US 20050159747 A1
A volar fixation system includes a plate intended to be positioned against the volar side of the radial bone. The plate includes threaded holes for receiving pegs which lock relative to the plate. The system also includes a guide which is provided on top of the volar plate and includes holes oriented according to the axes of the threaded holes for guiding a drill into the bone fragments at the required orientation.
1. A volar fixation system, comprising:
a) a substantially rigid volar plate having a distal head portion and a proximal body portion extending from the head portion, said head portion including a plurality of threaded holes defining a plurality of axes at least two of which are oblique relative to each other, and said body portion including at least one screw hole; and
b) a guide including a plurality of guide holes, said guide adapted to be positioned over at least a portion of said head portion of said volar plate such that said guide holes define drill guides adapted to direct a drill through said plurality of threaded holes in alignment with respective axes of said plurality of threaded holes.
2. A volar fixation system according to
said guide holes have fixed axes.
3. A volar fixation system according to
structure which aligns said guide over said head portion of said volar plate.
4. A volar fixation system according to
said head portion includes a bone contacting surface, and
at least two of said plurality of axes of said threaded holes diverge from said bone contacting surface.
5. A volar fixation system according to
said plurality of threaded holes in said head portion are linearly arranged.
6. A volar fixation system according to
said plurality of threaded holes are arranged in a generally medial to lateral direction where successive lateral threaded holes are situated distally relative to adjacent threaded holes.
7. A volar fixation system according to
at least two of said plurality of axes are oblique in two dimensions relative to each other.
8. A volar fixation system according to
at least one peg having a threaded head portion adapted to be engaged in a threaded hole of said head portion, and a shaft portion sized to be received through said threaded hole and extend along said axis of said threaded hole.
9. A volar fixation system according to
at least one screw adapted to be received in said at least one screw hole.
10. A volar fixation system according to
said at least one screw is a self-tapping screw.
11. A method of drilling through holes in a volar plate for fixation of a distal radius fracture, said method comprising:
a) providing a volar plate having a bone contacting surface and an opposite surface, and a distal head portion and a proximal body portion, the head portion including a plurality of threaded holes each defining a discrete axis, at least two of said axes being oblique relative to each other such that said at least two axes diverge from said bone contacting surface;
b) providing a guide having a plurality of holes defining fixed axes;
c) positioning a guide on the volar plate such that the fixed axes are aligned coaxially with the respective axes of the threaded holes in the head portion of the volar plate; and
d) drilling through the coaxially aligned holes in the guide and volar plate and into a fragmented portion of the distal radius beneath the volar plate.
This application is a continuation of U.S. Ser. No. 10/762,695, filed Jan. 22, 2004, which is a continuation-in-part of U.S. Ser. No. 10/315,787, filed Dec. 10, 2002, which is a continuation-in-part of U.S. Ser. No. 10/159,611, filed May 30, 2002, which is a continuation-in-part of U.S. Ser. No. 09/735,228, filed Dec. 12, 2000 and now issued as U.S. Pat. No. 6,440,135, which is a continuation-in-part of U.S. Ser. No. 09/524,058, filed Mar. 13, 2000 and now issued as U.S. Pat. No. 6,364,882, and U.S. Ser. No. 09/495,854, filed Feb. 1, 2000 and now issued as U.S. Pat. No. 6,358,250, the complete disclosure of which are hereby incorporated by reference herein.
1. Field of the Invention
This invention relates broadly to surgical devices. More particularly, this invention relates to a bone fixation system, and particularly to a fixation system adapted to fixate a distal radial fracture.
2. State of the Art
Alignment and fixation are typically performed by one of several methods: casting, external fixation, interosseous wiring, and plating. Casting is non-invasive, but may not be able to maintain alignment of the fracture where many bone fragments exist. Therefore, as an alternative, external fixators may be used. External fixators utilize a method known as ligamentotaxis, which provides distraction forces across the joint and permits the fracture to be aligned based upon the tension placed on the surrounding ligaments. However, while external fixators can maintain the position of the wrist bones, it may nevertheless be difficult in certain fractures to first provide the bones in proper alignment. In addition, external fixators are often not suitable for fractures resulting in multiple bone fragments. Interosseous wiring is an invasive procedure whereby screws are positioned into the various fragments and the screws are then wired together as bracing. This is a difficult and time consuming procedure. Moreover, unless the bracing is quite complex, the fracture may not be properly stabilized. Plating utilizes a stabilizing metal plate typically against the dorsal side of the bones, and a set of parallel pins extending from the plate into the holes drilled in the bone fragments to provide stabilized fixation of the fragments. However, the currently available plate systems fail to provide desirable alignment and stabilization.
It is therefore an object of the invention to provide an improved fixation and alignment system for a Colles' fracture.
It is another object of the invention to provide a volar fixation system which desirably aligns and stabilizes multiple bone fragments in a distal radial fracture to permit proper healing.
In accord with these objects, which will be discussed in detail below, a volar fixation system is provided which generally includes a T-shaped plate intended to be positioned against the volar side of the radial bone, a plurality of bone screws for securing the plate along a non-fractured portion of the radial bone, and a plurality of bone pegs which extend from the plate and into bone fragments of a Colles' fracture.
The plate is generally a T-shaped plate defining an elongate body, a head portion angled relative to the body, a first side which is intended to contact the bone, and a second side opposite the first side. The body portion includes a plurality of countersunk screw holes for the extension of the bone screws therethrough. The head portion includes a plurality of threaded peg holes for receiving the pegs therethrough. According to a first embodiment, the peg holes are preferably non-linearly arranged. According to a second embodiment, the peg holes are preferably linearly arranged. In either embodiment, the peg holes are positioned increasingly distal in a medial to lateral direction along the second side. According to a preferred aspect of the invention, axes through the holes are oblique relative to each other, and are preferably angled relative to each other in two dimensions. The pegs having a threaded head and a relatively smooth cylindrical shaft.
The system preferably also includes a guide plate which temporarily sits on top of the volar plate and includes holes oriented according to the axes of the peg holes for guiding a drill into the bone fragments at the required orientation. The volar plate and guide plate are also preferably provided with mating elements to temporarily stabilize the guide plate on the volar plate during the hole drilling process.
In use, the volar plate is positioned with its first side against the volar side of the radius and bone screws are inserted through the bone screw holes into the radius to secure the volar plate to the radius. The bone fragments are then aligned and the guide plate is positioned on the second side of the volar plate. A drill, guided by guide holes in the guide plate, drills holes into the bone fragments, and the guide plate is then removed.
The pegs are then inserted through the peg holes and into the holes in the bone, and the heads of the pegs are threadably engaged in the volar plate. The volar fixation system thereby secures the bone fragments in their proper orientation.
Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.
Turning now to
The body portion 118 includes three preferably countersunk screw holes 124, 126, 128 for the extension of the bone screws 104 therethrough. The first screw hole 124 has a center preferably 0.235 inch from the end of the body portion, the second screw hole 126 has a center preferably 0.630 inch from the end of the body portion, and the third screw hole 128 is preferably generally elliptical (or oval) and defines foci-like locations at 1.020 inches and 1.050 inches from the end of the body portion. The head portion 116 includes four threaded peg holes 130, 132, 134, 136 for individually receiving the pegs 108 therethrough. According to a first preferred aspect of the first embodiment of the invention, the peg holes 130, 132, 134, 136, preferably 0.100 inch in diameter, are preferably non-linearly arranged along the head portion 116, and are provided such that the adjacent peg holes are provided further distally in a medial to lateral direction along the second side. More particularly, according to a preferred aspect of the first embodiment of the invention, the peg holes are preferably arranged along a parabolic curve, with the center of peg hole 130 located approximately 0.321 inch proximal line P and approximately 0.719 inch medial of the lateral edge 137 of the head portion, the center of peg hole 132 located approximately 0.296 inch proximal line P and approximately 0.544 inch medial of the lateral edge 137, the center of peg hole 134 located approximately 0.250 inch proximal line P and approximately 0.369 inch medial of the lateral edge 137, and the center of peg hole 136 located approximately 0.191 inch proximal line P and approximately 0.194 inch medial of the lateral edge 137.
In addition, according to a second preferred aspect of the first embodiment of the invention, the peg holes define axes A1, A2, A3, A4 which are oblique (not parallel) relative to each other, and more preferably are angled in two dimensions (medial/lateral and proximal/distal) relative to each other; i.e., the pegs once inserted into the peg holes are also angled in two dimensions relative to each other. More particularly, the first axis A1 of the first peg hole 130 (that is, the most proximal and medial peg hole) is preferably directed normal to the first side 120 of the head portion 116. The axis A2 of the adjacent peg hole 132, i.e., the second axis, is preferably angled approximately 1-7° distal and lateral relative to the first axis A1, and more preferably approximately 2.5° distal and lateral relative to the first axis A1. The axis A3 of the peg hole 134 laterally adjacent the second peg hole 132, i.e., the third axis, is preferably angled approximately 7-13° distal and lateral relative to the first axis A1, and more preferably approximately 10° distal and lateral relative to the first axis A1. The axis A4 of the peg hole 134 laterally adjacent the third peg hole 132, i.e., the fourth axis, is preferably angled approximately 10-30° distal and lateral relative to the first axis A1, and more preferably approximately 20° distal and lateral relative to the first axis A1. The second side of the head portion 116, distal of the peg holes 130, 132, 134, 136 is preferably beveled.
Referring back to
Turning now to
The head portion 216 includes four threaded peg holes 230, 232, 234, 236 for individually receiving pegs 208 therethrough (
There have been described and illustrated herein embodiments of a volar fixation system and a method of aligning and stabilizing a Colles' fracture. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular materials for the elements of the system have been disclosed, it will be appreciated that other materials may be used as well. In addition, while a particular numbers of screw holes in the volar plates and bone screws have been described, it will be understood another number of screw holes and screws may be provided. Further, fewer screws than the number of screw holes may be used to secure to the volar plate to the radius. Also, fewer or more peg holes and bone pegs may be used, preferably such that at least two pegs angled in two dimensions relative to each other are provided. Moreover, while in the first embodiment it is preferred that the peg holes lie along a parabolic curve, it will be appreciated that they can lie along another curve. In addition, while a particular preferred angle between the head portion and body portion has been disclosed, other angles can also be used. Furthermore, while particular distances are disclosed between the peg holes and line P, it will be appreciated that the peg holes may be provided at other distances relative thereto. Moreover, while particular preferred medial/lateral and proximal/distal angles for the peg hole axes has been disclosed, it will be appreciated that yet other angles may be used in accord with the invention. Also, while a right-handed volar plate is described with respect to the first embodiment, and a left-handed volar plate is described with respect to the second embodiment, it will be appreciated that each embodiment may be formed in either a right- or left-handed model, with such alternate models being mirror images of the models described. In addition, aspects from each of the embodiments may be combined. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed.