first and second structures, and thus the tubular element and cutter together. Once the cutter breaks through the bone, the cutter spring-biased into the unloaded configuration, resulting in disengagement of the first structure from the driver to prevent rotation of either the tubular element or the cutter.