Hinge appliance for minimizing knee injuries

[0002] This application claims priority of U.S. Provisional Application Serial No. 60/139,756, filed Jun. 17, 1999.

[0003] 1. Field of the Invention

[0004] This invention relates generally to knee braces, and more particularly to a hinge appliance having juxtaposed rotating disks with a cam and stop members that prevent rotation when the knee is subjected to a blow from the front and prevent excessive lateral movement between the upper and lower leg and a pair of chambers in the disks filled with a colored liquid that is released upon the disks being subjected to a predetermined lateral force to give a visual indication that the knee joint has received a serious lateral impact and indicates that a replacement hinge assembly is needed.

[0005] 2. Brief Description of the Prior Art

[0006] Athletes and occasional participants in sporting events and recreational such as baseball, football, basketball, volley ball, tennis, running and cycling has often resulted in debilitating injuries, especially to the knee. Often, the injury requires surgical procedures to repair the joint followed by a program of physical therapy.

[0007] There are many patents directed toward knee braces and orthopedic appliances, most of which are bulky and/or complicated heavy metal devices that are worn after an injury to immobilize the joint, to allow only a limited range of motion, or to bear the weight of the wearer during the rehabilitation process.

[0008] Townsend, U.S. Pat. No. 4,773,404 discloses a multi-axis controlled motion knee orthosis appliance for controlling an unstable knee joint in the sagittal, coronal and transverse planes, comprising femoral and tibial cuffs joined by links which are interconnected to provide a novel mechanical joint wherein camming slots are formed in one of the links with cams disposed on the other link, the slots comprising straight segments and arcuate segments so as to provide approximately 8 millimeters of sliding movement between the femur and tibia, followed by relative rotation about the center of radius of the femoral condyle as the leg is flexed. The tibial cuff is conformed about the boney prominence or shin of the tibia to inhibit rotation of the leg beneath the knee within the brace itself.

[0009] Kausek, U.S. Pat. No. 4,966,133 discloses a knee brace for control of ligament instability in all planes having upper and lower cuffs above and below the knee, a polycentric hinge on the lateral side of the knee, and a medial articulation plate on the medial side of the knee. The cuffs are attached to the leg with non-stretchable straps and provide anterior-posterior stability. The medial pivot plate is designed to stabilize the brace on the medial side of the knee and in conjunction with the lateral hinge and a lateral plate provides medial-lateral stability.

[0010] Airy, U.S. Pat. No. 5,052,379 discloses a combination brace and exercise apparatus for body joints that is worn by the user in various configurations, including as a splint to hold a body joint immovable, as a brace to permit the body joint to move through a controlled range of motion and as an exercise apparatus to impart resistance to the flexing and/or extension movement of the body joint. The apparatus includes an articulating frame composed of a first frame section connectable to the first limb of a body joint and a second frame section connectable to a second limb of a body joint. The two frame sections are interconnected together by pivot joint assemblies to permit the frame to articulate about a transverse axis corresponding to the anatomical pivot axis of the body joint. A control plate having adjustable stop pins is mounted on the pivot joint assemblies to control the range of motion of the articulating frame. With the control plate in place, various types of resistance units may be employed to resist relative movement of the frame sections in either or both directions about the pivot axis.

[0011] Harris et al, U.S. Pat. No. 5,074,290 discloses a floating pivot hinge and knee brace that includes a thigh cuff having inner and outer spaced brace arms adapted to extend along the user's thigh toward the knee, a calf cuff including inner and outer spaced brace arms adapted to extend along the user's calf toward the knee, and floating pivot axis hinges rotatably connecting the inner and outer brace arms of each pair. The hinge is formed by a pair of juxtaposed hinge plates, each having a pivot face in opposition to a pivot face on the juxtaposed plate, with a concave groove in each of the face. A pivot bearing ball is confined between the opposed faces and retained in the concave grooves. A spring, bellville spring, or disk spring biases the hinge plates together when the pivot bearing ball is positioned in the opposed grooves between. The pivot bearing ball provides a floating pivot axis for hinge rotation of the hinge plates and braces relative to each other, the ball and concave grooves allowing the hinge plates simultaneously to slide and pivot relative to each other.

[0012] Gildersleeve, U.S. Pat. No. 5,316,547 discloses an orthopedic brace having one or more pneumatic pads mounted thereon to provide secure and comfort able support for the brace when positioned against the body of a user. Each pad includes at least one pneumatic bladder, formed from a flexible skin permanently sealed to enclose a volume of gas therein.

[0013] Most of the devices of the type described above are not suitable for use while participating in strenuous exercise or sports activities to prevent an injury from occurring in the first place, and some could even cause an injury to the wearer or other participant if worn during such activities.

[0014] Therefore it would be desirable to provide a lightweight disposable knee hinge appliance that may be worn to prevent injuries to the knee joint that supplements the natural resistance of the joint to excessive movement and will alert the wearer when the joint has received a substantial impact.

[0015] The present invention is distinguished over the prior art in general, and these patents in particular by a knee hinge appliance having a pair of hinge assemblies that are secured on the leg of a wearer on opposed lateral sides of the knee joint. Each hinge assembly is formed of juxtaposed first and second disks that rotate relative to one another about a transverse axis extending through the knee joint. The first disk has an upper arm secured to an upper strap or band that encircles the thigh just above the knee joint, and the second disk has a lower arm which is secured to a lower strap or band that encircles the lower leg just below the knee joint. The disks have a cam that slides freely in a circular channel with stop members that allow normal flexing of the knee joint but prevent rotation when the knee is subjected to a blow from the front and prevent excessive lateral movement between the upper and lower leg. A pair of chambers in the disks are filled with a colored liquid which is released upon the disks being subjected to a predetermined lateral force to give a visual indication that the knee joint has received a serious lateral impact and indicates that a replacement hinge assembly is needed.

[0016] It is therefore an object of the present invention to provide a knee hinge appliance to be worn around the knee joint that will minimize the degree and severity of damage to the knee.

[0017] It is another object of this invention to provide a knee hinge appliance that allows normal flexing of the knee joint but will prevent rotation when the knee is subjected to a blow from the front.

[0018] Another object of this invention is to provide a knee hinge appliance that allows normal flexing and will prevent excessive lateral movement between the upper and lower leg.

[0019] Another object of this invention is to provide a knee hinge appliance that will release a colored liquid when the knee joint is subjected to a lateral impact exceeding a predetermined force to give a visual indication that the knee joint has received a serious lateral impact and to indicate that a replacement hinge assembly is needed.

[0020] Another object of this invention is to provide a lightweight thin compact knee hinge appliance that may be worn while participating in strenuous exercise or sports activities that will not hinder the natural motion of the knee joint, and will not cause injury to the wearer or other participants if worn during such activities.

[0021] A further object of this invention is to provide a knee hinge appliance that has minimum of moving parts, and is rugged and reliable in use.

[0022] A still further object of this invention is to provide a knee hinge appliance that is simple in construction, inexpensive to manufacture, and may be disposed of after failure.

[0023] Other objects of the invention will become apparent from time to time throughout the specification and claims as hereinafter related.

[0024] The above noted objects and other objects of the invention are accomplished by a knee hinge appliance having a pair of hinge assemblies that are secured on the leg of a wearer on opposed lateral sides of the knee joint. Each hinge assembly is formed of juxtaposed first and second disks that rotate relative to one another about a transverse axis extending through the knee joint. The first disk has an upper arm secured to an upper strap or band that encircles the thigh just above the knee joint, and the second disk has a lower arm which is secured to a lower strap or band that encircles the lower leg just below the knee joint. The disks have a cam that slides freely in a circular channel with stop members that allow normal flexing of the knee joint but prevent rotation when the knee is subjected to a blow from the front and prevent excessive lateral movement between the upper and lower leg. A pair of chambers in the disks are filled with a colored liquid which is released upon the disks being subjected to a predetermined lateral force to give a visual indication that the knee joint has received a serious lateral impact and indicates that a replacement hinge assembly is needed.

[0025] FIG. 1 is an illustration of the hinge appliance in accordance with the present invention secured to the leg of a wearer by a fabric strap or band.

[0026] FIG. 2 is an exploded isometric view of the disk members of the hinge appliance, shown in an unassembled condition.

[0027] FIG. 3 is a plan view showing of the disk members in the assembled condition.

[0028] FIG. 4 is a side view of the disk members in the assembled condition.

[0029] FIG. 5 is an enlarged longitudinal cross section through the assembled disk members taken along line 5—5 of FIG. 3.

[0030] FIG. 6 is a transverse cross section through the assembled disk members showing the direction of rotation of the cam.

[0031] FIG. 7 is a transverse cross section through the assembled disk members, showing the cam and pin members in a position following a hard lateral impact.

[0032] Referring initially to FIG. 1, a pair of knee hinge appliances 10, in accordance with the present invention, are shown secured on the leg L of a wearer on opposed lateral sides of the knee joint. As described in detail hereinafter, each hinge appliance 10 has a hinge assembly 11 formed of juxtaposed first and second disks 12 and 24 that rotate relative to one another about a transverse axis 31 extending through the knee joint. The first disk 12 has an upper arm 23 secured to an upper strap or band 28 that encircles the thigh just above the knee joint, and the second disk 24 has a lower arm 27 which is secured to a lower strap or band 29 that encircles the lower leg just below the knee joint.

[0033] As shown in FIGS. 2 through 6, each hinge assembly 11 of the appliance 10 has a first circular disk 12 with a flat end wall 13 and a circumferential side wall 14. A generally C-shaped chamber 15 is spaced radially inward from the circumferential side wall 14 and has a circular outer wall 15A and a concentric inwardly spaced C-shaped inner wall 15B adjoined thereto by a top wall 15C that encloses the chamber. The annulus between the outer wall 15A of the chamber 15 and the circumferential side wall 14 serves as an open guide or circular channel 16 in which an arcuate cam 25 (described below) freely slides. A generally rectangular first stop member 17 is secured in the guide channel 16 in circumferentially offset relation to a vertical axis VA, extending through the center of the upper arm 23 as shown in FIG. 3.

[0034] A tubular bushing or hub 18 is disposed in the center of the first disk 12 and has an inwardly extending central bore 19. A circular outer wall 20 encircles the central hub 18 in concentric radially spaced relation and is adjoined thereto by a top wall 20A that forms a second enclosed chamber 21 surrounding the hub. A generally C-shaped second stop member 22 is secured between the outer wall 20 and the inner wall 15B of the chamber 15. A thin flat upper arm 23 extends vertically upward from the circumferential side wall 14 and its outer end is divided into diverging flat fingers 23A.

[0035] Each hinge assembly 11 has a second flat circular disk 24 with an arcuate cam 25 protruding from its flat surface. A cylindrical pin 26 protrudes from the center of the flat disk 24 and has a circumferential raised bead 26A at its outer end. A thin flat lower arm 27 extends vertically downward from the outer periphery of the flat disk 24 and its outer end is divided into diverging flat fingers 27A.

[0036] As best seen in FIG. 5, the bore 19 of the central hub 18 is provided with a circumferential groove 19A at its bottom end. The first disk 12 and second disk 24 are assembled by placing the pin 26 into the bore 19 and the cam 25 into the guide channel 16 and pressing the disks together until the bead 26A on the pin 26 snaps into sliding engagement with the groove 19A in the hub 18. The lower inner edge of the cam 25 may also be provided with a raised bead 25A that slidably fits into a mating groove 25B at the bottom of the outer wall 15A of the chamber 15. When assembled together, the first and second disks 12 and 24 rotate or pivot relative to one another.

[0037] As best seen in FIGS. 5 and 6, the enclosed chambers 15 and 21 are filled with a colored liquid 30, such as water mixed with food coloring, or other suitable colored liquid. This may be accomplished by injecting the liquid into the chambers 15,21 with a syringe or other by other suitable process during the production of the disks.

[0038] The disks 12 and 24 are formed of a semi-rigid plastic material. The arms 23 and 27 are sufficiently stiff to support weight in a longitudinal direction and the fingers 23A and 27A are sufficiently thin and flexible so as to wrap around the limb of the wearer, as described below. The wall thickness of the outer wall 15A of the chamber 15 and the wall thickness of the tubular hub 18 that receives the pin 26 are sufficiently thin so as to become distorted upon receiving a sufficient predetermined force and/or may be frangible to break or rupture upon receiving a sufficient predetermined force. The cam 25 and the pin 26 are sufficiently rigid to cause distortion or breakage of the outer wall 15A of the chamber 15 and the wall of the central hub 18, respectively, upon forceful engagement therewith. The stop members 22 and 17 are also sufficiently rigid to stop the travel of the cam 25 and pin 26, as described hereinafter. It should be understood that the various components just described may be formed out of different plastic materials, to achieve the described characteristics.

[0039] As shown in FIGS. 1 and 2, the diverging fingers 23A and 27A of the upper arms 23 and lower arms 27 are each secured to respective upper and lower fabric straps or bands 28 and 29. Each strap or band 28 and 29 is formed of an elastic material provided with VELCRO (tm) fastener s or other suitable material for securing it around the limb. The fingers 23A and 27A may be secured to the strap or band 28,29 by sewing them between two plies of the material, by gluing, or other conventional means. Preferably the straps or bands 28 and 29 are capable of slightly stretching along their x-axis but not along their y-axis. The inner facing surfaces of the hinge assembly which face the limb may also be provided with padding (not shown).

[0040] The straps or bands 28 and 29 are wrapped around the thigh and calf while the wearer is in a seated position with the knee joint bent at an angle of about 90°. The diverging fingers 23A,27A are of sufficient length and sufficiently flexible to partially encircle the limb. When properly positioned, the center of the hinge assemblies 11 are disposed on opposed lateral sides of the knee joint with their centers aligned along a transverse axis extending through the knee joint (FIG. 1).

[0041] As represented by dashed line in FIG. 1, after the hinge assemblies 11 are properly positioned and secured on the leg, a protective elastic stocking or sleeve 32 is pulled over the assembly. A commercially available elastic sleeve or elastic knee brace may be suitable for this use.

[0042] Referring again to FIG. 6, the hinge assembly 11 is shown in a rotating or pivot position during normal flexure of the knee joint. In the position shown, the kneecap of the wearer would be oriented toward the left-hand side of the figure. In this position as the knee joint flexes, the lower leg of the wearer moves relative to the upper leg, and the lower arm 27 of the second disk 24 moves relative to the upper arm 23 of the first disk 12, as indicated by arrow Al. During this action, the pin 26 rotates in the hub 18 and the cam 25 slides unrestricted in the channel 16, as indicated by the arrow A2. Should a blow to the front to the knee occur, the cam 25 will rotate to the right and engage the stop member 17 to prevent further travel, and the upper and lower arms 23 and 27 would be in approximately vertical alignment at the stopping point. This reduces the likelihood of serious injury to the knee from a front impact.

[0043] As stated above, the enclosed chambers 15 and 21 are filled with a colored liquid 30 and the wall thickness of the outer wall 15A of the chamber 15 and the wall of the central hub 18 that receives the pin 26 are sufficiently thin or flexible so as to become distorted or may be frangible to break upon a predetermined sufficient force. As shown in FIG. 7, when the knee joint receives a side or lateral blow of sufficient predetermined force, the cam 25 forcefully engages the outer wall 15A of the chamber 15 and the pin 26 forcefully engages the wall of the central hub 18 causing the thin walls to become distorted or to break. As the walls become distorted or broken, further travel of the cam 25 is halted by the stop member 22 and further travel of the pin is halted by the outer wall 20 surrounding the hub to reduce the likelihood of serious injury to the knee from a lateral impact.

[0044] Distortion or breakage of the walls 15A of the chamber 15 and hub 18 releases the colored liquid 30 from the chambers 15 and 21 which will then leak out of the hinge assembly and become visible as it is absorbed by the lower strap or band 29 or on the protective sleeve 32 generating a means for visually indicating relative movement between the wearer's thigh and calf exceeding a predetermined amount. This visually indicates that the knee joint has received a serious lateral or frontal impact and warns the wearer, and also indicates that a replacement hinge assembly is needed.

[0045] While this invention has been described fully and completely with special emphasis upon a preferred embodiment, it should be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described herein.