Field of Search:
128/89,89.1,92,92A,92B,92C,92D,92G 52/282,514 217/69 229/49 248/345.1 287/108,2.92R,2.92A,2.92C,189.36F
Other References:
DEPUY FRACTURE BOOK No. 18, Warsaw, Indiana, Oct. 1, 1941, pg. 87.
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to compression plates and more particularly to compression plates for angular-in-cross section bones such as the tibia bone and proximate ulna bones.
2. Description of the Prior Art
Prior art compression plates are generally flat or semicircular in cross section and are not adapted for securement to two sides of the tibia. Compression plates have been proposed which have perpendicular stiffening struts, or flanges, but such flanges are intended for insertion in slots cut in the bone by a saw. A compression plate of this type is disclosed in U.S. Pat. No. 2,133,859. While a compression plate having such a flange may provide some support against shifting of the bone portions above and below the fracture, it is characterized by the disadvantages of the surgeon having to cut a longitudinal slot in the bone thereby increasing the likelihood of infection and weakening the bone. Also, once the saw cut is made the surgeon has committed himself to the anatomical position of the bone portions and cannot thereafter adjust the transverse positioning thereof.
SUMMARY OF THE INVENTION
The angular compression plate of present invention is characterized by a pair of flanges connected together at their adjacent edges and adapted for overlying adjacent sides of a fractured angular bone. The compression plate may be sufficiently flexible to enable the plate portions to be flexed to adjust the angle therebetween for accommodating variations in angle between the adjacent sides of the bone.
An object of the present invention is to provide a compression plate which will support the fractured bone on two sides against transverse shifting.
Another object of the present invention is to provide a compression plate of the type described which is sufficiently flexible to accommodate variations in the angle between the sides of the bone throughout its length.
Other objects and advantages of the present invention will become apparent from a consideration of the following description when taken in conjunction with the accompanying drawing.
DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a compression plate embodying the present invention;
FIG. 2 is an elevational view of the compression plate shown in FIG. 1;
FIG. 3 is a vertical sectional view taken along the lines 3-3 of FIG. 1; and
FIG. 4 is a vertical sectional view of a modification of the compression plate shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The compression plate P of present invention is intended to compress a fracture 10 in an angular-in-cross section bone, such as a tibia bone 11, or the like. The plate P includes a pair of flanges or plate portions 13 and 15 which extend along respective adjacent sides 17 and 19 of the tibia 11 and are connected together along their adjacent edges to form a connecting corner 20.
Referring to FIG. 3, the cross section of the tibia 11 is approximately an equilateral triangle having an anterior corner 25 of 60°, and posterior medial and lateral corners 27 and 29, respectively, also of approximately 60°. Consequently, the angle between the plate portions 11 and 13 may likewise be approximately 60° and with the inherent flexibility of the plate P, such angle can be adjusted to fit the plate over any of the corners 25, 27 or 29. Also, the size and configuration of the tibia 11 varies throughout its length and the plate portions 14 and 15 can be flexed to accommodate the variations.
In the embodiment shown in FIGS. 1, 2 and 3, a plurality of screw-receiving bores 33 and 35 are included in the respective plate portions 13 and 15 and are arranged in staggered relationship whereby the screws 37 and 39 extended therethrough and screwed into the tibia cortex will be out of alignment with one another. It is noted that the bores 33 and 35 are included in projections 41 and 43 in the respective plate portions 13 and 15 whereby the screws 37 and 39 will engage the tibia 11 medially in the sidewalls thereof.
In the compression plate P' shown in FIG. 4, the bores 45 and 47 in the opposite sides 49 and 51 are in alignment whereby a transverse pin 53 may be inserted through such aligned bores and tightened into position to provide enhanced structural integrity.
In operation, the fractured tibia 11 may be X-rayed to determine on which corner 25, 27 or 29 of the tibia 11 the plate P should be positioned. This decision will depend on the location of the fracture 10 and the cleanliness thereof. That is, if one corner of the tibia is relatively dirty, the plate P should be located on a different corner to reduce the likelihood of infection. In instances where the fracture is fragmented or comminuted on one corner 25, 27 or 29, it would be desirable to locate the plate P over such corner to provide additional support. Accordingly, after X-ray and determination of the location where the plate is to be disposed, the incision is made and the tibia 11 stripped along a selected length for receipt of such plate. The plate P is placed over the fracture 10 and the fracture 10 compressed, as by the apparatus and method disclosed in my copending application filed June 17, 1968 and bearing U.S. Ser. No. 737,688. The screws 37 and 39 are then inserted to maintain the fracture 10 in compression, and the incision closed.
Installation of the compression plate P' is substantially the same as that described above except that the rod 51 is inserted through the aligned bores 45 and 47.
From the foregoing it will be apparent that the compression plate of present invention may be installed on the corticle surface without the necessity of making a saw cut in the cortex of the bone thus reducing the likelihood of infection and danger of splitting of the bone. Further, since the compression plate P is flexible it may easily be flexed to adjust the angular setting for accommodating different corners of the tibia and may likewise be adjusted for installation on the tibia of patients having differently angled tibias. Also, because of the angular configuration of the plate and resultant structural integrity, it can be shorter than the usual flat plate thus reducing the amount of the stripping required and lessening the likelihood of rejection. Also, because of the shorter incision and less stripping the operation time is less thus reducing the operative risk. Further, support is provided on two sides of the bone thus preventing shortening of the bone as a result of comminution in the area of the fracture.