Tumour-type knee joint prosthesis

Abstract

The utility model provides a kind of tumour type knee joint prosthesis, for reconstructing the bone defect after distal femur tumour resection of children, including femur prosthesis and tibia prosthesis, the top of femur prosthesis is used to connect with distal femur, the bottom of tibia prosthesis is used to connect with proximal tibia, the bottom of femur prosthesis and the top of tibia prosthesis are connected by pin shaft rotation, the front side of tibia prosthesis is provided with limiting portion, limiting portion is used to limit tibia prosthesis and femur prosthesis knee hyperextension.In the front side of limiting portion is provided with the concave groove of recession to the rear, the intersection of the top surface and the front side of limiting portion is provided with avoidance chamfer.So, when patient carries out knee joint flexion, limiting portion no longer occurs interference with the inner side of patella, avoid limiting portion to patella damage.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a tumor-type knee joint prosthesis. Background Technology

[0002] Osteosarcoma (OS) is the most common primary osteosarcoma in children. It is usually located in the metaphysis of long bones, with 50% of cases occurring around the knee joint, and most commonly in the distal femur. With the advent of neoadjuvant therapy, the survival rate of children with osteosarcoma has significantly improved, and most cases can be treated with limb salvage. After resection of periarticular tumors, tumor-type prostheses provide a near-anatomical appearance and good function, and are currently the most commonly used reconstruction method. For malignant tumors occurring around the knee joint, tumor resection often requires sacrificing the distal femoral and / or proximal tibial epiphysis to achieve safe surgical margins. The distal femoral epiphysis and proximal tibial epiphysis contribute 35% and 30% to the growth length of the lower limb, respectively. Therefore, after resection of periarticular tumors and knee prosthesis reconstruction, as patients grow and develop, problems such as limb length discrepancy (LLD), functional defects, gait disorders, pelvic tilt, and scoliosis are inevitable.

[0003] For distal femoral osteosarcoma, the commonly used method in China after tumor resection is to use a pediatric femoral prosthesis. This prosthesis features a simple hinge connection on the femoral and tibial sides, a platform device on the tibial side, and a thin, smooth tibial stem. The aim is to minimize the impact on the growth potential of the proximal tibial epiphysis and reduce the degree of leg length discrepancy later on. This prosthesis is a temporary device and needs to be replaced with an adult prosthesis after the patient stops growing. Therefore, patients will inevitably face the need for prosthesis revision. After revision, the metal edge of the anti-extension limiting part of the prosthesis hinge area can impact the patella during knee flexion and extension, causing patellar cartilage damage or even cortical bone breakage on the inner surface of the patella. This results in postoperative pain during joint flexion and extension, severely impacting the patient's quality of life and limb function. Utility Model Content

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention provides a tumor-type knee joint prosthesis, aiming to solve the problem in related technologies where the metal edge of the anti-hyperextension limiting portion of the tumor-type knee joint prosthesis interferes with the patella during knee flexion and extension.

[0005] This invention provides a tumor-type knee joint prosthesis for reconstructing bone defects after distal femoral tumor resection in children. It includes a femoral prosthesis and a tibial prosthesis. The top end of the femoral prosthesis connects to the distal femur, and the bottom end of the tibial prosthesis connects to the proximal tibia. The bottom end of the femoral prosthesis and the top end of the tibial prosthesis are rotatably connected by a pin. A limiting portion is provided on the anterior side of the tibial prosthesis to restrict hyperextension of the knee joint between the femoral and tibial prostheses. The limiting portion is characterized by having a rearwardly recessed clearance groove on its anterior side, and a clearance chamfer at the intersection of the top and anterior side of the limiting portion.

[0006] According to the tumor-type knee joint prosthesis provided by this utility model, the avoidance groove is an arc-shaped groove.

[0007] According to the tumor-type knee joint prosthesis provided by this utility model, the avoidance chamfer is a rounded corner.

[0008] According to the tumor-type knee joint prosthesis provided by this utility model, the tibial prosthesis further includes: Tibial plateau; A spinal needle, the tip of which is connected to the middle of the bottom surface of the tibial plateau; The bone screws include two, both of which are connected to the bottom surface of the tibial plateau and are located on the left and right sides of the medullary needle, respectively. A first rotating connection portion is disposed on the top surface of the tibial plateau, and the first rotating connection portion is provided with a first shaft hole, which penetrates the first rotating connection portion in the left-right direction. The limiting part is disposed on the top surface of the tibial platform and is located in front of the first rotating connection part.

[0009] According to the tumor-type knee joint prosthesis provided by this utility model, the femoral prosthesis includes: The femoral condyle has connecting arms extending downward on its left and right sides at the bottom. Each connecting arm has a second shaft hole that passes through the connecting arm in the left-right direction. When connected, the two connecting arms are located on the left and right sides of the first rotating connecting part, and the first shaft hole and the second shaft hole are coaxial. The bottom front side of the femoral condyle has a limiting surface for abutting against the top surface of the limiting part. Femoral stem, which is attached to the top of the femoral condyle.

[0010] This utility model has the following advantages due to the adoption of the above technical solution: This invention provides a tumor-type knee joint prosthesis for reconstructing bone defects after distal femoral tumor resection in children. It includes a femoral prosthesis and a tibial prosthesis. The top end of the femoral prosthesis connects to the distal femur, and the bottom end of the tibial prosthesis connects to the proximal tibia. The bottom end of the femoral prosthesis and the top end of the tibial prosthesis are rotatably connected. A limiting portion is provided on the anterior side of the tibial prosthesis to restrict hyperextension of the knee joint between the tibial and femoral prostheses. A posteriorly recessed clearance groove is provided on the anterior side of the limiting portion, and a clearance chamfer is provided at the intersection of the top and anterior sides of the limiting portion. Thus, during knee flexion and extension, the limiting portion no longer interferes with the medial surface of the patella, avoiding damage to the patella. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0012] Figure 1 This is a front view of a tumor-type knee joint prosthesis provided in an embodiment of the present invention; Figure 2 This is a top view of a tibial prosthesis provided in an embodiment of the present invention; Figure 3 This is a left view of a tibial prosthesis provided in an embodiment of the present invention.

[0013] Figure label: 110: Femoral condyle; 120: Connecting arm; 210: Tibial plateau; 220: Medullary nail; 230: Bone screw; 240: First rotating connection; 250: Limiting part; 251: Avoidance groove; 252: Avoidance chamfer. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0015] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0016] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0017] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0018] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0019] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0020] This invention provides a tumor-type knee joint prosthesis for reconstructing bone defects after distal femoral tumor resection in children. It includes a femoral prosthesis and a tibial prosthesis. The top end of the femoral prosthesis connects to the distal femur, and the bottom end of the tibial prosthesis connects to the proximal tibia. The bottom end of the femoral prosthesis and the top end of the tibial prosthesis are rotatably connected. A limiting portion is provided on the anterior side of the tibial prosthesis to restrict hyperextension of the knee joint between the tibial and femoral prostheses. A posteriorly recessed clearance groove is provided on the anterior side of the limiting portion, and a clearance chamfer is provided at the intersection of the top and anterior sides of the limiting portion. Thus, during knee flexion and extension, the limiting portion no longer interferes with the medial surface of the patella, avoiding damage to the patella.

[0021] The following is combined Figures 1 to 3 This invention describes the tumor-type knee joint prosthesis provided by this utility model.

[0022] An embodiment of this utility model provides a tumor-type knee joint prosthesis for reconstructing bone defects after distal femoral tumor resection in children. It includes a femoral prosthesis and a tibial prosthesis. The top end of the femoral prosthesis is used to connect with the distal femur, and the bottom end of the tibial prosthesis is used to connect with the proximal tibia. The bottom end of the femoral prosthesis and the top end of the tibial prosthesis are rotatably connected, with the rotation axis along the left-right direction.

[0023] The femoral prosthesis includes a femoral condyle 110 and a femoral stem. The bottom of the femoral condyle 110 has downwardly extending connecting arms 120 on both the left and right sides. The connecting arms 120 have a second axial hole that passes through the connecting arms 120 in the left-right direction.

[0024] The tibial prosthesis includes a tibial plateau 210, a medullary needle 220, a bone screw 230, and a first rotating connection 240. The medullary needle 220 is located at the bottom center of the tibial plateau 210. The bone screw 230 is connected to the bottom of the tibial plateau 210 and is located on the left and right sides of the tibial plateau 210. The first rotating connection 240 can be a connecting protrusion. The top of the connecting protrusion is an arc surface, and a first axial hole is provided on the connecting protrusion. The first axial hole passes through the connecting protrusion in the left and right direction.

[0025] During connection, the femoral stem is connected to the distal end of the femur, and the medullary nail 220 and bone screw 230 are connected to the proximal end of the tibia. The bone screw 230 is used to restrict the relative rotation of the tibial prosthesis and the tibia. The two connecting arms 120 of the femoral condyle 110 are located on the left and right sides of the connecting protrusion, respectively. At this time, the first shaft hole and the second shaft hole are coaxial. The installation is completed by passing the pin through the first shaft hole and the second shaft hole.

[0026] In addition, a limiting part 250 is provided on the tibial prosthesis. The limiting part 250 is located on the front side of the first rotating connection part 240. In the prior art, the limiting part 250 is a cuboid block structure. A limiting surface is also provided on the anterior bottom side of the femoral condyle 110 for abutting against the top surface of the limiting part 250. The abutment between the limiting part 250 and the limiting surface can effectively prevent hyperextension of the knee joint.

[0027] However, when the patient's knee joint is flexed or extended, the edge where the front and top surfaces of the limiting part 250 intersect with the patella, which can damage the patella.

[0028] Therefore, in the embodiments provided by this utility model, a rearwardly recessed avoidance groove 251 is provided on the front side of the limiting part 250, and the avoidance groove 251 can be an arc-shaped groove. At the same time, an avoidance chamfer 252 is made at the intersection of the front side and the top surface of the limiting part 250, and the avoidance chamfer 252 can be a rounded corner. In this way, when the patient performs knee flexion and extension, the limiting part 250 avoids the sliding trajectory of the patella, thus preventing damage to the patella caused by the limiting part 250.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A tumor-type knee joint prosthesis for reconstructing bone defects after distal femoral tumor resection in children, comprising a femoral prosthesis and a tibial prosthesis, wherein the top end of the femoral prosthesis is used to connect to the distal femur, the bottom end of the tibial prosthesis is used to connect to the proximal tibia, the bottom end of the femoral prosthesis and the top end of the tibial prosthesis are rotatably connected by a pin, and a limiting part (250) is provided on the anterior side of the tibial prosthesis for limiting hyperextension of the knee between the femoral prosthesis and the tibial prosthesis, characterized in that, The front side of the limiting part (250) is provided with a rearward recessed clearance groove (251), and the intersection of the top surface and the front side of the limiting part (250) is provided with a clearance chamfer (252).

2. The tumor-type knee joint prosthesis according to claim 1, characterized in that, The clearance groove (251) is an arc-shaped groove.

3. The tumor-type knee joint prosthesis according to claim 1, characterized in that, The chamfer (252) is a rounded corner.

4. The tumor-type knee joint prosthesis according to claim 1, characterized in that, The tibial prosthesis also includes: Tibial plateau (210); A spinal cord needle (220), the tip of which is connected to the middle of the bottom surface of the tibial plateau (210); Bone nails (230), including two bone nails (230), both bone nails (230) are connected to the bottom surface of the tibial plateau (210) and are located on the left and right sides of the medullary needle (220); The first rotating connection part (240) is disposed on the top surface of the tibial platform (210), and the first rotating connection part (240) is provided with a first shaft hole, which penetrates the first rotating connection part (240) in the left-right direction. The limiting part (250) is disposed on the top surface of the tibial platform (210) and is located in front of the first rotating connection part (240).

5. The tumor-type knee joint prosthesis according to claim 4, characterized in that, The femoral prosthesis includes: The femoral condyle (110) has connecting arms (120) extending downward on the left and right sides of its bottom. The connecting arms (120) have second shaft holes that penetrate the connecting arms (120) in the left and right direction. When connected, the two connecting arms (120) are located on the left and right sides of the first rotating connecting part (240), and the first shaft hole and the second shaft hole are coaxial. The bottom front side of the femoral condyle (110) has a limiting surface for abutting against the top surface of the limiting part (250). Femoral stem, which is attached to the top of the femoral condyle (110).

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