US3528085A - Bone compression plate - Google Patents

Description

- p 1970 w. REYNOLDS, JR 3,528,035

BONE COMPRESSION PLATE Filed March 22, 1968 1 N VEN TOR.

/Z'" Wal/(er Re yno/ds Jr BY 7 M, M I'M Af'fO/ZNEYS United States Patent 3,528,085 BONE COMPRESSION PLATE Walker Reynolds, Jr., 327 E. 10th St., Anniston, Ala. 36201 Filed Mar. 22, 1968, Ser. No. 715,443 Int. Cl. A61f /04 U.S. Cl. 128-92 4 Claims ABSTRACT OF THE DISCLOSURE A bone compression plate of a length to span adjacent bone sections and having openings therethrough disposed to overlie each bone section. At least one of the openings is elongated and receives a screw having a head adjacent one end with an under surface that tapers inwardly toward the other end of the screw. An inclined cam surface on the plate adjacent the elongated opening engages the inwardly tapered under surface of the screw to move the screw and the bone section connected thereto relative to the elongated opening.

BACKGROUND OF THE INVENTION This invention relates to a bone compression plate and more particularly to such a plate which not only secures bone fragments or sections to each other but also imparts relative movement between the bone sections whereby they are moved to proper positions relative to each other.

Heretofore in the art to which my invention relates, various devices have been proposed for moving adjacent fragments of a broken bone toward each other whereby the fragments may then be secured in a properly set position. Such devices not only require the drilling of additional openings in the bone but also require the use of additional tools which move one bone fragment relative to another bone fragment prior to securing the same in place. The use of such instruments for internal fixation thus requires a larger incision and requires considerable time for attachment and removal of the instruments which impart relative movement between the bone fragments.

BRIEF SUMMARY OF INVENTION My improved bone compression plate embodies an elongated plate of a length to span adjacent bone sections or fragments. Elongated openings are provided through the plate and extend longitudinally thereof in position to overlie each bone section. The screws extend through the elongated openings and penetrate the adjacent bone sections. The screws are provided with heads which have inwardly tapered under surfaces. Inclined cam surfaces are provided on the plate adjacent the elongated openings in position to engage the inwardly tapered under surfaces of the screws whereby upon tightening the screws, the screws and the bone sections connected thereto move relative to each other.

Apparatus embodying features of my invention is illustrated in the accompanying drawing, forming a part of this application, in which:

FIG. 1 is a perspective view showing the compression plate with the screws being omitted for the sake of clarity;

FIG. 2 is a bottom plan view of the compression plate;

FIG. 3 is an enlarged, sectional view showing the compression plate in use; and

FIG. 4 is a fragmental, sectional view showing the inclined cam surface on the compression plate as being disposed to move the screw members and the bone sections connected thereto away from each other.

Referring now to the drawing for a better understanding of my invention, I show an elongated compression 3,528,085 Patented Sept. 8., 1970 plate 10 which is provided with a relatively flat under surface, as shown in FIG. 2. As shown in FIG. 3, the compression plate 10 is of a length to span adjacent bonesections 11 and 12. Elongated openings 13 and 14 are provided in the plate 10 and extend longitudinally thereof, as shown in FIG. 1. Extending through the elongated opening 13 in position to penetrate the bone section 11 is a screw 16. In like manner, a screw 17 extends through elongated opening 14 in position to penetrate bone section112. That is, the screws 16 and 17 are screwed into the bone fragments 11 and 12 after openings are drilled in the bone fragments in a manner well understood in the art to which my invention relates. The screws 16 and 17 may be of the self-tapping type. The head of each screw 16 and 17 is provided with an inwardly tapered under surface 18 which tapers toward the other end thereof, as shown in FIG. 3.

Inclined raised cam surfaces 19 and 21 are provided on the plate 10 adjacent the elongated openings 13 and 14 and extend outwardly of the plate in a direction of the longitudinal axis of the plate in position to engage the inwardly tapered under surfaces 18 of the heads of screws 16 and 17 to move the screws relative to their elongated openings 13 and 14. In FIGS. 1 and 3, I show the inclined cam surfaces 19 and 21 as facing each other and extending downwardly and inwardly toward each other whereby upon tightening the screws 16 and 17, the screws move toward each other. Accordingly, as the screws 16 and 17 are tightened, the bone sections or fragments 11 and 12 are moved from the solid line position to the dotted line position shown in FIG. 3 whereby the adjacent ends of the bone sections 11 and 12 are in firm engagement with each other. It will thus be seen that upon tightening the screws 16 and 17, the bone sections 11 and 12 are not only drawn into proper alignment and contact with each other but the screws also retain the plate '10 and the bone sections 11 and 12 in this fixed position, as indicated in dotted lines in FIG. 3.

Additional openings 22 are provided through the plate 10 outwardly of the elongated openings 13 and 14 for receiving screws which also penetrate the bone sections 11 and 12 to further secure the bone sections to the elongated plate 10.

In FIG. 4 of the drawing, I show a modified form of my invention in which an elongated compression plate 10a is provided. Elongated openings are provided in the plate member 10a identical to the elongated openings 13 and 14. Also, additional openings 22 are provided in the plate member 10a which receive screws that further secure the plate 10 to the bone sections, as described hereinabove. However, FIG. 4 of the drawing only shows that portion of the plate 10a which is connected to the bone fragment or section 12, the other part of the plate 1011 being substantially identical to the portion shown in FIG. 4. Inclined cam surfaces 21a are provided on the plate 10a in position to slope downwardly and outwardly away from each other whereby upon engagement with the under surface 18 of a screw 17, the screw 17 is moved from the solid line position to the dotted line position shown in FIG. 4. Accordingly, the downwardly and outwardly inclined cam surfaces 21a are spaced longitudinally from each other at opposite sides of the fracture whereby upon tightening the screws, the screws and the bone sections connected thereto move outwardly away from each other to selected positions. The apparatus shown in FIG. 4 is substantially identical to the apparatus shown in FIGS. 1 through 3 with the exception that the cam surfaces 21a are inclined downwardly and outwardly away from each other instead of being inclined downwardly and inwardly toward each other, whereby the screws shown in the embodiment of FIG. 4 move away from each other upon tightening the screws.

From the foregoing description, the operation of my improved compression plate will be readily understood. Suitable openings are drilled in the bone sections 11 and 12 for receiving the screws 16 and 17 while the bone sections 11 and 1 2. are spaced from each other, as shown in the solid line position of FIG. 3. Upon tightening the screws 16 and 17, the under surfaces 18 of the screws engage the downwardly and inwardly inclined surfaces 19 and 21 to cause the screws to move inwardly toward each other to the dotted line position shown in FIG. 3. Since the screws 16 and 17 are secured to the bone sections 11 and 12, the bone sections move from the solid line position to the dotted line position of FIG. 3.

Where it is desired to move the bone sections away from each other, the embodiment shown in FIG. 4 is employed whereby upon tightening the screws, the under surfaces 18 thereof engage the cam surfaces 21a to move downwardly and outwardly to the dotted line position shown in FIG. 4.

From the foregoing, it will be seen that I have devised an improved compression plate for moving adjacent bone sections or fragments to selected positions relative to each other and at the same time provide means for securing the compression plate firmly to the bone sections in the final set position. By providing inclined surfaces which engage the under surfaces of the inwardly tapered heads of the screws, the screws and the bone sections connected thereto are moved inwardly immediately upon tightening the screws and without the necessity of employing additional tools, instruments or the like. Furthermore, by providing a composite unit wherein the means for moving the bone sections relative to each other and the means for securing the plate to the bone sections are carried by a single unit, the size of the incision is reduced and the time required to properly position and set the bone sections is greatly reduced.

While I have shown my invention in but two forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What I claim is:

1. In a bone compression plate for moving adjacent bone sections relative to each other;

(a) an elongated plate of a length to span adjacent bone sections,

(b) there being at least one elongated opening through said plate extending longitudinally thereof and disposed to overlie one bone section and there being another opening through said plate disposed to overlie the other bone section,

(c) a first screw of a length to extend through said elongated opening and penetrate said one bone section,

((1) a head adjacent one end of said first screw with the under surface of Said screw head tapering inwardly toward the other end of said screw,

(6) a second screw of a length to extend through said another opening and penetrate said other bone section, and

(f) an inclined raised cam surface on said plate adjacent said elongated opening extending outwardly of said plate in a direction of the longitudinal axis of said plate and engaging said inwardly tapered under surface of the head of said first screw to move said first screw relative to said elongated opening upon tightening said screw so that said one bone section is moved relative to said plate and said other bone section. a

2. A bone compression plate as defined in claim 1 in which said another opening is also an elongated opening and an inclined raised cam surface is provided on said plate adjacent said another opening extending outwardly of saidplate in a direction of the longitudinal axis of said plate and engaging an inwardly tapered under surface of a head of a screw which is adapted to penetrate said other bone section and move the screw longitudinally of said another opening upon tightening the screw so that said other bone section is moved relative to said plate and said one bone section.

3. A bone compression plate as defined in claim 2 in which said inclined cam surfaces adjacent said elongated openings slope downwardly and inwardly toward each other so that upon tightening said screws the screws and the bone sections connected thereto move toward each other.

4. A bone compression plate as defined in claim 2 in which the cam surfaces adjacent said elongated openings slope downwardly and outwardly away from each other so that upon tightening said screws the screws and the bone sections connected thereto move away from each other.

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