Patella bone plate and methods of fixation
A patella fracture fixation system includes a bone plate that is configured to be implanted along an anterior approach. The bone plate has a fixation hub and a plurality of fixation nodes that are connected to the fixation hub. The fixation hub and the fixation nodes can define respective fixation holes. The bone plate can further include legs that are configured to be bent around respective inferior aspects of the patella.
1. A bone plate including:
a plate body that defines a bone-facing body surface configured to face a bone and an outer body surface opposite the bone-facing body surface, wherein:
the bone plate defines a first aperture that extends through the plate body from the outer body surface to the bone-facing body surface along a central first aperture axis,
the plate body defines a first direction, a second direction perpendicular to the first direction, and a third direction opposite the second direction and perpendicular to the first direction, and
the bone plate defines a plurality of fixation holes that extend through the plate body from the outer body surface to the bone-facing body surface along respective central axes and are each configured to receive a respective bone anchor, wherein the first aperture is disposed between first and second ones of the fixation holes with respect to the first direction, such that a first straight line that passes through the first aperture and is oriented along the first direction also passes through the first and second ones of the fixation holes, and
the plurality of fixation holes further includes third and fourth ones of the plurality of fixation holes that are offset in their respective entireties from the first aperture in the second direction, such that 1) a second straight line that is oriented along the first direction and extends through the third one of the plurality of fixation holes also passes through the fourth one of the plurality of fixation holes, 2) no straight line that is oriented in the first direction that passes through the third and fourth ones of the plurality of fixation holes also passes through the first aperture, and 3) a central axis of the third one of the plurality of fixation holes is disposed between respective central axes of the first and second ones of the plurality of fixation holes with respect to the first direction;
a first leg that extends from the plate body along the third direction at a location aligned with the first aperture along the third direction, wherein the first leg defines a respective first fixation hole that is configured to receive a first respective bone anchor; and a second leg that extends from the plate body and defines a respective second fixation hole that is configured to receive a second respective bone anchor, wherein the first and second legs are the only legs that extend from the plate body.
2. The bone plate of claim 1 , wherein the first leg supports a first eyelet at an end of the first leg, the respective first fixation hole extends through the first eyelet, the second leg supports a second eyelet at an end of the second leg, and the respective second fixation hole extends through the second eyelet.
3. The bone plate of claim 2 , wherein the first eyelet and the second eyelet are both offset from the bone plate body in the third direction.
4. The bone plate of claim 2 , wherein the first and second legs have respective heights that are less than heights of the first and second eyelets, respectively, the heights measured along a direction perpendicular to each of the first, second, and third directions.
5. The bone plate of claim 1 , wherein the plurality of fixation holes and the respective first and second fixation holes define variable angle threading.
6. The bone plate of claim 1 , wherein the respective first fixation hole is the only hole that is supported by the first leg, and the respective second fixation hole is the only hole that is supported by the second leg.
7. The bone plate of claim 1 , wherein the plurality of fixation holes comprises differently sized fixation holes that extend through the bone plate body.
8. The bone plate of claim 1 , wherein each of the first and second legs is flexible.
9. The bone plate of claim 1 , wherein the first aperture has a perimeter defined by a first end, a second end opposite the first end, and an inner edge that extends from the first end to the second end, wherein the inner edge tapers in width from a maximum width of the inner edge located adjacent the second end to a minimum width located adjacent the first end.
10. The bone plate of claim 9 , wherein a length of the inner edge between the maximum width and the minimum width is substantially linear.
11. The bone plate of claim 10 , wherein the first aperture defines a through-hole that extends through the bone plate.
12. The bone plate of claim 1 , wherein a central axis of the fourth one of the plurality of fixation holes is disposed between the first and second ones of the plurality of fixation holes with respect to the first direction.
13. The bone plate of claim 1 , wherein the second leg flares away from the first leg as the second leg extends from the plate body.