A hip prosthesis device (100, 200) comprising a femoral stem (102, 202) which is provided to be implanted within a femoral bone, the femoral stem (102, 202) comprising: an elongate stem sleeve (110, 210) having a blind hole formed therein and extending in a longitudinal direction thereof and having a hole opening at an upper frontal end of the stem sleeve (110, 210); a stem core (120, 220) which has an elongate stem shaft (130, 230) inserted in the blind hole and arranged therein so as to be slidable in the longitudinal direction thereof, a neck (140, 240) with a lower neck portion (142, 242) which is fixedly attached, with a lower end thereof, to an upper end of the stem shaft (130, 230), and with an upper neck portion (144, 244) which is fixedly attached, with a lower end thereof, to an upper end of the lower neck portion (142, 242) and which has an upper end, to which a femoral head is attachable; and a closure cap (160, 260) positioned so as to close the hole opening and having a through hole provided therethrough, through which the neck (140, 240) extends with its lower neck portion (142, 242), characterized in that the femoral stem (102, 202) further comprising a shock absorber mechanism (150, 250) arranged within the stem sleeve (110, 210) and operatively provided between the stem shaft (130, 230) and the stem sleeve (110, 210) so as to act at least against a downwardly directed longitudinal sliding motion of the stem shaft (130, 230) relative to the stem sleeve (110, 210). an elongate stem sleeve (110, 210) having a blind hole formed therein and extending in a longitudinal direction thereof and having a hole opening at an upper frontal end of the stem sleeve (110, 210); a stem core (120, 220) which has an elongate stem shaft (130, 230) inserted in the blind hole and arranged therein so as to be slidable in the longitudinal direction thereof, a neck (140, 240) with a lower neck portion (142, 242) which is fixedly attached, with a lower end thereof, to an upper end of the stem shaft (130, 230), and with an upper neck portion (144, 244) which is fixedly attached, with a lower end thereof, to an upper end of the lower neck portion (142, 242) and which has an upper end, to which a femoral head is attachable; a neck (140, 240) with a lower neck portion (142, 242) which is fixedly attached, with a lower end thereof, to an upper end of the stem shaft (130, 230), and with an upper neck portion (144, 244) which is fixedly attached, with a lower end thereof, to an upper end of the lower neck portion (142, 242) and which has an upper end, to which a femoral head is attachable; and a closure cap (160, 260) positioned so as to close the hole opening and having a through hole provided therethrough, through which the neck (140, 240) extends with its lower neck portion (142, 242), characterized in that the femoral stem (102, 202) further comprising a shock absorber mechanism (150, 250) arranged within the stem sleeve (110, 210) and operatively provided between the stem shaft (130, 230) and the stem sleeve (110, 210) so as to act at least against a downwardly directed longitudinal sliding motion of the stem shaft (130, 230) relative to the stem sleeve (110, 210).