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. A system for reconstructing a knee joint with which a femur, a tibia, and a patella can each be prepared to receive a femoral prosthesis, a tibial prosthesis, and a patellar prosthesis, respectively, so as to provide substantially anatomic articulation between the prostheses, the system comprising:
- a) a femoral sizer which includes1) an anterior contacting element adapted to contact the anterior surface of the femoral cortex,2) 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, and3) a graduated scale between the anterior contacting element and the posterior contacting element having graduated markings to represent a range of prosthesis sizes and intermediate distances between adjacent prosthetic sizes;
b) a tibial measuring guide which includes1) an alignment rod to be mounted to the tibia,2) tibial resection guide slidably mounted on the rod, and3) at least one stylus rotatable in the resection guide for allowing the tibial resection guide to be slidable thereon to contact a highest or most intact side of the medial or lateral side of the tibial plateau, the at least one stylus including a scale having markings to determine the highest or most intact side of the tibial plateau and to indicate a proper tibial resection such that when the at least one stylus contacts the highest or most intact side of the tibial plateau, the tibial resection guide is slidable on the rod and stylus to thereby coincide with the marking corresponding to the highest or most intact side; and
c) a patella reaming apparatus which includes1) a clamp for securing a patella to be fitted with a patellar insert, and2) a reamer for reaming away a sufficient amount of patella to accommodate the patellar insert, the reamer including a depth scale to indicate a depth which has been reamed by the reamer.
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Accused Products
Abstract
A femoral resection apparatus and method is provided for resecting at least one of the posterior, anterior, and distal surfaces of the medial and lateral condyles of a femur to provide seating surface to receive a femoral prosthesis. The apparatus includes a measuring system to determine a location of the posterior, anterior, and distal resections to be made. The apparatus additionally includes a graduated scale to measure a distance between the anterior and posterior surfaces of the femoral condyles, including markings representing different prosthesis sizes and markings in between the size markings to account for the difference between the measured distance and the nearest prosthesis size. The femoral resection apparatus and method may be used in combination with a tibial resection apparatus and method for resecting a tibial plateau to provide a seating surface to receive a corresponding tibial prosthesis. The tibial apparatus includes a measurement scale to indicate a proper resection location. Additionally, a patellar reamer apparatus and method may be used to fit a patella with a patellar insert. The patellar reamer apparatus also includes a measurement scales to indicate a proper reaming depth which corresponds to a thickness of the patellar insert.
335 Citations
42 Claims
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1. A system for reconstructing a knee joint with which a femur, a tibia, and a patella can each be prepared to receive a femoral prosthesis, a tibial prosthesis, and a patellar prosthesis, respectively, so as to provide substantially anatomic articulation between the prostheses, the system comprising:
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a) a femoral sizer which includes 1) an anterior contacting element adapted to contact the anterior surface of the femoral cortex, 2) 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 3) a graduated scale between the anterior contacting element and the posterior contacting element having graduated markings to represent a range of prosthesis sizes and intermediate distances between adjacent prosthetic sizes; b) a tibial measuring guide which includes 1) an alignment rod to be mounted to the tibia, 2) tibial resection guide slidably mounted on the rod, and 3) at least one stylus rotatable in the resection guide for allowing the tibial resection guide to be slidable thereon to contact a highest or most intact side of the medial or lateral side of the tibial plateau, the at least one stylus including a scale having markings to determine the highest or most intact side of the tibial plateau and to indicate a proper tibial resection such that when the at least one stylus contacts the highest or most intact side of the tibial plateau, the tibial resection guide is slidable on the rod and stylus to thereby coincide with the marking corresponding to the highest or most intact side; and c) a patella reaming apparatus which includes 1) a clamp for securing a patella to be fitted with a patellar insert, and 2) a reamer for reaming away a sufficient amount of patella to accommodate the patellar insert, the reamer including a depth scale to indicate a depth which has been reamed by the reamer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A system for restructuring a knee joint by forming seating surfaces on a femur to receive a femoral prosthesis and to properly articulate with a tibial prosthesis received on a proximal end of a tibia and a patellar prosthesis received on a patella, said system comprising:
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means for determining 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 using a graduated size scale provided on the means for determining; a graduated size scale for comparing the first distance to at least two standard femoral prosthesis sizes closest to the first distance, and for measuring a second distance between the first distance and the size of a selected femoral prosthesis size so as to determine a thickness or thicknesses to be resected at the posterior surface of the medial and lateral femoral condyles; means for 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; means for resecting the determined thickness or thicknesses from the posterior surface from the medial and lateral femoral condyles; means for resecting distal ends of the medial and lateral condyles along a plane which accommodates the selected femoral prosthesis so as to produce a substantially horizontal joint line in the medial-lateral direction in extension when in an upright position; means for determining a thickness to be resected from the proximal end of a tibia so that an average joint line level of the femoral and tibial prostheses is substantially at an anatomic knee level of a patient receiving the prostheses; and means for reaming a patella to a predetermined depth to accommodate the patellar prosthesis. - View Dependent Claims (29, 30)
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31. A method for restructuring a knee joint by forming seating surfaces on a femur to receive a femoral prosthesis and to properly articulate with a tibial prosthesis received on a proximal end of a tibia and a patellar prosthesis received on a patella, said method comprising:
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measuring 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 a posterior surface of the medial and lateral condyles of a femur using a measuring system having a graduated size scale; comparing the first distance to at least two standard femoral prosthesis sizes closest to the first distance, as indicated by the graduated size scale on the measuring system; selecting one of the two closest standard femoral prosthesis sizes when the measured size falls between the two closest standard femoral prosthesis sizes; measuring a second distance between the first distance and the size of the selected femoral prosthesis size using the graduated size scale; determining a thickness or thicknesses to be resected at the posterior surface of the medial and lateral condyles of the femur by adding the thickness of the selected femoral prosthesis and the second distance if the size of the selected femoral prosthesis is smaller than the measured size, or, if the selected femoral prosthesis is larger than the measured size, subtracting the second distance from an average thickness of the posterior condyles of the selected femoral prosthesis; 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; resecting the determined thickness or thicknesses from the posterior surface from the medial and lateral femoral condyles; resecting distal ends of the medial and lateral condyles along a plane which accommodates the selected femoral prosthesis so as to produce a substantially horizontal joint line in the medial-lateral direction in extension when in an upright position; resecting a thickness from the proximal end of a tibia so that an average joint line level of the femoral and tibial prostheses is substantially at an anatomic knee level of a patient receiving the prostheses; and preparing patella to accommodate the patellar prosthesis. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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42. A method for reconstructing a knee joint by forming seating surfaces on a femur to receive a femoral prosthesis and to properly articulate with a tibial prosthesis received on a proximal end of a tibia and a patellar prosthesis received on a patella, the method comprising:
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A) providing a measuring system including 1) a femoral sizer which has a) an anterior contacting element adapted to contact the anterior surface of the femoral cortex, b) 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 c) a graduated scale between the anterior contacting element and the posterior contacting element having graduated markings to represent a range of prosthesis sizes and intermediate distances between adjacent prosthetic sizes; 2) 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 of the femoral sizer; 3) a tibial measuring guide which has a) an alignment rod to be mounted to the tibia, b) a tibial resection guide slidably mounted on the rod, the guide including a slot for receiving a saw blade to resect the tibia, and c) at least one stylus rotatable in the resection guide for allowing the tibial resection guide to be slidable thereon and for contacting a highest or most intact side of the medial or lateral side of the tibial plateau, the at least one stylus including a scale to indicate a proper tibial resection, the scale including markings to determine the highest or most intact side of the tibial plateau, wherein when the at least one stylus contacts the highest or most intact side of the tibial plateau, the tibial resection guide is slidable on the rod and stylus and made to coincide with the marking corresponding to the highest or most intact side; and 4) a patella reaming apparatus which has a) a base plate, b) a collet for securing a patella to be fitted with a patellar insert therebetween, the collet including a plurality of prongs located on a bottom side thereof and arranged to be generally equally spaced around the peak of the patella, c) a scale to indicate a distance between a location at which the prongs intersect the patella and the baseplate, and d) a reamer for reaming the patella and having a depth scale to indicate a depth to which the patella has been reamed; B) measuring for the size of the femoral prosthesis to be received by contacting the anterior contacting 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 therebetween, the tangent plane being determined according to a condition when no or equal amounts of bone loss are present from the posterior surfaces; C) 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 closest to the first distance, as indicated by the graduated size scale of t he femoral sizer; D) selecting one of the two closest standard femoral prosthesis, sizes when the measured size falls between the two closest standard femoral prosthesis sizes; E) measuring a second distance between the first distance and the size of the selected femoral prosthesis size using the graduated size scale; F) determining a thickness or thicknesses to be resected at the posterior surface of the medial and lateral condyles of the femur by adding the thickness of the selected femoral prosthesis and the second distance if the size of the selected femoral prosthesis is smaller than the measured size, or, if the selected femoral prosthesis is larger than the measured size, subtracting the second distance from an average thickness of the posterior condyles of the selected femoral prosthesis; G) 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; H) resecting the determined thickness or thicknesses from the posterior surface of the medial and lateral femoral condyles; I) measuring thicknesses to be resected from the distal ends of the medial and lateral condyles using the graduated scaled on the distal sizer, the thicknesses of the distal resections being determined so as to accommodate the selected standard femoral prosthesis and so as to produce a substantially horizontal joint line in the medial-lateral direction in extension when in an upright position; J) resecting the distal ends of the medial and lateral condyles along the measured thicknesses; K) 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; L) resecting along the measured proximal tibial resection; M) securing the patella between the base plate and collet in a patella reaming apparatus; and N) using the depth scale as a guide to ream the patella to a predetermined depth to accommodate the patellar insert.
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Specification