Knee joint replacement assembly type tibia base prosthesis

Abstract

The utility model discloses a knee joint replacement assembly type tibia base prosthesis, and belongs to the technical field of medical instruments. The defects that in the prior art, a traditional tibia base prosthesis is loosened, and movement of a knee joint is limited are overcome. The main structure of the tibia support assembly comprises a tibia support assembly central base, a near-end locking screw, a far-end locking screw and a tibia support assembly clamping groove matched with the tibia support assembly central base, the tibia support assembly central base is provided with a central inner hole thread and a positioning hole, and the tibia support assembly clamping groove is provided with a central hole and an inner hole thread. The near-end locking screw penetrates through the central hole and then is in threaded connection with a central inner hole thread in the central base of the tibia support assembly, and the far-end locking screw penetrates through the positioning hole and then is in threaded connection with an inner hole thread in the clamping groove of the tibia support assembly. The artificial total knee joint replacement device is mainly used for artificial total knee joint replacement.

Description

Technical Field

[0001] This utility model belongs to the field of medical device technology, and more specifically, it relates to a knee joint replacement tibial base prosthesis. Background Technology

[0002] Knee osteoarthritis is a degenerative disease characterized by knee pain, joint deformity, and limited mobility, causing significant inconvenience to patients' lives. Total knee replacement is currently an effective treatment for end-stage osteoarthritis and other related diseases. However, total knee replacement is a delicate surgery, and even slight angular misalignment during the procedure can affect the restoration of lower limb alignment. One of the keys to surgical success is a precise understanding of the knee joint's skeletal geometry. Only with a high degree of fit between the patient and the prosthesis can the mechanical and kinematic properties of the knee joint be restored to the greatest extent possible. However, the anatomical morphology of the knee joint at the proximal tibia varies among different individuals, which can affect the fit during surgery. In current techniques, poor prosthesis fit still occurs in actual surgical applications, especially during intraoperative rotation and alignment of the tibial prosthesis, where inadequate coverage of the osteotomy surface between the prosthesis and the osteotomy surface frequently occurs. For example, if the tibial abutment component is small, the posteromedial side often cannot be covered, leading to tibial plateau subsidence and loosening in the early postoperative period. Data from joint registry centers in various countries indicate that the main reason for knee revision is prosthesis loosening. Conversely, if the tibial abutment component is large, the prosthesis protrusion on the posterolateral side can irritate adjacent soft tissues, joint capsule and surrounding ligaments, causing postoperative pain, limited knee joint movement and other complications.

[0003] In conclusion, to address the prosthesis mismatch caused by inadequate tibial abutment coverage and improve joint function and prosthesis survival rate after total knee arthroplasty, it is essential to consider the differences in anatomical features when designing the tibial abutment component of the knee joint.

[0004] For example, Chinese utility model patent with authorization announcement number CN 202843854 U discloses a tibial base element and a knee joint prosthesis. It fixes the anterior cruciate ligament in the guide channel of the tibial base element through a locking mechanism. After the anterior cruciate ligament is fixed twice, it is sealed in the guide channel by a sealing rod. However, its shortcomings are that the positioning of the central base of the tibial support component and the tibial support component slot in the vertical and horizontal directions is inaccurate, and the reliability is low. The prosthesis is prone to loosening, which in turn causes postoperative pain and limited knee joint movement. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a knee replacement tibial base prosthesis.

[0006] To achieve the above objectives, this utility model employs the following technical solution:

[0007] A knee replacement tibial base prosthesis includes a central base for a tibial support assembly, a proximal locking screw, a distal locking screw, and a tibial support assembly slot that mates with the central base. The central base of the tibial support assembly has a central internal thread and a positioning hole. The slot of the tibial support assembly has a central hole and an internal thread. The proximal locking screw passes through the central hole and is threaded to the central internal thread on the central base of the tibial support assembly. The distal locking screw passes through the positioning hole and is threaded to the internal thread on the slot of the tibial support assembly.

[0008] Preferably, the bottom of the tibial support assembly slot is provided with a bottom pin post, and the central base of the tibial support assembly is provided with a top end face positioning hole for cooperating with the bottom pin post.

[0009] Preferably, the tibial support assembly slot is provided with a bottom groove, the upper end of the central base of the tibial support assembly is installed in the bottom groove, and the upper end face of the central base of the tibial support assembly matches the arc shape of the bottom groove.

[0010] Preferably, the top end face positioning hole, the central hole, and the positioning hole are all through holes.

[0011] Preferably, the internal thread is a blind hole.

[0012] Preferably, the central inner hole thread is a blind hole.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. By using proximal and distal locking screws, the connection strength between the central base of the tibial support component and the slot of the tibial support component is strengthened, and the stability of the entire prosthesis structure is improved. This can effectively prevent the prosthesis from loosening or shifting during use, ensuring the recovery of the patient's knee joint function after surgery and the safety of long-term use.

[0015] 2. The bottom pin at the bottom of the tibial support component slot and the positioning hole on the top end face of the central base of the tibial support component cooperate with each other to achieve precise alignment, simplify the surgical procedure, reduce the difficulty of the operation, and at the same time ensure the accuracy of the prosthesis installation position, which helps to reduce the occurrence of postoperative complications.

[0016] 3. The upper end face of the central base of the tibial support component matches the arc shape of the bottom groove, which not only helps to disperse pressure and reduce local stress concentration, but also better simulates the anatomical shape of the natural knee joint, improving patient comfort and user experience.

[0017] 4. The central internal thread and the internal thread adopt a blind hole design, which can avoid corrosion or contamination caused by the entry of liquid or foreign matter, thereby extending the service life of the prosthesis and reducing maintenance costs;

[0018] In summary, this utility model achieves the positioning and fixation of the tibial base in the inward and outward directions by aligning the bottom pin on the tibial support component slot with the positioning hole on the top end face of the central base of the tibial support component; it achieves the positioning of the tibial base in the vertical direction by inserting the top end face of the central base of the tibial support component into the bottom groove on the tibial support component slot; it achieves the vertical fixation by threading the proximal locking screw through the central hole on the tibial support component slot and threading it into the central inner hole on the central base of the tibial support component; and it achieves the vertical fixation by threading the distal locking screw through the positioning hole on the central base of the tibial support component and threading it into the inner hole on the tibial support component slot. Attached Figure Description

[0019] Figure 1 This is an exploded view of the present invention;

[0020] Figure 2 This is an exploded view of the present invention viewed from below;

[0021] Figure 3 This is a cross-sectional view of the present invention;

[0022] Figure 4 This is a structural diagram of the present invention in its installed and used state;

[0023] Figure 5 This is a schematic diagram showing the symmetrical structure of the central base of the tibial support component and the slot of the tibial support component in this utility model.

[0024] Figure 6 This is a schematic diagram of the asymmetrical structure of the central base of the tibial support component and the slot of the tibial support component in this utility model.

[0025] Figure 7 This is a schematic diagram of the tibial support component slots of different specifications and shapes in this utility model.

[0026] In the diagram: 1. Central base of tibial support assembly; 2. Tibial support assembly slot; 3. Proximal locking screw; 4. Distal locking screw; 5. Internal thread; 6. Bottom pin post; 7. Top end face positioning hole; 8. Central internal thread; 9. Bottom groove; 10. Central hole; 11. Positioning hole. Detailed Implementation

[0027] The present invention will be further described below through specific embodiments and in conjunction with the accompanying drawings.

[0028] Example 1:

[0029] like Figure 1-4 As shown, a knee replacement tibial base prosthesis includes a tibial support assembly central base 1, a proximal locking screw 3, a distal locking screw 4, and a tibial support assembly slot 2 that mates with the tibial support assembly central base 1. The tibial support assembly central base 1 has a central inner thread 8 and a positioning hole 11. The tibial support assembly slot 2 has a central hole 10 and an inner thread 5. The proximal locking screw 3 passes through the central hole 10 and is threaded to the central inner thread 8 on the tibial support assembly central base 1. The distal locking screw 4 passes through the positioning hole 11 and is threaded to the inner thread 5 on the tibial support assembly slot 2.

[0030] Specifically, the bottom pin 6 on the tibial support component slot 2 is aligned with the top end face positioning hole 7 on the central base 1 of the tibial support component to achieve the positioning and fixation of the tibial base in the inward and outward directions; the top end face of the central base 1 of the tibial support component is inserted into the bottom groove 9 on the tibial support component slot 2 to achieve the positioning of the tibial base in the vertical direction; the proximal locking screw 3 passes through the central hole 10 on the tibial support component slot 2 and locks with the central inner hole thread 8 on the central base 1 of the tibial support component to achieve vertical fixation; the distal locking screw 4 passes through the positioning hole 11 on the central base 1 of the tibial support component and locks with the inner hole thread 5 on the tibial support component slot 2 to achieve vertical fixation.

[0031] Example 2:

[0032] A knee replacement tibial base prosthesis differs from Embodiment 1 in that the bottom of the tibial support component slot 2 is provided with a bottom pin post 6, and the central base 1 of the tibial support component is provided with a top end face positioning hole 7 for cooperating with the bottom pin post 6.

[0033] Furthermore, the tibial support component slot 2 is provided with a bottom groove 9, the upper end of the central base 1 of the tibial support component is installed in the bottom groove 9, and the upper end face of the central base 1 of the tibial support component matches the arc shape of the bottom groove 9.

[0034] Furthermore, the top end face positioning hole 7, the central hole 10, and the positioning hole 11 are all through holes; the inner hole thread 5 and the central inner hole thread 8 are both blind holes.

[0035] Existing tibial abutments of different shapes and sizes are basically monolithic designs with poor interchangeability. Often, for tibial abutments of the same size, the anteroposterior and medial diameters are also unique, and the coverage of the tibial abutment is also fixed. It is not possible to make adjustments such as shape to obtain more matching options. This will result in situations where the tibial abutment covers well on one side but not on the other side due to different anatomical shapes. Early problems include tibial plateau subsidence and loosening, or prosthesis protrusion irritating tissues and causing pain, as well as limited knee joint movement. This utility model's modular tibial base assembly uses proximal locking screws 3 and distal locking screws 4 for locking and bottom pin positioning to assemble the central base 1 of the tibial support assembly with the slot 2 of the tibial support assembly. This achieves interchangeability of different shapes (symmetrical and asymmetrical) and sizes of the slot 2, ensuring optimal coverage of the tibial base and the proximal tibial osteotomy surface, meeting the needs of different patients with varying proximal tibial anatomy. It reduces tibial plateau subsidence and loosening, decreases post-knee replacement pain, and improves knee joint mobility. The slot 2 of the tibial support assembly of the knee prosthesis can achieve optimal coverage of the tibial base and the proximal tibial osteotomy surface according to different anatomical shapes and sizes. The central base 1 of the tibial support assembly can be designed in one specification, and can be combined with different shapes (symmetrical and asymmetrical, such as...) Figure 5-6 The tibial support assembly slots (shown) and different specifications cater to knee replacement patients with varying proximal tibial anatomical differences. Due to the simple structure of the tibial base assembly, compared to producing the same number of tibial bases, approximately 50% of raw materials can be saved, reducing production costs. The central base 1 of the tibial support assembly and the slots of the tibial support assembly can be used with the connectors of this invention to reduce the stock of tibial bases, while effectively helping surgeons to use a more suitable tibial support for different patients' knee joints during surgery, achieving better proximal tibial coverage.

[0036] In this invention, the tibial support component slot 2 can be designed with different shapes according to different anatomical morphologies of the proximal tibia of the knee joint (e.g., Figure 7 (As shown); at the same time, tibial support component slots 2 with different front-to-back diameters and inner and outer diameters can also be designed. The internal thread 5, bottom pin 6, bottom groove 9 and central hole 10 have the same structural dimensions when different specifications and different shapes of tibial support component slots 2 are matched.

Claims

1. A knee replacement tibial base prosthesis, characterized in that: The device includes a central base (1) for a tibial support assembly, a proximal locking screw (3), a distal locking screw (4), and a tibial support assembly slot (2) that mates with the central base (1) for the tibial support assembly. The central base (1) for the tibial support assembly is provided with a central inner hole thread (8) and a positioning hole (11). The slot (2) for the tibial support assembly is provided with a central hole (10) and an inner hole thread (5). The proximal locking screw (3) passes through the central hole (10) and is threaded to the central inner hole thread (8) on the central base (1) for the tibial support assembly. The distal locking screw (4) passes through the positioning hole (11) and is threaded to the inner hole thread (5) on the slot (2) for the tibial support assembly.

2. The knee replacement matching tibial base prosthesis according to claim 1, characterized in that: The bottom of the tibial support assembly slot (2) is provided with a bottom nail post (6), and the central base (1) of the tibial support assembly is provided with a top end face positioning hole (7) for cooperating with the bottom nail post (6).

3. The knee replacement matching tibial base prosthesis according to claim 2, characterized in that: The tibial support assembly slot (2) is provided with a bottom groove (9), the upper end of the central base (1) of the tibial support assembly is installed in the bottom groove (9), and the upper end face of the central base (1) of the tibial support assembly matches the arc shape of the bottom groove (9).

4. The knee replacement prosthesis with tibial base as described in claim 2, characterized in that: The top end face positioning hole (7), central hole (10) and positioning hole (11) are all through holes.

5. The knee replacement prosthesis with tibial base according to any one of claims 1-4, characterized in that: The internal thread (5) is a blind hole.

6. The knee replacement prosthesis with tibial base according to any one of claims 1-4, characterized in that: The central inner hole thread (8) is a blind hole.

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