Knee joint distractor

Abstract

The knee joint distractor comprises a thighbone end fixing module and a tibia end fixing module, the thighbone end fixing module comprises a thighbone end outer fixing frame, a dynamic sliding groove system and a positioning mark, and the dynamic sliding groove system and the positioning mark are arranged at the far end of the thighbone end outer fixing frame. The dynamic sliding groove system can be matched with the instantaneous rotation track of the knee joint, and locking hole positions with different retraction intervals are preset. The positioning mark is used as a reference for alignment with the rotation center of the knee joint; the tibia end fixing module comprises a tibia side outer fixing frame and a hinge connecting part, the hinge connecting part is fixedly arranged at the end of the tibia side outer fixing frame, and the hinge connecting part comprises a hinge shaft structure matched with the dynamic sliding groove system.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a knee joint traction device. Background Technology

[0002] The main drawbacks of existing knee joint traction devices include the following: ① Insufficient adaptability of the rotation center Most tensioning devices rely on manual adjustment of the rotation center, requiring repeated trial and error during surgery, and lack multi-radius groove design, making it difficult to accurately match the instantaneous changes in the rotation center of the knee joint.

[0003] ② Poor controllability of dynamic tension Traditional sliding groove systems only support phased static locking and cannot achieve continuous dynamic tension adjustment. Postoperatively, the position of the locking screws needs to be frequently adjusted, increasing the complexity of the operation.

[0004] ③ The contradiction between structural complexity and stability While modular design can improve adaptability, the hinge and pivot structure is prone to mechanical fatigue (such as wear of universal joints), and there is a risk of breakage after long-term use. Summary of the Invention

[0005] The present invention aims to provide a knee joint traction device, and the technical problems to be solved include at least how to accurately match the instantaneous rotation center changes of the knee joint based on joint kinematics, so as to achieve quantifiable adjustment of traction force and joint range of motion, and avoid soft tissue damage caused by excessive traction.

[0006] To achieve the above objectives, the present invention provides a knee joint distraction device, comprising a femoral end fixation module and a tibial end fixation module. The femoral end fixation module includes a femoral end external fixator, a dynamic sliding system, and a positioning mark. The dynamic sliding system and the positioning mark are disposed at the distal end of the femoral end external fixator. The dynamic sliding system is adaptable to the instantaneous rotation trajectory of the knee joint and has preset locking holes with different distraction distances. The positioning mark serves as a reference for alignment with the rotation center of the knee joint. The tibial end fixation module includes a tibial side external fixator and a hinge connection part. The hinge connection part is fixedly disposed at the end of the tibial side external fixator, and the hinge connection part includes a hinge shaft structure that matches the dynamic sliding system.

[0007] Preferably, the tibial end fixation module further includes functional components, including fixing screws and locking pins. The fixing screws are used for bilateral bone shaft fixation, and the locking pins are used for fixing the staged spacing of the slides in the dynamic slide system.

[0008] Preferably, the fixing screw is a cortical bone screw with a diameter between 4.5 mm and 6.5 mm.

[0009] Preferably, the locking pin is a detachable locking pin.

[0010] Preferably, the dynamic chute system includes multiple arc-shaped chutes with different radii, each of which can cover an activity range of 0° to 180°.

[0011] Preferably, the multiple arc-shaped grooves with different radii are arranged in parallel to each other.

[0012] In a preferred embodiment, the femoral end external fixator includes a circular plate and a fixation handle. The circular plate is disposed at the distal end of the fixation handle, and the circular plate and the fixation handle are smoothly connected. A plurality of arc-shaped grooves with different radii are arranged parallel to each other on the circular plate. The positioning mark is a central circular hole disposed on the circular plate, which is located at the common center of the plurality of arc-shaped grooves with different radii.

[0013] Preferably, the dynamic chute system includes a first arc-shaped chute and a second arc-shaped chute, the first arc-shaped chute and the second arc-shaped chute have different radii, and a central circular hole is provided at the center position of the first arc-shaped chute and the second arc-shaped chute.

[0014] Preferably, the fixing handle is provided with a fixing through groove along its length, the fixing through groove being used for the fixing screw to pass through.

[0015] In a preferred embodiment, the tibial lateral fixation frame includes a tibial fixation handle, and the hinge connection includes an upper hinge plate and a lower hinge plate. The upper hinge plate is fixedly disposed on the upper surface of the end of the tibial fixation handle, and the lower hinge plate is fixedly disposed on the lower surface of the end of the tibial fixation handle. The upper hinge plate is provided with an upper hinge hole, and the lower hinge plate is provided with a lower hinge hole. The positions of the upper hinge hole and the lower hinge hole correspond to the positions of the lower hinge hole.

[0016] Preferably, the tibial fixation handle is provided with a tibial fixation through groove along its length, the tibial fixation through groove being used for the fixation screw to pass through.

[0017] Preferably, a first washer is fitted onto the first fixing screw, a second washer is fitted onto the second fixing screw, a third washer is fitted onto the third fixing screw, and a fourth washer is fitted onto the fourth fixing screw.

[0018] This application also provides a method for operating a knee joint traction device, including the following steps: S1. Determine the knee joint rotation center and screw placement path using CT / MRI; select the model of femoral end external fixator and tibial side external fixator according to the patient's femoral and tibial bone dimensions; S2. Align the central circular hole on the femoral end external fixator, which serves as a positioning marker, with the rotation center of the knee joint, and fix the femoral end external fixator to the distal end of the femoral shaft using screws. S3. Insert the circular plate of the femoral end external fixator between the upper hinge plate and the lower hinge plate of the tibial side external fixator, insert the detachable locking pin into the upper hinge hole, the central circular hole and the lower hinge hole to realize the hinge connection between the tibial side external fixator and the dynamic sliding groove system on the femoral end external fixator, and fix the tibial side external fixator to the proximal tibia using screws. S4. Passively flex and extend the knee joint from 0° to 135° to verify the smoothness of hinge movement and fixation stability; S5. Remove the detachable locking pin and apply outward stress to pull the joint gap to the target spacing; S6. Select the corresponding groove radius hole according to the pulling distance, and insert the detachable locking pin to complete the fixation; S7. Dynamic adjustment of the pulling force can be achieved by changing the position of the detachable locking pin.

[0019] Preferably, the target spacing in step S5 is 5 mm.

[0020] Preferably, the dynamic adjustment of the traction force in step S7 specifically refers to gradually increasing the joint gap to 8mm.

[0021] More preferably, this application also provides a method for dynamic tension adjustment of a knee joint tensioner, comprising the following steps: S101. Align the central circular hole on the femoral end external fixator, which serves as a positioning marker, with the rotation center of the knee joint. S102. Insert the circular plate of the femoral end external fixator between the upper hinge plate and the lower hinge plate of the tibial side external fixator, and insert the detachable locking pin into the upper hinge hole, the central circular hole and the lower hinge hole to realize the hinge connection between the tibial side external fixator and the dynamic sliding groove system on the femoral end external fixator. S103. Passively flex and extend the knee joint from 0° to 135° to verify the smoothness of hinge movement and fixation stability; S104. Remove the removable locking pin and apply outward stress to pull the joint gap to the target spacing; S105. Select the corresponding groove radius hole position according to the pulling distance, and insert the detachable locking pin to complete the fixation; S106. Dynamic adjustment of the pulling force is achieved by changing the position of the detachable locking pin.

[0022] Compared with the prior art, the beneficial effects of the present invention include: ① Precise fit: The multi-radius design of the slide groove matches the instantaneous rotation center changes of the knee joint (based on joint kinematics).

[0023] ② Controllable mechanical environment: Through the parallel multi-slide design, the traction force and joint range of motion can be quantitatively adjusted to avoid soft tissue damage caused by excessive traction.

[0024] ③ Minimally invasive compatibility: Percutaneous fixation reduces soft tissue dissection and supports early rehabilitation training. Attached Figure Description

[0025] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the specific embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0026] Figure 1 This is a schematic diagram of the overall structure of the knee joint traction device described in this invention.

[0027] Figure 2 This is a schematic diagram of the overall structure of the knee joint tensioner described in this invention from another angle.

[0028] Figure 3 This is a schematic diagram of the external fixator for the femoral end described in this invention.

[0029] Figure 4 This is a schematic diagram of the tibial lateral fixation frame described in this invention. Detailed Implementation

[0030] The invention is described in more detail below to aid in understanding it.

[0031] like Figures 1 to 4 As shown, the knee joint distraction device of the present invention includes a femoral end fixation module and a tibial end fixation module. The femoral end fixation module includes a femoral end external fixator 1, a dynamic sliding groove system, and a positioning mark. The dynamic sliding groove system and the positioning mark are located at the distal end of the femoral end external fixator 1. The dynamic sliding groove system can adapt to the instantaneous rotation trajectory of the knee joint and has preset locking holes with different distraction distances. The positioning mark serves as a reference for alignment with the rotation center of the knee joint. The tibial end fixation module includes a tibial side external fixator 2 and a hinge connection part. The hinge connection part is fixedly located at the end of the tibial side external fixator 2 and includes a hinge shaft structure that matches the femoral end sliding groove system.

[0032] Preferably, the tibial end fixation module further includes functional components, including fixing screws and locking pins. The fixing screws are used for bilateral bone shaft fixation, and the locking pins are used for fixing the staged spacing of the slides in the dynamic slide system.

[0033] Preferably, the fixing screw is a cortical bone screw with a diameter between 4.5 mm and 6.5 mm.

[0034] Preferably, the locking pin is a detachable locking pin 3.

[0035] Preferably, the dynamic chute system includes multiple arc-shaped chutes with different radii, each of which can cover an activity range of 0° to 180°.

[0036] Preferably, the multiple arc-shaped grooves with different radii are arranged in parallel to each other.

[0037] In a preferred embodiment, such as Figure 3 As shown, the femoral end external fixator 1 includes a circular plate 11 and a fixation handle 12. The circular plate 11 is disposed at the distal end of the fixation handle 12. The circular plate 11 and the fixation handle 12 are smoothly connected. The multiple arc-shaped grooves with different radii are arranged parallel to each other on the circular plate 11. The positioning mark is a central circular hole 112 disposed on the circular plate 11. The central circular hole is located at the common center position of the multiple arc-shaped grooves with different radii.

[0038] Preferably, the dynamic chute system includes a first arc-shaped chute 113 and a second arc-shaped chute 114, the first arc-shaped chute 113 and the second arc-shaped chute 114 have different radii, and a central circular hole 112 is provided at the center position of the first arc-shaped chute 113 and the second arc-shaped chute 114.

[0039] Preferably, the fixing handle 12 is provided with a fixing through groove 121 along its length, the fixing through groove 121 being used for fixing screws ( Figure 1 An illustrative illustration shows the third fixation screw 43 and the fourth fixation screw 44 passing through and fixing the said femoral end external fixator 1 to the distal end of the femoral shaft.

[0040] In a preferred embodiment, such as Figure 4As shown, the tibial lateral fixation frame 2 includes a tibial fixation handle 22, and the hinge connection part includes an upper hinge plate 211 and a lower hinge plate 212. The upper hinge plate 211 is fixedly disposed on the upper surface of the end of the tibial fixation handle 22, and the lower hinge plate 212 is fixedly disposed on the lower surface of the end of the tibial fixation handle 22. The upper hinge plate 211 is provided with an upper hinge hole 213, and the lower hinge plate 212 is provided with a lower hinge hole 214. The position of the upper hinge hole 213 corresponds to the position of the lower hinge hole 214.

[0041] Preferably, the tibial fixation handle 22 is provided with a tibial fixation groove 221 along its length, the tibial fixation groove 221 being used for receiving fixation screws ( Figure 1 An exemplary illustration shows a first fixation screw 41 and a second fixation screw 42 passing through and fixing the tibial lateral fixator 2 to the proximal tibia.

[0042] Preferably, such as Figure 2 As shown, a first washer 411 is fitted on the first fixing screw 41, a second washer 412 is fitted on the second fixing screw 42, a third washer 413 is fitted on the third fixing screw 43, and a fourth washer 414 is fitted on the fourth fixing screw 44.

[0043] The operation procedure of the knee joint traction device of the present invention includes the following steps: (1) Preoperative preparation and positioning ① Imaging localization: Determine the knee joint rotation center and screw placement path using CT / MRI. ② Matching selection: Select the external fixator model based on the patient's femoral / tibial dimensions.

[0044] (2) Intraoperative installation ① Femoral end fixation: Align the central hole of the femoral end with the center of rotation of the knee joint, and fix the screw to the distal end of the femoral shaft.

[0045] ② Tibial end fixation: A hinge connects the tibial end to the femoral end via a sliding system, and screws fix the tibial end to the proximal tibia.

[0046] (3) Device testing Passive flexion and extension of the knee joint from 0° to 135° were performed to verify the smoothness of hinge movement and fixation stability.

[0047] (4) Dynamic tension adjustment ① Initial pull-out: Remove the hinge locking pins and apply outward stress to pull the hinge gap to the target distance (e.g., 5mm).

[0048] ② Locking Selection: Select the corresponding groove radius hole position according to the pulling distance, and insert the locking pin to complete the fixation.

[0049] ③ Postoperative adjustment: The traction force can be dynamically adjusted by changing the position of the locking screw (e.g., gradually increasing it to 8mm).

[0050] Based on the above operating procedures, this application also provides a method for operating a knee joint traction device, including the following steps: S1. Determine the knee joint rotation center and screw placement path using CT / MRI; select the model of femoral end external fixator and tibial side external fixator according to the patient's femoral and tibial bone dimensions; S2. Align the central circular hole on the femoral end external fixator, which serves as a positioning marker, with the rotation center of the knee joint, and fix the femoral end external fixator to the distal end of the femoral shaft using screws. S3. Insert the circular plate of the femoral end external fixator between the upper hinge plate and the lower hinge plate of the tibial side external fixator, insert the detachable locking pin into the upper hinge hole, the central circular hole and the lower hinge hole to realize the hinge connection between the tibial side external fixator and the dynamic sliding groove system on the femoral end external fixator, and fix the tibial side external fixator to the proximal tibia using screws. S4. Passively flex and extend the knee joint from 0° to 135° to verify the smoothness of hinge movement and fixation stability; S5. Remove the detachable locking pin and apply outward stress to pull the joint gap to the target spacing; S6. Select the corresponding groove radius hole according to the pulling distance, and insert the detachable locking pin to complete the fixation; S7. Dynamic adjustment of the pulling force can be achieved by changing the position of the detachable locking pin.

[0051] Preferably, the target spacing in step S5 is 5 mm.

[0052] Preferably, the dynamic adjustment of the traction force in step S7 specifically refers to gradually increasing the joint gap to 8mm.

[0053] More preferably, this application also provides a method for dynamic tension adjustment of a knee joint tensioner, comprising the following steps: S101. Align the central circular hole on the femoral end external fixator, which serves as a positioning marker, with the rotation center of the knee joint. S102. Insert the circular plate of the femoral end external fixator between the upper hinge plate and the lower hinge plate of the tibial side external fixator, and insert the detachable locking pin into the upper hinge hole, the central circular hole and the lower hinge hole to realize the hinge connection between the tibial side external fixator and the dynamic sliding groove system on the femoral end external fixator. S103. Passively flex and extend the knee joint from 0° to 135° to verify the smoothness of hinge movement and fixation stability; S104. Remove the removable locking pin and apply outward stress to pull the joint gap to the target spacing; S105. Select the corresponding groove radius hole position according to the pulling distance, and insert the detachable locking pin to complete the fixation; S106. Dynamic adjustment of the pulling force is achieved by changing the position of the detachable locking pin.

[0054] The key technological advantages of this application include: ① Precise fit: The multi-radius design of the slide groove matches the instantaneous rotation center changes of the knee joint (based on joint kinematics).

[0055] ② Controllable mechanical environment: Through the parallel multi-slide design, the traction force and joint range of motion can be quantitatively adjusted to avoid soft tissue damage caused by excessive traction.

[0056] ③ Minimally invasive compatibility: Percutaneous fixation reduces soft tissue dissection and supports early rehabilitation training.

[0057] The preferred embodiments of the present invention have been described above, but are not intended to limit the invention. Those skilled in the art can make modifications and variations to the embodiments disclosed herein without departing from the scope and spirit of the invention.

Claims

1. A knee joint traction device, characterized in that, The knee joint distraction device includes a femoral end fixation module and a tibial end fixation module. The femoral end fixation module includes a femoral end external fixator, a dynamic sliding system, and positioning marks. The dynamic sliding system and positioning marks are located at the distal end of the femoral end external fixator. The dynamic sliding system can adapt to the instantaneous rotation trajectory of the knee joint and has preset locking holes with different distraction distances. The positioning marks serve as a reference for alignment with the rotation center of the knee joint. The tibial end fixation module includes a tibial side external fixator and a hinge connection part. The hinge connection part is fixedly located at the end of the tibial side external fixator. The hinge connection part includes a hinge shaft structure that matches the dynamic sliding system.

2. The knee joint traction device according to claim 1, characterized in that, The tibial end fixation module also includes functional components, including fixation screws and locking pins. The fixation screws are used for bilateral bone shaft fixation, and the locking pins are used for fixing the staged spacing of the slides in the dynamic slide system.

3. The knee joint traction device according to claim 2, characterized in that, The fixation screw is a cortical bone screw, and the diameter of the cortical bone screw is between 4.5 mm and 6.5 mm.

4. The knee joint traction device according to claim 2, characterized in that, The locking pin is a detachable locking pin.

5. The knee joint traction device according to claim 1, characterized in that, The dynamic chute system includes multiple arc-shaped chutes with different radii, each of which can cover a range of motion from 0° to 180°.

6. The knee joint traction device according to claim 5, characterized in that, The multiple arc-shaped grooves with different radii are arranged parallel to each other.

7. The knee joint traction device according to claim 5, characterized in that, The external fixator for the femoral end includes a circular plate and a fixation handle. The circular plate is disposed at the distal end of the fixation handle, and the circular plate and the fixation handle are smoothly connected. Multiple arc-shaped grooves with different radii are arranged parallel to each other on the circular plate. The positioning mark is a central circular hole disposed on the circular plate, which is located at the common center of the multiple arc-shaped grooves with different radii.

8. The knee joint traction device according to claim 7, characterized in that, The fixing handle has a fixing through groove along its length, which is used for the fixing screw to pass through.

9. The knee joint traction device according to claim 1, characterized in that, The tibial lateral fixation frame includes a tibial fixation handle, and the hinge connection part includes an upper hinge plate and a lower hinge plate. The upper hinge plate is fixedly disposed on the upper surface of the end of the tibial fixation handle, and the lower hinge plate is fixedly disposed on the lower surface of the end of the tibial fixation handle. The upper hinge plate is provided with an upper hinge hole, and the lower hinge plate is provided with a lower hinge hole. The positions of the upper hinge hole and the lower hinge hole correspond to the positions of the lower hinge hole.

10. The knee joint traction device according to claim 9, characterized in that, The tibial fixation handle is provided with a tibial fixation through groove along its length, which is used for the fixation screw to pass through.

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