Bone fixation systems, devices, and methods
AssigneeBiomet Manufacturing, LLC
InventorsRobert Sixto, Juergen A Kortenbach, Elizabeth Perepezko
Life of this patent
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Abstract
Various systems, devices, and methods for improved bone fixation are disclosed. The system includes a bone plate and a plurality of variable angle screws. The bone plate comprises titanium and the variable angle screws comprise a TiMo alloy treated to have a hardness of at least 35 HRC. A method of manufacturing an implant is also disclosed. The method includes machining the TiMo alloy having a first hardness value and a first % elongation to form an implant; heat treating, quenching, and ageing the bone fastener to have a second hardness value that can be greater than the first hardness value and a second % elongation that can be both less than the first % elongation and greater than about 3% elongation.
Claims20
A bone fixation system, comprising:
- a bone plate defining a threaded screw hole that extends through the bone plate along a threaded screw hole axis;
- and
- a variable angle screw configured to attach to the bone plate by engaging the threaded screw hole of the bone plate, the variable angle screw comprising a threaded head having M threads that extend along at least a portion of a length of the threaded head, the variable angle screw comprising a shaft that extends from a distal end of the threaded head, the variable angle screw being formed from a TiMo alloy treated to have a hardness of at least 35 HRC, the variable angle screw being configured to lockingly engage the threaded screw hole in the bone plate such that when lockingly engaged, the M threads of the threaded head cut into N internal threads of the threaded screw hole at a selected angle relative to the threaded screw hole axis.
A method for engaging a bone fastener, the method comprising:
- drilling a pilot hole through a near cortex of a bone;
- penetrating the near cortex with a bone fastener via the pilot hole, the bone fastener being formed from a TiMo alloy treated to have a hardness of at least 35 HRC, the bone fastener including a head, the head including two threads having thread starts that are spaced 180 degrees apart about a proximal end of the head, at least a portion of at least one of a major diameter or a minor diameter of the threaded head tapering from the proximal end to a distal end thereof, the thread angle of each of the two threads being at least 90 degrees, the bone fastener further including a shaft that extends from the distal end of the head, the shaft including a helical thread that extends from a point proximate a distal end of the shaft towards a proximal end of the shaft, at least one of a major diameter or a minor diameter of at least a distal portion of the shaft tapering to a point on the distal end of the shaft, the distal portion of the shaft further including a drill portion, the drill portion including a blade, the blade including a cutting lip and a relief surface trailing from the cutting lip;
- and
- drilling the bone fastener through at least a portion of the far cortex of the bone, such that a portion of the shaft threadedly engaged with the near cortex and the distal portion of the shaft cooperate to drive the shaft into the far cortex.
A bone fixation system, comprising:
- a bone fastener formed from a TiMo alloy and treated to have a hardness of at least 35 HRC,
- the bone fastener including a head,
- the head including two threads having thread starts that are spaced 180 degrees apart about a proximal end of the head,
- at least a portion of at least one of a major diameter or a minor diameter of the threaded head tapering from the proximal end to a distal end thereof,
- the thread angle of each of the two threads being at least 90 degrees,
- the bone fastener further including a shaft that extends from the distal end of the head,
- the shaft including a helical thread that extends from a point proximate a distal end of the shaft towards a proximal end of the shaft,
- at least one of a major diameter or a minor diameter of at least a distal portion of the shaft tapering to a point on the distal end of the shaft,
- the distal portion of the shaft further including a drill portion,
- the drill portion including a blade,
- the blade including a cutting lip and a relief surface trailing from the cutting lip.
Dependencies are inferred from the claim text.