Cable Knee Brace System
It is the object of the invention to provide a knee bracing system that bolsters the body's natural ligaments to reduce the knees proneness to injury or re-injury. The invention is a cable system that acts much like the body's natural ACL and MCL. The cables are routed around the knee joint in a way that resists the forces that cause excessive joint movement and injury to the ACL and or MCL. As the leg travels through the range of motion the cables provide external hyper extension, bending, and rotation support preventing the tibia bone from moving forward (hyper extending) or twisting (lateral rotation) and or laterally bending with respect to the femur.
This present application is a continuation-in-part of U.S. patent application Ser. No. 11/744,213 filed on May 3, 2007, entitled Cable Brace System.
FIELD OF THE INVENTIONInvention relates to orthopedic devices for knees, and more specifically to a knee brace system utilizing a cable to mechanically support the knees natural ligaments.
BACKGROUND OF THE INVENTIONThe human knee is a complex mechanism that is highly vulnerable to injury in sports like football, hockey, skiing, snowboarding, and motocross. In these kinds of physically demanding sports the Anterior Cruciate Ligament (ACL) and Medial Collateral Ligaments (MCL) are commonly injured. The ACL controls forward movement of the tibia relative to the femur (hyper extension) and lateral rotation of the tibia with respect to the femur (over rotation). The MCL controls lateral movement of the tibia with respect to the femur. Hyper extending the leg and or laterally rotating or twisting or laterally bending of the leg can tear the ACL and or MCL. The ACL regulates the amount of movement the tibia has with respect to the femur both in forward movement, and lateral rotation. When the leg reaches full extension the ACL becomes taut and limits the knee from hyper extending or over rotating laterally. The MCL regulates how much the tibia can bend laterally with respect to the femur. The MCL becomes taut when a lateral force is applied to the leg preventing excessive bending. All too often in sports like motocross the leg is exposed to forces that exceed the ligament's ability to prevent excessive movement in the joint sometimes resulting in the tearing of the ACL and or MCL.
In order for a knee brace to be effective in resisting the excessive movement of the knee joint that tears the ACL and or MCL, it must provide an effective differential force to the tibia relative to the femur. Because of the large amount of flesh surrounding the tibia bone and femur bone the only way to prevent the leg from over extending or over rotating would be to fix a rigid structure to the bones with some sort of mechanical means such as screws. Of course this would be impractical and undesirable. Not only should a knee brace be practical, it must be comfortable, and most of all effective preventing knee injuries.
Most prior art (conventional) knee brace devices for ligament protection consist of a rigid femoral plate and tibial plate connected by hinges on either side of the knee. The plates are strapped to the leg tightly above and below the knee with straps that encircle the leg. The hinge locks as the leg reaches full extension and the rigid frame and straps act like a splint resisting hyperextension of the leg. There are many variations of the basic rigid hinged brace with differing hinge designs, strapping methods, and materials used. Conventional braces are limited in their effectiveness resisting excessive joint movement that causes injury to the knee. The biggest reason is that the flesh of the leg surrounding the femur and the strapping apparatus deform allowing the leg to hyper extend or rotate. Even when the strapping devices are tightened to the point of discomfort, they have limited effect preventing excessive movement of the knee joint when the leg is subjected to these forces.
SUMMARY OF THE INVENTIONIt is the object of the invention to provide a knee bracing system that bolsters the body's natural ligaments to reduce the knees proneness to injury or re-injury.
The invention is a cable system that acts much like the body's natural Anterior Cruciate Ligament (ACL) and Medial Collateral Ligaments (MCL). The cables are routed around the knee joint in a way that resists the forces that cause excessive joint movement and injury to the ACL and or MCL. As the leg travels through the range of motion the cables tighten preventing the tibia bone from moving forward (hyper extending) or twisting (lateral rotation) or bending laterally with respect to the femur.
The cable knee brace system of this invention can be tailored or adapted to prior art (conventional) braces increasing their effectiveness.
It is also anticipated by the Applicant that this cable knee brace system can be adapted to the elbow to prevent the arm from hyper extending. A humorous plate would substitute for the femoral plate 4, a radius plate would substitute for the tibial plate 2, and bicep plate would substitute for the femoral back plate 5 creating the differential resistive force across the elbow joint preventing hyperextension of the arm.
To be effective preventing injuries to the ACL 22 and or MCL 23 a knee brace must prevent the tibia bone 26 from moving forward (hyper extending), see
When a lateral rotation force 30 is applied to the leg as shown in
This invention comprises of a primary cable 1 and secondary cable 40 that can be made of any flexible material with a sufficiently high tensile strength. A tibial plate 2 that could be made of any rigid or semi rigid material is shaped to conform to the tibia bone 26, beginning just below the knee and ending approximately at the midpoint of the tibia bone 26. The tibial plate 2 is held in position with elastic straps 11b and 11c. Foam padding 12 is attached to the underside of the tibial plate 2 for comfort and to provide a firm grip on the individuals' tibia bone 26. A patellar plate 3 that could be made of any rigid or semi rigid material connecting the tibial plate 2 to the femoral plate 4. A femoral plate 4 that could be made of any rigid or semi rigid material is located on top of the thigh from just above the knee to approximately mid femur 18 and is held in position with elastic strap 11a and 11d. And back plate 5 that could be made of any rigid or semi rigid material located behind the leg and just above the knee joint to keep the cable 1 in the proper location, firmly holding the femur bone 18 as the differential force of the primary cable 1 is transmitted across the joint. Foam padding 14 is attached to the inside of the back plate 5 to help spread the force of the primary cable 1 comfortably to the leg. A cable tensioner dial 6 and locking/release button 7 with spring 8 are attached to the femoral plate 4 with retainer screw 9. These could be made from any metal or rigid material that will withstand the forces required to keep the primary cable 1 locked in place during use. Other cable tensioning and locking mechanisms could be used, but the dial tensioning and locking system gives a very wide range of fine tuned cable adjustability and ease of use.
The fundamental element of this invention is the routing of the cables. As best shown in
The cables could be made up of individual segments connected together to form the completed routing. For example first primary cable segment 1a and second primary cable segment 1b can be connected together with tibial plate 2 to complete the loop. First primary cable segment 1a begins attached to femoral plate 4 by first cable connector 15a, crosses behind the leg through the first cable guide hole 13a and second cable guide hole 13b in back plate 5 and attaches to the opposite side of tibial plate 2 with clamping screw 10a. Without having to loop over the leg the second primary cable segment 1b is attached to the opposite side of tibial plate 2 with clamping screw 10b. From clamping screw 10b the second primary cable segment 1b crosses behind the leg through the third cable guide hole 13c and forth cable guide hole 13d in back plate 5 and completes the loop by attaching to the opposite side of femoral plate 4 with cable connector 15b.
The primary cable 1 is adjusted by turning the cable tensioner dial 6 taking up the excess primary cable 1 length. The primary cable 1 is automatically locked into place by the ratcheting gears 16 on the cable tensioning dial 6 and spring 8 actuated locking/release button 7. The button 7 is also used to release the tension in primary cable 1 for installation and removal of the brace.
While an infinite number of secondary cable routings across the pivot points are possible, directly through the pivot points as shown in 46a is most desirable to achieve optimum tension on the secondary cable 40 throughout the legs full range of motion.
While the invention has been described and illustrated with regard to the particular embodiment, changes and modifications may readily be made, and it is intended that the claims cover any changes, modifications, or adaptations that fall within the spirit and scope of the invention.
Claims
1. A device designed to prevent an individual's leg from hyper-extending or laterally bending and or rotating by applying a net differential resistive force between the tibia and femur to serve the function of protecting damage to the anterior cruciate ligament and or medial collateral ligament, said device comprising;
- a femoral plate;
- a tibial plate;
- a patellar plate;
- a back plate;
- a movement control mechanism crossing over the joint and including a pair of flexible cables which from the rear of the leg connects to the tibial plate and with the femoral plate, characterized in that a first flexible cable crosses the joint behind the leg at the back plate connecting one side of the tibial plate with the opposite side of the femoral plate and a second flexible cable crosses the joint behind the leg at the back plate connecting one side of the tibial plate with the opposite side of the femoral plate in order to prohibit the tibial plate from rotating and bias the back plate toward the joint and to the fore and to bias the tibial plate toward the joint and to the rear.
2. The device as recited in claim 1, wherein said first and said second flexible cable is a flexible tension bearing substantially non-elastic metal, wire or polymeric cable.
3. The device as recited in claim 1, wherein the said first and said second flexible cable extends from a side face of the tibial plate, behind the leg above the joint to a opposite side face of the femoral plate.
4. The device as recited in claim 1 wherein said first and said second cables cross behind the leg above the joint at the back plate connecting one side of the tibial plate with the opposite side of the femoral plate.
5. A device designed to prevent an individual's leg from hyper-extending or laterally bending and or rotating by applying a net differential resistive force between the tibia and femur to serve the function of protecting damage to the anterior cruciate ligament and or medial collateral ligament, said device comprising;
- a femoral plate;
- a tibial plate;
- a patellar plate;
- a back plate;
- a movement control mechanism crossing over the joint and including a flexible cable which connects the tibial plate with the femoral plate, characterized in that a flexible cable crosses the joint on the inside, or medial side of the leg, connecting the outside, or lateral side of the femoral plate in order to prohibit the tibial plate from laterally bending and or rotating and bias the tibial plate and femoral plate inward or medially.
6. The device as recited in claim 2, wherein said flexible cable is a flexible tension bearing substantially non-elastic metal, wire or polymeric cable.
7. The device as recited in claim 2, wherein the said flexible cable extends from an outside, or lateral side face of the tibial plate, around the inside or medial side of the leg to an outside or lateral side face of the femoral plate.
8. The device as recited in claim 1 wherein said first and said second cables cross behind the leg above the joint at the back plate connecting one side of the tibial plate with the opposite side of the femoral plate.
9. The device as recited in claim 2 wherein said first and said second cables cross behind the leg above the joint at the back plate connecting one side of the tibial plate with the opposite side of the femoral plate.
10. The device as recited in claim 3 wherein said first and said second cables cross behind the leg above the joint at the back plate connecting one side of the tibial plate with the opposite side of the femoral plate.
Type: Application
Filed: Jan 8, 2011
Publication Date: Apr 28, 2011
Inventor: Darren Fleming (Vista, CA)
Application Number: 12/987,084
International Classification: A61F 5/00 (20060101);