Patent ID: 7201728

Claim:
A unilaterally-hinged osteoarthritis knee brace comprising: a rigid thigh engaging member; a rigid calf engaging member; and a unilateral lateral hinge lateral to the wearer's knee, connecting said thigh engaging member to said calf engaging member; wherein said thigh engaging member and said calf engaging member form rigid connections to said lateral hinge, wherein said lateral hinge further comprises a plurality of parallel, concentric, spherical shells and a plurality of cam follower pins and a plurality of cam slots distributed among said shells, wherein said plurality of cam follower pins engage said plurality of cam slots to rotatably engage said shells, and wherein a side of each of said cam follower pins is shaped to track a path parallel to a side of each of said cam slots in which said pin is engaged, wherein said lateral hinge has a first variable axis of rotation and comprises: a first shell, a second shell, and a third shell in the shape of a segment of a sphere, said first and third shells being concentric and fastened parallel to each other to form a first opening, said first and third shells being fastened to a lateral portion of either said thigh engaging member or said calf engaging member, said second shell having a first end designed to be inserted into said first opening and a second end fastened to a lateral portion of the other of said said thigh engaging member or calf engaging member, said first and third shells rotatably engaged to said second shell by said plurality of cam follower pins and said plurality of cam slots; wherein said lateral hinge further comprises: a first cam follower pin and second cam follower pin distributed among said shells and extending inside said first opening, said first pin located on said second shell and said second pin located on said third shell, and a first cam slot and second cam slot distributed among said shells to receive said first and second pins, respectively, said first shell comprising said first cam slot and said second shell comprising said second cam slot, whereby, in use, when the wearer's leg is extended, said first variable axis of rotation is in alignment with the wearer's condyles, and wherein said knee brace prescribes asymmetric three-dimensional anatomic motion in six degrees of freedom by actively prescribing flexion and extension, abduction and adduction, internal/external rotation, anterior/posterior translation, medial/lateral translation, and proximal/distal translation between a femur and a tibia of the wearer's leg.