US2632442A

US2632442A - Orthopedic brace

Info

Publication number: US2632442A
Application number: US129068A
Authority: US
Inventors: Anderson Roger
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-04-11
Filing date: 1949-11-23
Publication date: 1953-03-24
Anticipated expiration: 1970-03-24

Description

March 24, 1953 R. ANDERSN' 2,632,442

' oRTHoPEDIc BRACE:

original Filed Apri1 11, 1944 2 SHEETS- SHEET 1 f3: :wy/2

mvlamoR fqyer'/rdanson ATTORNEYS March 24, 1953 R. ANDERSON 2,632,442

ORTHOPEDIC BRACE original Filed :April 11, 1944v 2 SHEETS- SHEET 2 Evol-UTBON 4o 'or- Aca-roma lNoun-los sumas; wool aaa awiaav aso-m-laa swvu'sn'nw INVENTOR Q Y /r'ayer ndern/7 5'?. ATToRNEYs Patented Mar. 24, `1953 Y Roger Anderson, Seattle, Wash.

Original application Aprilv 11, 1944, ISerial No.

503,472.Y Divided and this application November 23, 1949, Serial No. 129,068

(Cl. 12S-90) 7 Claims.

While the conventional plaster of Paris cast is useful in providing valuable therapeutic results, it has many and recognized shortcomings. For example, the cast is characterized by excessive weight, its setting period to obtain maximum strength is long, it remains damp for long periods and thus often provides adverse condi'- tions from a therapeutic standpoint, it isdense, and to a greater degree when wet, to electrical rays, and it is highly absorbent to liquids including body secretions, water and airborne moisture. The absorbent characteristics of the plaster cast are not only favorable for germ incubation but the strength of the cast is progressively lost depending upon the` amount of secretions, water and moisture to which the cast is exposed. These disadvantages and others have provided a long feltne'ed in the art to provide an entirely' new type of cast or splint'.

i The objects of the present application are substantially the same as those of my Patent No.

2,489,252 of which the present application isa.

division and which objects are therein set forth. The invention of the present application differs from those ofA my said' patent in that the claims of the present application are drawn to the completed orthopedic brace as distinguished from.

the process of making the same.

It is further the object of the inventionto form a waterproof, relatively rigid unyielding and inelastic cast or splint which will. possess. a`

maximum strength combined. with.y a minimum weight.

In the present inventionA I provide aipl'astic fabrication which is very similar to the. touch and in, appearance to knitted yarn, as sweater material or stockinette and preferably provide` the same in the form of aA tubing or a form tting member or in strips of suitable width and thicknessso that suchmaterial may be properly fitted or wrapped about or adjacent an injured member and may be thereafter set-up to form a cast or splint.

It is a further object of. my inventionV toy provide a cast member characterized in. a. substantial maintaining of the structural form 'of' the tained in the completed cast to form a truss-` like structure in the completed cast.

It is a further object of the invention to provide a cast which may be readily cut or severed, mechanically, chemically, or both mechanically and chemically, for removal, extension, joining, local adjustment, or retting and a cast whichA after severance (or which may require repair for any other reason) may be readily repaired: or reenforced without loss of, but usually with increased structural strength.

It is a` further object of the invention tor provide a practical plastic cast which will bey unaffected by moisture, as body secretions, water or. air-borne moisture transparent to electrical rays, such as X-rays, or ultra-violet treating rays, and which may be of an open mesh structure so that the cast will facilitatetreatments, suchV as of the cast or the injured members by liquids of various natures.

It is a further object of the` invention to provide an open Weave mesh fabric as the starting material wherein by the brousor filament character and open Weave thereof, the wetting characteristics of the materiali are enhanced. Because of the use of my treating solution having limited dissolving properties, I a-ml able to' use an exceedingly open weave fabric without damagel to such fabric, a fabric having exceptional wetting properties, and a fabricl having theV de sired thickness and a minimum weight-thus providing' a completed cast of minimum weight and maximum strength.

It is'a further object of the invention to provide a cast-forming material' preferably' having inert threads therein which will aid in control of the shrinkage characteristics during forming` myl completed cast.

The above mentioned general objects of my invention, together with others inherent in the same, are attained by and illustrated in the structures illustratedv in the following drawings, the

` form ofl fabrication employing therein, in addi- 3 tion to the plastic, an inert thread or yarn;

Fig. is a view of the fabrication of Fig. 4 after final treatment;

Fig. 6 is a fragmentary view with portions shown in section and portions in elevation of a cast of my invention applied about a portion of the human body;

Fig. 7 is an enlarged fragmentary View of parts shown in section in Fig. 6;

Fig. 8 is a view similar to Fig. 6 except that the outer layer of the cast is provided by a tubular member instead of a bandage;

Fig. 9 is a sectional view taken substantially on broken line 9-9 of Fig. 8;

Fig. 10 is a fragmentary view and with portions shown in elevation and portions shown in section to illustrate the use of padding means between a sore spot or bony prominence, as an elbow, and a cast of my invention;

' Fig. 11 is a fragmentary view with portions shown in elevation and portions shown in section to illustrate a means of applying a solvent to remove portions, as a regular or irregular shaped hole, of a completed cast of my invention;

Fig. 12 is a fragmentary view with portions shown in elevation and portions shown in section of a completed cast of my invention in which an opening has been provided and the cast then repaired;

Fig. 13 is a view similar to Fig. 11 except that the nature of the opening to be provided in the cast is a long narrow slot such as may be employed in severing and removing the cast;

Fig. 14 is a view with parts shown in section and parts shown in elevation of a device which may be employed in applying treating solution of my invention to the fabrication of my invention; and

Fig. 15 is a chart comparing the saturation .A

values of a treating solution employed in my invention with the percentage of acetone employed in the said solution.

Plastic employed I employ a plastic which has the following characteristics: It is soluble in the treating solution employed (the relative extent being considered under the title Treating solution), it is relatively inelastic, and it is capable of being formed into pieces of hair-like dimension in section and preferably as a ber or threadlike filament so that a yarn or thread may be provided from the same. Typical examples of such plastics are:

A. The cellulosic plastics 1. Cellulose esters:

a. Cellulose nitrate; R and R.=NO2 b. Cellulose acetate; R and R.=OC`CH3 c. Cellulose acetate propionate;

R=OCCH3; R=OCC2H5 d. Cellulose acetate butyrate;

R=OCCH3; R=OCC`3II7 2. Cellulose ethers:

a. Ethyl cellulose: R and R=C2H5 volved.

B. Polystyrene plastics [-CH-ClhsHs n C. Vinyl ester plastics:

l. Polyvinyl acetate (The above chemical formulas are the conventional representations of the plastics in- I-Iowever, commercial furnished plastics are not completely esteried as might be indicated by the chemical formulas.)

Form of materials The various individual fibers or laments of the plastics mentioned in the foregoing paragraph are preferably woven into yarns, such as standard yarns of 150 denier weight. It is to be understood that the foregoing figure of denier Weight is not a limitation of this invention but is merely an example of a yarn which may be employed and which is at the same time a standard yarn. Preferably more than one piece of yarn is employed and as a practical example I have employed twelve individual pieces of yarn, each of 150y denier weight and employed them as a unit in the knitting process.

From the knitting process I preferably obtain, for cast forming purposes, a stretchable and relatively thick fabrication. Thus the type of stitch to be employed in the knitting machine preferably should be one which provides a relatively stretchable fabrication and at the same time the tension on the threads preferably should be relatively loose. As typical examples of various types of stitches which have been employed in the knitting of the fabrication employed in my invention, I have used the following stitches: cuff, link and link, full cardigan, full cardigan with rack, tubular and stockinette.

While the yarn employed in making the material into a stretchable and relatively thick knitted fabrication may be solely a plastic, I prefer to employ an inert material in each unit of yarn employed in the knitting process to control shrinkage. kThis material will be inert to the treating solution employed (treating solutions are hereinafter specifically considered) and if the treating solution employs therein acetone then the inert material (that is inert so far as acetone is concerned) may be cotton, regenerated rayon, glass, metal, nylon, etc. An example of an inert thread employed in the fabrication of my invention is shown in Figs. 4 and 5 of the drawings. In such figures a plurality of plastic threads or yarns are disposed alongside and adjacent inert threads, as an inert thread I0. In the event that an inert thread is employed, it will control adverse shrinkage in the ultimate overall size of the cast.

A theoretical explanation of the operation of the inert thread means is illustrated in Figs. 4

J and 5.` Fig. 4: illustrates a. fragment of the fabrication 26 before treatment and Fig. 5.- illustratesY the same after treatment. Thus the. thicknessA of the fabrication, as dimension I2 of Fig. 5v appears tol be reduced below thickness I3 of Fig. 4 butr the length I4 of both figures (a length or width dimension of the final cast) remains substantially constant. The inert thread meansl by providing the thick material of Fig. 4 with excess material therein, permits theV materiali` to reduce its thickness and preserves the length dimension at right angles thereto'.V

Fig. 1 illustrates the fabrication 26 beforetreatment. Fig. 2 illustrates the same'after pretreatment in accordance with the pretreating technic discussed under Pretreating of the cast-forming material, described hereinafter, and Fig. 3 illustrates thesame after final treatment. The threads or yarn of the fabrication as woven (Fig. l) appear thicker in section and have more fnap or fuzz. After pretreating as shown in Fig. 2, the loops have an apparent vgreater width asv dimension. I5 of Fig. 2 compared to` dimension I6 of Fig. 1.` Then after final treatment to provide a rigid supporting. means asa cast the dimension I1 of Fig. 3 is reduced over the comparable dimension I5 of Fig. 2'. However, the dimension. I8 of both Figs.. 2 and. 3 is substantially constant so the shrinkage of a. cast tending to reduce its size is substantially eliminated.

The fabrication is preferably provided` in strips whichrnay be of various widths. Theexact width of the material will be determined. by the type of arti-cle which is to be made. In other words, the narrower the strip the easier itwill be to conform the strip about an irregular shaped object and at the same time the wider the strip the faster the` material maybe applied'. Thus for practical purposes I have employed strips varying in Width from two to ten inches and of a length for convenient handling.

Another form of: fabrication which I. have employed. in my invention is knitted. tubi-ng or material knitted substantially to the shape. of a particular member, as a trunk', leg, etc., such. as a stocking. l

Other forms of fabrications will include Woven material, matted material, intertwined. material or intermeshed material. The means for holding the fabrication together so the same may be handled as a.L unit may be the cross threads of a weave or knit, the entangled threads of matted, intertwined or intermeshed material, or mechanical means as Weld-like means, adhesive means, sewing, porous flexible containers', or the like.

ited solubilitycharacteristics herein dened, were employed. Thus the structures-or fabrications within theA scope of this` invention will also` in-v clude (so long as the cross section of plastic employed is within the present teachings and regardlessof Whether a solid memberof plastic, ahollow member of plastic, or amember coated withr a plastic is employed). threads-long or short, tubeslong or short, andv other geometric solids, as beads, flat solids, etc. In the event that pieces of short length are employed they may be fabricated to be handled as a unit by employing them within-a porous flexible container' asa bag'. Also,k

flat solids may be secured together, much like shingles or sh scales, merely at one end. Also, if

an inert thread is selectively coated at longitudinally spaced locations, the flexibility of the`V uncoated portions may be utilized. In thev description and the claims the Word fabrication is so used and shall have such meaning unless the contextrequ-ires a different meaning.

Pretreating of the cast-forming. material Preferably the fabrication previouslyv described is. pretreated before application about an injured.

member so that the subsequent shrinkage characteristic of the material upon final. treatmentl is controlled or eliminated. The most practical technic for pretreating, I have discovered, com,-`

v full apparatus is illustrated and described in my The requisite characteristic of the fabrication is that it must comprise a plurality of' pieces wherein the plastic employed is of filament or threadlike dimension in section and the` pieces are interoonnected to provide a unit or fabrication. The structures of my earlier mentioned patent` and patentl application have a dimension in section of more than one thirty-second of an inch. In such instan-ces the size and dimension of the plastic: permitted the use of normal solvents, as acetone, Without excess dissolving. In the pres'- ent invention I employ plastics having a dimension of less than one thirty-second of an inch and which may be termed of thre'adlike dimension in section.y Because of their dimension they would be dissolved, lose shape, take too long. to dryl or set, or adverse amounts of gelatinousv matters would be formed'. if normal solvents, as'v distinguished from treating solutions; having the lim-- said Patent No. 2,489,252, of which the present application is a division. The pretreating process may employ a liquid treatment, a heat treatment, or a combination of the two may be employed but preferably a liquid treatment in whole or in part is employed asa more uniform treatment, cross-sectionally considered of the plastic, seems to result. y

If a heat treatment is employed, the temperature of the heat treating fluid may be between 350 F. and 425 F. and for a period of 30 to 10 second`s. A preferable temperature and time pe-A riod is about 375 F'. and for a period of approximately 25 seconds. VAs discussed under Treating solution, the saturation value of the pretreating solution should be below75.

I desire' to point out that in the technic of applying casts, control of the subsequent shrinkagey during setting of the cast is highly desirable. In many cases itis desirableA that there shall be no shrinkagev of the cast and in other cases variations in the degree of shrinkage are desirable for the utmost therapeutic results depending upon` the nature' of the injury involvedv and/or the nature of the treatment desired. For example, a cast may be applied about a recently amputated stump where the conditions are such that the surgeon desires pressure to reduce the swelling. In such cases the shrinkage during setting may be had so that pressure is applied to the swollen area. Also in such a type of case, a cast will have an increasingly greater litor conformation upon the gradual decrease of the swelling. A further advantage from applying myv cast in such a case is that a temporary artificial limb may be readilyV securedV to the cast and the patient will be prompt-V lyl ambulatory. Also a cast maybe applied about an injured limb shortly after the fracture and before considerable swelling has set in and in suchl cases a minimum of. shrinkage of the cast in the setting-up: process may be desired to allow for Any suitable apparatus mayY the anticipated subsequent swelling. Also a cast may be applied about very bony prominences and Where minimum swelling may be expected.

The technic of the use of casts varies with the individual case and the operator and it is not my intention to indicate a method of treatment but merely to indicate some examples showing possible uses of controlling the shrinkage characteristics of the cast during setting.

Treating solution A prime consideration in my invention is that the treating solution shall be of a character to become saturated at a very low concentration with the plastic employed and/or have the capacity below a predetermined maximum to react with the plastic employed even though the treating solution is liberally applied and an excess is present. This eliminates any necessity for a critical technic. Such treating solution may be a solvent for the plastic employed, such as ethyl acetate; a solvent for such plastic combined with a diluent, as acetone and petroleum ether; two or more non-solvents for such plastic which in combination act as a solvent, as chloroform and ethyl alcohol; or any of the foregoing which have been first saturated by such plastic.

In the event that my invention is to be employed in connection with the medical and surgical fields in providing casts or splints then the treating solution should be relatively volatile to provide for rapid setting of the cast or splint and rapid drying of solution, should not be harmful or irritating to the skin or exposed flesh or sores, if any, should not be toxic, and should not have an undesirable odor.

In order to determine the amount of a particular plastic required to saturate a particular treating solution (hereinafter termed saturation value of a treating solution), I employed one hundred cc. of the solution being tested and placed therein in finely comminuted form an excess of the plastic to be employed in connection with the particular treating solution and allowed the same to stand in a closed vessel for a substantial period of time to insure complete saturation of the treating solution by the plastic. While the treating solution and the plastic may only be in association with one another for a matter of minutes in actual use in my invention, nevertheless, for test purposes I permitted the treating solution and the plastic to stand in a closed vessel for twenty-four hours to obtain results capable of being duplicated as to saturation values. In View of the fact that an excess of plastic was employed to insure that the solubility characteristics of the treating solution would be fully satisfied some undissolved plastic and usually some gelatinous material were present. Then the liquid was passed through a filter paper so that only dissolved plastic would be present in the liquid ltrate. Thereafter a measured amount of liquid filtrate was evaporated to dryness and the residue weighed.

With such technic for determining the saturation values of treating solutions formed of various ingredients and a specific example of each combination (and to compare the same to the saturation value of pure acetonewith acetone less than enough plastic to leave undissolved pieces was employed so filtering was not needed) in connection with a typical commercial cellulose acetate yarn (at a room temperature of 8 about 70 F.) the following results were observed:

Millliugrams of Composition ce OSO ace" Tieatmg Solution (by volume) trtapiglgglc.

tion

Percent Acetone 100 over 100, 000.00 Acetone 68 35 0 Petroleum ether (-60 C.) 32

44 68 gg 32. 5 34. 5 Methyl formate 70 26 3 Petroleum ether (35-60 C.) 30 Methyl formate 60 Petroleum ether, 37%7 40 18. 3 Methanol, 2%% Methyl formate. 66 71 3 Ethyl ether 34 Chloroiorm 99% 49 5 Ethyl alcohol The striking contrast of the low saturation values of the various treating solutions, set forth by way of example in the previous table, to the extremely high saturation value of acetone is obviously apparent. This contrast will be helpful in understanding a possible theory involved in my invention. However, in setting forth such a table, it is to be expressly understood that the invention is not limited to the saturation values set forth in said table by way of example and the limits of the invention will be hereinafter dened.

Also, in the table it will be apparent to those skilled in the art that examples of a solvent and a diluent therefore are involved in some of the treating solutions. For example, acetone is a solvent for cellulose acetate and petroleum ether is a diluent for acetone. However, the acetone and the diluent obviously do not function in direct relation to the amount thereof present as the treating solution containing approximately two-thirds acetone and one-third petroleum ether (by volume) has a saturation value of 35 milligrams rather than two-thirds of one hundred thousand milligrams.

containing acetone has a saturation value of 2690 milligrams per loo cc. of treating solution. Thus, the saturation values increase very rapidly in comparison to the percentage of acetone included in the treating solution after a percentage such as 86% of acetone is reached. The percentage of acetone for obtaining any desired value of saturation for a treating solution comprising acetone and petroleum ether is believed obvious in view of said chart.

In view of the fact that those skilled in this art can readily prepare a saturation chart for any of the treating solutions which I have disclosed, I have deemedk it unnecessary to here set forth a chart for each treating solution. However, after a saturation chart is obtained for the treating solutionV embodying the technic which I have .9 hereinbefore disclosed, then a treating solution having Ltheproper saturation value may be Areadily obtained for `a .given plastic and .employed vin my invention. Many of thesattuation .charts ier the treating solutions whichIhave disclosed will follow generally the curve disclosed in Fig. 15. However, many of the treating solutions of this invention will have saturation value curves which are very dissimilar to the curve'represented in Fig. l`5. In connection with a treating solution comprising chloroform and ethyl alcohol, I may employ a solution wherein a very small amount of chloroform is present and a very large amount of ethyl alcohol is present and at the same time I may -employ a treating solution wherein a large amount -of chloroform and a very small amount of ethyl alcohol are present.

Another type of treatingsolution which may be employed in the invention includes solutions which have 'been previously treated Awith the plastic involved. For example any of the solutions mentioned in the said table may be treated by and even up to saturation vby .the plastic to be employed and even after :substantially com-plete saturation they are operable in my invention as treating solutions.

.Other types of treating solutions described in said table will include a solvent as ethyl .acetate or a combination of non-solvents in and of themselves which Vfunctionin combination as a solvent, aschloroform andethyl alcohol.

A possible theoretical explanation which `may be involved inthe actionof my treating solutions is that one liquid, as rethyl alcohol, may function as a disperser and another, as chloroform, may function as a swelling agent. Thus the chloroform may function to swell the plastic so portions will slurf-off and/ or be made available to be acted upon Aby the disperser. One ofthe facts which can be explained `by this `theory is 'that solutions containing a large amount of chloroform and a small amount of ethyl alcohol give limited solubility characteristics and at the same time solutions containing a .small amount of chloroform and a large amount of ethyl alcohol give similar results. Thus by either controlling the swelling action or by controlling the dispersing action, limited solubility may be obtained. The action to which I have referred as a swelling action may be appropriately referred to as merely a stage of or an action occurring in dissolving. As to treating solutions containing agents, as acetone, it appears that the swelling action, if present, and the dissolving action are brought about :by the same agent, acetone, ywhich seems to give credence to the theory that swellingis .a stage of dissolving. However, despite the theory involved, my experiments have demonstrated the utility of treating solutions having low saturation values.

'Ilrus my investigation indicates that it is necessary to employ Iatreating solution having a low saturation value for the plastic employed and/or a :treating solution having a capacity below a predetermined maximum to react with the plastic employed and .thus `provide the necessary settingup action. Unless such low saturation value of this invention (as distinguished from 'a higher saturation value) is provided in the treating solution, there is a destruction of the fabrication and its structural form to an adverse degree, and formation vof an adverse amount of gelatinous material-these result in prolonged setting and drying time anda thin and weakened cast.

While I. am unable Aat this time to positively,

state the theoretical reasons Vfor the phenomenon as .to why `treating solutionshaving low saturation values are operable in my invention, one possible explanation is that their capacity to dissolve plastic is satisfied before the occurrence of any substantial 'destruction of the structure of the fabrication and that the dissolved plastic is so dispersed -or distributed that substantial quantit-ies of .a gelati-nous mass are not formed. Also the preferably employed highly volatile treating solutions limit the time for the interaction between the treating solution andthe plastic so that where said preferable solutions are employed a minimum dissolving of the plastic takes place.` Also, a possible feature which may be involved in the theoretical explanation is that there .is a capillary attraction between the Various hair-like fibers or nlaments .making up the various pieces of yarn or thread or Yfabrica-tion and the treating solution so that in the time involved in Athe :reaction period, the major action is between the treating .solution which first wetted the plastic andthe .plastic itself and the excess Vor subsequent applications of treating solution do not bring about excessive dissolving of the plastic.

.A .possible theoretical reason .as to why` substantially saturated or partially saturated solutions will .be l.operable in .the invention is that of migration 'or exchange. Even though the treating solution is substantially saturated with the plastic involved, it appears that there is an expelling of the plastic which `saturated the solution and a simultaneous dissolvingof the plastic to .be treated so that by migration or exchange in the treatingsolution between .the plastic initially used to `saturate the solution and the plastic being treated, .the [plastic being treated is properly treated so ,it will subsequently set-up to provide a practical cast and without adverse destruction of the fabrication.

The setting-up action of my cast involves more than mere evaporation of an extremely dilute cement or adhesive. I have taken a saturated treating .solution of the character above discussed and applied the same to a material to which the solution is inert, as cotton, and evaporated all liquid. Instead of iin-ding, as might be expected some residue encrusting or hardening the cotton, the cotton appeared to be the same as it was before the treatment. There was such a small amount of residue that its presence was diflicult to detect by the physical appearance or the feel of the cotton. In contrast, the same treating solution when applied to a plastic 'fabrication provides a rigid structure. Thus the phenomenon of the setting-up action of a cast of my invention includes unexpected factors and cannot be explained as being merely the providing of a limited amount of cement in solution'and then evaporating the liquid.

-It appears that the minimumsaturation value of the treating solutions or their apparent capacity to dissolve additional plastic may be substantially zero and such treating solutions will be highly useful in my invention. As to the maximum saturation value for treating solutions Which may be employed in the invention, I have found for optimum commercial results in providing casts or splints that lthe same should be not more than 100 milligrams of plastic per 100 cc. of treating solution calculated at '70 F. It has been found that any lgreater saturation value than 100 milligrams of plastic per 1.00 cc. of treating solution is not necessary and limits latitude of technic in that careful handling is required `to prevent destruction of the structural for-m of the plastic fabrication, Thus in my tests I have purposely employed treating solutions having saturation values of not over '75 milligrams of plastic per 100 cc. of treating solution as I obtain the desired strength with the greatest latitude in technic of application. On the other hand, I have found that with careful technic the saturation value may be as high as 300 milligrams of plastic per 100 cc. of treating solution and still useful results will `be obtained. Also where the plastic fabrication has been pretreated, as has been discussed under title Pretreating of the cast-forming material, the treating solution to be employed may have a higher saturation value than when non-pretreated material is employed. For example, the range of 50 to 15G milligrams of plastic per 100 cc. of treating solution at '70 F. is practical for application to pretreated material. Also in the pretreating process the treating solution should have a lower saturation value than the saturation value of the solution to be employed in the nal treatment. I have found for practical purposes that the saturation value for the pretreating solution should be below 75. Thus where an untreated fabrication was employed, solutions having saturation values of over 100 require considerably more care in technic than where a treated fabrication was employed with solutions having the same saturation value. Also, in practical casts I have employed in the pretreating method, a treating solution having a saturation value of 10 milligrams of plastic per 100 cc. of treating solution and when such plastic pretreated cast material was finally treated in the cast-forming operation, it was found that a solution having a saturation value of 70 milligrams of plastic per 100 cc. of treating solution was highly practical.

I have further found that where a plastic f abrication is pretreated with a solution having a rather low saturation value, the loops in the weave are sufficiently self-sustaining so that the tendency of the material to run is substantially decreased. This feature of my invention has great utility in the cast eld and also has great utility in other fields, such as in the treatment of womens stockings or hosiery made of a soluble plastic. The mild or light pretreatment does not too adversely effect a harshness of the material and at the same time it provides sufficient loop retaining characteristics so that there results a practically run-proof product. The mild treating solution to be thus employed should have a saturation value in the neighborhood of l milligrams per 100 cc. of treating solution at 70 F. As the strength of solubility of the treating solution increases it increases the harshness of the material so that the treating solution, for practical purposes should be the lowest treating solution which will provide the desired run-proof characteristic.

It is interesting to Vnote the very small total weight of the cast material which normally will be dissolved by the treating solutions of this invention. A considerable excess of treating solution for a given cast was applied and the capacity of such solution to dissolve the plastic involved was determined. It was found that the weight dissolved was less than one-half of one percent by weight which again illustrates the low saturation values here involved.

In the event that the plastic material employed isother than cellulose acetate, obviously those skilled in the art can readily ascertain a treating solution for the plastic material employed and provide the same with a saturation value in accordance with the foregoing teachings to thereby obtain the benefit of my invention and employ various plastic materials.

Application of plastic fabric In the event that the invention is employed in providing a cast or splint, preferably the skin area to be contacted by the cast shall be covered with a material inert to the treating solution, such as stockinette, sheet wadding, felt or rayon bandage. In the event that it is desired to `apply the cast directly adjacent the skin of a patient, the comfort of the patient will be enhanced by shaving off any hair and applying a greasy coating as a viscous mineral oil.

Over the skin or over the padding layer, the plastic material in strip or bandage form is wrapped. In many cases it may be desired to wrap more than one layer from the strips being employed and in many cases it may be desired to wrap one layer with the joints lapping at approximately the center of the bandage and then to apply a second layer where the joints between adjacent edges are butted or a second layer in the form of a tubular member. In the event that the cast is to be formed of two layers it is preferable to apply the rst plastic layer wetted with treating solution and the second plastic layer dry. However, either layer may be applied wet or dry. I have found very desirable results may be obtained if the first layer comprises a plastic fabrication pretreated in accordance with the before mentioned method and then after said layer has substantially set to apply a second plastic layer of non-pretreated material-for appearance this may be a tubular member to thus provide a continuous exposed surface. By applying an outer non-pretreated layer it tends to shrink onto the first layer and unify the cast and at the same time the under layer of pretreated material will not shrink upon setting because of the pretreating method and thus I have a well conforming and unified cast.

Referring to Figs. 6 and '7 of the drawingsfl I6 indicates the inert'padding material, H1 indicates the first layer wherein adjacent portions are provided with lap joints, and H3 indicates the outer layer wherein the joints are preferably butted.

Referring to Figs. 8 and 9 of the drawings H6 again represents inert padding material, l Il again indicates the rst layer and 32 represents the outside stockinette or tubular layer formed of one piece.

In applying the treating solution to the plastic fabrication, the fabrication may be wetted with treating solution before it is applied or else the plastic fabrication may be applied and then the same wetted. In order to apply the treating solution to the plastic fabrication, the plastic fabrication may be immersed in treating solution or the treating solution may be poured on, applied by a syringe or spray gun, 0r applied by a brush to wet the plastic fabrication. A very practical Way of applying treating solution to a plastic fabrication, however, is by a syringe emitting a small stream or spray of treating solution. Also, if the plastic fabrication is to be immersed in the treating solution a very practical method is by the device shown in Fig. 14 of the drawings.

In said Fig. 14, H9 represents a container to provide therein a chamber E29. A split cover` member |2I has its end portions hinged :byhinge means .|21 to the .container H9.. Intermediate .the twopieces forming the .cover member 1| 21| tis provided an Vcperring through which a rod |22 may be slidingly moved. Preferably a catch means |28 is hingedly supported on the :cover member.j|;2:| `by pivot means |29 and a spring means t3@ angularly .movesthe catch :means dit into engaging relation vwith .a .rod |22.. .Thus if the rod |22 is moved upwardly it is only necessary to hold the cover .means '|21 y:downwardly and afterthe rod |22 .is positioned .in its sclesired upper position it will :be held such vupper 'posi- `tion by .reason Lof the ycatch .means 112i?. .n.,reservoir |23 Vtor treating solution l.is provided :and said reservoir |23 communicates with the :chamber |28 via port |24. A screw :cap 1:25 is .provided to function .as a llilling .means and also as a means 'to seal the reservoir 123. The :size :of the port V|2 is suchthat the treating solution inthe reservoir E23 will .be delivered :into 'the `clra-rnber 12.!! in a rather small stream and at .thesame time the liquid level in the .chamber |52!) will 'be up tothe level of the port |24. A tray-.like member |31 is provided 0n which a .roll .of plastic fabrication |26 may be disposed.

In the operation of the'deviceshown in Fir-g. 14 a roll of lplastic .fabrication is .disposed about the rod |22 and on the tray 13|. Then the cover means 1.2i yis .opened and the tray I3-l withL the fabrication `|213 thereon is lowered into vthe Acham-- ber |20 and below the liquid level ofthe treating solution in said chamber |29. After the plastic fabrication |2'b` :has been thoroughly wetted v4then the 'rod .|22 is moved upwardly .and .byreasonof the catch means .|28 it lis .retained at a level above the liquid solution in the chamber 1.28. Thus 4in an operating .room the fabrica-tion :L25 Awill be maintained in a closed container. Also at the same time, in view .of the tpreferable 'volatile na.- ture of the `treating -solutionin the chamber 12d., fumes of said treating solution will be presen-t so that a wetted fabrica-tion may :befmaintained in a wetted condition and in the absence -o-f dry-ing conditions so that it will -tbe readily available .so l that as the physician needs further wetted fabrrcation in applying |a cast there xwill :also be a supply readily available for him.

While it is possible to :provide an .open -cen tainer of `treating Asolution and to immerse the fabrication .|26 therein such procedure .is not -desirable and at the same timethe 'volatile treating solution will be evaporating and .thus .a device embodying the .struc-ture 4of y.sa-id Fig. 14 provesto be very practical. It can be 'readily understood that ,it requires a mere movement of the :rod .|22 upwardly to remove the fabrication AI 26 Vfrom the treating solution and at the .same time -when the fabrication is, first placed y"ont-he tray 43| that as the cover means close, Athe fabrication `may .be'at once immersed in the solution in the :chamber 52() or the fabrication may be maintained .at .la level Vabove the solution by .reason of the catch means |28 and thereafter vimmersed vas :and when desired by the physician.

When 'a plastic fabrication lis immersed in a treating solution `of vmy invention, I have found that some of the treating solutions .tend to be selectively exhausted as to one or more of the components of 'the treating :solution :and therefore it is desired to periodically `replace the treating solution into which the fabrication :is 'to 'be immersed so that the lsaturation value of the treating solution maybe maintained :within .the desired range.

lill

' 'In the event 2that the ,liquid .draining .from Lan immersed :fabrication is .notperm'itted to deposit inthe treating solution, then of course it will :not be desirable to periodically .replace the treating solution.

In vthe event that a cast is to be :applied over surfaces, .such as bony prominences or sore spots, it .may vbe `desired to provide `a padding at :such locations fand this .may be readily accomplished in my invention. Referring to Fig. 10, a padding material |33 such as cellulose acetate staple, or sheet wadding., orsoftglass wool is disposedfadjacent the local area and the ca-st material formed thereover .so that the desired padding structure is present. In the event that the padding material employed is a cellulose acetate staple, 'the outer portions will be adhered to the cast .and the inner portions will remain untreated in view of the resistance to wetting or being penetrated by a liquid of the cellulose acetate staple. In said Fig. 10 `the balance of the cast may follow the .structures of either Figs. 6 and 7 or Figs. Bland 9.

'In the event that -it is desired vto provide zexpansion joints or local `areas in the cast Winch are Y'not to be set-up, vthis may be accomplished by employing a ,material which will not be affected by the treating solution, will ynot be washed 01T or dissolved by the treating solution, and one which will envelope .or encase a portion of the .fabrication so that such fabrication in such area cannot be affected by the treating solution. As an example of such a substance which may be employed with the .fabrication .and the treating solution of this 'invention a thin jelly-like solution of gelatin and `water maybe employed. Furthermore, such jelly material Vma'ybe'vvashed or brushed out after the loastihas been .set-up and then upon removal of the jelly, the portion of the cast which was protected by the jellymaybe subjected to a treating solution and such portions then set-up.

Referring particularly to Figs. 8 and 9, |34 represents areas `which have been protected 'so that the same vhave not set-up and may provide expansion joints. The .method to be employed in providing non-set-up portions of .a cast is -rnore fully disclosed .in my copending lapplication Serial No. 4695843, the difference jin Ythe present instance being in .the nature of :the fabrication., thetreating solution, and the coating material.

.Another feature `of my invention .relates to the cutting of a cast .so .that `.the .cast `may :be removed, repaired, or adj-usted. In Tthe prior lart of plaster of Paris casts, the task vof .severing the cast .in .many cases., as a body cast, was such `a strenuous and tedious task that it .has been termed a hammer .and chisel job. `As .distinguished therefrom, in `my vcast the same may Fbe chemically or mechanically severed or a combination of the two may he .utilized .and at .the same time with a minimum of effort. Preferably an inert absorbent material, as vsheet wadding,is applied over the area (local or for the length of the cast) on which the cut 'is to be made. Then acetone lis sprayed or applied to the sheet wadding. The sheetwadding functions to provide acetone in `the 'desired area or region and at the same time the acetone can .function `as a dissolving agent of the cast. 'The cast which has "been so treated `has vbeen found to be readily severable .so that it isronly necessary to use ordinary bandage shears Aand the cast may be severed or local areas removed as may l'be desired. 'Thu-s I have been able to supplant the old process which was involved in plaster of Paris casts and which was a hammer and chisel task to a procedure wherein the cast may be severed by mere bandage shears. Even if the acetone isnot applied to provide the dissolving action above described, it has been found that the cast may be severed with greater ease and with less difficulty than was required with the old plaster of Paris cast.

Referring to Fig. 11 of the drawings a completed cast is illustrated as having disposed thereon sheet wadding |36. Thereafter the sheet wadding |36 is wetted with acetone and a desired local area of the cast |35 is so dissolved or softened that it may be readily removed or reshaped. Preferably the material will merely be reshaped, as an opening may cause window edema. I-Iowever, if an opening is provided, then as shown in Fig. l2 of the drawings, the material |31, which may be similar to material |36 of Fig. 1l, is preferably disposed in the opening provided in the cast |35 and cast-forming material |33 may be applied and the same may be adhered to and form an integral part of the cast |35. Thus, in the event of sore spots developing under a cast, portions of the desired shape of the cast may be softened, reshaped, retted, or removed, the pressure removed and the cast repaired to original strength. The lack of such characteristics has been one of the major shortcomings of plaster of Paris casts.

VAfter a cast involving my invention has been severed, it may be readily repaired and then a coating material embodying the fabrication of my invention may be applied and then upon the application of further treating solution, the patch or repair material will be firmly adhered to the cast and the cast will have its original strength. In the past where plaster of Paris casts were employed, the strength of the cast depended upon the maintaining of its original structural form and any repair caused a weakening of the cast unless the repair Work in substance involved the making of a new cast.

Referring to Fig. 13 of the drawings, a fragment of a cast |39 is illustrated and padding |40 similar to padding |36 of Fig. 11 is shown. Thus in the event that it is desired to provide slits in a cast to remove the cast or to adjust the cast for size, it is only necessary to provide the material |40 to form a strip and then acetone may be applied to the material |40 to dissolve the cast. Thereafter by bandage shears the cast may be severed for removal or adjustment. If the cast is severed for adjustment then a strip of bandage material may be applied similarly to the description in connection with Fig. 12, and the cast repaired after the adjustment has been made.

This invention accomplishes the Various objects which were set forth in the first part hereof and provides further results which have been set forth in the description of the various structures and methods. It is believed the same are therefoi'e sufficient without further setting forth the same at this place.

Obviously, changes may be made in `the forms, dimensions, and arrangements of the parts of my invention, without departing from the principles thereof, the above setting forth only pre-A ferred forms of embodiment.

I claim:

1. A substantially unyielding and inelastic orthopedic brace comprising a fabrication formed of plastic fibers thoroughly wetted by a volatile organic setting agent and thereafter set, the setting agent being characterized by having a saturation value for the plastic of between fifty milligrams and three hundred milligrams per one hundred cubic centimeters of setting agent at 7 0 F.

2. A substantially unyielding and inelastic orthopedic brace comprising an open mesh fabrication incorporating therein pieces of reinforcing material insoluble in the volatile organic setting agent to be used, said fabrication being thoroughly wetted by a volatile organic setting agent and thereafter set, the setting agent being characterized by having a saturation value for the plastic of between fifty milligrams and three hundred milligrams per one hundred cubic centimeters of setting agent at F.

3. A substantially unyielding and inelastic orthopedic brace comprising a pre-shrunk fabrication'formed of plastic fibers which is soluble in a volatile organic setting agent, the said preshrunk fabrication being thereafter thoroughly wetted by a volatile organic setting agent and thereafter set, the setting agent being characterized by having a saturation Value for the plastic of between fifty milligrams and three hundred milligrams per one hundred cubic centimeters of setting agent at 70 F.

4. A substantially unyielding and inelastic orthopedic brace comprising a pre-shrunk fabrication formed of plastic fibers which is soluble in a Volatile organic setting agent, the setting agent being characterized by having a saturation value of less than seventy-five milligrams per one hundred cubic centimeters of solvent at 70 F., the said pre-shrunk fabrication being thereafter thoroughly wetted by a volatile organic setting agent in which the same is soluble, the setting agent being characterized by having a predetermined saturation limit for said plastic to gelatinize and dissolve part thereof without destroying the structure of the fabric.

5. A substantially unyielding and inelastic orthopedic brace comprising a pre-shrunk fabrication formed of plastic fibers in a volatile organic setting agent and which has been preshrunk by heated uid at a temperature of between 350 F. and 425 F., the said pre-shrunk fabrication being thereafter thoroughly wetted by a volatile organic setting agent in which the same is soluble and thereafter set, .the setting agent being characterized by having a predetermined saturation limit for the plastic to gelatinize and dissolve part thereof without destroying the structure of the fabrication.

6. A substantially unyielding and inelastic orthopedic brace comprising a fabrication formed of plastic fibers thoroughly wetted by a volatile organic setting agent and thereafter set, the setting agent being characterized by having a saturation value for the plastic of between three hundred milligrams and one hundred fifty milligrams per one hundred cubic centimeters of setting agent at 7 0 F.

7. A substantially unyielding and inelastic orthopedic brace comprising a fabrication formed of cellulose acetate fibers thoroughly wetted by a volatile organic setting agent and thereafter set, the setting agent including therein acetone and a diluent which is a non-solvent for cellulose acetate, the setting agent being character- 17 n 18 ized by having a saturation value for the plastic UNITED STATES PATENTS of between fifty milligrams and three hundred Number Name Date milligrams per one hundred cubic centimeters of 696,123 Weidig Mar. 25, 1902 Settmg agent 70F- 2,219,829 Teague @qu 29, 1940 ROGER ANDERSON. 5 2,292,531 Lovell Aug. 11, 1942 OTHER REFERENCES REFERENCES CITED Industrial Solvents by Ibert Mellan, published The following references are of record in the by the Remhold Pubhshmg Corp of New York' l l0 New York. Copyrighted in 1939. Pages 47 and le of this patent. 52. Copy mmv. 64.