Knee replacement femoral positioning device

Abstract

The present application belongs to the technical field of medical devices. In view of the deficiencies of the prior art, the present application provides a femur positioning device for knee replacement, which comprises a base, a thigh support part, a popliteal fossa support part, a lower leg support part, an extension guide rod and a multi-stage drilling guide mechanism arranged on the base; wherein the multi-stage drilling guide mechanism is arranged at the end of the extension guide rod away from the thigh support part. The femur positioning device for knee replacement provided by the present application can perform multi-stage guiding on the surgical instruments used for drilling. The extension guide rod, the thigh support part and the popliteal fossa support part cooperate with each other to automatically make the drilling direction always parallel to the patient's femoral axis, prevent the drilling direction from deviating, realize one-stage guiding, and the multi-stage drilling guide mechanism can also perform two-stage guiding on the surgical instruments used for drilling, further stabilize the surgical instruments used for drilling, improve the stability of the surgical instruments used for drilling in the drilling operation, and improve the surgical effect.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a femoral positioning device for knee replacement. Background Technology

[0002] Knee replacement surgery is a surgical treatment for severe knee joint diseases. It improves joint function, relieves pain, and corrects deformities by replacing the knee with an artificial prosthesis. The specific steps of knee replacement surgery include incision exposure, soft tissue release, osteotomy, patellar treatment, prosthesis implantation, drainage placement, and incision closure. During the surgery, the patient usually lies flat with the operated leg close to the edge of the bed to allow for knee flexion and osteotomy of the knee joint's flexion arc.

[0003] The success of knee replacement surgery depends first and foremost on whether the femoral prosthesis is perpendicular to the mechanical axis of the lower limb. This mechanical axis is a straight line from the center of the femoral head to the center of the ankle joint, normally passing through the center of the knee joint. If the force line deviates significantly after prosthesis installation, the risk of prosthesis wear, loosening, and early failure increases substantially. Therefore, it is necessary to establish a reliable and repeatable anatomical axis reference to precisely control the varus / valgus angle and rotational alignment of the distal femoral osteotomy surface, ensuring the prosthesis position is consistent with the lower limb mechanical axis. Currently, before the osteotomy, a hole is typically drilled at the distal femur, and an intramedullary nail is inserted into the femoral medullary cavity for positioning. Then, an osteotomy guide is assembled, and the osteotomy module is installed. Finally, the osteotomy is performed through the opening on the osteotomy module.

[0004] However, during drilling operations, situations such as the surgeon's arm being unsteady or uneven force being applied while holding the drill, the drill bit slipping on the hard subchondral bone, or the drill bit being pulled off course after entering the cancellous bone due to asymmetry in bone density on both sides (such as osteoporosis or bone cysts) can lead to drill deviation. This deviation can directly affect the force line, rotational alignment, and postoperative joint function of the femoral prosthesis, resulting in problems such as uneven prosthesis wear and affecting the surgical outcome. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies. The technical approach of this invention is to provide a femoral positioning device for knee replacement surgery, including a base, and a thigh support, a groin support, a lower leg support, a telescopic guide rod, and a multi-stage drilling guide mechanism disposed on the base; wherein the multi-stage drilling guide mechanism is disposed at the end of the telescopic guide rod away from the groin support. The femoral positioning device for knee replacement surgery provided by this invention can provide multi-stage guidance for the surgical instruments used in drilling, ensuring that the prosthesis position is consistent with the mechanical axis of the lower limb. Specifically, the telescopic guide rod, the thigh support, and the groin support cooperate to automatically ensure that the drilling direction is always parallel to the patient's femoral axis, preventing drilling direction deviation and achieving primary guidance. The multi-stage drilling guide mechanism can provide secondary guidance for the surgical instruments used in drilling, further stabilizing the instruments, improving their stability during drilling operations, and enhancing surgical outcomes.

[0006] Based on the above technical concept, the technical solution adopted by this invention is as follows: A femoral positioning device for knee replacement includes a base, and a thigh support, a popliteal support, and a calf support disposed on the base, and further includes: The primary guide rod is a telescopic structure, with one end connected to the upper end of the thigh support and the other end connected to the upper end of the groin support. A multi-stage drilling guide mechanism is slidably mounted on one end of the first-stage guide rod near the leg support.

[0007] In the above technical solution, the preferred multi-stage drilling guide mechanism includes: The mounting plate is detachably connected to one end of the primary guide rod near the leg socket support. Clamping assembly, mounted on the mounting plate; The height adjustment bracket is slidably connected to the top surface of the clamping assembly. The drilling guide is mounted on the height adjustment frame.

[0008] Further defining the above technical solution, the borehole guide includes: The secondary guide tube has a second locking unit inside, which is engaged with the height adjustment frame. The telescopic guide bracket is slidably connected to the secondary guide cylinder; The third-level guide unit is slidably sleeved on the end of the second-level guide tube near the femur and abuts against the telescopic guide bracket.

[0009] Further defining the above technical solution, the three-level guidance unit includes: The outer guide ring is slidably sleeved on the outside of the secondary guide cylinder; The inner guide ring is located inside the outer guide ring and has an inner guide rod at one end. The inner guide rod is slidably connected to the secondary guide cylinder. Multiple guide claws, one end of which is connected to the end of the outer guide ring, the side of which is rotatably connected to the inner guide ring, and the other end of which abuts against the side of the drilling surgical instrument.

[0010] Further defining the above technical solution, the front end of the telescopic guide bracket is provided with an abutment ring, which is located inside the secondary guide cylinder, and a secondary abutment piece is fixedly provided on the outer surface of the abutment ring. The secondary abutment piece is used to abut against the side of the outer guide ring.

[0011] Further specifying the above technical solution, the second locking unit includes: The locking ring is located inside the secondary guide cylinder and is slidably connected to the telescopic guide bracket; Two conical blocks are symmetrically arranged at the rear end of the locking ring. One end of each conical block is connected to the side of the locking ring, and the other end passes through the secondary guide tube and engages with the height adjustment frame. Two locking tabs are located on one side of the locking ring and are slidably connected to the telescopic guide bracket.

[0012] To further specify the above technical solution, the clamping component includes: The guide rail is located on the side of the mounting plate closest to the femur; Two clamping plates are slidably connected to the guide rail, and the two clamping plates are connected by a rotating connecting rod; The adjustment unit is located on the front side of the guide rail, with its front side connected to the center of the rotating connecting rod, and its rear side penetrating the mounting plate.

[0013] To further specify the above technical solution, the adjustment unit includes: The T-shaped mounting block is located in the middle of the guide rail and is slidably connected to the bottom surface of the height adjustment frame; The mounting cylinder has one end located on the side of the clamping plate away from the mounting plate, and the other end passes through the mounting plate and connects to the side of the T-shaped mounting block. A rotating guide cylinder is rotatably installed inside the mounting cylinder, and one end passes through the mounting cylinder and is connected to the center of the rotating connecting rod (10); The rotary button has one end located outside the mounting cylinder and the other end inserted into the mounting cylinder and connected to the rotary guide cylinder.

[0014] To further specify the above technical solution, the rotary button includes: A spiral push rod, one end of which is inserted into the mounting cylinder and connected to the rotating guide cylinder; The push column is connected at one end to the other end of the helical push rod, and the other end is located outside the mounting cylinder.

[0015] Further specifying the above technical solution, the adjustment unit also includes a first locking unit, which includes: The locking block slides along the side of the push column; The locking lever has one end that passes through the mounting cylinder and connects to the locking block. The locking strip is located on the inner wall of the mounting cylinder and abuts against the locking block. Beneficial effects

[0016] I. This invention, through the combined design of a primary guide rod, a multi-stage drilling guide mechanism, and a thigh support, automatically ensures that the drilling direction is always parallel to the patient's femoral axis, achieving primary guidance to prevent drilling direction deviation. During drilling, the multi-stage drilling guide mechanism provides secondary guidance for the drilling instruments, such as electric drills. Furthermore, when drilling deeper into the femoral spinal cord, the leverage effect of the electric drill is at its maximum, and even minor hand tremors are amplified several times at the drill tip. As the electric drill penetrates deeper into the femoral spinal cord, the multi-stage drilling guide mechanism further guides the surgical instruments, preventing instrument vibration and deviation, thus preventing perforation of the anterior femoral cortex and intraoperative fractures, improving surgical safety and success rate.

[0017] Second, through the combined design of the clamping plate and the primary guide rod, this invention can automatically achieve axial alignment of the secondary guide tube at the distal end of the femur while determining the drilling direction, so as to provide a reference for the drilling position of the intramedullary positioning rod and quickly determine the drilling position of the intramedullary positioning rod.

[0018] Third, the present invention, through the combined design of a two-stage guide cylinder and a guide claw, can stabilize the electric drill at two points, thereby reducing the amplitude of the electric drill vibration and further stabilizing the direction of the electric drill, thus preventing the drill bit from tilting.

[0019] Fourth, through the combined design of the telescopic guide bracket and the three-level guide unit, this invention can increase the propulsion force of surgical instruments used by medical staff when drilling into a deeper position in the femur, so that medical staff can reduce the propulsion speed and better perceive the resistance of the drill bit, so as to stop drilling in time when encountering cortical bone and prevent the drilling depth from being too deep.

[0020] Fifth, the present invention can quickly complete the longitudinal height adjustment of the secondary guide tube and the automatic axial alignment of the femur through the first locking unit and the second locking unit, thereby improving the efficiency of drilling position determination and facilitating the subsequent installation of the intramedullary positioning rod. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 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.

[0022] Figure 1 This is a schematic diagram of a femoral positioning device for knee replacement provided in an embodiment of the present invention; Figure 2 for Figure 1 A front view of the device shown; Figure 3 for Figure 2 Enlarged view of point A in the middle; Figure 4 Figure 1 A schematic diagram of the device from another perspective; Figure 5 for Figure 4 Enlarged view of point B in the middle; Figure 6 This is a schematic diagram of a multi-stage drilling guide mechanism; Figure 7 This is a schematic diagram showing the connection between the clamping assembly and the drilling guide; Figure 8 for Figure 7 Disassembly diagram of the device shown; Figure 9 This is a schematic diagram of the height adjustment frame. Figure 10 This is a schematic diagram of the clamping assembly. Figure 11 for Figure 10 Schematic diagram showing the connection relationship between the clamping plate and the rotating guide cylinder; Figure 12 for Figure 11 Enlarged view of point C in the middle; Figure 13 for Figure 12 Cross-sectional view of the location of the second locking unit; Figure 14 This is a schematic diagram of the drilling guide. Figure 15 for Figure 14 A front view of the device shown; Figure 16 for Figure 14 Disassembly diagram of the device shown; Figure 17 This is a disassembly diagram of the telescopic guide bracket and the second locking unit; Figure 18This diagram illustrates the connection relationship between the outer guide ring, the inner guide ring, and the guide claw. Figure 19 This is a 3D diagram of a borehole guide.

[0023] Among them, 1. base; 2. thigh support; 3. leg arch support; 31. gear; 32. rack; 4. calf support; 5. primary guide rod; 51. sliding connecting block; 6. Mounting plate; 61. Sliding block; 62. First locking screw; 7. Height adjustment bracket; 71. Limiting post; 72. Second locking screw; 8. Drilling guide; 81. Secondary guide cylinder; 81a. Snap-fit ​​cylinder; 82. Telescopic guide bracket; 82a. Abutment ring; 82b. Secondary abutment piece; 83. Second locking unit; 83a. Locking ring; 83b. Conical locking block; 83c. Locking lever; 84. Outer guide ring; 85. Inner guide ring; 85a. Inner guide rod; 86. Guide claw; 87. Second return spring; 88. Third return spring; 9. Guide rail; 10. Clamping plate; 11. Rotating connecting rod; 12. Adjustment unit; 12a. T-shaped mounting block; 12b. Mounting cylinder; 12c. Rotary guide cylinder; 12d. Rotary button; 12d-1. Helical push rod; 12d-2. Push column; 12e. First locking unit; 12e-1. Locking block; 12e-2. Locking rod; 12e-3. Locking strip; 12e-4. First return spring; 13. C-shaped mounting block. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0025] In the description of this invention, it should be understood that the terms "length direction," "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not 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 the invention. Furthermore, features limited to "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] Example 1 This invention provides a femoral positioning device for knee replacement surgery, such as... Figures 1 to 19 As shown, it includes a base 1, a thigh support 2, a leg socket support 3, a calf support 4, a primary guide rod 5, and a multi-stage drilling guide mechanism.

[0028] The base 1 is a square plate structure. The thigh support 2, leg support 3, and calf support 4 are all vertically and fixedly mounted on the base 1. Specifically, a C-shaped mounting block 13 is fixedly mounted on the side of the base 1, and a locking screw is provided on the C-shaped mounting block 13. In use, the base 1 is placed on the hospital bed and the C-shaped mounting block 13 is engaged with the side of the hospital bed. Finally, the locking screw is rotated upward so that the upper end of the locking screw abuts against the bottom surface of the hospital bed board, thus fixing the base 1.

[0029] The thigh support 2 includes a first lifting rod and an inclined support plate fixedly mounted on the movable end of the first lifting rod. The calf support 4 includes a third lifting rod and an inclined support plate rotatably mounted on the movable end of the third lifting rod. The inclined support plate is used to contact the patient's leg and provide support.

[0030] The leg support 3 includes three equally spaced second lifting rods. A cylindrical support block for supporting the patient's leg is fixedly mounted on the upper end of the second lifting rod located in the middle position, and a gear 31 is fixedly mounted horizontally on the bottom end of the second lifting rod. Racks 32 are symmetrically arranged at the bottom of the second lifting rods on both sides, with the racks 32 symmetrically arranged around the gear 31 and meshing with it. A rotary motor is embedded inside the base 1, and its output end is fixedly connected to the center of the gear 31. When the rotary motor is activated, it drives the gear 31 to move the two racks 32 away from each other, allowing the patient's thigh to be placed on the thigh support 2 and the second lifting rod in the middle position. After the patient's thigh is placed, the rotary motor drives the gear 31 to reverse, causing the second lifting rods on both sides to move closer together through the gears 31 and racks 32, until the first-stage guide rod 5 engages with the side of the thigh support 2. Finally, the patient's lower leg is placed on the lower leg support 4, and the heights of the first, second, and third lifting rods are adjusted to ensure the patient's position meets the surgical requirements.

[0031] The first, second, and third lifting rods are all existing technologies, and this embodiment of the invention does not improve upon them. For example, the first, second, and third lifting rods are all DYT electric push rods.

[0032] The primary guide rod 5 is a telescopic rod. A square locking block is fixedly installed at one end of the primary guide rod 5, which engages with the side of the thigh support 2. A sliding connecting block 51 is fixedly installed at the other end. The side of the primary guide rod 5 is rotatably connected to the leg support 3. Correspondingly, a slot is provided on the side of the thigh support 2 for engaging with the square locking block. The primary guide rod 5 has a fixed tube and a sliding rod slidably connected to it. The length of the primary guide rod 5 is adjustable from 200mm to 400mm to accommodate patients with different leg lengths.

[0033] Thus, when the heights of the thigh support 2 and the groin support 3 change, the length of the first-stage guide rod 5 changes synchronously, so that the guide rod 5 can drive the multi-stage drilling guide mechanism to move synchronously. Among them, a groove communicating with the outside is opened at the center of the sliding connecting block 51. This groove is used to slide and connect with the multi-stage drilling guide mechanism so that the multi-stage drilling guide mechanism can provide multi-stage guidance for the electric drill, and after the guide contacts, the multi-stage drilling guide mechanism can be removed to facilitate the subsequent installation of the intramedullary positioning rod and osteotomy guide plate.

[0034] Since one end of the primary guide rod 5 is fixedly connected to the thigh support part 2 and the other end is rotatably connected to the leg socket support part 3, the primary guide rod 5 is always parallel to the axial direction of the patient's femur, thereby automatically ensuring that the drilling direction is always parallel to the axis of the patient's femur.

[0035] The multi-stage drilling guide mechanism includes a mounting plate 6, a clamping assembly, a height adjustment bracket 7, and a drilling guide 8.

[0036] The mounting plate 6 is a square plate structure, and a sliding block 61 is fixedly installed at one end. The sliding block 61 is located in the groove of the sliding connecting block 51. The side of the sliding block 61 is threaded with a first locking screw 62. Medical staff can manually adjust the position of the mounting plate 6 and then rotate the first locking screw 62 so that the end of the first locking screw 62 tightly abuts against the side of the sliding connecting block 51, thus fixing the position of the mounting plate 6. Since the groove of the sliding connecting block 51 and the first-stage guide rod 5 are on the same straight line, the mounting plate 6 is always perpendicular to the first-stage guide rod 5, thereby ensuring that the mounting plate 6 is always perpendicular to the axial direction of the femur.

[0037] It should be noted that the first locking screw 52 provided in this embodiment of the invention is prior art, and this embodiment of the invention does not make any improvements to it.

[0038] The clamping assembly includes a guide rail 9, two clamping plates 10, and an adjustment unit 12.

[0039] The guide rail 9 has a long strip structure with a T-shaped groove in the center, and the guide rail 9 is horizontally fixed on the side of the mounting plate 6 near the patient's femur.

[0040] Two clamping plates 10 are located on the side of the guide rail 9 near the patient's femur. Each clamping plate 10 has a fixed sliding rod at its bottom end. One end of the sliding rod is fixedly connected to the corresponding clamping plate 10, and the other end is slidably connected to the guide rail 9. The two clamping plates 10 are rotatably connected via a rotating connecting rod 11. Specifically, the rotating connecting rod 11 includes a central rotating rod, with connecting rods rotatably connected to both ends. Each connecting rod is rotatably connected to the side of the sliding rod at the bottom of the corresponding clamping plate 10. Thus, when the central rotating rod rotates, it drives the two clamping plates 10 to move synchronously closer or further away through the two connecting rods. Preferably, the opening and closing distance between the two clamping plates is between 20mm and 50mm.

[0041] The adjustment unit 12 is connected to the guide rail 9 and the two clamping plates 10 respectively; specifically, the adjustment unit 12 includes a T-shaped mounting block 12a, a mounting cylinder 12b, a rotating guide cylinder 12c and a rotating button 12d.

[0042] The T-shaped mounting block 12a is fixedly positioned at the center of the guide rail 9.

[0043] One end of the mounting cylinder 12b is fixedly connected to the center of the T-shaped mounting block 12a on the side away from the clamping plate 10, and the other end passes through the mounting plate 6 and is located on the outside of the mounting plate 6.

[0044] The rotating guide cylinder 12c is rotatably disposed inside the mounting cylinder 12b, and one end of the rotating guide cylinder 12c passes through the mounting plate 6 and the T-shaped mounting block 12a in sequence and is fixedly connected to the central rotating rod in the rotating connecting rod 11, while the other end is sleeved with the rotating button 12d.

[0045] The rotary button 12d includes a helical push rod 12d-1 and a push column 12d-2.

[0046] Specifically, the spiral push rod 12d-1 has a spiral ribbon structure. Correspondingly, a protrusion is fixedly provided on the inner side of the rotating guide cylinder 12c. When the spiral push rod 12d-1 rotates, its side abuts against the protrusion, and the protrusion pushes the rotating guide cylinder 12c to rotate. The rotating guide cylinder 12c drives the central rotating rod in the rotating connecting rod 11 to rotate in the same direction. Thus, the central rotating rod drives the two clamping plates 10 to move closer or further apart through the two connecting rods. In practical applications, the distance between the two clamping plates 10 is smallest when the central rotating rod in the rotating connecting rod 11 is in a vertical state, and the distance between the two clamping plates 10 is largest when the central rotating rod in the rotating connecting rod 11 is in a horizontal state.

[0047] The push column 12d-2 is a cylindrical structure. One end is inserted into the mounting cylinder 12b and then fixedly connected to the spiral push rod 12d-1. The other end is located outside the mounting cylinder 12b, and the push column 12d-2 is fixedly connected to the mounting cylinder 12b through the first locking unit 12e.

[0048] The first locking unit 12e is slidably disposed on the side of the push post 12d-2. Correspondingly, the side of the push post 12d-2 has a groove for sliding connection with the first locking unit 12e. Specifically, the first locking unit 12e includes a locking block 12e-1, a locking rod 12e-2, a locking strip 12e-3, and a first return spring 12e-4.

[0049] The first return spring 12e-4 is located in the groove on the side of the push post 12d-2, and one end of the first return spring 12e-4 is fixedly connected to the bottom surface of the groove of the push post 12d-2, and the other end is fixedly connected to the locking block 12e-1. The end of the locking block 12e-1 away from the first return spring 12e-4 is fixedly connected to the locking rod 12e-2. Two locking strips 12e-3 are symmetrically arranged on the side where the locking block 12e-1 is fixedly connected to the locking rod 12e-2. The locking strips 12e-3 are used to engage with the mounting cylinder 12b.

[0050] Correspondingly, multiple linearly arranged slots for engaging with the locking strip 12e-3 are provided on the inner side of the mounting cylinder 12b, and a sliding groove is provided on the side wall of the mounting cylinder 12b to facilitate the sliding of the first locking unit 12e.

[0051] The working principle of the clamping assembly provided in this embodiment of the invention is as follows: First, the medical staff pushes the locking rod 12e-2 into the mounting cylinder 12b with one hand. At this time, the first reset spring 12e-4 is compressed, and the locking strip 12e-3 is no longer engaged with the mounting cylinder 12b. With the other hand, the pushing column 12d-2 is pushed into the mounting cylinder 12b. The pushing column 12d-2 drives the spiral pushing rod 12d-1 to move in the same direction. Then, the side of the spiral pushing rod 12d-1 abuts against the protrusion, and pushes the rotating guide cylinder 12c to rotate through the protrusion. The rotating guide cylinder 12c drives the central rotating rod in the rotating connecting rod 11 to rotate in the same direction. Thus, the central rotating rod drives the two clamping plates 10 to gradually approach each other through the two connecting rods until the two sides of the distal femur are clamped. At the same time as the pushing column 12d-2 drives the spiral pushing rod 12d-1 to move, it drives the first locking unit 12e to slide synchronously in the groove on the side wall of the mounting cylinder 12b. After the clamping plate 10 is adjusted, the medical staff simultaneously release the locking rod 12e-2 and the pushing column 12d-2. The first reset spring 12e-4 returns to its natural state, thereby driving the locking block 12e-1 to move outward until the locking strip 12e-3 engages with the corresponding slot on the inner wall of the mounting cylinder 12b. At this time, the position of the locking rod 12e-2 is fixed, and the position of the pushing column 12d-2 connected to the locking rod 12e-2 is fixed. The pushing column 12d-2, through the spiral pushing rod 12d-1 and the rotating guide cylinder 12c in sequence, fixes the tilt angle of the central rotating rod in the rotating connecting rod 11, thereby fixing the distance between the two clamping plates 10 and achieving bilateral clamping and fixation of the distal femur. During the above process, the guide rail guides the two clamping plates 10 to prevent them from flipping over.

[0052] The height adjustment bracket 7 is slidably connected to the top of the T-shaped mounting block 12a. Specifically, the height adjustment bracket 7 includes a sliding base and two limiting posts 71 fixedly mounted on the sliding base. The two limiting posts 71 have slots on opposite sides, and multiple linearly arranged teeth are provided on the sides of the slots. These teeth are used to engage with the drilling guide 8. The sliding base of the height adjustment bracket 7 is threadedly connected to a second locking screw 72. The end of the second locking screw 72 away from the sliding base passes through the mounting plate 6 and is located on one side of the mounting plate 6. The adjustment range of the height adjustment bracket 7 is from 0.1mm to 15mm.

[0053] The drilling guide 8 is positioned between two limiting posts in the height adjustment frame 7, and both ends of the drilling guide 8 are respectively engaged with the corresponding limiting posts. The drilling guide 8 includes a secondary guide cylinder 81, a telescopic guide bracket 82, and a tertiary guide unit.

[0054] The secondary guide cylinder 81 includes a square guide portion and a cylindrical mounting portion fixedly connected to the square guide portion; wherein, the center of both the square guide portion and the cylindrical mounting portion is provided with a circular channel of the same size, and the two circular channels are coaxially arranged and interconnected; wherein, square-structured snap-fit ​​cylinders 81a are fixedly provided on both sides of the square guide portion, the snap-fit ​​cylinders 81a are used to install the second locking unit 83, and snap-fit ​​with the limiting post 71 on the same side through the second locking unit 83.

[0055] The second locking unit 83 is slidably disposed inside the side wall of the square guide portion in the two locking cylinders 81a and the secondary guide cylinder 81. Specifically, the second locking unit 83 includes a locking ring 83a, two conical locking blocks 83b and two locking levers 83c.

[0056] A locking ring 83a is slidably disposed inside the side wall of the secondary guide cylinder 81. Two conical blocks 83b are fixedly disposed on both sides of the locking ring 83a and are located inside the corresponding locking cylinder 81a. Two locking levers 83c are located on one side of the locking ring 83a and are fixedly connected to the side of the locking ring 83a. Correspondingly, an operating groove is provided on the top surface of the secondary guide cylinder 81 so that medical personnel can push the locking levers 83c to move through the operating groove. The width of the conical blocks 83b is smaller than the width of the locking cylinder 81a. Thus, when medical personnel push the locking levers 83c backward through the operating groove, the locking ring 83a and the conical blocks 83b move in the same direction, allowing the conical blocks 83b to slide backward inside the locking cylinder 81a until the conical blocks 83b are fully inserted into the locking cylinder 81a, so as to adjust the height of the drilling guide 8.

[0057] In practical use, to improve the engagement effect between the conical locking block 83b and the limiting post 72, a fourth return spring (not shown in the figure) is fixedly installed on the inner wall of the cylindrical mounting part in the secondary guide cylinder 81. The end of the fourth return spring away from the cylindrical mounting part is fixedly connected to the locking ring 83a. When the fourth return spring is in its natural state, the conical locking block 83b engages with the corresponding teeth on the limiting post 72 under the pushing action of the fourth return spring itself. When the medical staff pushes the locking lever 83c backward through the operating groove, the fourth return spring is stretched until the conical locking block 83b is fully inserted into the locking cylinder 81a to adjust the height of the drilling guide 8. After the height adjustment of the drilling guide 8 is completed, the medical staff releases the locking lever 83c. At this time, the fourth return spring returns to its natural state, thereby driving the locking ring 83a to move forward, so that the conical locking block 83b re-engages with the teeth on the limiting post 72. At this time, the height adjustment of the drilling guide 8 is completed.

[0058] The working principle of the second locking unit 83 provided in this embodiment of the invention is as follows: Medical staff use two fingers of one hand to move the two locking paddles 83c to the side away from the fourth return spring. The locking paddles 83c drive the two conical blocks 83b to move in the same direction through the locking ring 83a until the conical blocks 83b are completely inserted into the locking cylinder 81a, so that the two conical blocks 83b are separated from the limiting post 71, so that the medical staff can manually adjust the position of the secondary guide cylinder 81. After the adjustment is completed, the medical staff releases the two locking paddles 83c. At this time, the two locking paddles 83c return to the initial position under the action of the fourth return spring. At this time, the two conical blocks 83b are locked with the corresponding limiting post 71 again.

[0059] The telescopic guide bracket 82 includes four telescopic rods, which are arranged at equal intervals and are fixedly connected to the abutment ring 82a. The abutment ring 82a is slidably disposed inside the side wall of the secondary guide cylinder 81, and second abutment pieces 82b are fixedly disposed on both sides of the abutment ring 82a. The second abutment pieces 82b are used to abut against the tertiary guide unit.

[0060] Specifically, each telescopic rod includes a sleeve and a movable rod. The sleeve has a protrusion made of elastic material inside. In the initial state, the movable rod and the sleeve with the protrusion are in contact. When the sleeve pressure is high, the movable rod can overcome the pressure applied by the protrusion and enter the sleeve.

[0061] The end of each movable rod away from the sleeve is fixedly connected to the abutment ring 82a; the end of the sleeve away from the movable rod is sleeved with the movable rod, and the other end is located outside the secondary guide cylinder 81, and the four telescopic rods are fixedly connected by connecting rings.

[0062] Thus, when the electric drill penetrates deeper into the femur, the protrusions fixed on the inner wall of the cannula increase the pressure the surgeon needs to apply to push the drill, preventing the surgeon from reducing the drill bit's advance speed when drilling to deeper locations and avoiding excessive drilling depth. The shape of the protrusions is not limited in this invention; preferably, they are circular or triangular.

[0063] The abutment ring 82a has a square ring structure, and a secondary abutment piece 82b is fixedly provided on the outer surface of the abutment ring 82a. The end of the secondary abutment piece 82b away from the abutment ring 82a passes through the secondary guide cylinder 81 and is located outside the secondary guide cylinder 81 so that the secondary abutment piece 82b abuts with the tertiary guide unit.

[0064] The third-level guide unit is slidably disposed at one end of the second-level guide cylinder 81 near the femur, and is also slidably disposed at one end of the second-level guide cylinder 81 near the patient's femur. It is used to cooperate with the second-level guide cylinder 81 to further stabilize the drilling direction of the electric drill and prevent the drilling direction of the electric drill from deviating.

[0065] The three-stage guide unit includes an outer guide ring 84, an inner guide ring 85, and multiple guide claws 86.

[0066] The outer guide ring 84 is slidably sleeved on the outer surface of the secondary guide cylinder 81 and is fixedly connected to a plurality of second return springs 87 fixedly disposed on the outer surface of the secondary guide cylinder 81.

[0067] The inner guide ring 85 is located at the front end of the secondary guide cylinder 81 and is coaxially arranged with the outer guide ring 84. Specifically, multiple inner guide rods 85a are fixedly arranged on the side of the inner guide ring 85 closest to the secondary guide cylinder 81. The inner guide rods 85a are used for sliding connection with the secondary guide cylinder 81, and multiple connecting rods are fixedly arranged on the other side for rotatably connecting with the guide claw 86. Correspondingly, multiple sliding holes are opened at the front end of the cylindrical mounting part of the secondary guide cylinder 81 for sliding connection with the guide rods 85a. A third return spring 88 is fixedly arranged inside each sliding hole, and one end of the third return spring 88 is fixedly connected to the corresponding inner guide rod 85a.

[0068] The inner guide ring 85 has multiple three-stage abutment pieces arranged in a circular pattern at equal intervals on its outer surface. These three-stage abutment pieces are used to abut against the outer guide ring 84 so that the outer guide ring 84 can push the inner guide ring 85 to move in the same direction through the three-stage abutment pieces.

[0069] Multiple guide claws 86 are arranged circumferentially on one side of the outer guide ring 84. One end of each guide claw 86 is rotatably connected to the outer guide ring 84, and its side is rotatably connected to the connecting rod on the side of the inner guide ring 85. The other end is used to abut against the side of the surgical instrument. Among them, the end of the guide claw 86 that contacts the side of the electric drill is rotatably equipped with a guide ball.

[0070] The working principle of the drilling guide 8 provided in this embodiment of the invention is as follows: After determining the location of the intercondylar hole in the femur, the orthopedic electric drill is inserted into the central channel of the secondary guide tube 81 to drill the hole, thereby achieving secondary guidance of the orthopedic electric drill; When drilling to a certain depth, the front end of the handheld part of the orthopedic electric drill abuts against the connecting ring on the end of the telescopic guide bracket 82, and the front end of the handheld part of the orthopedic electric drill pushes the telescopic guide bracket 82 forward as a whole. When the abutment ring 82a moves to the middle position of the movable groove of the secondary guide cylinder 81, the secondary abutment piece 82b abuts against the side of the outer guide ring 84, thereby pushing the outer guide ring 84 to move in the same direction. Since the outer guide ring 84 is fixedly connected to the side of the secondary guide cylinder 81 through the second return spring 87, the second return spring 87 is stretched during the movement of the outer guide ring 84 in the same direction, thereby increasing the resistance to the advancement of the orthopedic drill. This initially reduces the speed at which the doctor pushes the orthopedic drill forward, allowing the drill to advance slowly so that medical staff can better perceive the drill bit resistance, thus facilitating... Drilling should be stopped promptly upon encountering cortical bone to prevent excessive drilling depth. The outer guide ring 84 moves in the same direction, and before it contacts the third-level abutment piece, the inner guide ring 85 remains stationary due to the lack of force. This causes the movable ends of each guide claw 86 to converge under the influence of the outer guide ring 84, thus abutting against the side of the orthopedic drill and achieving three-level guidance. Before the movable ends of the guide claws 86 converge, the drill bit has already entered the femur, and the movable ends of the guide claws 86 contact the smooth side of the drill, without affecting the normal operation of the drill or generating debris. After the outer guide ring 84 moves until it comes into contact with the three-stage abutment piece on the inner guide ring 85, the outer guide ring 84 drives the inner guide ring 85 to move synchronously through the three-stage abutment piece. The movable end of the guide claw 86 remains in a gathered state. At this time, the third return spring 88 is stretched, which further increases the resistance to the advancement of the orthopedic electric drill, causing the orthopedic electric drill to advance further slowly. Until the abutment ring 82a moves to the inner end of the movable groove of the secondary guide cylinder 81, the abutment ring 82a no longer moves forward. At this time, due to the restriction of the sleeve protrusion in the telescopic guide bracket 82, the forward resistance of the orthopedic electric drill further increases, thereby further reducing the speed at which the doctor pushes the orthopedic electric drill forward, so that the orthopedic electric drill can advance more slowly, so that medical staff can more accurately sense the resistance of the drill bit, so as to stop drilling in time when encountering cortical bone, and further prevent the drilling depth from being too deep. In this case, the pressure applied by the movable rod corresponding to the sleeve protrusion in the telescopic guide bracket 82 overcomes the elastic force of both the second return spring 87 and the third return spring 88.

[0071] It should be noted that after use, the drill guide 8 can be separated from the height adjustment frame 7, and each component can be cleaned and disinfected. The used drill guide 8 can be discarded and replaced with a new drill guide 8.

[0072] Application examples: Taking knee replacement surgery as an example, the use of the femoral positioning device for knee replacement provided in this embodiment of the invention includes the following steps: S1: Anesthesia and disinfection; Specifically, the patient is given general anesthesia. After the anesthesia takes effect, medical staff will thoroughly disinfect the surgical area and clean the skin around the knee joint with disinfectants such as povidone-iodine to reduce the probability of postoperative infection. After disinfection, sterile surgical drapes are laid to create a sterile environment for subsequent procedures. S2: Make a longitudinal incision approximately 10 to 15 centimeters long in front of the jellyfish knee joint, cutting through the skin, subcutaneous tissue, and fascia layer by layer. Then, enter the joint cavity and retract the patella laterally to fully expose the distal femur, proximal tibia, and articular cartilage surface. This step requires precise control of the incision location to avoid damage to surrounding blood vessels and nerves; S3: Place the patient's affected limb on the thigh support 2, the groin support 3, and the lower leg support 4, and adjust the height of the groin support 3 so that the patient's affected limb is flexed at 90° so that the patella can dislocate laterally naturally, exposing the distal femur and tibial plateau. Remove the hyperplastic synovium, meniscus remnants, anterior and posterior cruciate ligaments, and remove the osteophytes at the edges of the femoral condyle and tibial plateau. S4: Adjust the height of thigh support 2, groin support 3 and calf support 4 so that the patient's thigh is flexed at 45°; S5: Determine the borehole entry point; specifically, this step includes the following steps: S501: The medical staff pushes the locking rod 12e-2 into the mounting cylinder 12b with one hand and pushes the pushing column 12d-2 into the mounting cylinder 12b with the other hand. At this time, the side of the spiral pushing rod 12d-1 abuts against the protrusion and pushes the rotating guide cylinder 12c to rotate through the protrusion. The rotating guide cylinder 12c drives the central rotating rod in the rotating connecting rod 11 to rotate in the same direction. Thus, the central rotating rod drives the two clamping plates 10 to gradually approach each other through the two connecting rods until the two sides of the distal femur are clamped. The first-level guide rod 5 is used to achieve the first-level guidance. S502: Medical staff simultaneously release the locking lever 12e-2 and the pushing column 12d-2, and the first reset spring 12e-4 returns to its natural state, thereby driving the locking block 12e-1 to move outward until the locking strip 12e-3 engages with the mounting cylinder 12b; S503: Adjust the position of the secondary guide tube 81 according to the PCL stop point and Whiteside line, that is, adjust the position of the secondary guide tube 81 and the height adjustment bracket 7, and adjust the relative position of the secondary guide tube 81 and the T-shaped mounting block 12a, so that the secondary guide tube 81 is located in the center of the intercondylar fossa of the femur and about 1.0cm to 1.5cm in front of the PCL stop point; S6: Insert the orthopedic electric drill into the central channel of the secondary guide tube 81 to drill a hole and achieve secondary guidance of the orthopedic electric drill; S7: When drilling to a certain depth, the front end of the handheld part of the orthopedic electric drill abuts against the connecting ring on the rear end of the telescopic guide bracket 82, and the front end of the handheld part of the orthopedic electric drill pushes the telescopic guide bracket 82 forward as a whole. S8: When the abutment ring 82a moves to the middle position of the movable groove of the secondary guide cylinder 81, the abutment ring 82a abuts against the side of the outer guide ring 84, thereby pushing the outer guide ring 84 to move in the same direction; since the outer guide ring 84 is fixedly connected to the side of the secondary guide cylinder 81 through the second return spring 87, the second return spring 87 is stretched during the movement of the outer guide ring 84 in the same direction, thereby increasing the resistance of the orthopedic electric drill, thus initially reducing the speed at which the doctor pushes the orthopedic electric drill forward, and the orthopedic electric drill advances slowly so that medical staff can better perceive the resistance of the drill bit, so that they can stop drilling when they encounter cortical bone to prevent the drilling depth from being too deep; When the outer guide ring 84 moves in the same direction, the inner guide ring 85 remains unchanged because it is not under force. This causes the movable ends of each guide claw 86 to converge under the drive of the outer guide ring 84, thereby abutting against the side of the orthopedic electric drill and achieving three-level guidance for the orthopedic electric drill. S9: During the movement of the outer guide ring 84, it abuts against the three-stage abutment piece on the inner guide ring 85. Then, the outer guide ring 84 drives the inner guide ring 85 to move in the same direction through the three-stage abutment piece. At this time, the movable end of the guide claw 86 remains in a gathered state, and the third return spring 88 is stretched, which further increases the resistance to the advancement of the orthopedic electric drill, causing the orthopedic electric drill to advance slowly. Until the abutment ring 82a moves to the inner end of the movable groove of the secondary guide cylinder 81, the abutment ring 82a no longer moves forward. At this time, due to the restriction of the sleeve protrusion in the telescopic guide bracket 82, the forward resistance of the orthopedic electric drill further increases, thereby further reducing the speed at which the doctor pushes the orthopedic electric drill forward, and causing the orthopedic electric drill to advance further slowly. S10: Medical staff can gently increase the thrust of the electric drill so that the movable rod can overcome the pressure of the corresponding sleeve protrusion and enter the sleeve so that the electric drill can continue to drill. Since medical staff need to apply greater thrust, they can more accurately sense the resistance of the drill bit so as to stop drilling in time when they encounter cortical bone, further preventing the drilling depth from being too deep until the drilling is completed. S11: After drilling is completed, remove the mounting plate 6 and the various components set on the mounting plate 6 from the sliding connection block 51; S12: Insert the handle-equipped intramedullary rod into the femoral medullary cavity to a depth of approximately 10 to 15 cm. The rod should be oriented along the anatomical axis of the femur. S13: Install the osteotomy guide on the intramedullary rod and set the eversion angle according to the preoperative measurements; S14: Perform distal femoral osteotomy and remove the intramedullary rod after osteotomy; S15: Prosthesis Installation; Specifically, based on preoperative measurements, appropriately sized metal prostheses are selected and installed at the femoral and tibial ends, respectively. Bone cement or a bio-based fixation method is used to secure the prosthesis to the bone. A polyethylene spacer is then installed as the new joint interface, and joint mobility and stability are tested. S16: Wound closure; specifically, after thorough hemostasis in the surgical area, a drainage tube is placed, and the joint capsule, fascia, and subcutaneous tissue are sutured layer by layer. Finally, the skin incision is closed with intradermal sutures or skin staples, and a dressing is applied for pressure fixation. An X-ray is performed immediately postoperatively to confirm proper prosthesis placement.

[0073] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A femoral positioning device for knee replacement, comprising a base (1), and a thigh support (2), a groin support (3), and a lower leg support (4) disposed on the base (1), characterized in that, Also includes: The first-level guide rod (5) is a telescopic structure, with one end connected to the upper end of the thigh support part (2) and the other end connected to the upper end of the leg crouch support part (3); A multi-stage drilling guide mechanism is slidably mounted on one end of the first-stage guide rod (5) near the leg support (3).

2. The femoral positioning device for knee replacement according to claim 1, characterized in that, Multi-stage drilling guidance mechanisms include: The mounting plate (6) is detachably connected to one end of the first-stage guide rod (5) near the leg socket support (3); A clamping assembly is mounted on the mounting plate (6); The height adjustment bracket (7) is slidably connected to the top surface of the clamping assembly. The drilling guide (8) is mounted on the height adjustment frame (7).

3. The femoral positioning device for knee replacement according to claim 2, characterized in that, The borehole guide (8) includes: The secondary guide tube (81) is equipped with a second locking unit (83) inside, which is engaged with the height adjustment frame (7); The telescopic guide bracket (82) is slidably connected to the secondary guide cylinder (81); The third-level guide unit is slidably sleeved on the end of the second-level guide tube (81) near the femur and abuts against the telescopic guide bracket (82).

4. The femoral positioning device for knee replacement according to claim 3, characterized in that, The three-level guidance unit includes: The outer guide ring (84) is slidably sleeved on the outside of the secondary guide cylinder (81); The inner guide ring (85) is located inside the outer guide ring (84), and one end is provided with an inner guide rod (85a). The inner guide rod (85a) is slidably connected to the secondary guide cylinder (81). Multiple guide claws (86) are connected at one end to the end of the outer guide ring (84), rotatedly connected to the inner guide ring (85) on the side, and abutted against the side of the drilling surgical instrument at the other end.

5. A femoral positioning device for knee replacement according to claim 4, characterized in that, The telescopic guide bracket (82) is provided with an abutment ring (82a) at the front end. The abutment ring (82a) is located inside the secondary guide cylinder (81), and a secondary abutment piece (82b) is fixedly provided on the outer surface of the abutment ring (82a). The secondary abutment piece (82b) is used to abut against the side of the outer guide ring (84).

6. The femoral positioning device for knee replacement according to claim 3, characterized in that, The second locking unit (83) includes: The locking ring (83a) is located inside the secondary guide cylinder (81) and is slidably connected to the telescopic guide bracket (82); Two conical blocks (83b) are symmetrically arranged on both sides of the locking ring (83a). One end of each conical block (83b) is connected to the side of the locking ring (83a), and the other end passes through the secondary guide tube (81) and engages with the height adjustment frame (7). Two locking tabs (83c) are located at the rear end of the locking ring (83a) and are slidably connected to the telescopic guide bracket (82).

7. The femoral positioning device for knee replacement according to claim 3, characterized in that, The clamping assembly includes: Guide rail (9) is provided on the side of the mounting plate (6) near the femur; Two clamping plates (10) are slidably connected to the guide rail (9), and the two clamping plates (10) are connected by a rotating connecting rod (11); The adjustment unit (12) is located on the front side of the guide rail (9), and its front side is connected to the center of the rotating connecting rod (11), while its rear side passes through the mounting plate (6).

8. The femoral positioning device for knee replacement according to claim 7, characterized in that, The adjustment unit (12) includes: The T-shaped mounting block (12a) is located at the middle position of the guide rail (9) and is slidably connected to the bottom surface of the height adjustment bracket (7); The mounting cylinder (12b) has one end located on the side of the clamping plate (10) away from the mounting plate (6), and the other end passes through the mounting plate (6) and is connected to the side of the T-shaped mounting block (12a). The rotating guide cylinder (12c) is rotatably disposed inside the mounting cylinder (12b), and one end passes through the mounting cylinder (12b) and is connected to the center of the rotating connecting rod (11); The rotary button (12d) has one end located outside the mounting cylinder (12b) and the other end inserted into the mounting cylinder (12b) and sleeved with the rotary guide cylinder (12c).

9. A femoral positioning device for knee replacement according to claim 7, characterized in that, The rotary knob (12d) includes: The spiral push rod (12d-1) has one end inserted into the mounting cylinder (12b) and sleeved with the rotating guide cylinder (12c); The push column (12d-2) is connected at one end to the other end of the helical push rod (12d-1), and the other end is located outside the mounting cylinder (12b).

10. A femoral positioning device for knee replacement according to claim 5, characterized in that, The adjustment unit also includes a first locking unit (12e), which includes: The locking block (12e-1) is slidably connected to the side of the push column (12d-2); The locking lever (12e-2) passes through the mounting cylinder (12b) at one end and connects to the locking block (12e-1); The locking strip (12e-3) is located on the inner wall of the mounting cylinder (12b) and abuts against the locking block (12e-1).

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