Femoral extramedullary positioner in unicompartmental knee arthroplasty

Abstract

The invention provides a femoral extramedullary positioner in unicompartmental knee arthroplasty, which belongs to the technical field of unicompartmental knee arthroplasty, and comprises a positioning frame, a femoral medial condyle buckle, a femoral anterior condyle buckle and a test mold gasket fixing frame, and the positioning frame is provided with a positioning hole; the thighbone medial condyle buckle and the thighbone anterior condyle buckle are installed on the side, facing the knee joint, of the positioning frame, and the thighbone medial condyle buckle is transversely arranged and used for clamping the inner side and the outer side of the thighbone medial The femur precondyle buckle is longitudinally arranged and used for clamping the femur precondyle when the femur is located at the flexion position; the test mold gasket fixing frame is slidably installed at the bottom of the side, away from the knee joint, of the positioning frame and horizontally moves left and right along the positioning frame. The thighbone positioning device is simple in structure and convenient to operate, the thighbone positioning accuracy is improved, and the thighbone prosthesis placement accuracy is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of unicompartmental replacement, and in particular relates to a femoral extramedullary locator in unicompartmental replacement. Background Art

[0002] Currently, unicompartmental knee replacement involves installing a metal joint prosthesis on the articular surfaces of the diseased proximal tibia and distal femur, with a polyethylene liner implanted in between, in order to relieve the patient's pain, correct lower limb deformities, and restore joint movement.

[0003] To implant a unicompartmental prosthesis, the surgeon needs to remove enough bone from the surface of the tibia and femur, and then accurately install the femoral and tibial prostheses to replace the removed parts. The correct prosthesis position will directly affect the surgical effect and long-term prosthesis survival rate. Due to the small surgical field of view, the bone cutting needs to be accurately positioned to indicate the direction of the force line. Compared with the tibial osteotomy, the femoral side has higher requirements and is more difficult.

[0004] At present, intramedullary positioning is usually used for femoral positioning in unicompartmental hip replacement, which uses an intramedullary connecting rod and a femoral drilling guide auxiliary device to determine the drilling position of the fixation hole for installing the femoral prosthesis on the femur. The fixation hole is prepared under the guidance of the femoral drilling guide auxiliary device, the posterior femoral condyle is cut off and the meniscus is removed. After the initial shaping of the bone surface, a femoral trial mold with appropriate thickness of the distal condyle is selected and installed, the knee joint is repeatedly flexed and extended, and the femoral trial mold is used to determine the position of the longitudinal tibial osteotomy.

[0005] However, there are the following problems in intramedullary positioning of unicompartmental knee replacement: (1) Intramedullary positioning requires accurate positioning within the patient's femur, but if the patient has osteoporosis or bone disease, this may affect the accuracy of positioning and increase the difficulty of surgery.

[0006] (2) During the process of inserting the device into the femoral marrow for positioning, femoral fracture may occur, especially in cases of femoral osteoporosis or older patients, which increases the patient's pain.

[0007] (3) There is often micro-movement during drilling during intramedullary positioning, and the hardness of the femoral surface bone will also affect the micro-movement of the positioning point during drilling.

[0008] (4) Late in the surgery or during the surgery, the femoral intramedullary positioning may shift, resulting in inaccurate prosthesis positioning, which may require additional surgery for adjustment or repair.

[0009] (5) Insertion may cause complications such as infection, bleeding, or neurovascular damage, increasing surgical risks and recovery time.

[0010] In order to avoid the above problems, people have designed a way of extramedullary positioning. Patent CN113081408B discloses a unicompartmental replacement femoral prosthesis implantation positioner, including a handheld portion, a positioning portion and a connecting portion, wherein the positioning portion has a notch and a positioning groove, the opening of the notch faces the handheld portion and matches the drilling protrusion column, the opening of the positioning groove faces upward and matches the lower end of the drilling arc segment, when the positioning portion is placed on the tibial prosthesis, the protrusion column just fits into the notch, and the lower end of the drilling arc segment just fits into the positioning groove. The positioner is used in the unicompartmental replacement of fixed liner prosthesis. Since the position of the drill is fixed, the position of the hole made by the electric drill in the drilling protrusion column on the femur is in a predetermined position, so the femoral prosthesis can be installed in a predetermined position, and the positioning of the femoral prosthesis is indirectly realized. However, although the positioner can be positioned outside the femoral marrow, when used, it is necessary to first drill the tibial slot and position the femur through the tibial slot, which is mainly suitable for the unicompartmental replacement of fixed liner prosthesis. Summary of the invention

[0011] The problem to be solved by the present invention is to provide a femoral extramedullary locator in unicompartmental hip replacement.

[0012] In order to solve the above technical problems, the technical solution adopted by the present invention is: a femoral extramedullary locator in unicompartmental hip replacement, comprising a positioning frame, a medial femoral condyle buckle, an anterior femoral condyle buckle and a trial mold gasket fixing frame, wherein the positioning frame is provided with a positioning hole; the medial femoral condyle buckle and the anterior femoral condyle buckle are installed on the side of the positioning frame facing the knee joint, the medial femoral condyle buckle is horizontally arranged to clamp the inner and outer sides of the medial femoral condyle; the anterior femoral condyle buckle is longitudinally arranged to clamp the anterior femoral condyle when the femur is in a flexed position; the trial mold gasket fixing frame is slidably installed on the bottom of the positioning frame away from the knee joint, and the trial mold gasket fixing frame moves horizontally left and right along the positioning frame.

[0013] Furthermore, the positioning hole is located on the longitudinal center axis of the positioning frame.

[0014] Further, the positioning hole includes a first through hole and a second through hole, the first through hole is located above the second through hole, and the diameter of the first through hole is smaller than the diameter of the second through hole.

[0015] Furthermore, the cross-section of the medial femoral condyle buckle is a C-shaped structure with a horizontal middle and arc-shaped ends.

[0016] Furthermore, the longitudinal section of the anterior femoral condyle buckle is an inverted J-shaped structure with a vertical bottom and an arc-shaped upper end.

[0017] Furthermore, the anterior femoral condyle buckle is located at a central position above the medial femoral condyle buckle.

[0018] Further, the trial mold gasket fixing frame includes a frame-shaped frame body, the top of the frame-shaped frame body is provided with a sliding connection groove, the sliding connection groove is provided in cooperation with the T-shaped sliding protrusion at the bottom of the positioning frame away from the knee joint side, so as to realize the horizontal sliding of the trial mold gasket fixing frame relative to the positioning frame; the bottom of the frame-shaped frame body is open, the inner side wall of the frame-shaped frame body is provided with a symmetrical first sawtooth structure, the frame-shaped frame body is provided with a detachable gap adjustment block, the two ends of the gap adjustment block are provided with a second sawtooth structure, the first sawtooth structure and the second sawtooth structure cooperate to realize the insertion and removal of the gap adjustment block in the frame-shaped frame body, and the position of the gap adjustment block in the frame-shaped frame body can be adjusted to adapt to trial mold gaskets of different thicknesses, the trial mold gasket is inserted into the trial mold gasket fixing frame for use, and can be horizontally moved back and forth in the trial mold gasket fixing frame. When in use, the trial mold gasket is longitudinally limited in the frame-shaped frame body by the gap adjustment block.

[0019] Furthermore, a longitudinal strip-shaped through hole is provided on one side wall of the frame-shaped frame body, and a locking bolt passes through the strip-shaped through hole to lock the gap adjustment block.

[0020] Due to the adoption of the above technical solution, the present invention has the following beneficial effects: After the trial mold gasket is installed on the tibial side, the trial mold gasket fixing frame of the present invention is installed on the trial mold gasket, the medial femoral condyle buckle and the anterior femoral condyle buckle are trial installed, the patient's knee joint is flexed and extended, and the front, back, left and right positions of the medial femoral condyle buckle and the anterior femoral condyle buckle on the femur are continuously fine-tuned. When the trajectory line of the flexion activity coincides with the trajectory line of the extension activity, the medial femoral condyle buckle and the anterior femoral condyle buckle respectively clamp the inner and outer sides of the medial femoral condyle and the anterior femoral condyle. At this time, the position of the locating hole is the drilling position.

[0021] It can be seen that the present invention has a simple structure, the entire positioning process takes place outside the femoral marrow, is non-traumatic, easy to operate, and has accurate guidance, which improves the accuracy of femoral positioning in unicompartmental knee replacement, improves the accuracy of femoral prosthesis placement, and reduces patients' pain and surgical risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be described in detail below with reference to the accompanying drawings and in combination with examples, and the advantages and implementation methods of the present invention will become more obvious. The contents shown in the accompanying drawings are only used to explain the present invention and do not constitute any limitation to the present invention in any sense. In the accompanying drawings: Figure 1 It is a schematic diagram of the structure of the present invention.

[0023] Figure 2 It is the front view of the present invention.

[0024] Figure 3 It is a rear view of the present invention.

[0025] Figure 4 It is a side view of the present invention.

[0026] Figure 5 It is a top view of the present invention.

[0027] Figure 6 This is a usage state diagram of the present invention.

[0028] In the figure: 1. Positioning frame; 2. Medial femoral condyle buckle; 3. Anterior femoral condyle buckle; 4. Trial mold gasket fixing frame; 5. Positioning hole; 6. Trial mold gasket; 7. First through hole; 8. Second through hole; 9. Frame body; 10. Sliding connection groove; 11. Sliding protrusion; 12. First serration structure; 13. Gap adjustment block; 14. Second serration structure; 15. Locking bolt; 16. Strip through hole. DETAILED DESCRIPTION

[0029] like Figures 1 to 6 As shown, the present invention provides a femoral extramedullary positioner in unicompartmental hip replacement, comprising a positioning frame 1, a medial femoral condyle buckle 2, an anterior femoral condyle buckle 3 and a trial mold gasket fixing frame 4.

[0030] The positioning frame 1 is provided with a positioning hole 5 , which is located on the longitudinal center axis of the positioning frame 1 . The positioning hole 5 includes a first through hole 7 and a second through hole 8 . The first through hole 7 is located above the second through hole 8 , and the diameter of the first through hole 7 is smaller than that of the second through hole 8 .

[0031] The medial femoral condyle buckle 2 and the anterior femoral condyle buckle 3 are installed on the side of the positioning frame 1 facing the knee joint. The medial femoral condyle buckle 2 is arranged horizontally to clamp the inner and outer sides of the medial femoral condyle. The cross section of the medial femoral condyle buckle 2 is a C-shaped structure with a middle horizontal arrangement and arc-shaped arrangements at both ends; the anterior femoral condyle buckle 3 is arranged longitudinally to clamp the anterior femoral condyle when the femur is in a flexed position. The longitudinal section of the anterior femoral condyle buckle 3 is an inverted J-shaped structure with a vertical arrangement at the bottom and an arc-shaped upper end. The anterior femoral condyle buckle 3 is located at the center above the medial femoral condyle buckle 2.

[0032] The trial mold gasket fixing frame 4 is slidably installed at the bottom of the side of the positioning frame 1 away from the knee joint, and can move horizontally left and right along the positioning frame 1. The trial mold gasket fixing frame 4 includes a frame-like frame body 9, and a sliding connection groove 10 is arranged on the top of the frame-like frame body 9. The sliding connection groove 10 is arranged in cooperation with a T-shaped sliding protrusion 11 at the bottom of the side of the positioning frame 1 away from the knee joint to realize the horizontal sliding of the trial mold gasket fixing frame 4 relative to the positioning frame 1; the bottom of the frame-like frame body 9 is open, and the inner side wall of the frame-like frame body 9 is provided with a symmetrical first serration structure 12, and a detachable gap adjustment block 13 is arranged inside the frame-like frame body 9, and the two ends of the gap adjustment block 13 are provided with a second serration structure 14. The first serration structure 12 and the second serration structure 14 cooperate to realize the insertion and removal of the gap adjustment block 13 in the frame-like frame body 9, and the position of the gap adjustment block 13 in the frame-like frame body 9 can be adjusted to adapt to trial mold gaskets 6 of different thicknesses. The frame body 9 can also be marked with the thickness dimension of the trial mold gasket 6 (for example, 3-, 6-, 9-, etc.).

[0033] The test mold gasket 6 is inserted into the test mold gasket fixing frame 4 for use, and can be horizontally moved forward and backward in the test mold gasket fixing frame 4. When in use, the test mold gasket 6 is longitudinally limited in the frame body 9 by the gap adjustment block 13, and a longitudinal strip through hole 16 is provided on one side wall of the frame body 9, and the locking bolt 15 passes through the strip through hole 16 to lock the gap adjustment block 13.

[0034] Working process: After installing the trial mold gasket 6 on the tibial side, the trial mold gasket fixing frame 4 of the present invention is installed on the trial mold gasket 6, and the medial femoral condyle buckle 2 and the anterior femoral condyle buckle 3 are trial installed. The patient's knee joint is flexed and extended, and the front, back, left and right positions of the medial femoral condyle buckle 2 and the anterior femoral condyle buckle 3 on the femur are continuously fine-tuned. When the trajectory line of the flexion activity coincides with the trajectory line of the extension activity, the medial femoral condyle buckle 2 and the anterior femoral condyle buckle 3 respectively clamp the inner and outer sides of the medial femoral condyle and the anterior femoral condyle. At this time, the position of the positioning hole 5 is the drilling position.

[0035] The embodiments of the present invention are described in detail above, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A femoral extramedullary locator for unicompartmental knee replacement, characterized in that: It includes a positioning frame, a medial femoral condyle buckle, an anterior femoral condyle buckle and a trial mold gasket fixing frame, the positioning frame is provided with a positioning hole; the medial femoral condyle buckle and the anterior femoral condyle buckle are installed on the side of the positioning frame facing the knee joint, the medial femoral condyle buckle is horizontally arranged to clamp the inner and outer sides of the medial femoral condyle; the anterior femoral condyle buckle is longitudinally arranged to clamp the anterior femoral condyle when the femur is in a flexed position; the trial mold gasket fixing frame is slidably installed on the bottom of the positioning frame away from the knee joint, and the trial mold gasket fixing frame moves horizontally left and right along the positioning frame.

2. The femoral extramedullary locator in unicompartmental knee replacement according to claim 1, characterized in that: The positioning hole is located on the longitudinal center axis of the positioning frame.

3. The femoral extramedullary locator in unicompartmental knee replacement according to claim 2, characterized in that: The positioning hole includes a first through hole and a second through hole, the first through hole is located above the second through hole, and the diameter of the first through hole is smaller than the diameter of the second through hole.

4. The femoral extramedullary locator in unicompartmental hip replacement according to claim 1, characterized in that: The cross section of the medial femoral condyle buckle is a C-shaped structure with a horizontal middle and arc-shaped ends.

5. The femoral extramedullary locator in unicompartmental knee replacement according to claim 1, characterized in that: The longitudinal section of the anterior femoral condyle buckle is an inverted J-shaped structure with a vertical bottom and an arc-shaped upper end.

6. The femoral extramedullary locator in unicompartmental hip replacement according to claim 1, characterized in that: The anterior femoral condyle buckle is located at the center above the medial femoral condyle buckle.

7. The femoral extramedullary locator in unicompartmental knee replacement according to claim 1, characterized in that: The trial mold gasket fixing frame includes a frame-shaped frame body, a sliding connection groove is arranged on the top of the frame-shaped frame body, and the sliding connection groove is cooperated with the T-shaped sliding protrusion at the bottom of the positioning frame away from the knee joint side to realize the horizontal sliding of the trial mold gasket fixing frame relative to the positioning frame; the bottom of the frame-shaped frame body is open, and the inner side wall of the frame-shaped frame body is provided with a symmetrical first serration structure, and a detachable gap adjustment block is arranged inside the frame-shaped frame body, and second serration structures are arranged at both ends of the gap adjustment block, and the first serration structure and the second serration structure cooperate to realize the insertion and removal of the gap adjustment block in the frame frame body.

8. The femoral extramedullary locator in unicompartmental knee replacement according to claim 7, characterized in that: The test mold gasket is inserted into the test mold gasket fixing frame for use, and moves horizontally back and forth in the test mold gasket fixing frame.

9. The femoral extramedullary locator in unicompartmental hip replacement according to claim 7, characterized in that: A longitudinal strip-shaped through hole is arranged on one side wall of the frame-shaped frame body, and a locking bolt passes through the strip-shaped through hole to lock the gap adjustment block.

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