US 2243718 A
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May 27, 1941. F.- E. DE G. MOREIRA 3 SURGICAL DRILL Filed Nov.
Patented May 27, 1941 UNHTED STATES PAT OFFICE SUIRGllUAL DRILL Francisco Elias de Godoy Moreira, Sao Paulo, [Brazil 6 Claims.
My invention relates to a surgical drill apparatus and more particularly to an attachment for an electric motor designed to drill a channel through the parts of a fractured bone in order to permit or facilitate the entry of a bone-screw therethrough.
In my application filed November 2, 1938, I described a bone-screw having at least two different diameters along its length and I illustrated the entry of said bone-screw into a channel previously drilled for that purpose.
A bone-screw is of particular advantage in the fracture of the femur or hip bone and it is usually applied at the base of the trochanter, through the center of the neck of the femur and anchored in the ball or head thereof.
It is essential that a channel to receive the bone-screw be first drilled through the bone and to insure against any deviation of the drill from its prescribed course, a guide or Kirschner wire is caused to enter the said parts in a manner well known to the art. The Kirschner wire having been properly inserted, a drill having a longitudinal bore is applied thereover and the channel is duly drilled.
Bearing the foregoing in mind, it is an, object of my invention to provide a drill which may be actuated by an electric motor and which is designed to drill the channel to conform to the shape of the bone-screw to be subsequently lodged therein.
Another object of my invention is to provide means in combination with such a drill whereby the degree of penetration of said drill into the bone may b easily ascertained.
Another object of my invention is to provide means in combination with such a drill to insure against the rotation of the Kirschner wire while the drill is rotating around it.
Another object of my invention is to provide an electric motor attachment for such a drill which shall simplify and facilitate the procedure above outlined by affording the operator improved visual access to the site of entry of the drill.
Other objects of my invention will be obvious from the following description it being under stood that the above general statements of the objects of my invention are intended to explain and not to limit it in any manner.
Fig. 1 is a top view, partly in section of my apparatus, the bone operated upon being shown in dotted lines.
Fig. 2 is a section on the line 22 of Fig. 1. Fig. 3 is a longitudinal section through part of the drill.
Fig. 4 is a section on the line 44 of Fig. 1. Fig. 5 is a section on the line 55 ofFig. 1. Fig. 6 is a section on the line fi-6 of Fig. 1. Referring to the drawing, M represents an electric motor which is preferably portable, being directly connected to the drill in the preferred embodiment.
The action of the motor shaft S is translated 7 into perpendicular motion by the endless screw and worm gear mechanism W, which mechanism is located in the housing If] and the worm gear thereof is integral with the jack-shaft 11.
indicia on the periphery of the drill D is operative to adjust the effective length of the drill.
The opposite side of casing is is formed with a wall !8 which wall has the lugs 19 and 20 set thereon in any suitablemanner as by screwing or riveting. The casing l0 may generally be designated as an elbow shaped housing of which one arm is connected to and is in alignment with the motor shaft while the other arm is perpendicular thereto and supports the drill.
Detachably secured to the wall 58, is the tubular member 2 I, which by means of its wall 22 and slots 23 and 24, maybe secured to the wall l8 by receiving the lugs l9 and 28 in the apexes of slots 23 and 24. The tubular member 2! is hollow and is provided with an end nut 25, having a shank 26, which end nut and shank operate as a wall and peg for the coil spring 21 in the tubular member 25. The spring 21 is retained in the tubular member by the post 28, which is provided with a slotted head, and a pin 29 which is adapted for movement in the slot 30 formed in the tubular member 2!. Pressure on the post 28 is therefor effective to depress the spring 21, the pin 29 riding in the slot 33.
It will be noted that the drill D, the jack-shaft H, the worm gear of mechanism W, the wall I8, and the wall 22 are all formed with a central internal bore to receive the Kirschner or guide wire K.
My invention is practiced in the following manner: I
After anesthesia and the incision having been made in the body of the patient being operated upon the femur is exposed, the fracture having previously been reduced by suitable means well known in the art.
After determining the site that the bone-screw will occupy depending on the location of fracture and other facts which are known to the surgeon, the guide wire K is introduced thereat and inserted into the shaft, through the center of the neck and into the ball or head of the femur. This practice is standard and requires no explanation of its procedure. When the guide wire K has been thus inserted it should be tapped with a mallet so as to firmly lodge it in the spongy bone of the head of the femur.
The nut I having been adjusted, the drill D is applied over the guide wire K and the channel through the bone is drilled. The further end of the channel will be of less diameter than the nearer end due to the drill-bits l4 and I5. This result is required so that the channel is shaped according to the particular parts of the bonescrew which will thereafter occupy it, the section drilled by the drill-bit l4, being equivalent to the diameter of the shank of the drive-screw thread portion of the bone-screw.
My apparatus may be used without the tubular member 2|. In this manner, the guide wire K extends through the drill D, the jack-shaft II, the casing ID, the worm gear of mechanism W, and the wall l8, protruding through the outer end of said wall which is provided with an axial bore. As the drill progresses through the bone, more of the guide wire K protrudes through the wall l8 and the extent of penetration may be ascertained. In addition, it is most essential that action of the drill is not transmitted to the guide wire since said guide wire should not rotate during this process. It is obvious that should this occur the guide wire might traverse entirely the head of the femur, and, puncturing its wall, would probably prove fatal to the patient. Therefore, through my apparatus, the guide wire is exposed so that any rotation can be immediately detected, as well as the degree of penetration ascertained.
The tubular member 2| is of assistance in effecting the above results in an improved manher by preventing such rotation. When it is secured to the wall I8 as hereinabove described, the guide wire K can be firmly retained in the slotted head of post 28 which cannot rotate due to the pin 29 in slot 30. Thus the guide wire K is positively retained against rotation, it is visible through the slot 30 so that the degree of penetration of the drill D is ascertained and furthermore, the guide wire K is prevented from dislodging itself from the head of the femur by the pressure of the post 28. As the drill advances in the bone, the coil spring 21 recedes and permits the free longitudinal movement of the guide wire K against the action of said coil spring.
I have shown a preferred embodiment of my invention but it is obvious that numerous changes and omissions may be made without departing from its spirit.
1. The combination with a guide wire of a drill attachment for a motor comprising an elbow shaped housing having power transmission mechanism in one arm thereof, driven mechanism located within the other arm thereof, a drill operatively connected to said driven mechanism, said drill, driven mechanism and other arm being formed with an axial bore for the reception of said guide Wire therethrough and gripping means secured to said housing in alignment with said axial bore for engaging and preventing the rotation of said guide wire while said drill is being driven.
2. The combination with a guide wire of a drill attachment for a motor comprising an elbow shaped housing, having power transmission mechanism in one arm thereof, driven mecha nism within the other arm thereof, a drill operatively connected to said driven mechanism, a tubular member secured to said other arm of said housing, spring means within said tubular member, said drill, driven mechanism, other arm and tubular member being formed with an axial bor for the reception of said guide wire therethrough, said guide wire bearing against said spring means against the action of said spring, means, whereby said guide wire is inwardly urged by said spring means.
3. An attachment according to claim 2, wherein said tubular member includes means to prevent rotation of said guid wire.
4. The combination with a guide wire of a drill attachment for a motor comprising an elbow shaped housing having power transmission mechanism in one arm thereof, driven mechanism located within the other arm thereof, a drill operatively connected to said driven mechanism, a tubular member secured to said other arm of said housing in alignment with said drill, said drill, driven mechanism, other arm and tubular member being formed with an axial bore for the reception of said guide wire therethrough, spring means located within said tubular member whereby said guide wire may bear against said spring means, and means within said tubular member to prevent rotation of said guide wire, said tubular member having a slot formed in the wall thereof whereby the degree of penetration of said guide wire within said tubular member may be ascertained.
5. The combination with a guide wire of a drill attachment for a motor comprising an elbow shaped housing having power transmission mechanism in one arm thereof, driven mechanism located within the other arm thereof, a drill operatively connected to said driven mechanism, said drill, driven mechanism, and other arm being formed with an axial bore for the reception of said guide wire therethrough and combined means secured to said housing for preventing rotation of said guide wire and for urging said guide wire inwardly to prevent its outward displacement.
6. A device according to claim 5 wherein said means comprises a head for engaging the free end of said guide wire, a support for said head to prevent the rotation thereof and a spring actuating said head inwardly.
I'FRANCISCO ELIAS DE GODOY MOREIRAA.