Knee brace having a variable tensioning offset cam
Inventors
Fedon, Shane C. • Blecher, Andrew M.
Assignees
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Publication Number
US-10617550-B2
Publication Date
2020-04-14
Expiration Date
Abstract
A knee brace to stabilize the patella has a main body positionable over the knee, a hinged longitudinal support assembly, a buttress, a buttress retention flap overlaying the buttress, a cam positioned proximal to the support assembly and a tensioning line. The buttress is positioned against the side of the knee opposite the support assembly and applies a variable compression force to the knee. The tensioning line engages the cam and operatively connects it to the buttress via the buttress retention flap to automatically vary the compression force applied to the knee in response to rotation of the support assembly.
Core Innovation
The invention relates to a variable tensioning assembly for an orthopedic knee brace that stabilizes the patella and supports patellar stabilization in a patellofemoral knee brace. A longitudinal support assembly positions a pivot adjacent to a knee joint and enables a knee brace operative motion between a full flexion position and a full extension position.
The longitudinal support assembly includes a first longitudinal member and a second longitudinal member rotatably connected by the pivot so that the first and second longitudinal members change alignment between perpendicular at full flexion and collinear at full extension. A rotatable cam is fixably attached at the pivot to the proximal end of a longitudinal member, and the cam has an arcuate operating surface positioned in the tensioning line path.
The arcuate operating surface includes an out of round offset point that engages the tensioning line when the longitudinal members rotate away from one another toward full extension and disengages the tensioning line when the longitudinal members rotate toward one another toward full flexion. The tensioning line path redistributes line travel between a vertical segment and a horizontal segment using engagement and disengagement behavior as the brace passes an automatic tension transition point, with a transition located around an orientation angle of about 30° to about 35°.
Claims Coverage
The independent claims include 5 inventive features centered on a cam-driven variable tensioning mechanism coupled to a pivoted longitudinal support assembly, with additional refinements for knee sleeve and buttress retention flap structures and tension-line path geometry.
Pivoted longitudinal support with flexion-extension alignment
A longitudinal support assembly with first and second longitudinal members rotatably connected by a pivot such that the members are perpendicular at full flexion and collinear at full extension, with the pivot positioned adjacent to a knee joint in horizontal alignment during operative position.
Rotatable cam with out-of-round offset point for automatic line engagement
A rotatable cam fixably attached at the pivot to the proximal end of one longitudinal member, with an arcuate operating surface in the tensioning line path and an out of round offset point adapted to engage and disengage the tensioning line as the members rotate.
Automatic tension transition by rotation angle crossing
The out of round offset point engages the tensioning line when rotation angle decreases below an automatic tension transition point and disengages the tensioning line when rotation angle increases above the automatic tension transition point, producing variable line tension behavior tied to the transition point.
Knee sleeve and buttress retention flap applying variable tension
A knee sleeve with a pliant main body and a buttress retention flap positioned in horizontal alignment with the pivot, with the main body maintaining the pivot adjacent to the knee joint and the second anchored end of the tensioning line connected to the second side of the buttress retention flap.
Tensioning line path geometry and segment redistribution
A tensioning line path having vertical and horizontal segments of fixed total length, where engagement and disengagement of the out of round offset point selectively redistributes travel distance between the vertical and horizontal segments to change variable line tension.
The claims cover a rotatable cam with an out-of-round offset point that engages and disengages a tensioning line as pivoted longitudinal members move between full flexion and full extension, producing variable line tension based on crossing an automatic tension transition point. Additional coverage includes knee sleeve and buttress retention flap structures and tensioning line path geometry.
Stated Advantages
Improved patellar stabilization in a patellofemoral knee brace by stabilizing the patella using the described variable tensioning mechanism.
Documented Applications
Patellofemoral knee brace use for patellar stabilization and dynamic tracking of the patella in the trochlear groove during knee extension and flexion.
Application of a knee sleeve and compression components including enhanced and reduced compression panel embodiments to improve proprioception and emulate venous return [procedural detail omitted for safety].
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