WO2012107571A1

WO2012107571A1 - Resilient venous compression ortheses having a foot tip with reduced pressure

Info

Publication number: WO2012107571A1
Application number: PCT/EP2012/052334
Authority: WO
Inventors: Pascal JOLLIVET
Original assignee: Pierre Fabre Medicament
Priority date: 2011-02-11
Filing date: 2012-02-10
Publication date: 2012-08-16
Also published as: FR2971417B1; FR2971417A1

Abstract

The invention relates to a compression article having resilient venous compression (RVC), which has a therapeutic and/or physiological effect, and which is provided with a foot tip and with a seam positioned on the top of the foot before the toes, and designed to allow a reduced pressure at the toes and the hallux, in order to increase the comfort and to avoid the risks of wounds associated with the seams at the foot tip as found in the prior art.

Description

Elastic venous compression orthoses with a tip of foot with reduced pressure.

The invention relates to the field of elastic venous compression orthoses (C VE), which are indicated in the various clinical manifestations of venous insufficiency of the lower limbs.

A CVE orthosis makes it possible to obtain a therapeutic and / or physiological effect through a mechanical mode of action. There is indeed a correlation between the decrease of the superficial venous pressure by the wearing of an elastic compression on a lower limb, its importance, the duration of the port, and the improvement of the symptoms of the venous insufficiency.

These orthotics, formerly known as "compression stockings" or "compression socks", are textile medical devices producing a therapeutic effect by compression / compression of the lower limbs.

Contention and compression define different effects, confused in the common language.

- The compression is provided by a fixed and inelastic device that produces a variable pressure on the limb segment according to muscular activity (plaster, inelastic band).

Medical compression by elastic venous compression orthosis or elastic band exerts a dynamic effect depending on the muscular activity of the limb in particular during walking, the device delivering a constant pressure and decreasing from bottom to top, to favor Physiological venous return and to fight against the force of gravity.

It is necessary to differentiate these products from stockings or socks known as "support", "support", "anti-fatigue" or "fashion" stockings that do not constitute medical devices for therapeutic purposes.

Compression results from the force exerted by an elastic orthosis that acts "actively" on a limb segment. It is the transverse elongation of the orthosis that delivers a pressure defining the level of compression or compression. CVE orthoses known in the prior art, are designed to produce a therapeutic and / or physiological effect by compression of the lower limb over a greater or lesser extent with a pressure (Po) measured at the ankle from 10 to more than 36 mmHg (ie 13 to more than 48 hPa, the two units of measurement being used as a unit of measurement of pressure in the field of phlebology and medical compression by those skilled in the art). Clinical indications are associated with these pressures.

In France, medical compression stockings meet strict manufacturing criteria (ASQUAL technical reference: "Quality Association", created by the Technical Centers of the textile, clothing, maintenance and accredited COFRAC sector), is a certification body for products and has filed with the Ministry of Industry the standard for orthotics and medical compression stockings, with publication in the Official Journal on July 20, 2002. It uses a COFRAC accredited laboratory for the corresponding tests that guarantee a theoretical pressure on the members to treat and maintaining that pressure over time.

Each country currently has its own regulations for medical orthosis. In France, the Interministerial Tariff of Health Services (TIPS) defines specifications that distribute socks according to their pressure. The measurement of the pressure is carried out at the ankle by dynamometry, by an approved laboratory, according to the standard AFNOR NFG 30 -102 B.

The lows are divided into four classes defined by the pressure measured at the ankle as follows:

- class I (between 10 and 15 mmHg);

- class II (between 15, 1 and 20 mmHg);

- class III (between 20, 1 and 36 mmHg);

- class IV (above 36 mmHg).

Even though there is no normative harmonization in Europe with respect to stockings, the European Committee of Standardization proposes the following classification:

- class I (from 15 to 21 mmHg);

- class II (from 23 to 32 mmHg); - Class III (from 34 to 46 mmHg);

- Class IV (above 49 mmHg).

We note that these pressure values are significantly higher than the French values, the European class I equivalent to a French class II.

CVE orthoses have the advantage of being able to be put in place by the patient with a good regularity of compression and degressivity.

The elastic venous compression orthoses consist of several threads with well-defined tasks: a group of threads of relatively inelastic material (called knit thread) forms stitches, constituting the framework of the knit and ensuring its strength, a group of threads elastic material (said weft yarn) is distributed perpendicular to the mesh, and conditions the circumferential elasticity. The weft yarn consists of: an elastic core that can be covered ("gimped") by elastic or inelastic threads. The elastic core is an elastic yarn which can be inter alia elastane, elastodiene or elastomer of natural or synthetic origin. By mesh is meant a loop of threads which serves to form a fabric.

To allow strong compression of the lower limbs, the orthoses are made from a knitted mesh texture more or less tight with an elastic weft thread inserted between 2 rows of stitches. The weft yarn, thus applied generally spirally around the orthosis, ensures the delivery of a controlled and regular pressure on the leg and the foot. The orthoses are dimensioned according to the dimensions of the patient's limb, to ensure, by its elasticity, the desired pressure level and the desired pressure profile.

The circular knitting avoids sewing, working with a fixed number of needles, the circular loom gives the same number of stitches on the circumference of the orthosis (same number of stitches to cover the ankle and the thigh). Control of the compression level is effected, inter alia, by the tension applied to the yarn of the weft and the longitudinal distance between the rows of wefts obtained by widening the mesh. This is achieved without increasing or decreasing the number of meshes.

In contrast, straight knitting, made on the basis of a distance between constant weft yarns, requires to vary the pressure at the different desired points to increase and or decrease the number of stitches. This type of knitting requires the performing a longitudinal seam, from bottom to top along the entire length of the leg.

The compression orthoses, made in circular knitting, are then sewn by a seam to close the tip.

By tip is meant the reinforced part of the same mesh or different mesh ending the orthosis and which covers the toenails of the foot. "Forehead" means the portion of the orthosis that lies before the tip and which covers the proximal portion of the toes. The tip and forehead parts therefore cover the end of the foot and cover the entire toe.

For all orthoses marketed, this tip is obtained by circular knitting and is closed at its end by a stitch called "fish mouth". This seam is located, when it is placed on the edge on the end, facing the toes (Figure 2) which represents an inconvenience for the user.

The pressure on the foot and at the base of the toes, respectively in zones of pressure a and v (Figure 5) is, for all the orthotics of the closed foot elastic venous compression orthoses market, greater than 70% of the pressure measured in ankle and more often than 80%.

In the case of a Class II medical compression stocking, that is to say a pressure of between 15 and 20 mmHg, the foot pressures (at point in FIG. 5) that have been measured range from 14 to 19 mmHg. This pressure remains constant from the middle of the foot to the tip. This has little medical interest for the patient but is a source of discomfort.

The compression exerted by the orthosis at the base of the toes, in point v of Figure 5, is not always supported by the wearer of the orthosis. This pressure is not bearable in the case of a hallux valgus for example. In addition, sewing the end of the tip is considered a nuisance for users and is not bearable for some. In addition, these orthotics, prescribed for the treatment of venous conditions, often affect elderly patients, clumsy, sometimes physically disabled, affected by arthritic phenomena deforming the hands and feet, etc., that is to say, say that sensitivity to discomfort is increased. In the past, the compression orthoses were made with a non-elastic material tip, these orthoses therefore did not adapt to the shape of the user's foot. Either the point was too short and the pressure on the toes was painful for the patient, or the surplus of tissue formed a heap at the tip of the foot facing toes source of discomfort for the user.

There are also compression orthoses called "open foot" which are characterized by the absence of tip. This type of orthosis is less and less used because it does not allow to keep in place optimally the compression orthosis because it is not maintained at the tip.

The technical problem, which had been a long time, was to propose a compressive orthosis that alleviates the lack of comfort wearing the orthosis and avoids the risk of injury related to the seam facing the toes.

Some inventions have attempted to partially solve this problem. This is particularly the case of the invention described in the patent FR 2 671 485 which describes a medical compression stocking where the pressure on the toes is less strong and with less excess material at the tip but retains the seam the tip facing the toes, which despite the lower pressure remains a source of discomfort for the user.

Elastic venous compression orthoses currently marketed are knitted in closed foot generally in single size. For example, a size II compression is manufactured for ankle circumferences of 22 to 24 cm which corresponds to a size coverage of 36 to 41. To cover this difference in size it is necessary, in addition to the intrinsic elasticity to therapeutic compression, to cover a variation between the minimum and maximum size of 3.5 cm. The orthosis, in the part of the foot, is stretched in its extreme and the tip "hangover" will press the seam on the end of the toes. The patient will hardly bear this tension on his toes.

Foot compression is necessary to prevent the patient from having edema. On the other hand, a too strong compression in the front part is a case of non-ob servance of the treatment of the venous disease by stockings of medical compression. The Applicant has discovered, surprisingly and unexpectedly, that:

- the pressure drop in the part of the fore-tip and the tip so as to be less than 60% of the ankle pressure and

- a seam tip returned,

improve the comfort of the orthosis worn.

The invention proposes to modify in a new way the rheology of the orthosis, that is to say its characteristic of elasticity (characteristic pressure / circumference), in the part of the fore-tip and the tip.

The object of the invention is to associate with this lower pressure a closure seam of the tip which is not facing the toes as currently in the CVE orthoses.

The present invention thus makes it possible to reduce the pressure at the level of the toes and to eliminate the inconvenience caused by the seam on the ends of the toes.

The present invention relates to a compressive orthosis of the lower limb, obtained by knitting a knit yarn and a weft yarn, characterized in that the pressure is decreased at the base of the toes at the point v (FIG. to be less than 60% of the ankle pressure at point b (Figure 5) and characterized by an inverted tip.

By "compressive orthosis" is meant all items of elastic venous compression brace type such as, mid-low, low with or without self-fixing tape, sticky, maternity tights, monolayer or hemicellant or leg tights, etc. .

Preferably, the present invention relates to a medical compression stocking.

"Lower limb" means members of the locomotion including the gluteal region (located between the pelvis and the thigh), the femoral region or thigh (located between the hip and the knee region), the knee region ( located between the thigh and the leg), the crural area or the leg (located between the knee and the ankle), the talo-crural region or the ankle also called instep (located between the feet and the leg) and the lower part (foot area). By "tip returned" we mean a tip obtained as a heel by decreasing and increasing mesh. The closure of this point is performed by a seam on the top or bottom of the foot.

Preferably, the closing seam will be on the top of the foot (Figure 6).

Advantageously, the total length including the fore-tip and the tip will cover the toes over their entire length, regardless of the type of foot (Greek foot, square or Egyptian) and its length.

The orthosis according to the invention will comprise a compressive part extending upwards and adapted, after the orthosis has been placed on the limb, to exert in the circumferential direction an elastic restoring force capable of producing a compression of the Member at a therapeutic pressure level.

The orthosis according to the invention will comprise a compressive portion with an ankle portion capable of producing, when the orthosis is in place on the limb, a compression at a therapeutic pressure level. The ankle portion, elastically deformed at the circumference Co of the member's ankle (FIG. 5), exerts in the circumferential direction an elastic restoring force producing a nominal textile pressure when worn Po (Po = Π x Fo / Co per unit length where Fo is the force exerted by the elastic wire at the circumference Co.

Advantageously, the pressure on the toes will be less than 15 mmHg, preferably between 10 mmHg and 5 mmHg and still more preferably 8 mmHg for class II orthosis according to the AFNOR NFG 30 -102 B standard or 10 mmHg for class III stockings according to the standard AFNOR NFG 30 -102 B. This pressure is measured according to the control protocol that we have developed to do this.

The foot of the orthosis according to the invention is obtained by knitting, such as the leg with so-called knit yarns and so-called weft yarns. The foot may be preferentially knitted with a weft yarn per knitted row (FIG. 3) or with a weft yarn for two knitted rows (FIG. 4).

We define the length of the lightened part as follows: The foot of the orthosis is stretched to a length corresponding to the size considered (called length of the foot). This tension is applied thanks to an elongation table (called marking-board). Once stretched the total length including fore-tip and the tip will be at least:

Tip and tip length = (0.275 x Foot length) - 4.07

In Figure 1, there is shown the various parts of the lower part of a CVE orthosis which, in the example shown, is an orthosis closed at the bottom and wrapping the foot, for example, a stocking or a tights ( but the invention is equally applicable to all types of elastic venous compression orthoses previously mentioned).

The elasticity profile of the orthosis according to the invention can be obtained by various means well known to those skilled in the art: by selection of the fibers used for the knitting yarn and / or for the weft yarn orthosis, by a specific covering of these son, by specific parameters of knitting, or by a combination of these various choices.

According to one embodiment of the invention, CVE orthoses are obtained by circular knitting; they are manufactured on automatic circular looms with different cylinder diameters (for example 3 "1/4, 3" 1/2, 3 "3/4, 4", 4 "1/4, etc., 6", 6 "1/2, ...) These different diameters are used to make different sizes of orthoses (eg 3" 1/4, 3 "1/2, 3" 3/4, 4 "for sizes 1, 3 "3/4, 4", 4 "1/4, 4" 1/2 for sizes 2, etc.) These automatic knitting machines perform in one and the same operation all the different parts constituting a stocking with, for example for example, his belt, his pants, his leg, his heel, his foot, his point (Figure 1).

The invention can be realized independently of the choice of the mesh and the wires,

Preferably, the CVE orthoses according to the invention are manufactured from elastic yarns, such as elastane or elastodiene, and non-elastic yarns, such as polyamide, viscose, cotton or any other textile material. synthetic, chemical or natural. The sizing of the mesh rows is defined so as to apply predetermined pressures at different altitudes of the leg, for example at the height of the ankle, from the calf, at the calf, to the hollow popliteal, etc. up to the thigh in the case of a thigh-high or pantyhose. The measurement points are defined by placing the orthosis on metrological templates such as the leg-model defined by the French standard NF G 30-102b, Appendix B, or the Hohenstein model leg according to the German standard RAL-GZ. 387.

The title of a thread is its linear density. Minimum wire titles are described in a specification to ensure the achievement of the required compression levels, but also the consistency of compression over time.

In a particular embodiment of the invention the medical compression stockings are knitted in leg with a weft yarn and a knit yarn. The weft yarn uses a 310 decitex core yarn with a double cover which may be of synthetic yarn and or natural fiber. We will use for example a 310 decitex elastane yarn with an inner cover of polyamide 22 decitex and a 240 metric cotton outer cover. We will use in knitting an elastic thread gimped with a yarn of elastane 22 decitex coated with a polyamide 78 decitex. The leg mesh will for example be based on a row of solid jersey knit with a weft thread inserted in 1x (even needle for example) and the following row of weft will be inserted in alternating lxl (odd needle for example). ).

The medical compression stocking of the invention will preferably comprise a heel made with a gimped elastic thread. For example, we will use a 22 decitex elastane yarn with 2 covers of 78 decitex polyamide. The heel is made of woven mesh jersey so as to make a pocket obtained by decreasing and increasing the number of stitches.

In a preferred embodiment the foot will be knitted material and mesh like the leg. The forehead, will be lightened in pressure so as to obtain a pressure in this part less than 60% of the ankle pressure (measured on dynamometer after placement of the orthosis on table elongation or marking-board). Ideally this pressure will be less than 8 mmHg.

The pressure relief of this part can be obtained by increasing the distance between two weft son or by the use of a weaker weft yarn. The increase in the distance between two weft yarns may be obtained preferentially by increasing the stitch height, with a weft yarn all the rows of knits, or even more preferably by increasing the distance between two weft yarns by knitting. two rows of knits for a row of weft (Figure 4).

In another embodiment of the invention, it is also possible, during the production of the foot, to change automatically on the knitting machine the weft yarn by a weft thread weaker in strength. For example, we can replace 310 decitex spandex weft yarn covered with 22 decitex polyamide and 240 metric number cotton by a 130 decitex elastane with a 44 decitex polyamide inner cover and 160 metric cotton outer cover.

In one embodiment of the invention, the returned tip will be knitted in jersey knit with an elastic yarn. We will preferentially use the same type of wire as the heel wire.

Preferably the tip thus obtained will be closed by a suture "surjet" 3 thread s (Figure 7)

This seam thus achieved will avoid the pressures that we usually have on the ends of the toes.

This point, associated with a lower pressure of at least 60% of the ankle pressure (FIG. 8), will guarantee an improvement in the wearer's comfort at the bottom as well as a better observance of the compression compression stocking.

Description of the figures:

Figure 1: Complete structure of a bottom and name of its different parts Figure 2: Positioning of a tip seam, positioned opposite the toes, called "fish mouth"

Figure 3: Knitting with a weft yarn per knitted row.

Figure 4: Knitting with a weft thread for 2 knitted rows.

Figure 5: Main areas of pressure studied:

a = pressure zone in the middle of the foot

b = pressure zone at the circumference (Co) of the ankle v = forehead pressure zone

Figure 6: Positioning a seam tip, positioned on the top of the foot, before the toes.

Figure 7: 3-thread suture seam

Figure 8: Percentage pressure as established by the invention to be lightened at the foot and the forefront.

Claims

claims

1. compressive orthosis of the lower limb, obtained by knitting a knit yarn and a weft yarn, characterized in that the pressure is decreased at the base of the toes (v) so as to be at least less than 60 % of the ankle pressure (b) and characterized by an inverted tip.

2. compressive orthosis according to claim 1, characterized in that the orthosis is a knee-high, a stocking with or without a self-fixing band, a pantyhose, a maternity pantyhose, a monolayer or a hemicellant or a glue a leg.

3. compressive orthosis according to claim 1, characterized in that the orthosis is a medical compression stocking.

4. compressive orthosis according to one of claims 1 to 3, characterized in that the tip returned has a closure seam located on the top of the foot.

5. compressive orthosis according to one of claims 1 to 4, characterized in that the pressure is decreased on the length of the toes to be between 10 mmHg and 5 mmHg.

6. compressive orthosis according to claim 5, characterized in that the pressure is decreased on the length of the toes to be 8 mmHg for class II stockings according to the standard AFNOR FG 30 -102 B.

7. compressive orthosis according to claim 5, characterized in that the pressure is decreased on the length of the toes to be 10 mmHg for class III stockings according to the standard AFNOR NFG 30 -102 B.

8. compressive orthosis according to one of claims 1 to 7, characterized in that the length comprising the tip and the forward tip has the following formula: Tip length and leading edge = (0.275 x Foot length) - 4.07.

9. compressive orthosis according to one of claims 1 to 8, characterized in that it has a length of the fore-tip and the tip to cover the toes along the entire length, regardless of the type of foot and its length.

10. compressive orthosis according to one of claims 1 to 9, characterized in that the increase in the distance between two weft son allows obtaining the pressure relief in the forefront, said distance increase being obtained by increasing the height of mesh, with a weft yarn all the rows of knitting.

11. compressive orthosis according to one of claims 1 to 9, characterized in that the increase in the distance between two weft son by knitting two knitted rows for a row of weft allows obtaining the relief of pressure in the forehead.

12. compressive orthosis according to one of claims 1 to 9, characterized in that the use of a weaker weft yarn allows to obtain pressure relief in the forefront.

13. compressive orthosis according to one of claims 1 to 12, characterized in that the tip returned is made with the same thread as the bead wire.

14. compressive orthosis according to one of claims 1 to 13, characterized in that the tip returned is made of jersey mesh with an elastic thread.