This invention relates to a custom-formable knee immobilizer product, knee immobilizer and method.
The invention has particular application in the orthopedic medical field, where injured or diseased knees are often supported and immobilized with a splint or brace so that the patient can continue to walk, albeit with a stiff leg, while the injury heals. Typical injuries which can sometimes require immobilization may include, but are not limited to, pulled or torn quadriceps muscles and tendons and/or the patellar tendon, chondromalacia patellae, pulled or torn medial or lateral collateral ligaments, and posterior or anterior cruciate ligaments. Certain related degenerative conditions, as well post-operative recovery and therapy following a wide range of orthopedic surgical procedures, may also require immobilization of the knee.
In such cases, it is essential to immobilize the knee in such a way as to prevent articulation., which can strain healing muscles, tendons, ligaments and bone surfaces. In addition, the knee must be stabilized to prevent eversion and inversion.
The invention of the present application takes advantage of polymer chemistry to permit quick and easy molding of an immobilizer to the knee and adjacent thigh and calf portions of the leg. The close, custom fit achieved is in distinct contrast to so-called xe2x80x9cone size fits allxe2x80x9d braces or splints wherein bendable plastic rods or stays provide support, and are held in place by a heavy fabric tube.
The particular embodiment of the immobilizer disclosed in this application will accommodate a wide range of sizes and can be fitted to either the right or left knee. Thus, a much reduced inventory is required. This feature also substantially reduces design and manufacturing costs, and promotes use through ease of fitting. The custom-fit of the immobilizer not only permits easy removal for bathing, dressing or adjustment, but also easy and mistake-proof replacement even by children.
Prior art immobilizers include numerous types of splints and braces which typically include a soft component to place near the skin and a semi-rigid metal or plastic stays which are bent into a shape conforming to the aspect of the knee against which the stay resides. The soft component, for example, fiber padding, foam or an air bladder, is intended not only to provide a cushion, but also to accommodate itself to the varying configurations of differing sized and shaped body parts. For this reason, the cushioned part is substantially greater in thickness than required merely to provide the protection from injury or irritation caused by direct contact with the stays.
Some prior art knee braces include stays which are constructed of thermosetting materials which are heated and then formed to the body while heated. These products require a source of heat, and are susceptible to either over-or-underheating. In addition, body heat itself can soften or increase the flexibility of the stays, thereby decreasing the effectiveness of the protection offered.
The present invention permits quick and easy application of a immobilizer to a knee in such a way as to achieve a true custom fit. The. moisture curable resin system used results in a very rigid splint which holds the shape of the molded splint to a very high degree. No heat is required, and a source of water is the only additional material necessary to achieve a cure. Atmospheric moisture alone will cure the splint into its hardened position in a relatively short period of time, but in practice the resin in or on the splint will typically be activated by dipping the splint in water and then removing the excess water by rolling the splint in a towel immediately before the splint is applied to the knee.
Therefore, it is an object of the invention to provide a custom-formable knee immobilizer.
It is another object of the invention to provide a knee immobilizer which can be molded to a knee to stabilize the knee against articulation, eversion and inversion.
It is another object of the invention to provide a knee immobilizer which can be custom-formed to a particular patient.
It is another object of the invention to provide knee immobilizer having a shape which permits it to be used on either the left or the right knee.
It is another object of the invention to provide knee immobilizer which hardens in the presence of moisture to form a very rigid but very lightweight splint portion.
It is another object of the invention to provide a knee immobilizer which is stored in a moisture-proof pouch until ready for being custom-fitted to the knee.
It is another object of the invention to provide a knee immobilizer which is custom-molded to a patient""s knee in such a way that it can be initially held in place with an elongate elastic strip to reduce edema, and thereafter held in place with a strap or straps during later stages of healing.
These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a custom-formable knee immobilizer product for being custom-formed to the shape of a knee while flexible and upon hardening providing a rigid, knee-supporting custom fit. The knee immobilizer product comprises an outer container formed of moisture-impervious material and a plurality of elongate knee splint segments positioned in the container in substantially moisture-free conditions and sealed therein against entry of moisture until use. Each of the knee splints comprises an elongate substrate, and a reactive system impregnated into or coated onto the substrate. The system remains stable when maintained in substantially moisture-free conditions and hardens upon exposure to moisture to form a rigid, self supporting structure. A flexible protective outer cover is positioned over the substrate along its length to enclose the substrate. The substrate and outer cover thus form a unitary structure for being molded while flexible to an aspect of the knee and adjacent thigh and calf portions of the leg. A bandage is provided for being positioned on and held in a closely-conforming configuration around the knee and adjacent thigh and calf portions of the leg. Splint supports cooperate with the splints and the bandage for maintaining the plurality of splints on the bandage in closely conforming position in vertically spaced-apart relation around the knee for substantially immobilizing the knee in a predetermined recovery position.
According to one preferred embodiment oft he invention, the splint supports include first and second complementary hook-and-loop elements on respective mating surfaces of the bandage and the splints.
According to another preferred embodiment of the invention, the splint supports include a plurality of vertically-extending pockets formed in the bandage for positioning and supporting the vertically-extending splints around the knee.
According to yet another preferred embodiment of the invention, the container is fabricated of an aluminum foil laminate having an outer tear resistant layer, a central aluminum foil layer and an inner heat sealable plastic layer.
According to yet another preferred embodiment oft he invention, the substrate is formed from a plurality of knitted or woven fabric layers.
According to yet another preferred embodiment of the invention, the bandage is formed from a foam sheet material.
Preferably, the foam material is chosen from the group consisting of open or closed cell EVA or polyurethane.
According to yet another preferred embodiment of the invention, the bandage includes a fabric material covering at least one side of the foam sheet material.
According to yet another preferred embodiment of the invention, the fabric of the outer cover is chosen from the group consisting of woven, knitted or non-woven fabric.
According to yet another preferred embodiment of the invention, the reactive system comprises a blended polyisocyanate, polyol, catalyst and stabilizer.
According to yet another preferred embodiment of the invention, the bandage is a tube for being pulled onto the leg over the foot.
According to yet another preferred embodiment of the invention, the bandage includes a flat sheet having cooperating mechanical fasteners for releasably holding the sheet around the knee.
According to yet another preferred embodiment of the invention, the mechanical fasteners comprise first and second complementary hook-and-loop elements on mating surfaces of the flat sheet.
According to yet another preferred embodiment of the invention, an elongate elastic strip is provided for being wrapped around the knee over the bandage and splints during curing of the moisture-curable resin and thereby holding the bandage and splints in closely conforming position on the knee.
According to yet another preferred embodiment of the invention, the splints are approximately one inch wide.
According to yet another preferred embodiment of the invention, at least one retaining strap is provided for releasably encircling and maintaining the custom-molded bandage and splints in supporting position on the knee.
In accordance with a subcombination of the product, a custom-formable knee immobilizer is provided for being custom-formed to the shape of a knee while flexible and upon hardening providing a rigid, knee-supporting custom fit. The knee immobilizer comprises a plurality of elongate knee splints, each comprising an elongate substrate and a reactive system impregnated into or coated onto the substrate. The system remains stable when maintained in substantially moisture-free conditions and hardens upon exposure to moisture to form a rigid, self supporting structure. A flexible protective outer cover is positioned over the substrate along its length to enclose the substrate. The substrate and outer cover form a unitary structure for being molded while flexible to an aspect of the knee and adjacent thigh and calf portions of the leg. A bandage is positioned on and held in a closely-conforming configuration around the knee and adjacent thigh and calf portions of the leg. Splint supports cooperate with the splints and the bandage for maintaining the plurality of splints on the bandage in closely conforming position in vertically spaced-apart relation around the knee for substantially immobilizing the knee in a predetermined recovery position.
An embodiment of the method of therapeutically immobilizing a knee according to the invention includes the steps of providing a plurality of elongate knee splints, each comprising an elongate substrate and a reactive system impregnated into or coated onto the substrate. The system remains stable when maintained in substantially moisture-free conditions and hardening upon exposure to moisture to form a rigid, self supporting structure. A flexible protective outer cover is positioned over the substrate along its length to enclose the substrate, the substrate and outer cover forming a unitary structure for being molded while flexible to an aspect of the knee and adjacent thigh and calf portions of the leg. A bandage is provided for being positioned on and held in a closely-conforming configuration around the knee and adjacent thigh and calf portions of the leg. Splint supports cooperate with the splints and the bandage for maintaining the plurality of splints on the bandage in closely conforming position in vertically spaced-apart relation around the knee for substantially immobilizing the knee in a predetermined recovery position. The bandage is placed in a closely-conforming configuration around the knee and adjacent thigh and calf portions of the leg. The splints are wetted and placed into engagement with the bandage by cooperation with the splint supports in vertically spaced-apart relation around the knee to thereby substantially immobilize the knee in a predetermined recovery position. The bandage and engaged splints are held in the closely-conforming configuration for a period of time sufficient to allow the resin to harden the splints.
According to one preferred embodiment of the invention, the step of placing the bandage in a closely-conforming configuration around the knee and adjacent thigh and calf portions of the leg comprises the step of pulling a tubular bandage over the foot and onto the knee portion of the leg.
According to another preferred embodiment of the invention, the step of placing the bandage in a closely-conforming configuration around the knee and adjacent thigh and calf portions of the leg comprises the step of placing a flat sheet around the knee and releasably securing the sheet around the knee with mechanical fasteners.
According to yet another preferred embodiment of the invention, the step of securing the sheet around the knee with mechanical fasteners comprises the step of connecting first and second complementary hook-and-loop elements carried on matable surfaces of the flat sheet.
According to yet another preferred embodiment of the invention, the method includes the step of maintaining the bandage and engaged splints in the closely-conforming configuration for a period of time sufficient to allow the resin to harden the splints comprises the step of wrapping an elongate elastic strip around the knee. over the bandage and splints during curing of the moisture-curable resin, thereby holding the bandage and splints in closely conforming position on the knee.
According to yet another preferred embodiment of the invention, the step of placing the splints into engagement with the bandage comprises the step of inserting the splints into respective vertically-oriented pockets formed in the bandage.
According to yet another preferred embodiment of the invention, the step of placing the splints into engagement with the bandage comprises the step of attaching to the bandage with complementary hook-and-loop elements.