Natural alignment knee instruments
First Claim
1. A method for aligning a femoral and tibial implant for knee joint replacement, comprising:
- assessing bone and cartilage deficiency of a joint surface of a distal femur from a pre-degenerated state to a degenerated state caused by wear of the knee joint, the joint surface having a first distal extent associated with a first condyle, the first distal extent being in a first location when the joint surface is in the pre-degenerated state and being in a second location when the joint surface is in the degenerated state;
placing a distal resection assembly to the distal femur adjacent the joint surface, the distal resection assembly having a reference surface and at least one adjustment member extendable from the reference surface;
extending the at least one adjustment member a predetermined distance from the reference surface based on the bone and cartilage deficiency such that when the distal resection assembly is mounted to the distal femur, the reference surface is separated from the second location and disposed tangent to the first location; and
resecting the distal femur along a resection plane parallel to and offset from the reference surface and first location, thereby forming a distal resected surface.
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Accused Products
Abstract
A method for aligning an orthopedic implant in a joint replacement includes determining the bone and cartilage deficiency from an undegenerated state caused by wear of a joint. Then a resection of a bone in the joint is made based on the deficiency of bone and cartilage from the undegenerated state and the size of a joint implant so as to locate the joint surface of the implant in the undegenerated cartilage location. The condylar wear from the undegenerated states may be assessed at a distal and posterior location on each of a medial and a lateral femoral condyle. A distal cut is made on the femur at a location adjusting for the condylar wear from the undegenerated state. The distal cut varus-valgus angle is oriented parallel to a plane across the distal femur after adjusting for wear in the distal location on the medial and lateral condyle.
144 Citations
13 Claims
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1. A method for aligning a femoral and tibial implant for knee joint replacement, comprising:
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assessing bone and cartilage deficiency of a joint surface of a distal femur from a pre-degenerated state to a degenerated state caused by wear of the knee joint, the joint surface having a first distal extent associated with a first condyle, the first distal extent being in a first location when the joint surface is in the pre-degenerated state and being in a second location when the joint surface is in the degenerated state; placing a distal resection assembly to the distal femur adjacent the joint surface, the distal resection assembly having a reference surface and at least one adjustment member extendable from the reference surface; extending the at least one adjustment member a predetermined distance from the reference surface based on the bone and cartilage deficiency such that when the distal resection assembly is mounted to the distal femur, the reference surface is separated from the second location and disposed tangent to the first location; and resecting the distal femur along a resection plane parallel to and offset from the reference surface and first location, thereby forming a distal resected surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of resecting a distal femur having a first and second condyle, the first condyle having a first distal extent, the second condyle having a second distal extent, the method comprising the steps of:
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determining a first location of the first distal extent when in a pre-degenerated state; determining a second location of the first distal extent when in a degenerated state caused by wear of the distal femur; placing a planar reference surface adjacent the second location and tangent to the first location; resecting the distal femur along a resection plane a predetermined distance from the planar reference surface and first location. - View Dependent Claims (12, 13)
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Specification