SYSTEM AND METHOD FOR MEASURING MUSCULAR-SKELETAL ALIGNMENT TO A MECHANICAL AXIS
First Claim
1. A method of measuring alignment to a mechanical axis comprising the steps of:
- positioning a joint to a first target flexion value;
rotating the joint between a first point and a second point where the first and second points are on opposing sides of the joint;
calculating an alignment value of a first bone relative to the mechanical axis;
positioning the joint to a second target flexion value;
rotating the joint about a third point and a fourth point where the third and fourth points are on opposite sides of the joint;
calculating an alignment value of a second bone relative to the mechanical axis; and
calculating alignment relative to a mechanical axis of the first and second bones.
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Accused Products
Abstract
A system and method is disclosed herein for measuring alignment of the muscular-skeletal system. The system comprises a sensored module that can be placed within a prosthetic component to measure load, position of load, and joint alignment. The system further includes a remote system for receiving, processing, and displaying quantitative measurements from the sensors. Alignment relative to a mechanical axis is measured. In a two bone system with a joint therebetween the total alignment measured comprises offsets measured for each bone. The joint is placed in a predetermined flexion that supports measurement of the joint as it is moved. The joint pivots on a point that is along the mechanical axis. Points along the arc made by the joint rotating between a first and second point are measured. An arc maximum is determined. The arc maximum is then converted to varus or valgus offset relative to the mechanical axis.
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Citations
20 Claims
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1. A method of measuring alignment to a mechanical axis comprising the steps of:
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positioning a joint to a first target flexion value; rotating the joint between a first point and a second point where the first and second points are on opposing sides of the joint; calculating an alignment value of a first bone relative to the mechanical axis; positioning the joint to a second target flexion value; rotating the joint about a third point and a fourth point where the third and fourth points are on opposite sides of the joint; calculating an alignment value of a second bone relative to the mechanical axis; and calculating alignment relative to a mechanical axis of the first and second bones. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of measuring alignment of a tibia to a mechanical axis of a leg comprising the steps of:
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placing a heel of a leg in an approximately fixed location; positioning a knee joint to a target flexion value; rotating the knee joint between a first point and a second point, where the first and second points are respectively on a medial and lateral side of the knee joint, and where the knee joint is pivoting on the heal of the leg during rotation; measuring points along an arc made by the knee joint as the knee joint is moved between the first and second points; and calculating an alignment value of the tibia relative to the mechanical axis. - View Dependent Claims (12, 13, 14, 15)
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16. A method of measuring alignment of a femur comprising the steps of:
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positioning a knee joint to a target flexion value; rotating the knee joint between a first point and a second point, where the first and second points are respectively on a medial and lateral side of the knee joint, where the knee joint is pivoting on a hip joint of the leg during rotation; and calculating an alignment value of the femur relative to the mechanical axis. - View Dependent Claims (17, 18, 19, 20)
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Specification