A locking tack for attaching a bone fixation device to a bone, comprising: an elongated body including a distal portion formed of a weldable material and suitable to be received within a bore through a portion of a target bone and a proximal portion which, when the distal portion is in a desired position within a target bone, extends out of the bone; and a channel extending longitudinally through the elongated body from a proximal end thereof to a channel distal end within the distal portion of the elongated body; characterized in that the locking tack further comprises: an engaging feature at a distal end of the channel configured to engage an extraction mechanism so that forces applied to the extraction mechanism are transmitted to the distal portion of the elongated body, wherein the engaging feature is in the form of an insert that is permanently mounted within the channel at the distal end thereof, the insert being formed of substantially rigid material capable of exerting a torque on the locking tack sufficient to cause disengagement from a bone fixation device to which the locking tack has been welded; and a ring around the elongated body at a proximal end of the distal portion, the ring having a diameter greater than a diameter of the distal portion, the ring being sized and shaped to mate with a welding mechanism. an elongated body including a distal portion formed of a weldable material and suitable to be received within a bore through a portion of a target bone and a proximal portion which, when the distal portion is in a desired position within a target bone, extends out of the bone; and a channel extending longitudinally through the elongated body from a proximal end thereof to a channel distal end within the distal portion of the elongated body; characterized in that the locking tack further comprises: an engaging feature at a distal end of the channel configured to engage an extraction mechanism so that forces applied to the extraction mechanism are transmitted to the distal portion of the elongated body, wherein the engaging feature is in the form of an insert that is permanently mounted within the channel at the distal end thereof, the insert being formed of substantially rigid material capable of exerting a torque on the locking tack sufficient to cause disengagement from a bone fixation device to which the locking tack has been welded; and a ring around the elongated body at a proximal end of the distal portion, the ring having a diameter greater than a diameter of the distal portion, the ring being sized and shaped to mate with a welding mechanism. an engaging feature at a distal end of the channel configured to engage an extraction mechanism so that forces applied to the extraction mechanism are transmitted to the distal portion of the elongated body, wherein the engaging feature is in the form of an insert that is permanently mounted within the channel at the distal end thereof, the insert being formed of substantially rigid material capable of exerting a torque on the locking tack sufficient to cause disengagement from a bone fixation device to which the locking tack has been welded; and a ring around the elongated body at a proximal end of the distal portion, the ring having a diameter greater than a diameter of the distal portion, the ring being sized and shaped to mate with a welding mechanism.