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US 4,421,112 AGranted
Tibial osteotomy guide assembly and method
AssigneeMinnesota Mining and Manufacturing Company
InventorsDouglas B. Mains, Kenneth E. Merte
Life of this patent
Estimating the term…
Abstract
A method and guide assembly for use in a tibial osteotomy wherein two pairs of parallel guide pins are inserted into the tibia at a predetermined angle with respect to each other through a guide block. The adjacent surfaces of the pairs of pins are then used to precisely guide a saw by which a wedge-shaped segment of the tibia is removed.
Claims11
An osteotomy guide assembly comprising:
- four guide pins, each having a cutting end surface adapted to cut bone tissue upon rotation of said guide pin about its axis with said cutting end surface pressed against said tissue, at least two of said guide pins having a locating mark a first predetermined distance from said cutting end surface;
- a guide block having a first pair of spaced parallel guide bores adapted to closely receive the two of said guide pins having said locating marks, and a second pair of spaced parallel guide bores adapted to receive the other two of said guide pins, said second pair of parallel guide bores converging with respect to said first pair and being oriented to direct the guide pins extending through the second bores so that a second plane tangent to and defined by the surfaces of the second pair of pins adjacent the first pair of pins will intersect a first plane tangent to and defined by the surfaces of the first pair of pins adjacent the second pair of pins at a predetermined angle and at a second predetermined distance from a locating surface on said guide block;
- said second predetermined distance having a known relationship to said first predetermined distance;
- and
- means mounted on said guide block for fixing the position of said guide block along said first pair of pins against movement toward a surface positioned on the side of said block toward which said bores converge.
2 more elements
A method for performing a tibial osteotomy to correct varus and valgus deformities comprising the steps of:
- inserting a first pair of parallel guide pins in the tibia just below the knee joint so that the intersection of a plane through the axes of both guide pins with a sagittal plane of the body is generally parallel to the plane of the knee joint, and the intersection of the plane through the axis of both pins with a longitudinal plane is generally parallel to or angled generally away from the plane of the knee joint starting from the point of insertion of the guide pins;
- inserting a second pair of parallel guide pins in the tibia below the first pair and disposing the second pair of guide pins at a predetermined angle with respect to the first pair of guide pins so that a second plane tangent to and defined by the surfaces of the second pair of guide pins adjacent the first pair of pins will intersect a first plane tangent to and defined by the surfaces of the first pins adjacent the second plane within the tibia adjacent its cortical shell on its side opposite the side from which the pins are inserted at a line of intersection generally parallel to a sagittal plane of the body;
- guiding an osteotomy saw blade along first one and then the other of the pairs of guide pins on their surfaces adjacent the other pair of guide pins to cut a wedge-shaped segment from the tibia;
- removing the segment and the pairs of guide pins from the tibia;
- bending the tibia about the line of intersection of the planes to close the space provided by the removed segment;
- and
- fastening the tibia in the bent condition.
4 more elements
A method for performing an osteotomy to correct deformities comprising the steps of:
- inserting a first pair of parallel guide pins in the bone;
- inserting a second pair of parallel guide pins in the bone adjacent the first pair and disposing the second pair of guide pins at a predetermined angle with respect to the first pair of guide pins so that a second plane tangent to and defined by the surfaces of the second pair of guide pins adjacent the first pair of pins will intersect a first plane tangent to and defined by the surfaces of the first pins adjacent the second plane within the bone adjacent its cortical shell on its side oppoiste the side form which the pins are inserted;
- guiding an osteotomy saw blade along first one and then the other of the pairs of guide pins on their surfaces adjacent the other pair of guide pins to cut a wedge-shaped segment from the bone;
- removing the segment and the pairs of guide pins from the bone;
- bending the bone about the line of intersection of the planes to close the space provided by the removed segment;
- and
- fastening the bone in the bent condition.
4 more elements
Dependencies are inferred from the claim text.