# US 12,758,389 B2 · Knee joint endoprosthesis set and instruments > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,758,389 B2 - Document ID: US12758389B2 - Status: Granted - Kind: B2 - Application number: 17/312,378 - Filed: 2019-12-10 - Published: 2022-01-20 - Granted: 2026-10-13 - Earliest claimed: 2018-12-10 - Assignees: Waldemar Link GmbH & Co. KG - Applicants: WALDEMAR LINK GmbH & Co. KG - Inventors: Harm-Iven Jensen; Helmut D. Link - Web page: https://patentgrep.com/patent/US12758389B2 ## CPC - A61F 2/3859: {Femoral components} - A61F 2/389: {Tibial components (A61F2/3868 takes precedence)} - A61F 2/461: {of knees} - A61F 2/4657: {Measuring instruments used for implanting artificial joints (for surgical instruments A61B90/06)} - A61F 2002/30125: {elliptical or oval} - A61F 2002/30327: {differing in diameter} - A61F 2002/30538: {for adjusting angular orientation} - A61F 2002/30616: {Sets comprising a plurality of prosthetic parts of different sizes or orientations} - A61F 2002/3863: {Condyles fitted on an anchored base} - A61F 2002/4662: {for measuring penetration depth} - A61F 2002/4668: {for measuring angles} - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract A knee joint endoprosthesis set including modular knee joint endoprostheses in different sizes. Each knee joint endoprosthesis includes a tibial component. The femoral component includes a joint element for articulated cooperation with the tibial component and comprises a shaft for anchoring in the femur. The set includes shafts in different sizes. In the femoral component, the shape of the shafts tapers from a distal end, facing toward the joint element, to a proximal free end of the shaft. An oval cross-section is provided at the distal end, and a round cross-section is provided at the proximal free end of the shaft. ## Claims ### Claim 1 A knee joint endoprosthesis set comprising: modular knee joint endoprostheses in different sizes, each knee joint endoprosthesis comprising a tibial component for anchoring at a proximal end of the tibia, a femoral component for anchoring at a distal end of the femur, the femoral component comprising: a joint element for articulated cooperation with the tibial component and a shaft configured for anchoring in a medullary canal of the femur, the set comprising shafts in different sizes, each shaft having a shape that tapers from a distal end, facing toward the joint element, to a proximal free end of the shaft, and is designed with an oval cross-section at the distal end and with a round cross-section in both a horizontal transverse plane and a coronal plane, forming a hemispherical shape at the proximal free end of the shaft, wherein an ovality defined by the oval cross-section increases as the size of the shafts increases, wherein the different sizes are graded according to the ovality, wherein the shafts each have a lateral surface, wherein the lateral surface extends from the distal end to the proximal free end, and wherein the lateral surface is a transition surface between the oval cross-section at the distal end and the round cross-section at the proximal free end, and wherein the ovality is elliptical. ### Claim 2 (depends on 1) The knee joint endoprosthesis set as claimed in claim 1, wherein the oval cross-section has an ovality of the kind whose major axis lies in a medial to lateral (ML) direction and whose minor axis lies in an anterior to posterior (AP) direction, wherein a ratio of the long axis to the short axis lies in the range of between 1.1 and 1.4. ### Claim 3 (depends on 1) The knee joint endoprosthesis set as claimed in claim 1, wherein a degree of ovality increases as the size of the shaft increases. ### Claim 4 (depends on 1) The knee joint endoprosthesis set as claimed in claim 1, wherein the lateral surface corresponds to a conical transition body between an oval cross-section at one end and a circular cross-section at the other end. ### Claim 5 (depends on 1) The knee joint endoprosthesis set as claimed in claim 1, wherein the shafts are curved, with a curvature that has a radius of curvature of in the range of between 1200 mm and 1800 mm. ### Claim 6 (depends on 1) The knee joint endoprosthesis set as claimed in claim 1, wherein the shafts are curved, wherein the curvature of the shafts in an anterior to posterior (AP) direction and a medial to lateral (ML) direction is different, wherein the shafts are more strongly curved in the AP direction, and not curved in the ML direction. ### Claim 7 (depends on 1) The knee joint endoprosthesis set as claimed in claim 1, wherein the shafts are designed as short shafts with a length of less than 7 times an equivalent diameter at the distal shaft end. ### Claim 8 (depends on 1) The knee joint endoprosthesis set as claimed in claim 1, wherein the free end of the shafts has a rounded dome shape, wherein the free end is rounded all the way around. ### Claim 9 (depends on 1) The knee joint endoprosthesis set as claimed in claim 1, wherein adapters are provided which are configured to connect the joint element to one of the shafts with a screw, wherein adapters are provided in different lengths, and wherein the adapters are configured to contact both the joint element and the shaft in a connected configuration, and wherein the adapters are one piece. ### Claim 10 (depends on 9) The knee joint endoprosthesis set as claimed in claim 9, wherein the adapters can be locked at an adjustable angle, and wherein the adapters are provided with a double cone. ### Claim 11 (depends on 1) The knee joint endoprosthesis set as claimed in claim 1, wherein shafts for fastening by means of cement and shafts for cementless fastening are provided, wherein the shafts for fastening by means of cement each have a predetermined undersize relative to the corresponding shafts for cementless fastening. ### Claim 12 (depends on 11) The knee joint endoprosthesis set as claimed in claim 11, wherein the shafts for fastening by means of cement have a smooth lateral surface or are provided with a maximum of five furrows, and/or the shafts for cementless fastening have a corrugated lateral surface. ### Claim 13 (depends on 1) The knee joint endoprosthesis set as claimed in claim 1, wherein the sizes of the shafts are graded regularly according to a medial to lateral (ML) dimension, on the basis of a module dimension. ### Claim 14 (depends on 13) The knee joint endoprosthesis set as claimed in claim 13, wherein there are between 8 and 14 different module dimension sizes. ### Claim 15 (depends on 1) An instrument kit for implanting a femoral component of a knee joint endoprosthesis from the knee joint endoprosthesis set as claimed in claim 1, wherein the femoral component has a shaft and a joint element, wherein the instrument kit comprises: a tool for forming a cavity, dimensioned to receive the shaft, at the distal end of the medullary canal of a femur, a gauge for producing a seat for the joint element at the distal end of the femur, a depth-measuring device for determining a positioning of the shaft in the cavity created to receive the shaft, and an insertion instrument for implanting the femoral component at the distal end of the femur, wherein the depth-measuring device is designed to display a required length of the shaft and/or of an adapter for fastening the shaft to the joint element. ### Claim 16 (depends on 15) The instrument kit as claimed in claim 15, wherein an angle-measuring device is further provided, which is designed to determine a rotation angle of the shaft within the medullary canal, wherein a separate indicator for a rotation direction of the shaft within the medullary canal is provided. ### Claim 17 (depends on 16) The instrument kit as claimed in claim 16, wherein the depth-measuring device and the angle-measuring device are designed as a combined element. ### Claim 18 (depends on 1) A method for implanting a femoral component of a knee joint endoprosthesis from the knee joint endoprosthesis set as claimed in one claim 1, wherein the femoral component has a shaft and a joint element, the method comprising: preparing a knee joint for the implantation of a knee joint endoprosthesis, forming a cavity at the distal end of the femur for receiving the shaft, producing a seat for the joint element at the distal end of the femur by means of a gauge, determining a positioning of the shaft in the cavity, and inserting the femoral component with its shaft and the joint element, wherein a suitable size of the shaft is selected from the knee joint endoprosthesis set. ### Claim 19 (depends on 18) The method as claimed in claim 18, the method further comprising: selecting a suitable size of the shaft on the basis of a ML dimension, and/or determining a length of an adapter for fastening the shaft to the joint element by measuring a depth of the cavity, and selecting the corresponding adapter, and/or measuring an angular position for determining an angle of rotation of the shaft within the medullary canal, wherein a rotation direction of the shaft within the medullary canal is determined by means of a separate indicator, and/or measuring an angular position for determining an angle of rotation of the shaft within the medullary canal, wherein a rotation direction of the shaft within the medullary canal is determined by means of a separate indicator, preferably by setting a relative angle of rotation between shaft and joint element by means of the adapter. ### Claim 20 (depends on 1) The knee joint endoprosthesis set as claimed in claim 1, wherein the oval cross-section has an ovality of the kind whose major axis lies in a medial to lateral (ML) direction and extends from a first end of the major axis to a second end of the major axis and whose minor axis lies in an anterior to posterior (AP) direction and extends from a first end of the minor axis to a second end of the minor axis, and wherein a material of the shafts extends from the first end of the major axis to the second end of the major axis and extends from the first end of the minor axis to the second end of the minor axis. ### Claim 21 (depends on 1) The knee joint endoprosthesis set as claimed in claim 1, wherein the shaft comprises the oval cross-section at the distal end and with a round cross-section in a median plane at the proximal free end of the shaft.