Abstract:
A patellofemoral brace consisting of a sleeve adapted to be worn by a user in the knee area and having a patella interior opening is provided with a glide which is adjustably carried by the sleeve and which includes a patella engaging brace pad which may be silicon filled and which is generally U-shaped having one longer leg and one shorter leg. The brace is used to influence proper positioning of the patella by the generation of a force applied to the superolateral aspect of the patella to correct misalignment of the patella.

Description:
FIELD OF THE INVENTION 
   This invention relates to knee braces and particularly to a patellofemoral knee brace employing a sleeve and an adjustable position glide for biasing the patella. 
   BACKGROUND OF THE INVENTION 
   Patellar malalignment is known as a translational or rotational deviation of the patella in any axis that causes aberrant dispersion of the forces transmitted through the patellofemoral joint. Ideally the patella is located centrally in the trochlear groove where the imposed forces of the quadriceps and the patella tendon are properly established over the patellofemoral joint. Malalignment of the patella, laterally, medially, rotationally, vertically or any combination thereof including tilt, can adversely impact the mechanics of the patellofemoral joint and cause pain during flexion of the knee. Observation of malalignment shows lateral misalignment to be more common than medial. 
   It has been known to apply positioning forces to the patella to resist mispositioning, such positioning forces being applied by many different types of devices. 
   A common positioning technique is the use of tape applied to the skin at the patella and tensioned in a direction chosen to accommodate proper positioning of the patella. One known example is the McConnel taping technique. While such taping for patellar subluxation may reduce abnormal movement of the patella and may assist in proper positioning, proper positioning of the tape and the proper application of force vectors generated by the taping are difficult to predictably, repetitively achieve. Additionally the tape itself is discomforting, temporary and may be unduly binding of the knee joint while placing undesirable tension on the skin. 
   As an alternative to taping it has been known to employ various types of knee braces and supports, including sleeves received about the leg and positioned over the knee. Such sleeves can include anterior patellar openings and may include affixed pads for restricting movement of the patella. One such sleeve device is shown, for example in U.S. Pat. No. 4,084,584. In such a construction, the fixed position of the pad with respect to the sleeve requires that all adjustment of the pad for effect on the patella be through adjustment of the position of the sleeve on the leg with the action of the pad being essentially static. Attempts to apply a dynamic force may be defeated by movement of the sleeve during normal or energetic flexion of the knee joint. 
   It has been suggested to apply adjustable biasing means either to patella-engaging pads fixed to the sleeve adjacent the anterior opening, such as shown in U.S. Pat. No. 4,296,774 or pads which are affixed to a separate tensioning body which may be received around the sleeve, such as shown in U.S. Pat. No. 5,613,943. While such devices provide some control over the degree of force exerted by the pad on the patella, that force is generally limited to a medial force such that the ability of the bracing pad to properly align the patella is limited. 
   It would therefore be an advance in the art to provide a patellar alignment system or brace having a wide range of adjustability which is comfortable to wear and which can apply forces to both the lateral and superior borders of the patella. It would be a further improvement in the art to provide such a brace that is self-conforming to the patella and where the force is applied over a wider area of contact with the patella in a direction offsetting the particular misalignment experienced by the patient. 
   SUMMARY OF THE INVENTION 
   This invention provides an improved patellofemoral brace consisting of a sleeve and a glide, with the glide carrying a pad. The sleeve is a generally tubular body adapted to be slipped over the foot and positioned around the knee. It has a generally ovaloid anterior opening in a frontal portion thereof adapted to be positioned over the patella exposing the patella region and skin of the user. Preferably the sleeve is formed of an elastic material and may be at least partially provided with, at least on its undersurface, a woven or non-woven fabric-like material. 
   The glide of this invention consists of a generally U-shaped member having a pad at the bight and extending legs. The bight section is affixed to the sleeve adjacent the anterior opening with the pad extending over the opening edge at least at one side of the opening and along a portion of the top or bottom of the opening. To this end, the pad itself is generally U or C-shaped having one longer leg and one shorter leg whereby the inside of the bight of the same can be brought into contact with a side of the skin covered patella while the longer leg may be brought into contact with a top or bottom area of the skin covered patella. The legs of the glide can then be adjusted with respect to one another to provide force application at the patella as desired to urge the patella to a proper position. Generally the glide will be attached at the lateral side of the opening with the pad biasing lateral and superior areas of the patella to urge it medially and reduce inferior tilt. 
   To secure the legs of the glide to the sleeve, both the glide leg&#39;s undersurface and portions of the outersurface of the sleeve may be provided with fasteners such as hook and loop fasteners. 
   The pad is preferably formed of a material which will resist sliding over the skin while being yieldable, with resistance, so as to be able to provide a force vector to the patella, determined by the relative position and tensioning of the legs of the glide. Additionally the pad may be contoured, at least on its undersurface, to assist in conforming to the general shape of the force receiving surfaces of the patella whereby boundary areas of the skin covered patella may be nestled in the pad. 
   It is therefore an object of this invention to provide an improved patellofemoral joint brace. 
   It is also an object of this invention to provide a patellar alignment system that provides an alignment force that is adequate to align a wide range of patellar malalignments. 
   It is a further object of the invention to provide a patellar alignment system that provides an alignment system that may be easily tailorable to individual patients. 
   It is a further object of the invention to provide a patellar alignment system that may be easily applied and easily adjusted after application. 
   A further object of the invention is to provide a patellar alignment system that is stable even under the rigors present during intense exercise. 
   It is also an object of the invention to provide a patellar alignment system that is cost effective to manufacture and relatively simple to operate. 
   It is another and more particular object of the invention to provide a patellofemoral brace which is adjustable to apply selective pressure to areas of the patella to compensate for patellar malalignment. 
   It is another and more particular object of this invention to provide a knee brace including a sleeve received over the leg of the user in the knee joint area with a frontal opening receiving the patella, a glide member having a pressure pad carried thereby carriable by the sleeve, the glide member having tension adjusting strap members repositionably attachable to the sleeve for engaging the pad against the kneecap with patient specific force vectors applied by the pad to the kneecap to urge the kneecap towards a normal positioning. 
   It is a specific object of this invention to provide a brace for use at the patellofemoral joint of a human consisting of an open ended sleeve receivable over the foot of the user and positionable at the joint, the sleeve formed, at least in part, of a material resisting slippage with respect to the user&#39;s skin and being elastic to grip the user&#39;s leg to remain substantially in place thereon during flexure of the joint, the sleeve having an anterior opening therethrough positionable over the patella area, the sleeve having affixed thereto a glide including a generally yieldable resilient pad for engaging at least lateral and superior surface portions of the skin covered patella, the glide being moveably adjustable on the sleeve and including tension applying members selectively positionable and repositionably attached to the sleeve for the purpose of applying force vectors at the patella to urge the patella towards a properly aligned position at the patellofemoral joint. 
   These and other objects of the invention will be apparent by those of ordinary skill in the art from the following description of the preferred embodiment, it being understood that those of ordinary skill in the art will readily ascertain that the invention may be practiced in different modes employing different selected materials or variations thereof. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a partial view of the leg having the glide sleeve of this invention positioned at the knee. 
       FIG. 2  is a front view of the glide sleeve of this invention showing underlying portions in dotted lines. 
       FIG. 3  is a back view of the glide sleeve of this invention showing underlying portions by dotted lines. 
       FIG. 4  is an outside view of the glide of this invention. 
       FIG. 5  is an inside view of the glide of this invention. 
       FIG. 6  is a cross section taken along the line VI-VI of  FIG. 5 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   As shown in  FIG. 1 , a brace  10  is received over the knee region  11  of a leg  12 . The brace includes a sleeve  13 , a glide  14  and a pad  15  which is contactable with the skin at an outer boundary area of the patella. 
   The sleeve  13  is generally tubular having a larger front face  16  which has a greater axial extent than a back portion  17 . The sleeve is preferably made of resilient material that will resist slipping when positioned on the leg of the user in contact with the skin. Neoprene is a suitable material for construction of the sleeve. The sleeve, although being generally tubular, may have a somewhat constricted central section so as to conform to the general anatomical exterior shape of the leg above, below and at the knee joint. 
   Portions  21  of the sleeve, including at least the interior of the back surface portion  17 , may be coated with, or constructed of, a woven or non-woven fibrous material to provide increased comfort and wearability and to accommodate flexure of the knee at the back side. For example, in a preferred embodiment, the interior of the back of the sleeve may be felt-lined, whereas in a further embodiment the sleeve could be constructed of two pieces utilizing a fabric portion having, preferably, elastomaric qualities woven thereinto such as is commonly found, in example, in elastic bandages and wraps. The fabric portion will then form at least part of the back portion  17  and can be attached to the remainder of the sleeve  13  in various ways such as by sewing. 
   Although a greater or lesser extent of the sleeve may be formed of or with a lining of woven or non-woven natural or synthetic fibrous materials, in a preferred embodiment the majority of the circumference and axial length of the sleeve is formed of a material such as Neoprene which has a tendency to frictionally engage the skin so as to resist relative movement once properly secured in place and which is elastomaric to grip the leg. This is particularly important for less sedentary patients and in particular for those who may engage in athletic activities requiring forceful knee flexion. 
   The front portion  16  is provided with an anterior opening  25  to expose the patella area exposing the skin covered patella through the opening. While the opening may be of any shape appropriate for such exposure, the use of an elongated opening, either oval, ovaloid or egg shaped is preferred, a generally egg shaped opening being shown in  FIGS. 2  and, by dotted lines, in  FIG. 3 . The wider end  26  of the opening  25  is optimally positioned at the lateral side of the sleeve when in place on the wearer&#39;s leg. It will be appreciated that the sleeve may be inverted for use on the other leg or may be inverted on either leg if the force to be applied to the patella is medial and/or upward. 
   A glide  14  cooperates with the sleeve to provide force vectors to the patella, the glide being generally illustrated as U-shaped, consisting of a bight  30  and generally parallel extending legs  31  and  32 . Preferably at least portions of the legs of the glide are formed of an elastomaric material, and generally of a material having a greater maximum resilient strength than that of the sleeve as the legs will be placed under tension. In a preferred embodiment, a firm Neoprene or other synthetic rubber may be used for the glide or at least the leg portions thereof. 
   A pad  15  is carried by the glide  14  projecting from an undersurface  33 . The pad  15  is again preferably U-shaped or C-shaped with one extended leg, having a bight  40  and upper  41  and lower  42  legs. The legs  41  and  42  overlie the undersurface of the legs  31  and  32  spaced from the ends  34 . Preferably the upper leg  41  is longer than the lower leg  42  and the space between the legs is chosen to create an inside bight area  44  dimensioned to engage and partially cup the lateral surface of the skin covered patella. As the patella itself generally has a rounded lateral edge, the cross section shape of the pad  15  may have a somewhat rounded or concave inner surface  18  whereby a superior portion  19  of the pad may conform to the rounded superolateral surface of the patella at least above the principal axis of the patella. To facilitate nestling of the patella with respect to the pad, the pad will preferably have a thickness greater than one half the thickness of the patella adjacent its superolateral edges such that the boundary regions of the patella can be received partially within the innermost boundary of the pad. 
   The longer leg  41  continues along inside surface of the pad and will overlie the superior surface of the patella at least for a portion of the width of the patella whereby in addition to medial force vectors from the bight area of the pad  15 , more vertically oriented force vectors can be applied to the top of the patella. The pad  15  may be formed as a separate part of the glide and affixed to the leg portions  31  or may be an integrated portion. The pad portion has a thickness greater than the thickness of the legs and is formed of, or filled with, a yieldable or displaceable material, such as silicon or other gels, which will allow the surfaces of the pad contacting the skin at the patella to generally conform to the shape of the patella in the area of force application. Although many different construction techniques will be apparent to those of ordinary skill in the art, the pad can be formed as a bladder portion of the glide and filled with a fluid with at least portions of the bladder wall being elastic. In other constructions the pad can be separately formed and adhered to an undersurface portion of a U-shaped glide base. In other forms the pad may be formed as a separate body forming at least portions of the bight of the glide and adhered to elastic leg members or straps. 
   The glide is affixed at the bight end to the sleeve adjacent the lateral side of the opening  25 . As illustrated, in order to allow for maximum positioning of the glide, a tab  50  may be affixed to project from the outer surface of the glide, with the tab securely fastened, at least at its outer portions to the sleeve. The use of a tab allows pivoting movement of the glide with respect to the sleeve. While various forms of attachment will be apparent, including thermal bonding, adhesives, stapling, riveting or the like, in a preferred embodiment the tab may be stitched to the sleeve as stitching can facilitate a range of movement between the sleeve and the glide. Although the preferred embodiment illustrates only one such tab  50 , it will be apparent that others can be utilized, however it is desired that the attachment of the glide to the sleeve accommodate pivotal movement of the glide with respect to the sleeve, at least to the extent desirable to secure an appropriate degree of contact between the upper leg  41  and superior surfaces of the skin covered patella. 
   Fasteners  52 ,  36  are provided for attaching the legs to the sleeve with the legs  31  and  32  under varying degrees of tensions. Preferred fasteners include hook and loop fasteners  36 ,  52  engagingly secured both to the outer surface of the sleeve in the areas of the sleeve which will underlie the legs and to the undersurface of the legs. The portions of the fastener attached to the sleeve should allow both medial and vertical tensioning of the legs. Either a plurality of attachment parts may be separately carried by the brace, or the sleeve carried portion  52  may extend over a vertical extent allowing a range of attachment points. Other forms of fastening allowing for adjustability of the position and tensioning of the legs will be obvious to persons of ordinary skill in the art, such as, by way of example, the use of adjustable position buckles. 
   It will further be appreciated that wherein this invention has been described utilizing terminology such as lateral and superior, referring to the outer and top sides of the patella area, that in certain instances the patellar malalignment may be otherwise such that the terms medial, inside, lower or bottom may be appropriate for a particular patient&#39;s condition. 
   In use, after the sleeve has been positioned on the leg in the knee area with the patellar area aligned with the opening, the pad will be brought into contact with the appropriate surfaces of the skin over the patella and the leg tension will thereafter be adjusted to provide a proper force vector, as desired for biasing the patella towards proper alignment. A greater or lesser amount of force can be applied by greater or lesser stretching of the legs of the glide and vertical force orientations can be controlled both by adjusting the tension on the legs and by rotation of the glide with respect to the sleeve in the vertical plane. It will be further appreciated that while the pad has been shown in the preferred embodiment as having a “swoosh”-like shape, where the end of at least the upper leg  41 , and preferably upper and lower legs  41  and  42  taper together, and where the upper leg is longer than the lower leg, thereby facilitating superolateral forces to enhance realigning properties of the sleeve, other shapes may be chosen as desired.