A bone anchoring device is provided comprising a bone anchoring element (1,1',1",1''',1'''') having a head (3,3',3",3''',3'''') and a shaft (2,2',2",2''',2'''') for anchoring in the bone, a receiving part (4,4',4",4''',4'''') for coupling the bone anchoring element (1,1',1",1''',1'''') to a rod (100), the receiving part (4,4',4",4''',4'''') comprising an accommodation space (8,8',8",8''',8'''') for accommodating the head (3,3',3",3''',3'''') and a bore (41,41',41",41''',41'''') being in communication with the accommodation space (8,8',8",8''',8''''), the bore (41,41',41",41''',41'''') having a bore axis, a pressure member (6,6',6",6''',6'''') configured to move in the bore (41,41',41",41''',41'''') and comprising a first surface for engaging the head (3,3',3",3''',3'''') and a second surface on which the rod (100) acts, wherein the pressure member (6,6',6",6''',6'''') is configured to assume a first position in which it exerts a preload onto the head (3,3',3",3''',3'''') that results from friction between the first surface and the head (3,3',3",3''',3'''') to enable the shaft (2,2',2",2''',2'''') to be maintained in a desired angular position before locking the head (3,3',3",3''',3'''') in the receiving part (4,4',4",4''',4''''), and a second position in which the head (3,3',3",3''',3'''') is locked with respect to the receiving part (4,4',4",4''',4''''), and wherein the first position is obtained by moving the pressure member (6,6',6",6''',6'''') by the action of a predefined force acting onto the pressure member (6,6',6",6''',6'''') in an axial direction and wherein the pressure member (6,6',6",6''',6'''') is maintained in the first position by interaction with the receiving part (4,4',4",4''',4'''') and can be released from the first position through action of an axial force.本案提供一種骨骼固定裝置，包括骨骼固定元件(1,1',1",1''',1'''')，具有頭部(3,3',3",3''',3'''')，和固定於骨骼之幹部(2,2',2",2''',2'''')；容納件(4,4',4",4''',4'''')，供骨骼固定元件(1,1',1",1''',1'''')聯結於桿件(100)，容納件(4,4',4",4''',4'''')包括包容頭
