Method and apparatus for locating bone cuts at the distal condylar femur region to receive a femoral prothesis and to coordinate tibial and patellar resection and replacement with femoral resection and replacement
First Claim
1. An apparatus enabling the formation of planar resections on the medial and lateral condyles of a femur to provide seating surfaces to receive a femoral prosthesis, the apparatus comprising:
- a measuring system for indicating a thickness of a prospective planar resection from the posterior of the medial and lateral condyles and which is initiated along a line parallel to a plane tangent to the posterior surfaces of the medial and lateral condyles, the measuring system includingan anterior contacting element adapted to contact the anterior surface of the femoral cortex;
a posterior contacting element adapted to simultaneously contact the posterior surfaces of both of the medial and lateral condyles when no bone loss or equal bone loss is present from the posterior surfaces of the medial and lateral condyles; and
a graduated scale between the anterior contacting element and the posterior contacting element and including graduated markings to represent a range of prosthesis sizes and to indicate a distance between the anterior surface of the femoral cortex and a plane tangent to the posterior surfaces of the medial and lateral condyles, and to indicate intermediate distances between adjacent prosthetic sizes so that a difference between a prosthetic size and the distance between the anterior surface and the tangent plane can be measured to determine the thickness of the prospective planar resection.
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Abstract
An apparatus and method of using same to form planar resections on the medial and lateral condyles of a femur and a corresponding resection of a tibia in a knee includes a caliper feeler and measurement plate to measure for the size of the femoral prosthesis to be received and a tibial resection guide. The caliper feeler and measurement plate are used to determine a first distance between an anterior surface of the femoral cortex and a plane tangent to a posterior surface of the medial and lateral condyles of a femur. A graduated scale between the caliper feeler and the measurement plate compares the first distance to at least two standard femoral prosthesis sizes so that the most suitable size can be selected, and measures a second distance between the first distance and the size of the selected standard femoral prosthesis size to determine a thickness or thickness to be resected at the posterior surface of the femoral condyles. The tibial resection guide includes a pair of styli which slide and rotate in the resection guide to contact the proximal tibial surface. The styli include incremental markings to properly place the guide for resection.
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Citations
55 Claims
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1. An apparatus enabling the formation of planar resections on the medial and lateral condyles of a femur to provide seating surfaces to receive a femoral prosthesis, the apparatus comprising:
a measuring system for indicating a thickness of a prospective planar resection from the posterior of the medial and lateral condyles and which is initiated along a line parallel to a plane tangent to the posterior surfaces of the medial and lateral condyles, the measuring system including an anterior contacting element adapted to contact the anterior surface of the femoral cortex; a posterior contacting element adapted to simultaneously contact the posterior surfaces of both of the medial and lateral condyles when no bone loss or equal bone loss is present from the posterior surfaces of the medial and lateral condyles; and a graduated scale between the anterior contacting element and the posterior contacting element and including graduated markings to represent a range of prosthesis sizes and to indicate a distance between the anterior surface of the femoral cortex and a plane tangent to the posterior surfaces of the medial and lateral condyles, and to indicate intermediate distances between adjacent prosthetic sizes so that a difference between a prosthetic size and the distance between the anterior surface and the tangent plane can be measured to determine the thickness of the prospective planar resection. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. An apparatus for enabling planar resections to be made on the medial and lateral condyles of a femur of a knee joint to form seating surfaces to receive a femoral prosthesis, the apparatus comprising:
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means for obtaining a measurement of the femur at the knee joint based on a plane tangent to the posterior surfaces of both the medial and lateral condyles when no bone loss or equal bone loss is present from the posterior medial and lateral condyles, and for selecting a suitable prosthesis size to be received onto the femur based on the obtained measurement; and means for measuring a difference between the selected prosthesis size and the obtained measurement so as to determine a thickness to be resected from the posterior of the medial and lateral condyles along a plane initiated along a line parallel to the tangent plane. - View Dependent Claims (24, 25, 26)
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27. A method for reconstructing a knee joint by forming planar resections on the medial and lateral condyles of a femur to form seating surfaces to receive a femoral prosthesis and to properly articulate with a tibial prothesis and a patellar prosthesis, the method comprising the steps of:
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providing a measuring system including a sizing instrument having a graduated scale; using the sizing instrument to measure for the size of the femoral prosthesis to be received by determining a first distance between an anterior surface of the femoral cortex and a plane tangent to the posterior surfaces of the medial and lateral condyles of a femur as determined when no or equal amounts of bone loss are present from the posterior surfaces; comparing the first distance to at least two standard sizes of femoral protheses using the graduated scale on the sizing instrument; measuring a second distance between the first distance and the size of the smaller standard femoral prosthesis when the first distance falls between two femoral prosthesis sizes; and measuring a thickness or thicknesses to be resected from the posterior surfaces of the medial and lateral condyles of the femur by adding an average thickness of the posterior condyles of the smaller standard femoral prosthesis and the second distance, such that when no bone loss or equal bone loss is present from the posterior medial and lateral condyles, the thickness to be resected from the posterior medial condyle is measured to be substantially equal to the thickness to be resected from the posterior lateral condyle and the thickness is to be resected along a plane initiated at a line parallel to the plane tangent to both the posterior medial and lateral condyles. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
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45. A method for reconstructing a knee joint by forming planar resections on the medial and lateral condyles of a femur to form seating surfaces to receive a femoral prosthesis with a built-in varus angulation and to properly articulate with a tibial prothesis and a patellar prosthesis, the method comprising:
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providing a measuring system including a sizing instrument having a graduated scale; using the sizing instrument to measure for the size of the femoral prosthesis to be received by determining a first distance between an anterior surface of the femoral cortex and a plane tangent to the posterior surfaces of the medial and lateral condyles of a femur as determined when no or equal amounts of bone loss are present from the posterior surfaces; comparing the first distance to at least two standard sizes of femoral prostheses using the graduated scale on the sizing instrument; choosing the femoral prosthesis having the larger standard size when the first distance falls between two femoral prosthesis sizes; measuring a second distance between the first distance and the size of the larger femoral prosthesis; measuring a thickness to be resected from the posterior surfaces of the medial and lateral condyles of the femur by subtracting the second distance from an average thickness of the posterior condyles of the larger femoral prosthesis, such that when no bone loss or equal bone loss is present from the posterior medial and lateral condyles, the thickness to be resected from the posterior medial condyle is measured to be substantially equal to the thickness to be resected from the posterior lateral condyle, and the thickness is to be resected along a plane initiated at a line parallel to the plane tangent to both the posterior medial and lateral condyles. - View Dependent Claims (46, 47, 48, 49)
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50. A method for reconstructing a knee joint by forming planar resections on the medial and lateral condyles of a femur of a knee to form seating surfaces to receive a femoral prosthesis and to properly articulate with a tibial prosthesis and a patellar prosthesis, the method comprising the steps of:
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measuring a thickness to be resected by a prospective planar resection to be made from the posterior surfaces of the medial and lateral condyles of a femur at which a distance between an anterior surface of the femoral cortex and the prospective planar resection is substantially equal to an interior dimension of a femoral prosthesis to be fitted on the femur, the prospective planar resection producing resection of the medial and lateral condyles from the posterior surfaces of respective thicknesses which are substantially equal and which is initiated along a line parallel to a plane tangent to the posterior surfaces of the medial and lateral condyles when no bone loss or equal bone loss is present from the posterior surfaces of the medial and lateral condyles; resecting from the anterior surfaces of the medial and lateral condyles along a plane substantially flush with the anterior surface of the femoral cortex and parallel to the prospective planar resection, and then resecting along the prospective planar resection; and resecting a distal end of the medial and lateral condyles along a plane which produces respective resected thicknesses at the medial and lateral condyles so that a distal femoral surface resulting from the distal resection is substantially level or horizontal in extension. - View Dependent Claims (51, 52)
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53. A method for reconstructing a knee joint by forming planar resections on the anterior, posterior, and distal surfaces of the medial and lateral condyles of a femur to form seating surfaces to receive a femoral prosthesis and to properly articulate with a tibial prosthesis and a patellar prosthesis, the method comprising:
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providing a measuring system including an anterior contacting element adapted to contact the anterior surface of the femoral cortex, a posterior contacting element adapted to simultaneously contact the posterior surfaces of both of the medial and lateral condyles when no bone loss or equal bone loss is present from the posterior surfaces of the medial and lateral condyles, a graduated scale between the anterior contacting element and the posterior contacting element, a distal sizer having a graduated scale with graduated markings corresponding to the graduated scale between the anterior contacting element and the posterior contacting element, and a tibial measuring guide; measuring for the size of the femoral prosthesis to be received by contacting the anterior contacting element to the anterior surface of the femoral cortex and by placing the posterior contacting element along a plane tangent to the posterior surfaces of the medial and lateral condyles element to determine a first distance between therebetween, the tangent plane being determined according to a condition when no or equal amounts of bone loss are present from the posterior surfaces; using the graduated scale between the anterior contacting element and the posterior contacting element to compare the first distance to at least two standard femoral prosthesis sizes; measuring a second distance between the first distance and the size of the smaller standard femoral prosthesis using the graduated size scale between the anterior contacting element and the posterior contacting element when the measured size falls between the at least two standard femoral prosthesis sizes; determining a thickness to be resected at the posterior surface of the medial and lateral condyles of the femur by adding the thickness of the smaller femoral prosthesis and the second distance, such that the respective thicknesses to be resected from the posterior surface of the medial condyle and from the posterior surface of the lateral condyle are substantially equal to each other and is initiated along a line parallel to the plane tangent to the posterior surfaces of the medial and lateral condyles when no bone loss or equal bone loss is present from the posterior surfaces of the condyles; resecting the medial and lateral condyles along a plane at the anterior surfaces thereof substantially flush with the anterior surface of the femoral cortex and parallel to the prospective planar resection, and then along the determined parallel plane at the posterior surfaces of the medial and lateral condyles; measuring thicknesses to be resected from the distal ends of the medial and lateral condyles using the graduated scale on the distal sizer, the thicknesses of the distal resections being determined so as to accommodate the smaller-sized standard femoral prosthesis and so that a distal femoral surface resulting from said distal resection is substantially level or horizontal in extension; resecting the distal ends of the medial and lateral condyles along the measured thicknesses; using the tibial measuring guide to measure a thickness of a proximal tibial planar resection so as to place the average level of the joint line of the femoral prosthesis substantially at anatomic level; and resecting along the measured proximal tibial resection. - View Dependent Claims (54, 55)
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Specification