Bender For Contouring Surgical Implants

Abstract

A pair of benders for contouring surgical implants, particularly a hip fixation plate having a flat bowl-shaped head portion with four transverse bores and an elongated handle portion. One of the benders grips the bowl portion of the plate and consists of an upper and lower jaw pivotally interconnected at their one end and means, such as a swing bolt and associated wing nut, for releasably interconnecting their other ends. The inner surface of the upper jaw has four nipples which register with and slidably engage the transverse bores of the bowl portion when the jaws are clamped over the same. The inner surface of the lower jaw has a dome-shaped protrusion against which the inside of the bowl portion seats. A handle is attached to the bottom of the lower jaw for gripping purposes. The second of the benders grips the handle portion of the plate and consists of a housing having a longitudinal channel extending through it, a jaw member disposed within said channel and adapted for vertical movement therein and means for raising and lowering the jaw member. The top side of the channel is contoured to conform to the handle portion and the top side of the jaw member is similarly contoured and spaced from the top side of the channel. The handle portion is gripped by sliding it into that space and raising the jaw member.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to bending tools for contouring metallic surgical implants, especially bone plates.

2. Description of the Prior Art

Surgical implants such as bone plates are made in standard sizes and shapes. In many instances a surgeon must contour such implants to fit the anatomy of the patient in which they are to be implanted. Such contouring is achieved by bending the implant, usually during surgery. Under such circumstances it is obviously desirable that the bending be done easily and quickly. Also the surface of the implant should not be marred by the bending because surface defects may become focal points for stress failure of the implant.

All implant bending is done by gripping the implant at two distant points and bending the implant at a point intermediate said distant points. The most prevalently used bender now in use -- sold as a Jewett bender -- comprises a pair of tools similar to monkey wrenches but without adjustable jaws.

SUMMARY OF THE INVENTION

The present invention concerns a pair of bending tools, one of which is specifically adapted for use in bending a particular hip fixation plate and the other of which is adaptable for use on bending a wide variety of metallic surgical implants including said hip fixation plate.

The particular hip fixation plate for which the first of said benders is especially adapted has an elongated handle portion adapted to conform to the femur shaft and a flat bowl-shaped head portion adapted to conform to the lower portion of the greater trochanter of a femur. The head portion has opposed sides and at least one bore transversing it for receiving a hip screw therethrough.

Said first bender is designed to grip the head portion of the plate and basically comprises an upper jaw and a lower jaw pivotally interconnected at one of their ends and means for releasably interconnecting their other ends. The jaws are adapted to be clamped about the head portion with the inner surfaces thereof facing the opposed sides of the head portion. The inner surface of one of the jaws has a nipple (or nipples if the head portion has a plurality of transverse bores) extending inwardly from it which registers with the transverse bore of the head portion and is adapted to be slidably engaged therein when the jaws are clamped about the head portion. The inner surface of the other jaw is adapted to close against the side of the head portion facing it. An elongated handle is rigidly attached to the bottom of the lower jaw for gripping purposes.

The second bender may be used to grip any generally flat implant having opposed sides. It comprises a housing having a channel extending longitudinally through it, one side of which is contoured to conform to the contour of one of the opposed sides of the implant, a jaw member disposed within the channel and adapted for vertical movement therein, one side of which is spaced from said one side of the channel and is contoured to conform to the other of the opposed sides of the implant, means interconnecting the side of the jaw member opposite said one side to the housing and means for vertically raising and lowering the jaw member within the channel. An elongated handle extends from the housing for gripping purposes. The second bender is used by sliding the implant into the channel in the space between its said one side and the jaw member and the jaw member is raised until the implant is clamped between it and said one side of the channel.

In the embodiment of the second bender which is adapted to grip the above described hip fixation plates the channel and jaw member are contoured to conform to the handle portion of the plate.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate an embodiment of the benders of the invention being used to bend a hip fixation plate. In these drawings:

FIG. 1 is a diametric view of said benders;

FIG. 2 is an enlarged sectional view taken along line 2--2 of FIG. 1;

FIG. 3 is a sectional view taken along line 3--3 of FIG. 2;

FIG. 4 is a sectional view taken along line 4--4 of FIG. 2;

FIG. 5 is a sectional view taken along line 5--5 of FIG. 4; and

FIG. 6 is a sectional view taken along line 6--6 of FIG. 4.

DETAILED DESCRIPTION OF THE EMBODIMENT SHOWN IN THE DRAWINGS

The benders shown in the drawings are tailored for use in bending a specific hip fixation plate, generally designated 1 in FIGS. 1 and 2. Plate 1 is spoon-shaped and comprises an elongated curved handle portion 2 and a bowl portion 3. Handle portion 2 is intended to be attached to and conform to the upper portion of the shaft of a femur whereas bowl portion 3 is intended to be attached to and conform to the lower portion of the greater trochanter. In order for such conformance to be achieved it is often necessary to bend plate 1 at the junction 4 (FIG. 2) between handle portion 2 and bowl portion 3.

As seen in FIGS. 2, 5 and 6 bowl portion 3 has four bores 5 transversing it and spaced in a square configuration. Bores 5 are intended to receive hip screws which attach the plate to the femur.

A pair of benders, generally designated 6 and 7 respectively, are used to bend plate 1 at junction 4. Bender 6 is adapted to grip bowl portion 3 and bender 7 is adapted to grip handle portion 2.

Bending tool 6 operates on a principal similar to that of a vise. It includes an upper jaw 8 and a lower jaw 9 pivotally interconnected at their one ends by a pair of bars 10, 14 and a pair of pins 15, 16. For the purpose of receiving said bars and pins upper jaw 8 has a pair of vertical ways 17, 18 and a horizontal bore 19 and lower jaw 9 similarly has a pair of vertical ways 20, 24 and a horizontal bore 25. Their other ends are releasably interconnected by a swing bolt 26, one end of which is journaled on a pin 27 within a vertical way 28 in said other end of upper jaw 8. Lower jaw 9 has a vertical way 29 in its said other end for receiving the other end of swing bolt 26. Jaw 8 has a horizontal bore 30 for receiving pin 27. Said other end of swing bolt 28 is threaded at 34 and fitted with a wing nut 35 and a retaining collar 36 which are adapted to slide under the bottom side of lower jaw 9 when it and jaw 8 are closed (FIG. 4). The jaws 8, 9 are secured tightly together by merely tightening wing nut 35.

The inner surface of lower jaw 9 has a dome-shaped protrusion 37 (FIG. 4) of the same curvature as the bowl portion 3 of plate 1. Correspondingly the inner surface of upper jaw 8 has four spaced nipples 38 formed on it which register with bores 5 of bowl portion 4. As shown in FIGS. 2 and 5 the bowl portion 3 is placed between jaws 8, 9 with the inner surface thereof against dome-shaped protrusion 37. When the jaws are closed nipples 38 are slidably engaged within bores 5. In this manner said bowl portion is held firmly between the jaws.

Upper jaw 8 has an anvil plate 29 (FIG. 2) mounted on its side adjacent the location of junction 4 between the handle and bowl portions of plate 1. Screws 40 secure plate 39 to said side. The lower edge 44 of plate 39 has the same curvature (see FIG. 1) as handle portion 2 and is adapted to engage handle portion 2 at junction 4. A second anvil plate 41 is mounted on lower jaw 9 at the side opposite anvil plate 29 for bending of plate 1 when it is positioned in tool 6 with handle portion 2 extending in the direction opposite that shown in FIG. 1. The upper edge 42 of anvil plate 41 is convexly curved so as to engage the concave surface of handle portion 2 at the point of its juncture with bowl portion 3.

Lower jaw 9 has a handle 45 attached to its bottom surface. It also has a threaded vertical bore 46, and handle 45 has a threaded end 47 adapted to be screw threadedly received in bore 46 for this purpose.

Bending tool 7 operates similarly to a positive, lock action compression wrench. It comprises a generally rectangular housing 48 having a longitudinal channel 49 extending through its entire length. The surface 50 (FIG. 3) defining the upper side of channel 49 has the same curvature as handle portion 2. Otherwise channel 49 is rectangular. Disposed within channel 49 is a jaw member 54 adapted for vertical movement within channel 49. The top side 55 of jaw member 54 also has the same curvature as handle portion 2 (FIG. 3) and is spaced from said surface 50 defining the upper side of channel 49. Otherwise, it too is rectangular. A pair of screws 56 interconnect housing 48 and the bottom of jaw member 54. As shown in FIGS. 2 and 3 screws 56 are received through bores 57 and counterbores 58 which combined extend from the bottom of housing 48 through to channel 49. Screws 56 have decreased diameter, threaded end portions 59 which are screw threadedly received within bores 60 in the bottom of jaw member 54. A compression spring 64 is seated within each counterbore 58, one end of which bears on the shoulder of the counterbore and the other end of which bears on the bottom of the head of screw 56.

Bender 7 is equipped with a handle 65 having a threaded end 66 (FIG. 2). Threaded end 66 is screw threadedly received within a threaded bore 67 located in the center of the bottom of housing 48 and opening through said bottom to the channel 49. End 66 has a flat head 68 which is adapted to bear against the bottom of jaw member 54. Jaw member 54 is raised and lowered within channel 49 by turning handle 65. By tightening handle 65 head 68 is moved upwardly against the bottom of jaw member 54, further tightening forces member 55 upwardly within channel 49. When handle 65 is backed off the weight of jaw member 54 and compression springs 64 force member 54 downwardly in channel 49.

Plate 1 is bent by locking bowl portion 3 within bender 6 and inserting handle portion 2 longitudinally through the space in channel 49 between the curved top 55 of jaw member 54 and the curved surface 50 defining the upper side of channel 49 and tightening handle 65. Such tightening forces jaw member 54 up against the inner surface of handle portion 2 thereby locking it within channel 49. Handles 45 and 65 are then gripped and pulled in opposite directions (FIG. 2) thereby forcing the juncture 4 between handle portion 2 and bowl portion 3 against the lower edge 44 of anvil plate 39 and bending said juncture thereagainst.

As will be evident to those of ordinary skill bender 7 may be adapted to grip other surgical implants by merely altering the contour of the top of jaw member 54 and surface 50. The jaw member and upper portion of the housing may be made exchangeable for this purpose.

Other modifications of the above described invention and embodiment thereof which are obvious to those of ordinary mechanical skill are intended to be within the scope and spirit of the following claims.

Claims

1. A bender for a bending assembly, for gripping a surgical implant having opposed sides comprising:

a. a housing;

b. a channel extending through said housing, the surface defining one side of said channel being contoured to conform to the contour of one of said opposed sides of said surgical implant;

c. a jaw member disposed within said channel and adapted for vertical movement therein, one side of said jaw member being spaced from said surface defining one side of said channel and being contoured to conform to the contour of the other of said opposed sides of the surgical implant;

d. means interconnecting the side of said jaw member opposite said one side thereof and the housing; and

e. means for vertically raising and lowering said jaw member within said channel whereby said implant may be gripped between said surface defining one side of said channel and said one side of said jaw member and released

2. The bender according to claim 1 wherein said means for interconnecting said jaw member and said housing includes:

f. at least one bore/counterbore combination extending through said housing to said channel;

g. a screw adapted to be received within said bore/counterbore combination and screw threadedly engage said side of said jaw member opposite said one side thereof; and

h. a compression spring disposed within said counterbore between the shoulder defining the transition from said bore to said counterbore and

3. The bender according to claim 1 wherein said means for vertically raising and lowering said jaw member includes:

f. a threaded bore extending through said housing to said channel; and

g. a handle having a threaded end which is adapted to be screw threadedly received in said threaded bore and bear against the side of said jaw

4. The bender according to claim 1 wherein said means for interconnecting said jaw member and said housing includes:

f. at least one bore/counterbore combination extending through said housing to said channel;

g. a screw adapted to be received within said bore/counterbore combination and screw threadedly engage said side of said jaw member opposite said one side thereof; and

h. a compression spring disposed within said counterbore between the shoulder defining the transition from said bore to said counterbore and the head of said screw; and said means for vertically raising and lowering said jaw member includes:

i. a threaded bore extending through said housing to said channel; and

j. a handle having a threaded end which is adapted to be screw threadedly received in said threaded bore and bear against the side of said jaw

5. A bender for use in a bending assembly in bending a hip fixation plate comprising a flat bowl-shaped head portion having at least one transverse bore and an integral elongated handle portion comprising:

a. an upper jaw having a nipple on its inner surface which registers with and is adapted to be slidably received within said transverse bore;

b. a lower jaw, the inner surface of which has a protrusion which is adapted to seat snugly against one side of said head portion;

c. means for pivotally interconnecting said upper and lower jaws at one of their ends; and

6. The bender according to claim 5 wherein said means for releasably interconnecting the other of their ends includes:

e. a swing bolt one end of which is pivotally attached to the upper jaw and the other end of which is threaded;

f. a way in said lower jaw adapted to receive said other end of said swing bolt; and

g. a nut adapted to be screw threadedly received on said other end of said

7. The bender according to claim 5 wherein said means for pivotally interconnecting said upper and lower jaws includes:

e. a pair of spaced vertical ways in each of said one ends of said upper and lower jaws;

f. a pair of vertical bars received in said ways and interconnecting said upper and lower jaws; and

g. a pair of pins extending transversely of each of said ways on which said

8. The bender according to claim 5 including:

9. The bender according to claim 5 including:

e. an anvil plate affixed to at least one of said jaws and positioned and adapted to engage the junction between said handle portion and said head

10. A bender for a bending assembly, for gripping and bending a hip fixation plate comprising a flat bowl-shaped head portion having four transverse bores and an elongated handle portion comprising:

a. an upper jaw having four nipples on its inner surface which register with and are adapted to be slidably received within said transverse bores when said plate is gripped;

b. a lower jaw, the inner surface of which has a dome-shaped protrusion which is adapted to seat snugly against one side of said head portion when said plate is gripped;

c. a pair of vertical ways in one end of each of said lower and upper jaws;

d. a pair of pins transversing said ways at the top and bottom thereof;

e. a pair of bars adapted to be received within said ways and journaled about said pins whereby said upper and lower jaws are pivotally interconnected at one of their ends;

f. a swing bolt, one end of which is pivotally attached to the other end of the upper jaw and the other end of which is threaded;

g. a way in said lower jaw adapted to receive said other end of said swing bolt;

h. a nut adapted to be screw threadedly received on said other end of said swing bolt and seat against the bottom of the lower jaw when said plate is gripped;

i. a handle affixed to the bottom of the lower jaw; and

j. an anvil plate affixed to at least one of said jaws and positioned and adapted to engage the junction between said handle portion and said head

11. A bending assembly for use in bending a hip fixation plate comprising a flat bowl-shaped head portion having at least one transverse bore and an integral elongated handle portion having opposed sides, comprising the combination of:

a. a first bender including;

1. a housing,

2. a channel extending through said housing, the surface defining one side of said channel being contoured to conform to the contour of one of said opposed sides of said handle portion,

3. a jaw member disposed within said channel and adapted for vertical movement therein, one side of said jaw member being spaced from said surface defining one side of said channel and being contoured to conform to the contour of the other of said opposed sides of the handle portion,

4. means interconnecting the side of said jaw member opposite said one side thereof and the housing, and

5. means for vertically raising and lowering said jaw member within said channel whereby said handle portion may be gripped between said surface defining one side of said channel and said one side of said jaw member and released thereby, respectively; and

b. a second bender including;

1. an upper jaw having a nipple on its inner surface which registers with and is adapted to be slidably received within said transverse bore,

2. a lower jaw, the inner surface of which has a protrusion which is adapted to seat snugly against one side of said head portion,

3. means for pivotally interconnecting said upper and lower jaws at one of their ends, and

4. means for releasably interconnecting the other of their ends.