AU700537B2 - Traction leg splint - Google Patents

Description

4 4 2 BACKGROUND OF THE INVENTION THIS invention relates to a traction limb splint, that is, a device for applying stretching tension to a limb in which one or more bones have been fractured or broken. The invention is particularly concerned with such a device which can be used in emergency and other like situations away from a hospital.

One such form of traction limb splint commonly in use employs a ratchet arrangement to stretch the limb.

The problem with a ratchet, however, is that one cannot make fine adjustments to the degree of stretching and there is a tendency for the ratchet to slip backwards by up to about 5mm immediately prior to it being locked in position. This results in reduced effectiveness of the device having regard to the fact that fine tolerances of the order of millimetres are usually required to S* accurately stretch a limb by the prescribed amount in order to achieve an optimal result.

OBJECT OF THE INVENTION It is therefore an object of the present invention to provide a traction limb splint which does Snot have the aforementioned disadvantages and/or which provides the public with a useful alternative.

SUMMARY OF THE INVENTION According to the present invention there is provided a traction limb splint comprising a foot restraining module captured by, and moveable along, two spaced apart rails having a common connector element at one end region thereof for fitting to a patient's thigh and having a common belt anchor adjacent the opposite end region thereof, said belt anchor acting to secure an end of a belt which passes through a movement limiting device connected to the foot restraining module and which terminates in a pull grip, said movement limiting device being designed to enable fractional/rapid movement or restraint of the belt, said fractional movement only possible when the belt is pulled by the grip in a direction counter to the directional forces exerted by a restrained limb.

The movement limiting device includes a fulcrum about which the belt passes and an associated restraining plate, which plate is spring biased so that an edge portion thereof presses the belt against the fulcrum and restrains the belt from movement except when the belt is pulled by the grip in a direction counter to the directional forces exerted by a restrained limb. Ideally, both the fulcrum and the plate have serrated edge portions which press against the belt to prevent the belt from slipping.

Preferably, the connector element is detachably connectable to the rail ends to assist in the fitting of the splint to the patient, and the rails are extendable/retractable in length.

The traction limb splint enables limb tension to i" be accurately applied by medical personnel at the site of 20 the accident by the steps of: Fastening the connector element to the patient's thigh after sliding it up under the patient's limb without necessarily moving the limb, ensuring that the rails lie on each side of the limb.

When the rails are not initially connected to the connector element, subsequently placing the rails on each *side of the patient's limb and connecting them to the S*e connector element. Lengthening or shortening the rails if need be to accommodate the length of the limb. (3) •Fastening the patient's ankle (and, preferably, foot) to 30 the foot restraining module. Pulling the pull grip so :that the attached belt moves the foot restraining module and patient's foot in a direction away from the patient's thigh. Releasing the pull grip to enable the full gripping action of the fulcrum and plate to come into play immediately to thereby prevent the belt from slipping and the limb from contracting.

In order to release the pressure on the limb, it >4 is merely a simple expedient of pushing the 4 restraining plate about its pivot by hand so as to rotate the serrated edge portion away from the belt and adjacent fulcrum. The foot restraining module is then immediately freed up so that it can move back in the direction of the contracting limb muscles, thereby immediately freeing the limb from restraint.

Preferably, each of the support rails is lengthwise extendable to accommodate different lengths of limbs. A suitable manner of achieving this is to have one rail slidable within the other and lockable at the desired degree of extension by a collet or like arrangement. To this end, the rails are preferably of differing tubular configuration.

It is also preferable to have more than one S15 connector element for use with the rails in order to accommodate limbs of different circumferences. The connector element is preferably a deformable pad or ischial ring which locates firmly against the pubis and over the trochanter area of the patient. The pad suitably has a substantially cylindrical configuration and its ends are joined to form a closed loop by the straps or the like. Preferably, one of the straps has a plain end and the other has two rings to enable adjustable connection.

It is also preferable, and often necessary, to connect an intermediate section of the limb to the rails which extend on both sides of the limb and to this end a support strap can be wrapped around the rails and the limb, preferably just above the knee. Such a strap is preferably a plastic strap with a domed connecting arrangement but a webbed belt with velcro connections can also be used.

In view of the fact that a person's limb increases in diameter from the ankle to the thigh, the support rails which are located on either side of the limb, can clearly not be restrained in parallel alignment. They are therefore suitably connected to a respective pivot support adjacent the belt anchor so that they can move in a small planar arc. As a consequence of such movement, the foot restraining module which is suitably captured on the rails, is captured by slotted winged sections which extend about the rails.

The foot restraining module preferably includes a vertical plate against which the sole of the foot can be firmly held. Retention of the foot is achieved by the use of an ankle strap which firmly wraps around the ankle and is tied to the base of the vertical plate. The ankle strap can consist of a fabric webbing, preferably including pads, which is designed to accommodate a range of ankle sizes. Fitting to the ankle can be maintained by VELCRO® connectors appropriately positioned on the webbing. A separate strip of adjustable length webbing 15 connects the ankle webbing to the foot restraining module.

A loose strap is also preferably wrapped around the foot, adjacent the toes, to prevent the foot from flopping sideways. This strap cannot be wound too tightly or else the "pedal pulse" will be impeded.

Ideally, the vertical plate of the foot restraining module is hingedly connected to the slotted wing sections so that, when not in use, it can be rotated into a plane which is parallel to the plane carrying the support rails, thereby taking up less vertical space and making it more suitable for storage.

The slotted wing sections are suitably formed as integral parts of the foot restraining module. These sections may each be in the form of inverted channels in which slots for accommodating a respective support rail are formed in the walls of the opposing flanges. The two slotted wing sections can conveniently be connected to one another by a common web where the movement limiting device is located. As described above, the movement limiting device comprises a fulcrum and a spring-biased restraining plate, each of which preferably have serrated edge portions. These parts are housed on the common web, between the support rails.

The fulcrum is basically a support firmly fixed to the movement limiting device about which the belt partially wraps so that the belt can slide thereover and pull the foot restraining module along the support rails away from the patient when the belt grip is pulled by hand in a direction away from the patient. A particularly suitable fulcrum is a metal rod or pin which extends between support brackets on the upper surface of the common web, substantially at right angles to the longitudinal axes of the support rails, preferably having a roughened or serrated surface against which the spring biased plate presses the belt.

The spring-biased plate is arranged so that an edge the serrated edge is normally located hard up 15 against the belt passing over the fulcrum so that the :serrations bind into the belt and prevent the belt from becoming loose once it has been tensioned against a restraining force exerted by a patient's limb. In order ~to enable the spring-biased plate to be manipulated away from the belt when it is desired to release the tension, the plate is preferably pivoted at an over-centre location relative to its serrated edge. This permits the plate to be pushed by hand about its over-centre pivot to thereby move the serrated edge away from the belt.

Because of the spring biasing, the serrated edge returns immediately to its normal position of contact as soon as the manual counter pressure is removed.

It is to be understood that the tension in the biasing spring will be selected so that the belt can be pulled by hand over the fulcrum without too much effort yet be such that there is no possibility of the belt slipping back when the hand pulling tension is released, due to the counter forces acting through the patient's limb.

One preferred form of spring-biased plate has a rectangular configuration with a slight curvature to enable it to be easily and comfortably pivoted by hand.

A lower longitudinal edge has a solid semi-cylindrical region with a roughened surface which constitutes the serrated edge portion. The plate is pivoted on a pin or pins extending out of the shorter edges thereof, adjacent to the lower longitudinal edge.

Preferably a locking means is fitted to the spring-biased plate to prevent accidental pivoting thereof as could occur if a heavy blanket or other item is placed on the plate. Such a locking means can take many forms. One such arrangement comprises a locking pin which is retractable in an out of a recess formed in the side edge of the plate. The locking pin is housed in a flap on the web and is spring loaded in its flap housing so as to normally protrude between the flap housing and the plate. Pivoting of the plate can only be achieved by 15 firstly or simultaneously manipulating an indent on the locking pin to slide the pin from the plate.

S- The traction belt can be constructed from any **9 material which is tear resistant, pliable and strong.

S""Suitable fabrics may be manufactured from woven fibres, both natural and artificial, as well as leather, sheet plastics and rubber materials, and various composites. A particularly preferred belt is a webbing made from woven plastics material.

The traction limb splint preferably includes a framework support adjacent to the foot restraining module for the purpose of elevating the splint and hence the patient's foot above the floor or ground surface. Such a framework support preferably comprises a U-shaped band which extends between the rails and is restrictively movable along the rails between the region of the foot restraining module and two annuli, one of which is fitted to each rail in the ankle region. Suitably, the U-shaped band is designed so that it can be pivoted into a plane parallel to the rails so that less space is occupied when the splint is to be stored.

The traction limb splint provides a stretching and locking system with infinitely variable non-slip adjustment without the need to manually align the various parts. In ambulance and like emergency situations where patients are required to have broken limb bones correctly aligned and stabilised as soon as possible under a wide range of situations and conditions, such provision has tremendous advantages.

DESCRIPTION OF THE DRAWINGS Figure 1 is perspective view of a traction leg splint according to one aspect of the present invention, fitted to a patient's limb, Figure 2 is a side-on cross-sectional view of a movement limiting device embodied in the Figure 1 arrangement, with the device in an engaging configuration, 15 Figure 3 is a similar view to Figure 2 but with the device in a disengaged configuration, *Figure 4 is a plan view of the splint of Figure 1, without the patient's limb, and Figure 5 is a side-one view of the splint of Figure i, without the patient's limb.

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.4 DESCRIPTION OF PREFERRED EMBODIMENT A preferred embodiment of the invention will oo •now be described with reference to the accompanying drawings. In all of the drawings, like reference numerals refer to like parts.

Referring primarily to Figures 1, 4 and 5, the traction leg splint comprises a foot restraining module, indicated generally at 10, two side support rails 11 and 12, a connector element 13 at one end, a belt anchor arrangement 14 at the other end, and a belt 15 which passes through a movement limiting device 16 and which has a pull grip 17 on its free end.

The movement limiting device 16 is fitted between two slotted wings 18, 19 which are an integral component of the foot restraining module 10 and which guide the foot restraining module in its movement along the rails 11, 12.

The rails are pivoted at points 20, 21 to enable a small arcuate movement so that different diameter thighs 22 can be accommodated. Intermediate collets 23, 24 are provided to enable lengthwise adjustment of the rails by telescoping one within the other, in order to fit different length limbs. The fitting shown is for a child's limb but for older children and adults, an intermediate support band is wrapped around an appropriate part or parts of the leg.

It will be noted that the slots 25, 26 on the wings are of a sufficient length to enable sideways arcuate movement of each rail 11, 12 to fit the particular width of thigh the splint is to be fitted to.

The connector element 13 consists of a semitubular deformable pad (ischial ring) 27 having associated slotted housings 28, 28a (see figure 4 also) adjacent each end thereof to enable snap or friction connection to the rails 11, 12. An adjustable length belt 29 with buckle 30 enables the connector element to be firmly fitted to the patient's thigh 22.

The patient's foot 31 is firmly secured to a vertical plate 32 of the foot restraining module by means of an ankle strap 33 which cradles the ankle and includes a connector piece 34 tying it to the vertical plate 32.

The plate 32 is hingedly connected to the winged section of the foot restraining module. A further band 51 loosely fits around the patient's foot and the plate 32 to prevent the foot from flopping to either side.

The movement limiting device 16 is shown in more detail in Figures 2 and 3 and reference is now made to these figures as well as to Figure 1. The device consists of a fulcrum 35 about which the belt partially wraps. The fulcrum 35 is retained by pins 38, 39 (see Figure 4) which extend through flanges 36, 37 projecting integrally with and perpendicular to the winged sections 18, 19.

The fulcrum 35 consists of a metal rod which has one section ground down to form a roughened surface The roughened surface is such as not to impede the movement of the belt thereover as shown in Figure 3.

A spring-biased plate 41 comprises the other main component of the movement limiting device. This consists of a metal plate which is curved at its outer end 42 for easy gripping and incorporates an enlarged inner end 43, a portion of which has a serrated surface 44. In its normal configuration, the spring-biased plate 41 is pressed against the belt 15 and the fulcrum 35 as shown in Figure 2. This configuration prevents the belt from slipping.

When the belt 15 is pulled in the direction this causes the spring-biased plate 41 to rotate counter clockwise (as illustrated in Figure 3) and, due 15 to the over-centre pivot 46, causes the spring-biased plate to release contact with the belt as shown in Figure S3. This permits the fulcrum 35 and attached foot restraining module to be moved to the right (as illustrated). As soon as the tension in the belt 15 is released by the operator releasing the grip 17 or allowing the belt to slacken, the spring-biased plate 41 immediately rotates back to the position shown in Figure 2, thereby preventing the foot restraining module from retracting.

A framework support bracket comprising a Ushaped bracket 47 pivoted to collets 48, 49 slidable along opposing rails 11, 12, is located between the movement limiting device 16 and ring stops 50, 51 on each rail. This bracket functions to elevate the patient's foot 31 off the surface to prevent any unnecessary strain being placed upon the limb and to enable the limb to be stretched without hindrance. The bracket 47 can be folded flat with the rails in the direction shown by the heavy arrows in Figure 5. This enables the splint to be stowed in a compact manner.

Whilst the above has been given by way of illustrative example of the invention, many modifications and variation may be made thereto by persons skilled in 11 the art without departing from the broad scope and ambit of the invention as herein set forth.

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S THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A traction limb splint comprising a foot restraining module captured by, and moveable along, two spaced apart rails having a common connector element at one end region thereof for fitting to a patient's thigh and having a common belt anchor adjacent the opposite end region thereof, said belt anchor acting to secure an end of a belt which passes through a movement limiting device connected to the foot restraining module and which terminates in a pull grip, said movement limiting device being designed to enable fractional/rapid movement or restraint of the belt, the said movement limiting device including a fulcrum about which the belt passes and an associated restraining plate, which plate is spring-biased so that an edge portion thereof presses the belt against the fulcrum and restrains the belt from movement except when the belt is pulled by the grip in a direction counter to the directional forces exerted by a restrained limb.

2. A traction limb splint as claimed in claim 1, I 20 wherein the fulcrum includes a serrated edge portion against which the belt is pressed by the plate.

3. A traction limb splint as claimed in claim 1 or claim 2, wherein the plate has a serrated edge portion which presses the belt against the plate.

4. A traction limb splint as claimed in any one of the preceding claims, wherein the connector element is detachably connected to the rail ends.

oo A traction limb splint as claimed in any one of the preceding claims, wherein the connector element 30 comprises an open ischial ring element with a strap connected to each end thereof.

6. A traction limb splint as claimed in any one of the preceding claims wherein the restraining plate has an associated locking means to prevent accidental pivoting thereof.

7. A traction limb splint as claimed in any one of the preceding claims, wherein the rails are lengthwise extendable to accommodate limbs of differing lengths.

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Claims (10)

1. 8. A traction limb splint as claimed in claim 7, wherein each rail consists of two tubular sections, one of which is slidable within the other and which are lockable together by a collet connected to the end of one of the tubular sections.
2. 9. A traction limb splint as claimed in any one of the preceding claims and including a support strap extending between the rails for wrapping around an intermediate region of the patient's limb.
3. 10. A traction limb splint as claimed in any one of the preceding claims, wherein the foot restraining module is captured on the rails by slotted winged sections which extend about the rails.
4. 11. A traction limb splint as claimed in any one of the preceding claims, wherein the foot restraining module includes a vertical plate against which the sole of the patient's foot can be held.
5. 12. A traction limb splint as claimed in any one of the preceding claims, wherein the patient's foot is 20 restrained in the foot restraining module by means of an ankle strap.
6. 13. A traction limb splint as claimed in claim 11, wherein the vertical plate is hingedly arranged so that, when not in use, it can be rotated into a plane which is substantially parallel to the plane carrying the support rails.
7. 14. A traction limb splint as claimed in claim wherein the slotted wing sections are formed as integral parts of the foot restraining module, which sections are 30 each in the form of inverted channels in which slots for accommodating a respective rail are formed in the walls of opposing flanges; the said sections being connected to one another by a common web. A traction limb splint as claimed in claim 14, wherein the fulcrum is a rod which extends between support brackets on the upper surface of the common web, substantially at right angles to the longitudinal axes of the support rails. CI 1 r 14
8. 16. A traction limb splint as claimed in any one of the preceding claims and including a framework support adjacent to the foot restraining module for the purpose of elevating the splint above the patient's resting surface.
9. 17. A traction limb splint as claimed in claim 16, wherein the framework support comprises a generally U- shaped band which extends between the rails and is restrictively moveable along the rails between the region of the foot restraining module and two annuli, one of which is fitted to each rail in the patient's ankle region.
10. 18. A traction limb splint substantially as herein described with reference to the accompanying drawings. DATED this 30th day of October 1998 FERNO AUSTRALIA PTY LTD By their Patent Attorneys CULLEN CO. S S S 555 t, 5 S S S. 5 S S S S. S S. S @5 *SOS S 0 S S S 7,l ABSTRACT (Fig. 1) A traction splint for applying stretching ae r tension to a limb having a fracture or broken bone. It 5 comprises a foot restraining module which is moveable on a a two substantially parallel rails and a connector element fitted to an end of the rails which encircles the patient's thigh. A movement limiting device is Sassociated with the module through which a manipulable belt passes. The movement limiting device is designed to enable fractional movement or restraint of the belt to accurately control the tension applied to the limb. a •o roooo