PROBLEM TO BE SOLVED: To provide a bone opening instrument, when placing an artificial bone, for example, in a joint, capable of stably and reliably performing an operation of adjusting a rotational angle between first long bodies, and an operation of adjusting a rotational angle between second long bodies, and quickly and easily placing the artificial bone after the operations.SOLUTION: A bone opening instrument 1 includes a first blade 2A, a second blade 2B, a first connecting member 5, and a second connecting member 6. When an angle adjusting member 4A of the first blade 2A is operated in a mounting state where the first connecting member 5 is mounted and the second connecting member 6 is mounted, in conjunction with adjustment of a rotational angle between first long bodies 21A, a rotational angle between second long bodies 21B is adjusted to the same angle as the rotational angle thereof, and the rotational angle after the adjustment is displayed by an angle scale.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2019,JPO&INPIT
