A cruciate retaining anatomic femoral condylar knee prosthesis

Abstract

This invention relates to the field of artificial joint prosthesis technology, and discloses an anatomical femoral condyle knee joint prosthesis that does not preserve the cruciate ligament. The prosthesis includes a femoral condyle, a tibial plateau pad, and a tibial plateau support. The femoral condyle comprises a medial condyle and a lateral condyle. The medial and lateral condyles, in lateral view, respectively form medial condyle curve contours and lateral condyle curve contours. The medial condyle curve contour is located lateral to the lateral condyle curve contour, and the movement trajectory length of the medial condyle curve contour is 15%-25% longer than that of the lateral condyle curve contour. The tibial plateau pad has medial condyle curved grooves and lateral condyle curved grooves that respectively conform to the medial and lateral condyles. The slope of the medial condyle curved groove is greater than that of the lateral condyle curved groove. This invention provides an anatomical femoral condyle knee joint prosthesis that does not preserve the cruciate ligament, solving the problem of poor compatibility between existing prostheses and surrounding tissues after implantation.

Description

Technical Field

[0001] This invention relates to the field of artificial joint prosthesis technology, specifically to an anatomical femoral condyle knee joint prosthesis that does not preserve the cruciate ligament. Background Technology

[0002] Artificial knee joint prostheses are mainly used to treat knee osteoarthritis, rheumatoid arthritis, severe knee fractures, ligament injuries, and knee tumors. They can also be used for revision knee joints that have experienced problems such as prosthesis loosening, infection, or wear after the initial knee replacement.

[0003] Existing knee prostheses have the following problems: The existing prosthesis has equal lengths of the medial and lateral condyles, which does not conform to the natural anatomical structure of the human knee joint, where the medial condyle is longer and the lateral condyle is shorter. This results in poor matching between the prosthesis and the surrounding tissues after implantation, affecting the natural movement of the knee joint and failing to restore the normal shape and function of the knee joint. Patients may experience discomfort after surgery, such as unnatural and unsmooth flexion, extension, and rotation of the knee joint, and limited range of motion.

[0004] Because existing prostheses have equal medial and lateral condyles, while the medial condyle of the human skeleton is longer and the lateral condyle is shorter, the osteotomy during installation can easily result in over- or under-removal of bone, leading to misalignment of the prosthesis after implantation. This makes it difficult to achieve soft tissue balance after surgery, potentially causing postoperative soft tissue tension or relaxation, affecting knee joint stability and motor function, increasing the risk of postoperative pain and swelling, and even complications such as dislocation. Furthermore, misalignment after installation can lead to loosening and wear after a period of use, affecting the prosthesis's lifespan and long-term efficacy, increasing the risk of revision surgery, and indicating insufficient stability and durability of the prosthesis. Summary of the Invention

[0005] The purpose of this invention is to provide an anatomically shaped femoral condyle knee prosthesis that does not preserve the cruciate ligament, in order to solve at least one of the aforementioned problems existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: An anatomically type femoral condyle knee prosthesis that does not preserve the cruciate ligament includes a femoral condyle, a tibial plateau pad, and a tibial plateau support. The femoral condyle includes a medial condyle and a lateral condyle. The medial condyle and the lateral condyle respectively form a medial condyle curve profile and a lateral condyle curve profile in the lateral view. The medial condyle curve profile is located outside the lateral condyle curve profile, and the movement trajectory length of the medial condyle curve profile is 15%-25% longer than that of the lateral condyle curve profile. The tibial plateau pad has a medial condyle curved groove and a lateral condyle curved groove that respectively conform to the medial condyle and the lateral condyle. The slope of the medial condyle curved groove is greater than that of the lateral condyle curved groove. An enclosing beam is provided on the femoral condyle, and a column is provided on the tibial plateau pad, with the column located inside the enclosing beam.

[0007] This technical solution features a 15%-25% longer trajectory length for the medial condyle curve compared to the lateral condyle curve. This aligns with the natural anatomical structure of the human knee joint, where the medial condyle is longer and the lateral condyle is shorter. It conforms to the natural anatomy and movement characteristics of the human body, restoring the normal knee joint shape and better fitting the actual structure of the knee joint. This results in greater stability of the prosthesis within the body, reducing the risk of loosening and displacement, improving patient comfort and satisfaction, and making the patient feel more natural. This technical solution better conforms to the kinematics and biomechanics of the human knee joint, more accurately restoring the normal movement trajectory. During flexion, extension, and rotation, the medial and lateral condyle structures coordinate more naturally, resulting in smoother and more natural movement. This increases the range of motion of the knee joint, allowing patients to walk and climb stairs more freely in daily activities. It improves postoperative proprioception and biomechanics of the knee joint, restoring the patient's ability to climb stairs and squat, achieving normal leg flexion and extension movements, and increasing patient satisfaction. Because the prosthesis design is more in line with the natural anatomy and movement characteristics of the human body, postoperative recovery is smoother, patients recover knee joint function faster and better, and experience fewer adverse reactions such as pain and swelling. They can return to normal life and exercise more quickly, improving their quality of life and satisfaction with the surgery.

[0008] Existing prostheses have equal medial and lateral condyles, but human bones are not of equal length. This can easily lead to over- or under-resection of bone during implantation and osteotomy. Therefore, implanting existing prostheses with equal medial and lateral condyles presents certain technical challenges. This new design, with a longer medial condyle and a shorter lateral condyle, can reduce the difficulty of osteotomy during surgery to some extent, making the procedure simpler. After implantation, this prosthesis also reduces the risk of prosthesis loosening, helps achieve better soft tissue balance, and avoids postoperative soft tissue tension or relaxation, thereby reducing the risk of prosthesis loosening due to soft tissue imbalance. Because the tibial plateau pad has medial and lateral condylar curved grooves that respectively conform to the medial and lateral condyles, with the medial condylar groove having a larger slope than the lateral condylar groove, the curved surface and movement curve between the tibial plateau pad and the femoral condyle reduce the risk of wear. The reasonable force distribution and trajectory more in line with the natural movement of the human body reduce the risk of abnormal wear of the polyethylene tibial plateau pad, improving the durability of the prosthesis, extending its lifespan, and reducing the risk and burden of postoperative revision for patients. Furthermore, the larger slope of the medial condylar groove and the smaller slope of the lateral condylar groove provide better restraint on the medial side during femoral condyle flexion, preventing dislocation; the smoother lateral side allows for internal and external rotation of the knee joint with the medial side as a fulcrum.

[0009] To provide a structure that does not preserve the cruciate ligament, an enclosing beam is provided on the femoral condyle, and a column is provided on the tibial plateau pad. The column is located within the enclosing beam. The addition of the column leaves space on the posterior side of the femoral condyle and the posterior beam, which can limit excessive anterior movement.

[0010] Furthermore, in order to improve the structural stability of the prosthesis, a column is integrally formed on the tibial plateau pad, and an enclosing crossbeam is integrally formed on the femoral condyle.

[0011] Furthermore, to limit excessive forward movement, the front end of the column is sloped, and the enclosed crossbeam includes an upwardly extending U-shaped portion. A rear crossbeam is provided at the upper rear end of the U-shaped portion. Both the U-shaped portion and the rear crossbeam are located between the inner and outer condyles, and an movable gap is left between the column and the rear crossbeam.

[0012] Furthermore, in order to provide a better motion trajectory, the motion trajectory length of the inner condyle curve profile is 20% longer than the motion trajectory length of the outer condyle curve profile.

[0013] The beneficial effects of this invention are as follows: In this technical solution, the movement trajectory length of the medial condyle curve is 15%-25% longer than that of the lateral condyle curve, which conforms to the natural anatomical structure of the human knee joint, where the medial condyle is longer and the lateral condyle is shorter. This conforms to the natural anatomy and movement characteristics of the human body, restores the normal knee joint shape, and better fits the actual structure of the human knee joint, making the prosthesis more stable within the body, reducing the risk of prosthesis loosening and displacement, improving patient comfort and satisfaction, and making patients feel more natural. This technical solution is more in line with the kinematics and biomechanical properties of the human knee joint, and can more accurately restore the normal movement trajectory of the knee joint. During flexion, extension, and rotation, the medial and lateral condyle structures cooperate more naturally, resulting in more natural and smooth movement, thereby increasing the range of motion of the knee joint. This allows patients to walk more freely, climb stairs, and perform other daily activities, improving postoperative proprioception and biomechanics of the knee joint, restoring the patient's ability to climb stairs and squat, achieving normal leg flexion and extension movements, and improving patient satisfaction. Because the prosthesis design is more in line with the natural anatomy and movement characteristics of the human body, postoperative recovery is smoother, patients recover knee joint function faster and better, and experience fewer adverse reactions such as pain and swelling. They can return to normal life and exercise more quickly, improving their quality of life and satisfaction with the surgery.

[0014] Existing prostheses have equal medial and lateral condyles, but human bones are not of equal length. This can easily lead to over- or under-resection of bone during implantation and osteotomy. Therefore, implanting existing prostheses with equal medial and lateral condyles presents certain technical challenges. This new design, with a longer medial condyle and a shorter lateral condyle, can reduce the difficulty of osteotomy during surgery to some extent, making the procedure simpler. After implantation, this prosthesis also reduces the risk of prosthesis loosening, helps achieve better soft tissue balance, and avoids postoperative soft tissue tension or relaxation, thereby reducing the risk of prosthesis loosening due to soft tissue imbalance. Because the tibial plateau pad has medial and lateral condylar curved grooves that respectively conform to the medial and lateral condyles, with the medial condylar groove having a larger slope than the lateral condylar groove, the curved surface and movement curve between the tibial plateau pad and the femoral condyle reduce the risk of wear. The reasonable force distribution and trajectory more in line with the natural movement of the human body reduce the risk of abnormal wear of the polyethylene tibial plateau pad, improving the durability of the prosthesis, extending its lifespan, and reducing the risk and burden of postoperative revision for patients. Furthermore, the larger slope of the medial condylar groove and the smaller slope of the lateral condylar groove provide better restraint on the medial side during femoral condyle flexion, preventing dislocation; the smoother lateral side allows for internal and external rotation of the knee joint with the medial side as a fulcrum.

[0015] To provide a structure that does not preserve the cruciate ligament, an enclosing beam is provided on the femoral condyle, and a column is provided on the tibial plateau pad. The column is located within the enclosing beam. The addition of the column leaves space on the posterior side of the femoral condyle and the posterior beam, which can limit excessive anterior movement. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a top view of the structure of the present invention; Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure at point AA; Figure 4 This is a side view of the structure of the present invention; Figure 5 This is a schematic diagram of the femoral condyle from a first-view perspective in this invention; Figure 6 This is a schematic diagram of the femoral condyle from a second perspective in this invention; Figure 7 This is a schematic diagram of the lateral view of the femoral condyle in this invention; Figure 8 This is a top view schematic diagram of the femoral condyle in this invention; Figure 9 for Figure 8 Schematic diagram of the cross-sectional structure at point BB; Figure 10 This is a schematic diagram of the tibial plateau pad in this invention; Figure 11 This is a top view of the tibial plateau pad in this invention; Figure 12 for Figure 11 A schematic diagram of the cross-sectional structure at the CC section; Figure 13 This is a side view of the tibial plateau pad in this invention.

[0017] In the figure: 1. Femoral condyle; 2. Tibial plateau pad; 3. Tibial plateau support; 4. Medial condyle; 5. Lateral condyle; 6. Medial condyle curve outline; 7. Lateral condyle curve outline; 8. Medial condyle curved groove; 9. Lateral condyle curved groove; 14. Post; 14.1. Inclined surface; 15. U-shaped part; 16. Posterior transverse beam; 17. Movement gap. Detailed Implementation

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0019] Example 1: like Figures 1-13 As shown, this embodiment provides an anatomically type femoral condyle knee prosthesis that does not preserve the cruciate ligament, including a femoral condyle 1, a tibial plateau pad 2, and a tibial plateau support 3. The femoral condyle 1 includes a medial condyle 4 and a lateral condyle 5. The medial condyle 4 and the lateral condyle 5 respectively form a medial condyle curve contour 6 and a lateral condyle curve contour 7 in the lateral view direction. The medial condyle curve contour 6 is located lateral to the lateral condyle curve contour 7, as shown. Figure 9 As shown, the thickness of the inner condyle 4 is greater than that of the outer condyle 5, and the trajectory length of the inner condyle curve profile 6 is 15%-25% longer than that of the outer condyle curve profile 7; as Figure 3 As shown, the tibial plateau pad 2 has a medial condyle curved groove 8 and a lateral condyle curved groove 9 that respectively conform to the medial condyle 4 and the lateral condyle 5, as shown. Figure 12 As shown, the slope of the medial condyle curved groove 8 is greater than that of the lateral condyle curved groove 9. The tibial plateau pad 2 and the tibial plateau support 3 are fixedly locked together, and the lateral condyle 5 and the medial condyle 4 slide within the lateral condyle curved groove 9 and the medial condyle curved groove 8 on the tibial plateau pad 2; An enclosed transverse beam is provided on the femoral condyle 1, and a column 14 is provided on the tibial plateau pad 2, with the column 14 located inside the enclosed transverse beam.

[0020] In this technical solution, the medial condyle curve contour 6 is located lateral to the lateral condyle curve contour 7. The movement trajectory length of the medial condyle curve contour 6 is 15%-25% longer than that of the lateral condyle curve contour 7. This conforms to the natural anatomical structure of the normal human knee joint, where the medial condyle 4 is longer and the lateral condyle 5 is shorter. This design conforms to the natural anatomy and movement characteristics of the human body, restores the normal knee joint shape, and better fits the actual structure of the human knee joint. This makes the prosthesis more stable within the body, reduces the risk of prosthesis loosening and displacement, improves patient comfort and satisfaction, and makes patients feel more natural. This technical solution better conforms to the kinematics and biomechanics of the human knee joint, and can more accurately restore the normal movement trajectory of the knee joint. During flexion, extension, and rotation, the structures of the medial condyle 4 and lateral condyle 5 cooperate more naturally, resulting in more natural and smooth movement. This increases the range of motion of the knee joint, allowing patients to walk and climb stairs more freely in daily activities, improving postoperative proprioception and biomechanics of the knee joint, restoring the patient's ability to climb stairs and squat, achieving normal leg flexion and extension movements, and improving patient satisfaction. Because the prosthesis design is more in line with the natural anatomy and movement characteristics of the human body, postoperative recovery is smoother, patients recover knee joint function faster and better, and experience fewer adverse reactions such as pain and swelling. They can return to normal life and exercise more quickly, improving their quality of life and satisfaction with the surgery.

[0021] Existing prostheses have equal medial and lateral condyles, but human bones are not of equal length. This can easily lead to over- or under-resection of bone during implantation and osteotomy. Therefore, implanting existing prostheses with equal medial and lateral condyles presents certain technical challenges. Our proposed design, with a longer medial condyle 4 and a shorter lateral condyle 5 (the movement trajectory of the medial condyle curve contour 6 is longer than that of the lateral condyle curve contour 7), can reduce the difficulty of osteotomy during surgery to some extent, making the procedure simpler. After implantation, this prosthesis also reduces the risk of prosthesis loosening, helps achieve better soft tissue balance, and avoids postoperative soft tissue tension or relaxation, thereby reducing the risk of prosthesis loosening due to soft tissue imbalance. Because the tibial plateau pad 2 has medial condyle curved groove 8 and lateral condyle curved groove 9 that respectively conform to the medial condyle 4 and lateral condyle 5, and the slope of the medial condyle curved groove 8 is greater than that of the lateral condyle curved groove 9, the curved surface and movement curve between the tibial plateau pad 2 and the femoral condyle 1 can reduce the risk of wear. The reasonable force distribution and trajectory that better conforms to the natural movement of the human body reduce the risk of abnormal wear of the polyethylene tibial plateau pad 2, improve the durability of the prosthesis, extend its service life, and reduce the risk and burden of postoperative revision for patients. Furthermore, the greater slope of the medial condyle curved groove 8 and the smaller slope of the lateral condyle curved groove 9 provide better restraint on the medial side of the femoral condyle 1 during flexion, preventing dislocation; the smoother lateral side allows for internal and external rotation of the knee joint with the medial side as a fulcrum.

[0022] To provide a structure that does not preserve the cruciate ligament, a surrounding beam is provided on the femoral condyle 1, and a post 14 is provided on the tibial plateau pad 2, with the post 14 located within the surrounding beam. The addition of the post 14 provides space on the posterior side of the femoral condyle 1 and the posterior beam 16, thus limiting excessive anterior displacement. To improve the structural stability of the prosthesis, the post 14 is integrally formed on the tibial plateau pad 2, and the surrounding beam is integrally formed on the femoral condyle 1.

[0023] Example 2: This embodiment is an optimization based on the above embodiment 1.

[0024] Without preserving the anterior and posterior cruciate ligaments, in order to limit excessive forward movement, the front end of the column 14 is a sloping surface 14.1. The enclosed crossbeam includes an upwardly extending U-shaped portion 15. A rear crossbeam 16 is provided at the upper rear end of the U-shaped portion 15. Both the U-shaped portion 15 and the rear crossbeam 16 are located between the inner condyle 4 and the outer condyle 5. An movable gap 17 is left between the column 14 and the rear crossbeam 16.

[0025] Example 3: This embodiment is an optimization based on the above embodiment 1.

[0026] To provide a better motion trajectory, the motion trajectory length of the inner condyle curve profile 6 is 20% longer than that of the outer condyle curve profile 7.

[0027] It should be noted that, depending on the condition of the bone lesion and the integrity of the cruciate ligament, a knee prosthesis that does not preserve the cruciate ligament can be selected. This technical solution provides a design that does not preserve the cruciate ligament, which can meet the needs of those who require cruciate ligament removal for certain reasons.

[0028] It should be noted that current knee prostheses offer limited personalization. Most prostheses are produced in a standardized manner, making it difficult to fully meet the individual anatomical differences and movement needs of different patients. This is especially true for certain populations, such as those with skeletal abnormalities or specific movement requirements, where the inability to provide a precisely matched prosthesis may affect surgical outcomes and the patient's quality of life. Based on this technical solution, the design with a longer medial condyle and a shorter lateral condyle can, to some extent, accommodate the anatomical differences in the knee joints of different patients. By utilizing a national skeletal database, size discrepancies can be reduced in densely distributed areas, increasing the range of available sizes and providing greater flexibility for personalized surgery. Surgeons can select the appropriate prosthesis model and size based on the patient's specific condition for precise matching, improving surgical outcomes and patient satisfaction.

[0029] This technical solution differentiates the curvature radius and motion trajectory length of the lateral condyle 5 and medial condyle 4 to match the natural anatomical structure of the human body. By optimizing the contact surface shape of the lateral condyle 5 and medial condyle 4, it achieves knee flexion, extension, and rotation movements that more closely resemble physiological states. This design can significantly reduce prosthesis wear, improve joint stability, and adapt to different ligament conditions and anatomical variations in patients. The femoral condyles 1 are designed asymmetrically, with the motion trajectory length of the medial condyle 4 increased by 15%-25% (preferably 20%) compared to the lateral condyle, to accommodate high mobility requirements, while the lateral condyle 5 provides stability support.

[0030] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A femoral condyle knee joint prosthesis that does not preserve the cruciate ligament, characterized in that: The device includes a femoral condyle, a tibial plateau pad, and a tibial plateau support. The femoral condyle comprises a medial condyle and a lateral condyle. The medial and lateral condyles respectively form a medial condyle curve profile and a lateral condyle curve profile in the lateral view. The medial condyle curve profile is located outside the lateral condyle curve profile, and the movement trajectory length of the medial condyle curve profile is 15%-25% longer than that of the lateral condyle curve profile. The tibial plateau pad has a medial condyle curved groove and a lateral condyle curved groove that respectively conform to the medial and lateral condyles. The slope of the medial condyle curved groove is greater than that of the lateral condyle curved groove. An enclosing beam is provided on the femoral condyle, and a column is provided on the tibial plateau pad, with the column located inside the enclosing beam.

2. The femoral condyle knee joint prosthesis without preserving the cruciate ligament as described in claim 1, characterized in that: A column is integrally formed on the tibial plateau pad, and an enclosing crossbeam is integrally formed on the femoral condyle.

3. A non-retaining, cross-ligament, anatomic femoral condylar knee prosthesis according to claim 2, wherein: The front end of the column is sloping, and the enclosed crossbeam includes an upwardly extending U-shaped part. A rear crossbeam is provided at the upper rear end of the U-shaped part. Both the U-shaped part and the rear crossbeam are located between the inner and outer condyles, and there is an movable gap between the column and the rear crossbeam.

4. The non-retaining, cross-ligament, anatomic femoral condyle knee prosthesis of Claim 1, wherein: The length of the motion trajectory of the inner condyle curve profile is 20% longer than the length of the motion trajectory of the outer condyle curve profile.

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