US2998007A - Internal tubular splint for the fixation of bone fractures and method of applying it - Google Patents

Description

Aug. 29, 1961 K. HERZOG 2,998,007

INTERNAL TUBULAR SPLINT FOR THE FIXATION OF BONE FRACTURES AND METHOD OF APPLYING IT Filed Feb. 17, 1956 2 Sheets-Sheet 1 g- 1961 K. HERZOG INTERNAL TUBULAR SPLINT FOR THE FIXATION OF BONE FRACTURES AND METHOD OF APPLYING IT Filed Feb. 17, 1956 2 Sheets-Sheet 2 ETERNAL TUBULAR SPLINT FOR THE FIXA- TION OF BONE FRACTURES AND METHOD OF APPLYING IT Kurt Herzog, 52 Sollbruggenstrasse, Krefeld, Germany Filed Feb. 17, 1956, Ser. No. 566,305 Claims priority, application Germany Feb. 19, 1955 Claims. (Cl. 12892) The present invention relates to a tubular internal splint for the fixation of fractured bones.

It is already known that fractures may be treatedby the insertion of a splint into the osseous tube by knocking the splint through the upper fragment of bone (i.e. that nearer the body) beyond the point of fracture into the lower fragment of bone (i.e. that further from the body) and to leave the splint in position until the fracture has healed, and then to withdraw it.

Conventional splints of this kind are of an elastic material capable of both longitudinal and transverse deformation. To make full use of the elasticity of the material the cross section of the splint must be slightly compres sible during insertion to ensure that the splint firmly applies itself to the inner walls of the cavity by re-expanding after compression. This is necessary to guard against any subsequent relative displacement of the two fractured ends. However, the desired fixation of the fractured bone cannot be adequately secured by using a split, transversely elastic, splint because the osseous tube is not an ideal tube inasmuch as its tubular cavity is constricted in the middle part of the bone and widens out towards either end. A conventional splint of this kind will therefore only lie against the middle of the bone. If adequate contact is nevertheless to be enforced the dimensions of the splint in relation to the internal diameter of the osseous tube must be comparatively large. This entails the risk of splitting the bone and of the splint seizing on the internal osseous wall. Moreover, excessive pressure may give rise to undesirable infiammations and lead to the decomposition of the osseous structure itself.

When applying such means of fixation its has become the practice first to introduce a wire or pin into the osseous tube to align the two broken fragments and to provide a guide for the subsequent insertion of the tubular splint. The use of a split splint is risky because of the danger of the guide pin becoming jammed in the slot and preventing the splint from being knocked in any further.

Whereas in the case of one type of split splint the marrow that enters the splint remains in vascular connection with the main part of the marrow so that its continued nourishment is assured, another type of splint maintains this connection only at its open upper or lower extremity and this may not be sufiicient to support adequate nourishment and to keep the marrow alive inside the bone. If the tube is closed at its lower end considerable quantities of the soft marrow are displaced and the internal pressure within the osseous tube may dangerously rise, a most undesirable consequence.

It is the object of the tubular splint constructed according to the present invention to eliminate these decisive defects that are inherent in known types of internal splint. More particularly, the introduction of the splint into the osseous tube with the aid of a guide pin is to be rendered more safe, and capable of being performed without producing more than slight radial pressure upon the inner walls of the cavity. At the same time, the possibility must be created of preventing in the most effective possible way the occurrence of relative movement between the fractured ends of the bone once the fragments have been aligned, so as to promote the process of healing by allowing the fracture to be loaded axially by having Patented Aug. 29, 1961 to support the natural Weight at the earliest possible time. Moreover, the novel splint is to be adaptable more particularly to the internal fixation of tibial fractures in the case of which known splints fail or can be supplied only with greatest of difficulty.

According to the present invention the stated problem is solved by the provision of a tubular splint open at both ends and of a wall section suflicient to prevent transverse deformation under the conditions prevailing in an operation of this kind. The splint walls are provided with longitudinal slots through which contact can be established between the portions of marrow entering the splint and the portions remaining outside.

If intended for the fixation of a tibial fracture the upper end of the tube is curved so that it can be easily forced into the bone from the tuberosity below the knee, and equally easily removed. The lower end of the tube may be bevelled inside and out, the bevel surfaces being orientated in a direction which corresponds with that of the bend at the upper end of the splint. These bevelled edges allow the tubular splint to slide smoothly and without scraping along the inner osseous wall as well as along the guide pin by means of which the fracture has been previously brought into alignment.

The slits are arranged on the tube substantially along a line which begins on the inside of the upper bent end and extends symmetrically thereto in the downward direction. Additional slots on either side of this line may be disposed anywhere along the tube according to the nature of the fracture that is to be treated. The slots offer the possibility of allowing elastically sprung, straight bent, or helically wound, wires to project from the inside of the tube and to anchor themselves in the cancellus (spong-iosa) in a manner calculated to prevent relative displacement of the fractured parts. Insertion of the wires is performed by guiding for instance the bent end of the wire down the unslotted portion inside the tube, twisting the wire when its end is level with one of the slots, and pushing it out until it enters the spongiosa. If wires of siutable section are used two or more may be introduced in this manner and pushed out into the cancellus (spongiosa).

The slots on the inside of the upper bent portion are particularly convenient for withdrawing the splint from the bone, a matter of especial significance in the treatment of a tibial fracture because the extracting hook can be inserted from the front of the bone without a great deal of preliminary probing. If the hook is suitable for insertion into the tube, probing to find the slot will be practically unnecessary. The back of the bent portion of the tube contains a further opening in line with the tube axis which provides a passage for the guide pin.

A preferred form of construction of the internal splint according to the present invention is illustrated in the accompanying drawings, in which FIG. 1 is a general view of the splint;

FIG. 2 shows the lower end of the tube in section, with an outline indicating the inner osseous wall;

FIG. 3 shows the splint inserted into a fractured femur;

FIG. 4 shows the splint inside a femur fractured near the knee;

FIG. 4a is a detailed perspective view of an upper end of the splint and its associated parts;

FIG. 5 shows the splint inside a tibia likewise fractured near the knee.

The splint 1 consists of a drawn steel tube. As is customary in such applications the steel is corrosion resistant. For an external diameter of say 8 mm. the wall thickness of the tube would be 1.5 mm. and would therefore resist deformation under radial load. The tube is open at both ends, the upper extremity being curved as shown at 2. Along a line 3, indicated by dots and dashes,

extending symmetrically from the inside of the bend 2 downwards, longitudinal slots 4 are provided in the tube wall, which may have been milled or sawn out in the usual manner. They can therefore be provided in greater or lesser number and have varying lengths according to the natureof the application taken in view. The extraction hook engages the slots 5 when the splint is to be removed from the bone. The most convenient method is to insert the hook into the inside of the tube and it will be readily understood that engagement can be eflected without much preliminary probing. It is an advantage to provide two slots 5, one being a reserve slot if the other should tear out during extraction.

Two further slots 6 are arranged on either side of the line 3. Their purpose will be hereinafter described. The conformation and disposition of the slots may, of course, dilfer from that shown in the example.

The slot 7 on the back of the bent portion aligns with the main axis of the splint. This slot provides a passage for the guide pin, more particularly in the case of fractures near the joint when it is important to guide the splint until it has been driven onto position without hitting the guide pin. The hammer blows can be confined to the end of the tube.

As shown in FIG. 2 the lower end of the tube has two bevelled edges 8 and 9 the incidence of the bevelled surfaces being in conformity with the direction of the bond 2. It will be seen that the inner bevel 8 prevents the tube from seizing on the previously inserted guide pin 10 and allows it to slip down smoothly. Similarly the outside bevel 9 assures a smooth sliding movement down the bone wall 11, for instance the rear wall of a tibia.

FIG. 3 shows the splint inserted into a femur 12 fractured at 13. The position shown in the drawing is that the lower fragment 14 has been set and aligned with the upper fragment 15 by means of a guide pin (cf. FIGS. 2, 10) and the splint 1 driven along the guide pin into the lower'fragment 14. The drawing shows the splint after the guide pin has been withdrawn. Two spring wires 16 and 17 have been pushed down the inside of the tube, their leading ends 16' and 17 sliding down the inside wall where no slots are provided, so that they cannot pass to'the outside through the slots 4 and 5. As soon as the Wires have been pushed down for enough to be level with slots 6 they are twisted and pushed through the said slots to the outside. By further pushing down the wires until they reach the positionsat 18 and 19 they become anchored in the cancellus (spongiosa). The correct moment for twisting the wires into alignment with the slots can be gauged by a temporary stop secured at the appropriate distance from the end of the Wire. The loop used to handle the wire, which prevents its further displacement when it reaches the edge of the tube may be conveniently used as a mark. It will be readily understood that additional wires may be pushed through alternative s'lots if desired, for instance in the region of the upper part of the fractured bone. In this manner relative fixation of the parts 14 and 15 of the fractured bone can be secured without very close contact between the splint and the inner wall of the cavity. The fracture can therefore be put under axial load as quickly as possible to promote the rapidity of the healing process without incurring the risk of axial straining or radial displacement.

As shown in FIG. 4 it is also possible to force wires 2% and 21 through slots in such manner as to perforate both compact (compacta) and soft tissues. 22 indicates a wire which has been pushed right through the bone of the lower part 14 of the fractured member into the soft tissues. 23 shows the manner in which the lower end of the wire can be deformed and looped back and the upper end 24 twisted over the edge of the splint 1 to ensure a really reliable anchorage. This procedure also allows the surfaces 13, of the fracture to be axially drawn tightly together. To prevent the splint from being pulled down into the bone when the wire 21 is stretched taut a suitable external retaining pin can be passed through the slot 5 and a corresponding slot in the opposite wall of the tubular splint 1. FIG. 4 further discloses that the upper end of the tubular splint need not be bent for the treatment of a fractured femur.

FIG. 5 shows a, tibia 25 fractured at 13 near the knee joint. The internal splint 1 has been inserted into the osseous tube, and a wire 26 bent back at an acute angle has been pushed into the splint and then threaded through a slot 28 by withdrawing it in the upward direction. In this way the wire can be pulled into the cancellus (spongiosa) of the upper part of the bone. Removal of the wire is effected by first pushing it downwards into the splint 1 and then extracting it together with the splint. The bent upper portion of the splint prevents it from twisting in the upper part of the bone especially if it is allowed slightly to project-perhaps 1 to 2 mm.-from the top of the bone.

What I claim is:

1'. An internal tubular splint for the fixation of long medullated bones that have fractured, said splint being open at each end and being transversely undeformable during insertion into the bone, one end' of said splint being curved, said splint having at least one longitudinal slot along the inner line of the curve and at least one longitudinal slot along the outer line of the curve, a plurality of longitudinal slots aligned along the line of the tube continuing. the inner line of the said curve and an additional aligned slots which are along the uncurved portion of the splint and along lines not co-incident with the lineofsaid first mentioned aligned slots.

2. A tubular internal splint for longitudinally setting fractured long medullated bones, said splint having a wall strength sufficient to prevent transverse deformation, said splint being open at both ends, the tubular wall of the splint having a, continuous longitudinal area and a plurality of separate longitudinal slots to permit elastic anchoring wires passing alongthe said area and then being turned to pass through selected slots from the tubular wall, said tubular wallhaving in the region, of its lower open end an external bevel and having at its opposite peripheral zone an internal, bevel.

3. A tubular internal splint according to claim 2, said longitudinal slots opening forwardly, rearwardly and sidewardly in the wall of the splint.

4. Internal, splint device for the fixation of long tubular medullated bones that have been fractured, comprising in combination a tubular internal splint for insertion along the length of the bone and at least one anchoring element therefor, said tubular splint having a wall which remains transversely rigid during insertion into the bone and being open at both ends and having closed-ended longitudinal slots in and a continuous unslotted part along said wall, and said anchoring element being an elongated resilient element longitudinally displaceably arranged in elastically flexed condition in the inside of the splint with its leading end slidable along said continuous unslotted part. of the inside of said wall of the splint and insertable through one of said closed ended longitudinal slots.

References'Cited in the file of this patent UNITED sTATEs PATENTS 2,239,088, Ettinger Apr. 22, 1941 2,327,434 Johnston Aug. 24, 1943 2,396,276 Lang i Mar. 12, 1946 2,537,070 Longfellow Jan. 9, 1951 2,579,968 ,Rush Dec. 29, 1951 2,631,584 Purificato Mar. 17, 1953 FOREIGN PATENTS 923,084 Germany Feb. 3, 1955 893,401 France Jan. 31, 1944 1,012,223 France Apr. 9, 1952 118,595. Sweden Apr. 15,1947

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