Anchoring element for use in spine or bone surgery, methods for use and production thereof

An anchoring element for use in spinal or bone surgery;

• said anchoring element comprising:
• a screw member comprising a spherical segment-shaped head and a shaft with a bone thread;
• a receiving part comprising a longitudinal axis, a first bore in axially symmetrical alignment therewith and having a first diameter of sufficient size to permit the bone thread of the shaft to pass through but not to permit the head to pass through, and a second bore coaxial with the first bore and having a second diameter of sufficient size to permit the head to pass through, the receiving part further comprising a U-shaped recess forming a channel for the reception of a rod and two legs having free ends, the legs comprising a first thread, the legs further providing an
• exterior end surface of the receiving part, the rod having a pre-determined diameter (D) and an outer surface;
• a cylindrical pressure element having an outer diameter of a size capable of being inserted into the receiving part. having first side shaped to engage the head of the screw element and a second side opposite the first side shaped to receive a rod inserted into the V-shaped recess;
• and
• a securing element comprising a second thread that engages and cooperates with the first thread;
• whereby a first distance between the exterior end surface of the receiving part and a closest portion of the outer surface of the rod in an axial direction is a pre-determined distance (A);
• the first thread extends from the exterior end surface of the receiving part to a second distance that is smaller than or equal to the pre-determined distance (A);
• and
• the receiving part further comprising en undercut adjacent to the first thread, the undercut having an edge farthest away from the first thread, the edge being located at a thud distance (B) from the exterior end surface, the distance (B) being larger than the pre-determined distance (A).

A method for performing spinal or bone surgery, the method comprising:

• providing a bone anchoring element comprising:
• a shaft for anchoring in a vertebra or bone section;
• a receiving part, which is connected to the shaft, is structured and arranged to connect to a rod having a pre-determined diameter (D) and an outer surface, the receiving part having a longitudinal axis and comprising a U-shaped recess forming a channel for the reception of the rod and two legs having free ends, the legs comprising a first thread, the legs further providing an exterior end surface of the receiving part;
• and
• a securing element comprising a second thread that engages and cooperates with the first thread;
• whereby a first distance between the exterior end surface of the receiving part and a closest portion of the outer surface of the rod in an axial direction is a pre-determined distance (A);
• the first thread extends from the exterior end surface of the receiving part to a second distance that is smaller than or equal to the pre-determined distance (A);
• and
• the receiving part further comprising an undercut adjacent to the first thread, the undercut having an edge farthest away from the first thread, the edge being located at a third distance (B) from the exterior end surface, the distance (B) being larger than the pre-determined distance (A);
• screwing the shaft into a vertebra or bone section;
• positioning a rod into the U-shaped recess;
• and
• fixing the rod in the bone anchoring element with the securing element.

A method for performing spinal, or bone surgery, the method comprising:

• providing a bone anchoring element comprising:
• a screw member comprising a spherical segment-shaped head and a shaft with a bone thread;
• a receiving part comprising a longitudinal axis, a. first bore in axially symmetrical alignment therewith and having a first diameter of sufficient size to permit the bone thread of the shaft to pass through but not to permit the heed to pass through, and a second bore coaxial with the first bore and having a second diameter of sufficient size to permit the head to pass through, the receiving part further comprising a U-shaped recess forming a channel for the reception of a. rod and two legs having free ends, the legs comprising a first thread, the legs further providing an exterior end surface of the receiving part, the rod having a pre-determined diameter (D) and an outer surface;
• a cylindrical pressure element having an outer diameter of a size capable of being inserted into the receiving part, having a first aide shaped to engage the head of the screw element and a second side opposite the first side shaped to receive a rod inserted into the U-shaped recess;
• and
• a securing element comprising a second thread that engages and cooperates with the first thread;
• whereby a first distance between the exterior end surface of the receiving part and a closest portion of the outer surface of the rod in an axial direction is a pre-determined distance (A);
• the first thread extends from the exterior end surface of the receiving part to a second distance that is smaller than or equal to the pre-determined distance (A);
• and
• the receiving part further comprising an undercut adjacent to the first thread, the undercut having an edge farthest away front the first thread, the edge being located at a third distance (B) from the exterior end surface, the distance (B) being larger than the pre-determined distance (A);
• screwing the screw member of a pre-assembled receiving part, screw member and cylindrical pressure element into a vertebra or bone section;
• positioning a rod into the U shaped recess;
• adjusting the angular orientation of the receiving part relative to the screw member;
• and
• fixing the rod in the bone anchoring element with the securing element.

An anchoring element for use in spinal or bone surgery;

• said anchoring element comprising:
• a shaft for anchoring in a vertebra or bone section;
• a receiving part winch is connected to the shaft, is structured in the range to connect to a rod having a pre-determined diameter (D) and an outer surface, the receiving part having a longitudinal axis and comprising a U-shaped recess forming a channel for the reception of the rod and two legs having free ends, the legs comprising a first thread, the legs further providing an exterior end surface of the receiving part;
• and
• a securing element comprising a second thread that engages and cooperates with the first thread;
• whereby a first distance between the exterior end surface of the receiving part and a closest portion of the outer surface of the rod in an axial direction is a pre-determined distance (A);
• the first thread extends from the vicinity of the exterior end surface of the receiving part to a second distance that is smaller than or equal to the pre-determined distance (A);
• and
• the receiving part further comprising an undercut adjacent to the first thread, the undercut having an edge farthest away from the first thread, the edge being located at the third distance (B) from the exterior end surface, the distance (B) being larger than the pre-determined distance (A).