GLASS PLASTIC CAST

ROGER ANDERSON, M.D. AND HERBERT R. ERICKSON, M.S. SEATTLE, WASHINGTON

I N a recent article,’ one of the authors as resistance to water, lightness of weight, discussed the attributes of an idea1 porosity, transparency to x-ray, and &an- cast, and described a new, open-mesh, Iiness in application. (Figs. I, 2, and 3.)

FIG. I. The bandage is so knitted from glass and pIastic fibers that it is flexible, porous, and elastic. Its strength comes from the truss-like design. The band- age is made in severa widths and is packaged in ceIIophane for ease of handIing and to keep it cIenn.

waterproof, pIastic cast that in most respects met the requirements. The cIinica1 effectiveness of this type of pIastic cast has aheady been estabhshed by appIication to a substantia1 number of patients at the United States NavaI HospitaI, as reported by KuIowski, French, and Erickson.2 In brief, the bandage then reported and the improved form to be discussed here is a knitted, a11 pIastic bandage which, after being wetted with setting soIution, hardens into a rigid cast.

The pIastic bandage previousIy reported had many outstanding advantages, such

There were, however, a few drawbacks. For exampIe, considerabIe care was re- quired in its appIication, especiaIIy to avoid applying the bandage under tension, which sometimes Ied to contraction of the cast. The spraying on of the setting Iiquid required considerabIe time. By modifying the composition of the origina bandage, these fauIts have been eliminated, and the desirabIe characteristics of the bandage have not onIy been retained but even bettered.

The modification which has made this major improvement possibIe is the substi-

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300 American Journal of Surgery Anderson, Erickson-Plastic Cast SwrEMBEH, I

FIG. 2. The gIass plastic cast can be applied directly to the skin. Although very light, it is surprisingly durabIe and will withstand a good deal of wear. SoiIing can be removed with soap and water. Aire-Lite can be sterilized in the usua1 manner in the autocIave, and since it can be applied close to or directly over the wound, a new approach to the treatment of wounds, burns, com- pound fractures, and plastic procedures is provided.

FIG. 3. T. B., Perthe’s disease of the right hip. Radiograph taken through an Aire-Lite cast shows onIy slight obstruction to the rays. The great strength of the material makes it possible to hold major fractures, such as those of the peIvis or upper femur, with such a thin cast that cIear radiographs can be obtained. The Iight weight helps the patient to become ambuIatory even when wearing a spica cast.

New SERIES VOL. LXIX. No. 3 Anderson, Erickson-PIastic Cast American Journal of surgery 30 I

tution of gIass flaments of Fiberglas for interior finish. The wetted cast sets and the regenerated ceIIuIose or rayon content. dries considerabIy faster than did the WhiIe various combinations of soIubIe previously reported type. The compIeted

FIG. 4. Although the components of the bandage are sIightIy heavier than water, the porous structure of a cast of several layers entraps suffkient air to give it e&gh buoyancy to float.

pIastics, with or without insoIubIe pIastics, have proved successfu1, the preferred com- position is ceIIuIose acetate 80 per cent and gIass 20 per cent by weight. Since both the gIass and pIastic fiIaments are finer than hair, smooth and fIexibIe, the final knit bandage is soft, flexibIe, and eIastic. By empIoying a specia1 knitting technic and by reguIating the physical-chemica1 pretreating process and the FibergIas con- tent, it is possibIe to capitaIize on the eIastic characteristics of the bandage so that it can be applied under tension with- out danger of subsequent contraction.

The bandage is wetted by immersion in the setting Iiquid just before it is appIied. The action of the fluid on the entwined pIastic and gIass fiIaments fuses them into a rigid but smooth cast with a cooI, silky

cast is Iight and porous. AIthough the component pIastics are heavier than water, the structure of the cast is such that it wiI1 actuaIIy float in water. (Fig. 4.) The open mesh provides free circuIation of Iight and air.

The setting or weIding fluid is cIinicaIIy a non-toxic soIution with a sIight winter- green odor that most users do not consider disagreeabIe. AIthough it is inffammabIe, no greater precautions need to be taken than for ether. The soIution is compounded of chemicaIs with Iow boiIing points to insure rapid evaporation. WhiIe various setting soIutions can be used, the Iiquid used at present is a combination of acetone, methy saIicyIate, and a group of hydro- carbons. The accurate formuIation of this bIend defines and reguIates its action so

302 American Journal of Surgery Anderson, Erickson-PIastic Cast SEPIEMBEH, ,945

that ; the glass and plastic fiiaments will action on the skin of the hands from fuse together without the celIuIose acetate extensive use of the setting liquid, but the bein .g appreciabIy dissolved or softened. authors have had no diffIcuIty. This is

FIG. 3. The bandage is easy to apply. As illustrated, the bandage is wetted by immersion in the Erickson Immersion Can. Since the bandage is etastic, it can be wrapped on under tension so as to con- form to body contours.

This permits the cast to dry in a relativeIy short time.

Regarding possibIe reaction of the Iiquid on the body, there are two factors which make it safe to use, as verified by substan- tiaI cIinica1 experience: First, the com- ponents have been carefuIIy chosen for their non-toxic quaIities and non-irritant characteristics, and second, the extreme voIatiIity of the bIend, coupIed with the designed porosity of the cast, make it virtuaIIy impossible to maintain the Iiquid in contact with the body for more than a few minutes. As for the operator, there have been a few reports of a drying-out

easily prevented by the use of rubber gIoves or the appIication of two or three drops of mineral oi1 to the hands prior to using the liquid.

There have been no reported aIIergic reactions from wearing of the gIass plastic cast, and, judging from experience with pIastics in other fieIds, their incidence shouId be extremeIy Iow. CeIIuIose acetate has been used in a host of ways in contact with the body, ranging from such items as Iingerie and stockings to such articIes as teething rings for babies, without appreci- abIe reaction. FibergIas, too, is quite inert as far as body tissues are concerned. For

NEW SERIES VOL. LXIX, No. 3 Anderson, Erickson-PIastic Cast American Journal of surgery 303

exampIe, it is being used without harmfuI application of the cast, stockinet is used, effects in sutures, in surgica1 sponges, and with one end Ieft extended so that it can as a burn dressing.3s4’” be held by an overhead support. If stocki-

FIG. 6. Mrs. J. C., flail lower extremities from a recent attack of poIiomyelitis. She is being taught to walk again through hydrotherapy. Later the foot portion of the cast wiII be removed, and the cast bivalved and applied onIy during walking exercises.

The question of infIammabiIity of the compIeted cast is an interesting one. The gIass portion, of course, is compIeteIy non- inflammable and the ceIIuIose acetate burns reIuctantIy, especiaIIy when in the form of a cast. It burns Iess readiIy than cIothes or bedding.

net is not desirabIe, the hand can be sup-

ported by means of finger traps. Th’In strips of feIt can be pIaced to assist Iater in wedging, bivaIving, or remova of the cast. The bandage can be appIied direct to the skin, and when properIy appIied the inside of the cast wiI1 be practicaIIy as smooth as a dinner pIate. If the skin is dusted with taIcum powder, the cast wil1 not adhere to hairs or skin. Since the band- age can be steriIized by the usua1 auto- claving methods, it can be pIaced safeIy over or into open wounds.

TECHNIC

The technic of appIying the gIass pIastic bandage is simpIe and in a genera1 way resembIes that for a pIaster cast. It can be quickly Iearned.

The part to be casted can be padded in the usua1 manner with sheetwadding. However, since the bandage is eIastic, it can be so smoothIy and accurateIy appIied that padding is unnecessary. To have a good support for the extremity during

The bandage is wetted by immersion in the setting fluid (preferabIy in a suitabIe device, such as iIIustrated in Figure 5). The bandage is immediateIy withdrawn from the Iiquid and with some tension it is wrapped in pIace. After the cast has been

304 American Journd of Surgery Anderson, Erickson-PIastic Cast SEPTEMBEH. ,915

compIeted, an ordinary eIastic cotton bandage is wrapped over the entire cast. The cast is then shaped, smoothed down, and circuIarIy rubbed with the paIm for a few minutes, after which the cotton bandage is removed. Setting can be has- tened by using a smaI1 hair drier.

Disadvantages, fortunateIy, are few and are not serious impediments to successful use. Their partiaI if not compIete eradica- tion appears a near possibihty. The one disadvantage of any concern is that the setting time is sIightIy Ionger than that for pIaster. However, this is IargeIy compen- sated for by the fact that an Aire-Lite cast will dry out faster than a pIaster cast. Recent improvements have considerabIy lessened the setting time, and, judging by the trend of continuing research, it wiI1 be stiI1 further reduced.

The cost of the pIastic cast is at present somewhat higher than plaster. However, this difference in cost becomes negIigibIe when a11 of the cost factors invoIved are taken into account. For exampIe, with pIaster, the need of extra Iinen and gowns, the Iaundering expense, the tracking and cIeaning of floors and carpets, and the time and expense of frequent cast changes add up to a substantia1 amount. The outIook is for a continued Iowering of the price of pIastics as a resuIt of ever increasing technoIogica1 advances.

Another drawback has been that the process of moIding the cast to correct such conditions as cIub foot or anguIated fracture couId not be readiIy done because pressure of the hands wouId interfere with evaporation. This situation has been met by aIIowing the eIastic cotton bandage to remain in pIace at the site of the con- tempIated moIding until the adjoining areas have set. When the desired degree of rigidity has been attained in the contiguous portions, the cotton bandage is removed. The ‘usua1 moIding or anguIar correction is then made, and the soft portion of the cast is Ieft uncovered to harden in position of correction, in the usua1 manner.

Clinical Advantages. The gIass pIastic bandage can be used for a11 types of immobiIization and for unusual therapeutic measures.

Since the materia1 is waterproof, the patient can bathe, and the cast can be cIeansed with soap and. water. In the treatment of poIiomyeIitis, arthritis, hand and other infections, and most traumatic conditions, hot packs and hydrotherapy can be carried on without disturbing immobiIization. (Fig. 6.)

Since the cast components do not absorb Iiquids or odors, invoIuntaries of seniIe or infant patients do not harm the cast and can be removed by washing.

AIthough an Aire-Lite cast weighs only one-fourth to one-sixth as much as a pIaster cast, it is so strong and durabIe that changes are seIdom necessary.

The eIastic bandage is knitted with an open mesh and is so processed that it can be safeIy applied under tension to conform to every contour. It is as suitabIe for a IittIe finger cast as for a Iarge spica cast.

It is idea1 for immobiIization of hand and foot injuries and faciIitates earIy return to work because the cast wiI1 not soften from absorption of Iiquids and can be readiIy cIeansed of dirt.

The cast can be cut with an ordinary cast cutter, or, by appIying the setting Auid or a softening cream, it can be cut with bandage scissors.

The cast is coo1 to wear, its porous structure admits Iight and air, and even when the cast is wet it does not bIock x-ray penetration. It can be used in the tropics because it does not absorb moisture and is not affected by humidity, molds, or fungi.

The bandage can be steriIized in the autocIave, and since it can be appIied direct to the skin, numerous improved technics become possible. The preIiminary cIinica1 work in these fieIds shows promise and points to it as a usefu1 addition to the armamentarium of the surgeon. The charac- teristics of the cast open a whole new avenue of theraDv in such varied fieIds as

NEW SERIES VOL. LXIX, No. 3 Anderson, Erickson-Plastic Cast ~~~~~~~~ ~~~~~~~ of surgery 305

the treatment of compound fractures,

osteomyelitis, burns, skin plastics, and

orthopedic and urological reconstructions.

3. SCHOLZ, ROY PHILIP and ,~‘IOUNTJOY, PHILIP S. Fiberglas srrtnre material. Am. J. Surg., $6, htc) 621, 1942.

REFERENCES

4. I.I:.WISON, EDWAKD F. Rayable gauze as a factor 01 safety in surgical operations. Bull. Am. Coil. Surg., 27: 39-40, 1942.

I. ANDEKSON, ROGER: New waterproof plastic cast. 5. ~IIRSIIFELD, JOHN W., Q'ILLIAMS, HAROLD H., Northwest Med., 43: 365, 1944. ABBOTT, WILLIAM E., HELLER, CARL G. and

2. KULOWSKI, J., FRENCH, A: M. and ERICKSON, I-1. R. PILLING, MATTHEW A. Significance of the nitrogen Aire-Iite, a new pIastic medium of clinica im- loss in the exudate from surface burns. Sureqv, mobilization. Am. J. .%r,q., 66: 315-327, 1944. 15: 766-773. ‘944.

AMPUTATION at the wrist should be planned, if possibIe, so as to save the thumb and a finger or other portion of the hand against which the thumb

may be apposed. Amputation at tbe wrist prevents the proper fitting of an artificial hand and wrist mechanism without undue length, and should br

avoided.

From “PrincipIes and Practice of Surgery” by W. Wayne Babcock

(Lea & Febiger).