Abstract:
An orthopaedic implant knee brace and surgical method for minimally invasive insertion of the orthopaedic implant knee hinge. The apparatus and method stabilizes the knee in patients after conventional fixation of distal femur and/or proximal tibia fractures. The orthopaedic implant knee brace allows the body weight of the patient to be offloaded from the knee joint to allow for weight bearing on the leg within days, rather than months, from the surgery.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to orthopedic implants and minimally invasive methods for insertion thereof. Specifically the present invention relates to an orthopaedic implant knee brace and surgical method for minimally invasive insertion thereof. 
       BACKGROUND OF THE INVENTION 
       [0002]    Distal femur and/or proximal tibia fractures often occur in high energy injuries, such as from a car crash. The breaks may extend into the knee joint and may shatter the bone into many pieces. These injuries are amongst the most challenging fractures to treat. 
         [0003]      FIGS. 1   a  and  1   b  show the conventional means to fix the fractures  19  in the distal femur regions. Bone screws  21  with or without bone plates  20  are typically used to fix these fractures  19 .  FIGS. 1   c  and  1   d  show the conventional means to fix the fractures  19  in the proximal tibia region. Bone screws  21  with or without bone plates  20  are typically used to fix these fractures  19  also. Fixation by these techniques may require as much as 3 months or more of healing before weight bearing can be done safely. During this time, the patient will need crutches or a walker to move around. 
         [0004]    Thus, there is a need in the art for an apparatus and method for supporting the knee in patients after fixation of distal femur and/or proximal tibia fractures and allowing the offloading of the body weight from the knee joint to allow for weight bearing on the leg within days, rather than months, from the surgery. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides for an orthopaedic implant knee brace supporting the knee in patients after fixation of distal femur and/or proximal tibia fractures and allowing the offloading of the body weight from the knee joint to allow for weight bearing on the leg within days, rather than months, from the surgery. The orthopaedic implant knee brace may comprise two elongated plates, each of said elongated plates may have more than one affixation opening therein to accommodate affixation means passing through said affixation opening. One of said two elongated plates may be adapted to be placed subcutaneously, but supra-muscularly on the medial side of the patient&#39;s knee spanning from at least the distal femur to the proximal tibia. The other of said two elongated plates may be adapted to be placed subcutaneously, but supra-muscularly on the lateral side of the patient&#39;s knee spanning from at least the distal femur to the proximal tibia. The knee brace may also include at least four affixation means per elongated plate to affix the knee brace to the bones of the femur and tibia, at least two of said at least four affixation means passing through said more than one affixation opening in each end of each of said elongated plates. 
         [0006]    The affixation openings may be threaded, said affixation means may be a screw and said screw may have a threaded head which may cooperate with said threading in said affixation openings. The affixation means may be a screw and said screw may have threading on the shaft only on the end thereof that will be inserted into the bone. One or both of the elongated plates may have offsets regions and/or irregular shape to provide for proper placement on the femur and tibia. The affixation means mat also be a threaded rod combined with nuts to anchor said elongated plates to said rods. The elongated plates and said attachment means may be formed from a material selected from the group consisting of titanium, stainless steel or a bio-compatible polymer material. 
         [0007]    The knee brace may comprise a single elongated plate placed on either the medial or lateral said of said knee, the single elongated plate formed of two elongated subplates joined together by a connector plate. One of said subplates may be adapted to be placed subcutaneously, but supra-muscularly adjacent one of the distal femur or the proximal tibia. The other of said subplates may be contoured and adapted to be placed sub-muscularly adjacent the other of the distal femur or the proximal tibia. The connector plate may comprise a lockable hinge. 
         [0008]    The knee brace may comprise a single elongated plate placed on either the medial or lateral said of said knee, said single elongated plate formed of two elongated subplates joined together by a connector plate. One of said subplates may be contoured and adapted to be placed sub-muscularly adjacent the distal femur. The other of said subplates may be contoured and adapted to be placed sub-muscularly adjacent the other of the proximal tibia. The connector plate may comprise a lockable hinge. 
         [0009]    The surgical method for minimally invasive insertion of the orthopaedic implant knee brace may comprise providing an orthopaedic implant knee brace comprising two elongated plates, each of said elongated plates having more than one affixation opening therein to accommodate affixation means passing through said affixation opening; one of said two elongated plates adapted to be placed subcutaneously, but supra-muscularly on the medial side of the patient&#39;s knee spanning from at least the distal femur to the proximal tibia and the other of said two elongated plates adapted to be placed subcutaneously, but supra-muscularly on the lateral side of the patient&#39;s knee spanning from at least the distal femur to the proximal tibia. The method may further comprise the step of tunneling said orthopaedic implant knee brace subcutaneously in the subcutaneous fat layer parallel to the length dimension of the femur and tibia, one each along the lateral and medial side of the leg. The method may also comprise the step of attaching the ends of each elongated plate to the distal end of the femur and the proximal end of the tibia, wherein said orthopaedic implant knee brace remains disposed in the subcutaneous fat layer and away from, but parallel to the femur and tibia once attached thereto. 
         [0010]    The tunneling step may include the further step of creating one or more incisions in the skin on both the lateral and medial side of the leg near both the distal end of the femur and the proximal end of the tibia, and said two elongate plates may be implanted, one on the lateral side and one on medial side of the knee. 
         [0011]    The step of attaching the ends of the orthopaedic implant knee brace to the distal end of the femur and the proximal end of the tibia may further include the step of inserting at least four affixation means per elongated plate to affix the knee brace to the bones of the femur and tibia. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0012]      FIG. 1   a  depicts the conventional fixation of distal femur fractures using only bone screws; 
           [0013]      FIG. 1   b  depicts the conventional fixation of distal femur fractures using bone screws and a bone plate; 
           [0014]      FIG. 1   c  depicts the conventional fixation of proximal tibia fractures using only bone screws; 
           [0015]      FIG. 1   d  depicts the conventional fixation of proximal tibia fractures using bone screws and a bone plate; 
           [0016]      FIG. 2  is a depiction of a front view of a knee joint with the knee brace of the present invention attached thereto; 
           [0017]      FIG. 3  is a depiction of a front view of the knee joint with another embodiment of the knee brace of the present invention attached thereto; 
           [0018]      FIG. 4  is a depiction of the front view of the knee joint with yet another embodiment of the internal brace of the present invention attached thereto; 
           [0019]      FIG. 5  is a depiction of the front view of the knee joint with still another embodiment of the internal brace of the present invention attached thereto; 
           [0020]      FIG. 6  depicts a preferred affixation means, a screw, useful to affix the inventive knee hinge. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    The present invention is a internal knee brace orthopedic implant device and method for application thereof.  FIG. 2  is a depiction of a front view of a knee joint with the knee brace of the present invention attached thereto. The knee joint does not show and of the muscles, ligaments or tendons. In its most basic form the knee brace is composed of two elongated plates  15  one placed on either side of the knee joint with multiple affixation openings therein. 
         [0022]    The two elongated plates  15  are attached to both the femur  1  and the tibia  2 . The knee brace allows the weight of the body to be offloaded from the femur  1  above the injured knee to the tibia  2  below the injured knee, allowing the limb to bear weight without additional injury or stress to the knee joint. The two elongated plates  15  are connected to the tibia and femur using attachment means  12  which pass through the elongated plates  15  via affixation openings  15 ′ and into the femur  1  and tibia  2 . If needed, one or both of the elongated plates may have offsets regions and irregular shape to provide for proper placement on the femur  1  and tibia  2 .  FIG. 2  shows the brace of the present invention used in conjunction with the conventional fixation of proximal tibia fractures using bone screws  21  as shown in  FIG. 1   c  (the fixation could also have used a bone plate  20  as in  FIG. 1   d ). In fact, the knee brace can be used in conjunction with conventional fixation of distal femur and/or proximal tibia fractures, including those shown in  FIGS. 1   a - 1   d  and combinations thereof. 
         [0023]      FIG. 3  is a depiction of the front view of the knee joint with the knee brace of the present invention attached thereto. Again the knee joint does not show any of the muscles, ligaments or tendons. It should be noted that the elongated plates of the knee hinge of the present invention are placed subcutaneously but supra-muscularly. This allows for proper stabilization of the knee without having to cut through the muscles and tendons to place the plates against the bones. In  FIG. 3 . the knee has fractures of the distal femur  19  which have been conventionally fixed as shown in  FIG. 1   b  using bone screws  21  and a bone plate  20  (the fixation could also have used just bone screws  21  as in  FIG. 1   a ). As in  FIG. 2  above, the knee brace allows the weight of the body to be offloaded from the femur  1  above the injured knee to the tibia  2  below the injured knee, allowing the limb to bear weight without additional injury or stress to the knee joint. 
         [0024]      FIG. 4  is a depiction of the front view of the knee joint with another embodiment of the internal brace of the present invention attached thereto. Again the knee joint does not show any of the muscles, ligaments or tendons. The knee has fractures  19  of the distal femur which have been conventionally fixed as shown in  FIG. 1   b  using bone screws  21  and a bone plate  20  as in  FIG. 1   b.  However, unlike the conventional fixation technique, an additional plate  15  has been inserted subcutaneously along the proximal tibia and secured to the tibia vial attachment means  12 . The additional plate  15  is attached to the conventional fixation plate  20  used on the femur by a connector plate  22 . This connector plate allows for offloading of the body weight from the conventional fixation plate  20  through the connector plate  22  and into plate  15  which transfers the load to the tibia, once again allowing the limb to bear weight without additional injury or stress to the knee joint. 
         [0025]    The connector plate may also take the form of a lockable hinge. This would allow the leg to bear weight when the hinge is locked and allow for bending of the knee (if appropriate) when the hinge is unlocked. This would allow the patient to retain range of motion in the knee joint from the beginning of the healing process and yet be able to bear weight on the limb. 
         [0026]    It should be noted that the embodiment in  FIG. 4  can also be used for injury to the proximal tibia such as shown in  FIG. 1   d  where the conventional plate  20  would be attached to the tibia and the additional plate  15  would be attached subcutaneously (supra-muscularly) along the distal femur by attachment means  12 . As with the other embodiment, the additional plate  15  is attached to the conventional fixation plate  20  used on the tibia by a connector plate  22 . Once again, this connector plate allows for offloading of the body weight from the femur  1  to plate  15 , through the connector plate  22  and into the conventional fixation plate  20  which transfers the load to the tibia. 
         [0027]      FIG. 5  is a depiction of the front view of the knee joint with yet another embodiment of the internal brace of the present invention attached thereto. As always, the knee joint does not show any of the muscles, ligaments or tendons. This embodiment can be used on the knee when there are distal femur fractures, proximal tibia fractures or both. The embodiment uses conventional screw  21  and plate  20  fixation of the fractures and screw  21  and plate  20  attachment to any non-fractured bone of the knee joint. Again, the knee has fractures  19  of the distal femur which have been conventionally fixed as shown in  FIG. 1   b  using bone screws  21  and a bone plate  20  as in  FIG. 1   b.  The unfractured tibia is fitted with a conventional screw  21  and plate  20  fixation implant. Then the conventional plate  20  on the femur and the conventional plate  20  on the tibia are connected together by a connector plate  22 . This connector plate allows for offloading of the body weight from the conventional fixation plate  20  on the femur through the connector plate  22  and into the conventional plate  20  on the tibia, which transfers the load to the tibia, once again allowing the limb to bear weight without additional injury or stress to the knee joint. Again, the connector plate may take the form of a lockable hinge to provide the benefits described above. 
         [0028]      FIG. 6  depicts a preferred affixation means  12 , a screw. The screw  12  may preferably have a threaded head  13  which may cooperate with threading in the affixation openings  15 ′ of the elongated plates  15 . The affixation openings  15 ′ may be threaded as in locking plate technology. This feature allows the elongated plates  15  to remain in place subcutaneously but supra-muscularly without being pressed against the muscles, yet holding the bones firmly in place. The screw  12  also preferably has thread  14  only on the portion of the shaft thereof that will be inserted into the bone. Alternatively, a threaded rod may also be used to attach the plates to the bones using nuts or the like to anchor the plates to the rods in the subcutaneous position. The elongated plates  15 , the attachment means  12  and the connector plate  22  may be formed from titanium, stainless steel or a bio-compatible polymer material. 
         [0029]    The knee brace may be placed into the subcutaneous fat layer through two incisions in the skin. One incision is near the distal end of the femur  1  and the other is near the proximal end of the tibia  2 . The incisions may be approximately two inches or less on each end. Of course, the plates  15  may come in many different sizes to accommodate different sized people and bones. This placement of the elongated plates  15  just under the skin prevents disruption of the muscle tissue and since there is no dissection, there is little chance for infection. It should be noted that the braces are not a permanent implant, but rather should be removed after the injury to knee joint has healed. 
         [0030]    It is to be expected that considerable variations may be made in the embodiments disclosed herein without departing from the spirit and scope of this invention. Accordingly, the significant improvements offered by this invention are to be limited only by the scope of the following claims.