US3433220A - Intramedullary rod and cross-nail assembly for treating femur fractures - Google Patents

Description

March 18. 1969 INTRAMEDULLAR Filed Dec. 30, 1966 E. ZICKEL R. Y ROD AND CR -NAIL ASSEMBLY FOR TREATING FEMUR ACTURES Sheet 012 INVENTOR.

Babel- If. Zia/set w am y March 18, 1969 R. E. zlcKEL 3,433,220

INTRAMEDULLARY non AND CROSS-NAIL ASSEMBLY FOR TREATING FEMUR FRACTURES 2 Filed Dec. 50, 1966 Sheet of 2 ll 16v [7 United States Patent 3 433,220 INTRAMEDULLARY ROD AND CROSS-NAIL ASSEMBLY FOR TREATING FEMUR FRA'CTURES Robert E. Zickel, 115 E. 61st St., New York, N.Y. 10021 Filed Dec. 30, 1966, Ser. No. 606,145 US. Cl. 12892 Int. Cl. A61f 5/04 6 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a surgical appliance for use in treating fractures of the femur and, more particularly, to an intramedullary rod assembly especially adapted for immobilizing the femur parts involved in fractures occuring in the upper one third or subtrochanteric portion of the femur.

It is known that the bone parts or fragments involved in such fractures have commonly been difiicult to immobilize satisfactorily, in part because of the extent and direction of muscular stresses in that area. As a result, treatments by known expedients too often involve or produce the need for undesirable mechanical post operative procedures. For example, in cases employing well known types of fixation devices, as nail-plate combinations, which are usually elfective for immobilizing intertrochanteric fractures, such devices often have been inadequate for treatment of fractures occurring in said upper third or sub-trochanteric region of the femur shaft. The more serious failures include bending or breaking of the plates and/ or nails, loosening of the attaching screws and medial migration of the femoral shaft. Accordingly, to avoid or offset these difficulties, at least in part, it has often been necessary to unduly complicate the treatment by applying post operative traction to the injured parts during the healing period.

Known forms of standard or conventional intramedullary rods, which are occasionally employed successfully in treatments for reducing transverse fractures in lower parts of the femur shaft, fail to povide effective fixation when employed in connection with fractures occurring in upper or higher sub-trochanteric portions of the femur. Their use in this area fails to prevent various angulation and/or severe comminution or shredding of the bone structure at the fracture.

Accordingly, an object of the present invention has been to provide a surgical appliance including an intramedullary rod of simple and rugged construction which with accessory anchoring devices is capable of being employed with special advantage to produce effective fixation or immobilization of the bone fragments or parts and thereby to facilitate reduction of fractures in the upper third or subtrochanteric portion of the femur shaft.

A further object has been to provide a fixation appliance which in use substantially eliminates need for post operative traction and prevents varus angulation and bone comminution in the fracture area.

In general, an appliance embodying the present invention comprises, when assembled in operative condition,

3,433,220 Patented Mar. 18, 1969 primarily three cooperating elements conveniently identified as (1) an intramedullary rod, (2) an anchoring de vice, as a cross-nail including a peripherally grooved portion, and (3) means for maintaining the cross-nail in operative rod locking condition while the rod is operatively engaged in a fractured femur. Said rod is advantageously of generally square cross-sectional contour and includes a head and a stem connected thereto by a tapered neck, the longitudinal axis of said stem being disposed at an angle to the longitudinal axis of the head in a direction and to an extent whereby the rod being of proper dimensions may snugly occupy or fit into the femur marrow canal. When assembled with the rod in use, an intermediate portion of the cross-nail is engaged in an angulated hole or tunnel extending transversely through said head at an angle to the head axis and in a direction whereby end portions of the nail are engaged in the bone process of adjoining trochanteric portions of the femur. A set screw mounted longitudinally in a threaded axial bore in the head is positioned with its inner end extending into said angulated hole therein and engaging said grooved intermediate part of the nail, thereby locking the latter against endwise displacement and in operative rod retaining or anchoring condition in the femur cavity.

It is contemplated that other and further objects and advantages in use of my invention will appear from the following specification and the accompanying drawings wherein:

FIG. 1 is a front view partly in longitudinal vertical section of the intramedullary rod element of the subject fixation appliance as applied in FIG. 10;

FIG. 2 is an inner or left side view of the rod as seen in FIG. 1;

FIG. 3 is a transverse section across the head of said rod on the line 33 of FIG. 1;

FIG. 4 is a transverse section across the tapered neck portion of the rod on the line 4--4 of FIG. 1;

FIG. 5 is a transverse section across a lower end portion of the rod stem on the line 55 of FIG. 1;

FIG. 6 is a side elevation of a cross-nail designed for use with the rod of FIGS. 1 and 2;

FIG. 7 is a transverse section on the line 77 of FIG. 6;

FIG. 8 is a side elevation partly in longitudinal vertical section of a set screw designed for use in locking the cross-nail of FIG. 6 in operative relation to the rod of FIGS. 1 and 2;

FIG. 9 is an end elevation showing the outer end of the set screw of FIG. 8; and

FIG. 10 is a fragmentary front view partly in longitudinal section showing a typical assembly of elements of the subject fixation appliance as operatively applied to a right leg femur having a transverse fracture in the sub-trochanteric region thereof.

Referring to the drawings, a fixation appliance according to my invention comprises an intromedullary rod 10, FIGS. 1 and 2, a cross-nail 11, FIG. 6, and a set screw 12, FIG. 8, said parts being shown in operative assembled relation in FIG. 10. These parts are advantageously formed from a cobalt chromium molybdenum alloy produced by Austenal Company and sold under the trademark Vitallium.

As seen in FIGS. 1 and 2, rod 10 includes a head 13, a neck 14 and a stem 15, the central longitudinal axis of said rod being in effect bent or curved to conform to the normal axial contour of the femur marrow cavity. Also, said rod tapers from maximum thickness in its head portion to a reduced thickness at its stem end, thus to substantially conform in volume distribution to the greater dimensions of the medullary canal at its proximal or top end and to the reduced dimensions thereof at its distal or lower end. To achieve the desired conforming curvature of the rod shown in FIG. and as adapted for use in a right side femur, the stem portion of said rod is deflected downwardly, as seen in FIG. 1, to bring its longitudinal axis into a position at an angle of approximately 12 from the plane of the inner side surface A of head 13; and is also deflected in the direction as seen in FIG. 2, to bring its longitudinal axis into position at an angle approximately 9 from the plane of the rear surface B of head 13. These axial deflections produce a rod which in general eflectively conforms to the axial direction of the medullary canal thus not only facilitating insertion of the rod but also producing more effective immobilization.

Head 13 of rod 10 is advantageously provided with a transversely extending angulated hole or tunnel 23 opening through the opposite side faces A and D, FIG. 1, of said head, said hole being shaped and dimensioned to receive the cross-nail 11, FIG. 6, which may conveniently be of generally cylindrical cross-section interrupted at an inner end portion by longitudinal grooves 16 alternating with fins 17, FIG. 7, which are advantageously provided with chisel shaped ends. An outer end portion of said cross-nail 11 is provided with peripheral grooves 18 alternating with ribs 19. A transversely extending slot 24, FIGS. 1 and 2, which opens through the oposite faces A and D may be employed to facilitate handling in manufacture and/or in removal of the rod from engagement in the medullary canal. As seen in FIGS. 1 and 2, a notch N is provided in the surface A of head 13 to aid in locating hole 23 by X-ray when the rod is operatively engaged in the femur canal as hereinafter noted.

Head 13 is also formed with a threaded axial bore 20 extending inwardly and opening into hole 23. Thus, when cross-nail 11 is operatively engaged in hole 23, FIG. 10, one or another of said peripheral grooves 18 is conveniently located opposite said inner end opening of bore 20. Cross-nail 11 can be locked in said operative or rod anchoring position by advancing said set screw 12 to bring its inner end into pressing engagement with one of said grooves 18 between peripheral ribs 19 of the cross-nail. The outer end of set screw 12 conveniently may be formed with a recess or socket 21, FIG. 8, to receive and be actuated by a suitable wrench or the like.

As seen in FIG. 1, the inner or distal end of stem 15 is advantageously shaped to a chisel like edge 22 to facilitate advance of rod 10 into effective operative position in the femur canal.

Various procedures involving use of the above described appliance may be employed by surgeons skilled in the reduction and treatment of femur fractures. However, favorable results have been achieved in operative technique with the aid of certain accessory instruments such as standard Kuntschner reamers, McReynolds driverextractors, Allen screw drivers, an open end wrench, a tunnel finding gauge. Thus, with the patients leg properly positioned the fracture site is opened to expose the medullary canal of the distal (lower) fragment. The canal is reamed where necessary to accommodate the proper size (i.e. cross-sectional area) medullary rod 10 the stem of which is driven into the canal or the distal fragment to insure ease of fit and then is extracted.

The proximal (upper) fragment is reamed through the greater trochanter canal to provide a coaxial hole opening through the tip of said trochanter to readily receive the wide or thicker (head) end of rod 10. Said rod of proper size and design, i.e. for right or left femur, is attached to a McReynolds driver and introduced through said opening into said hole at the tip of the greater trochanter, said rod being oriented so that notch N is on the medial side. It is then driven distally to cross the fracture site F, FIG. 10, after reducing the fracture, the parts being held by appropriate means to effectively con- 4. nect the component fragments in their proper positions as the rod is driven.

Rotation of the rod during driving is conveniently controlled by use of the open end wrench to ensure that the axis of the tunnel or bore 23 matches the anteversion or retroversion of the femoral neck. The rod is impacted or driven until it is seated against the medial cortex, usually leaving about A. inch extending outwardly from the opening in the tip of the greater trochanter.

A tunnel finding gauge is attached to the exposed end of rod 16 in a known manner and a standard anteriorposterior roentgenogram is taken which, by reference to notch N, accurately reveals the angular position of the hole 23, the angle that the cross-nail will take and where, in the trochanter mass, the longitudinal center of the cross-nail will enter the femoral neck. It will be understood that the rod can be longitudinally adjusted to bring the hole 23 to the desired position by driving or extracting.

With rod 10 in proper position, the arm of the tunnel finding gauge will point to the spot on the lateral femoral cortex where a bone hole coaxial with the hole 23 in rod 10 is to be made by suitable instruments to receive the cross-nail 11 which is now inserted in said bone hole and driven through hole 23 in rod 10 into the femoral neck bone process approximately as seen in FIG. 10. Said cross-nail is now locked in operative anchoring condition by set screw 12 as previously noted, the Allen screw driver being conveniently employed for this purpose as well as for withdrawing set screw 12 as and when desired. Also, the McReynolds driver-extractor may be similarly employed to withdraw cross-nail 11 by engaging the threaded end of said instrument in the threaded socket 11' at the outer end of said cross-nail.

From the foregoing description it appears that my improved surgical appliance provides an effective anchor for the medullary rod in both the proximal and distal fragments of a fractured femur; that the appliance parts are so securely interconnected and anchored in the bone structure that greatly improved immobilization of the femur parts is obtained; that angulation and rotation of the fragments are controlled; and that earlier ambulation by the patient is permitted even where comminuted fragments are present in the fractured bone.

What is claimed is:

1. A surgical appliance for use in treating fractures of the femur comprising an intramedullary rod having a head and a stem arranged with their longitudinal axes intersecting at an angle and shaped and proportioned to be operatively located in and to substantially occupy a major portion of the length of the marrow canal of a femur, a cross-nail arranged and adapted in use to operatively engage said rod and portions of the femur wall to anchor the rod against longitudinal and rotative displacement in said marrow canal, said head having a cross-nail receiving hole extending transversely therethrough and with its longitudinal axis disposed at an angle to the longitudinal axis of said head, and said head having an axially extending threaded hole open at its outer end and opening at its inner end into an intermediate portion of said cross-nail hole, and a set screw mounted in said axially extending hole and longitudinally movable therein toward and from operative locking engagement with the cross-nail thereby to retain said rod in operative position in the femur.

2. An appliance according to claim 1 and wherein an end portion of the cross-nail is provided with a plurality of longitudinally spaced peripheral grooves arranged and adapted to be operatively engaged selectively by the inner end of the set screw whereby the cross-nail may be locked in the cross-nail receiving hole of said rod at different longitudinal positions of engagement therein.

3. An appliance according to claim 2 and wherein the opposite end portion provides a terminal chisel-drill.

4. An appliance according to claim 1 and wherein inner end portions of said stem are of approximately quadrangular cross-sectional contour tapered to provide a chisel-like terminal edge.

5. An appliance according to claim 1 and wherein said rod is of substantially square cross-sectional contour and includes a neck portion connecting said head and said stem and tapering toward said stem.

6. An appliance according to claim 5 and wherein the longitudinal axis of said stem extends at one angle from the plane of one longitudinal face of the head and at a different angle from the plane of an adjoining longitudinal face of the head which plane is substantially normal to the plane of said first mentioned face.

References Cited UNITED STATES PATENTS 2,48 6, 1 3 6 10/1949 Ericsson 12892 2,614,559 10/1952 Livingston 128-92 FOREIGN PATENTS 757,951 11/ 1953 Germany. 935,859 12/1955 Germany. 118,595 4/ 1947 Sweden. 235,382 4/ 1945 Switzerland.

RICHARD A. GAUDET, Primary Examiner.

RONALD L. FRINKS, Assistant Examiner.

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