Femoral interlocking intramedullary nail far-end locking accurate navigation device

Abstract

The invention relates to a thighbone interlocking intramedullary nail far-end locking accurate navigation device, which is characterized in that a navigation locking device I and a navigation locking device II are arranged to carry out preliminary position determination navigation and further position determination on an intramedullary nail at a thighbone far-end; due to the size corresponding relation of the balance rod, the three locking blocks and the three locking holes, the intramedullary nail can be conveniently determined when the intramedullary nail cannot be well anastomosed at the far end of the femoral bone, and due to the arrangement of the aiming rod, the anastomosis position of the intramedullary nail at the far end of the femoral bone can be conveniently adjusted by observing an image of the far end of the femoral bone through a computer. Through the arrangement of the flat end and the convex section of the intramedullary nail and the flat section and the concave section of the guide tube, the intramedullary nail can easily enter the guide tube when being inserted into the guide tube, and meanwhile, the intramedullary nail can be well fixed through the matching of the convex section and the concave section; when the position of the intramedullary nail is changed, the position of the intramedullary nail in the guide tube can be conveniently changed due to the scalability of the inner cavity of the guide tube.

Description

Technical Field

[0001] The invention relates to the field of medical devices, and in particular to a precise navigation device for distal locking of a femoral interlocking intramedullary nail. Background Art

[0002] When a long bone fracture occurs in the human body, repair surgery often requires inserting an intramedullary nail into the medullary cavity and fixing the fracture area and the intramedullary nail by inserting a screw into the intramedullary nail locking hole. However, for the proximal hole locking nail, the doctor can accurately determine its spatial position in the medullary cavity through the matching aiming instrument. However, since the long medullary cavity has a certain arc shape, the distal end of the intramedullary nail will deform with the change of the shape of the medullary cavity after being inserted into the medullary cavity, resulting in the inability to accurately determine the spatial position of the distal hole (the error needs to be controlled within 2mm), which may eventually lead to surgical failure; interlocking intramedullary nails are widely used in clinical practice as the gold standard for the treatment of femoral shaft fractures, but there are certain difficulties in locking the distal end. At present, the main reasons for the difficulty of locking the interlocking intramedullary nail in the distal femur are as follows: first, the distal femoral medullary cavity is horn-like and wide, and the medullary cavity is angulated. The intramedullary nail cannot fit well with the curved medullary cavity. The shear force and gravity relationship at the distal end of the fracture cause the intramedullary nail to deform, resulting in the distal end of the intramedullary nail swinging and making it difficult to lock the distal end. Secondly, the length and diameter of the main nail are improperly selected or the sleeve size that guides the interlocking intramedullary nail into the nail is not selected. The improper size matching of the interlocking intramedullary nail and the sleeve is also an important reason why it cannot fit well with the medullary cavity at the distal end. At present, the mainstream methods for the distal fixation of the interlocking intramedullary nail include the freehand locking method and the widely used aiming frame assisted positioning locking method. However, the former exposes the surgeon and the patient to a large amount of X-ray radiation during the operation, while the latter has the disadvantages of complex and time-consuming aiming frame structure construction and possible mechanical deformation, resulting in low accuracy of one-time locking of the distal end of the intramedullary nail and high radiation exposure to the surgeon and the patient. In order to solve these problems, modern medical technology has developed some auxiliary positioning technologies. Among them, computer-assisted technology is widely used in fracture surgery. This technology can realize three-dimensional reconstruction and simulation of the surgical area through previously acquired patient bone CT images, and then perform real-time positioning and precise navigation through the navigation system. This technology can reduce radiation exposure during surgery, improve surgical accuracy and safety, and reduce the risk of surgical failure. In computer-assisted navigation, the registration of navigation tools and data collection are complex and require an additional 5 to 7 minutes. The fixation of the reference frame during surgery requires additional incisions, which increases the trauma of the patient.

[0003] (I) Technical solution

[0004] In order to solve the above technical problems, the present invention provides a precise navigation device for locking the distal end of a femoral interlocking intramedullary nail, which utilizes computer-assisted navigation and mechanical aiming navigation to perform hybrid precise navigation to lock the distal end of the femoral interlocking intramedullary nail.

[0005] A precise navigation device for locking the distal end of a femoral interlocking intramedullary nail comprises a navigation locking device I, a navigation locking device II, a fixed aiming device, an intramedullary nail, and a control device.

[0006] Furthermore, the navigation locking device I includes an expansion fixing ring, a telescopic rod I, a telescopic rod II, a navigation locking head, an aiming rod I, and an aiming rod II; the expansion fixing ring is in the shape of a circular ring, and moves along the patient's surgical incision toward the distal femoral medullary cavity to expand the incision to a certain extent, and one end of the telescopic rod I and the telescopic rod II are fixed above and below the arc of the expansion fixing ring.

[0007] Furthermore, imagers are provided at the front ends of aiming rods I and II, and aiming rods I and II are electrically connected to an external computer, and images of the distal end of the femur taken by the imagers are transmitted to the computer via signals.

[0008] Furthermore, the telescopic rod I and the telescopic rod II are connected to respective power devices, and the respective power devices drive the telescopic rod I and the telescopic rod II to respectively perform telescopic movements.

[0009] Furthermore, the other ends of telescopic rod I and telescopic rod II are respectively fixedly connected to the navigation locking head, and the navigation locking head is provided with an entrance section and a slope section; the entrance section is square, and a nail entry opening I is opened on one side surface of the square entrance section, and the other side of the square entrance section is connected to a trapezoidal slope section, and a nail exit opening I is arranged on the side of the slope section away from the entrance section, and an intramedullary nail passage I of corresponding shape is formed from the nail entry opening to the top outlet by the square entrance section and the trapezoidal slope section, and the intramedullary nail enters from the nail entry opening I of the square entrance section and passes out from the nail exit opening I of the trapezoidal slope section.

[0010] Furthermore, a perforated block is arranged between the nail entrance and the upper and lower top surfaces of the square entrance section, and the upper and lower perforated blocks are both provided with entry rod ends for the aiming rod exit hole, and the exit rod ends of the aiming rod exit hole are arranged on the upper and lower slopes of the trapezoidal slope section. From the entry rod end to the exit rod end, two rod exit channels are formed upper and lower inside the entrance section and the slope end. The rod enters through the upper and lower perforated blocks arranged on the square entrance section, and exits from the upper and lower slopes of the trapezoidal slope section.

[0011] Furthermore, the aiming rod may also be a fixed rod.

[0012] Furthermore, the navigation locking device II includes a guide tube, a connecting rod, a locking rod, and a balance rod; the guide tube is connected to the balance rod through the connecting rod, the guide tube is inserted through the surgical incision, and the end of the guide tube remaining outside the patient's body is fixedly connected to the locking rod, and locking blocks I, II and III are arranged from top to bottom along the upper and lower directions of the locking rod; locking blocks I-III are all arranged in the through hole on the locking rod, and locking blocks I-III are all connected to the control device, and can be extended and retracted in the through hole under the control of the control device.

[0013] Furthermore, the balance pole is arranged outside the patient's body.

[0014] Furthermore, the sizes of locking blocks I-III are different, the volume of locking block I is X0, the volume of locking block II is X1, and the volume of locking block III is X2.

[0015] Furthermore, the guide tube is hollow, one end of the guide tube is provided with a nail entry port II, the other end of the guide tube is provided with a nail exit port II, the interior of the guide tube forms an intramedullary nail passage channel II from the nail entry port II to the nail exit port II, the outer wall of the guide tube is a flat rectangular shape, and the intramedullary nail passage channel II forms a flat section I, a concave section I, a flat section II, and a concave section II between the inner wall of the guide tube and the outer wall of the guide tube; the flat section I is arranged at one end outside the patient's body; the concave section I, the flat section II, and the concave section II extend into the patient's body along the surgical incision, one end of the concave section I is connected to the flat section I, the other end of the concave section I is connected to the flat section II, the other end of the flat section II is connected to the concave section II, and the other end of the concave section II abuts against the square entrance section of the navigation locking device I.

[0016] Furthermore, the nail outlet II formed on the other side of the concave section II is butted against the nail inlet I on the square inlet section and have the same size.

[0017] Furthermore, the intramedullary nail passes through channel II and forms a flat section I, a concave section I, a flat section II and a concave section II between the inner wall of the guide tube and the outer wall of the guide rod. The materials of the flat section I and the concave section II are all rubber, and the outer wall material of the guide tube is an inelastic material.

[0018] Furthermore, the concave section I and the concave section II are both arc-shaped.

[0019] Furthermore, the intramedullary nail includes a gripping portion at the bottom, a flat section I, a convex section I, a flat section II, a convex section II, and a nail head section; the gripping portion is outside the guide tube when the intramedullary nail is inserted into the guide tube, one end of the gripping portion is connected to the flat section I, the other end of the flat section I is connected to one end of the convex section I, the other end of the convex section I is connected to the flat section II, the other end of the flat section II is connected to the convex section II, and the other end of the convex section II is connected to the nail head section.

[0020] Further, the length of the intramedullary nail is longer than the length of the guide tube.

[0021] Furthermore, the intramedullary nail completely passes through the guide tube when inserted into the distal femoral medullary cavity. When the intramedullary nail is completely passed through, the overall length of the flat section I, the convex section I, the flat section II, and the convex section II is equal to the overall length of the flat section I, the concave section I, the flat section II, and the concave section II.

[0022] Furthermore, when the intramedullary nail is in a completely penetrated state, the positions of the flat section I, the convex section I, the flat section II, the convex section II and the flat section I, the concave section I, the flat section II, and the concave section II correspond one to one.

[0023] Furthermore, the positions corresponding to the convex section I and the concave section I form the intramedullary nail clamping section I, the positions corresponding to the convex section II and the concave section II form the intramedullary nail clamping section II, the positions corresponding to the flat section I and the flat section I form the intramedullary nail passing section I, and the positions corresponding to the flat section II and the flat section II form the intramedullary nail passing section II.

[0024] Furthermore, the inwardly concave curvature of the concave section I and the inwardly concave section II is the same, and both are lower than the height of the flat section I-II, and the outwardly convex section I and the outwardly convex section II is the same, and both are higher than the height of the flat section I-II.

[0025] Furthermore, when the intramedullary nail is in a fully penetrated state, the nail head section passes through the intramedullary nail inside the navigation locking device I and enters the distal femoral medullary cavity through channel I. The nail head section is conical in shape, and the conical section of the nail head section and the intramedullary nail inside the navigation locking device I fit together with the inner walls of the upper and lower slopes of the trapezoidal slope section in channel I.

[0026] Furthermore, the fixed aiming device includes a locking rod, a cross bar, and a handle; the interior of the locking rod is hollow, the upper end of the locking rod is fixedly connected to the cross bar, the other end of the cross bar is connected to the handle through a hole, and three locking holes I-III are provided on the side wall of the locking rod and penetrate the entire internal cavity.

[0027] Furthermore, when locking, the locking rod is inserted into the cavity of the locking rod, and the three locking blocks Ⅰ-Ⅲ correspond to the three locking holes Ⅰ-Ⅲ one by one. The volume of locking block Ⅰ is X0, which is completely matched with the size of locking hole Ⅰ, the volume of locking block Ⅱ is X1, which is completely matched with the size of locking hole Ⅱ, and the size of locking hole Ⅲ is larger than the volume X2 of locking block Ⅲ.

[0028] (ii) beneficial effects;

[0029] The present invention performs preliminary position navigation and further intramedullary nail position determination on the distal femur of the intramedullary nail by setting a navigation locking device I and a navigation locking device II. Due to the corresponding size relationship between the balance rod, three locking blocks and three locking holes, the intramedullary nail can be easily determined when it cannot be well anastomosed at the distal femur. Due to the setting of the aiming rod, the anastomotic position of the intramedullary nail at the distal femur can be easily adjusted by observing the distal femur image on a computer. The flat end of the intramedullary nail, the outer convex section, the flat section of the guide tube and the inner concave section are set so that the intramedullary nail can be easily inserted when inserted into the guide tube. At the same time, the intramedullary nail can be well fixed by the cooperation of the convex section and the concave section. When the position of the intramedullary nail is changed, the position of the intramedullary nail in the guide tube can be conveniently changed due to the retractability of the inner cavity of the guide tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Attached Figure 1 This is a schematic diagram of navigation locking device I.

[0031] Attached Figure 2 Schematic diagram of locking the intramedullary nail using navigation locking device I.

[0032] Attached Figure 3 It is an overall schematic diagram of the navigation device.

[0033] Attached Figure 4 This is the planing view when the intramedullary nail is completely penetrated.

[0034] Attached Figure 5 Schematic diagram of intramedullary nail.

[0035] 1-Open the fixing ring, 2-Telescopic rod I, 3-Telescopic rod II, 4-Navigation locking head, 5-Aiming rod I-

[0036] Ⅱ, 6-nail outlet Ⅰ, 7-slope section, 8-aiming rod outlet hole, 9-entrance section, 10-punch block,

[0037] 11-nail entry port Ⅰ, 12-intramedullary nail, 13-guide tube, 14-connecting rod, 15-balance rod, 16-locking rod, 17-locking block Ⅰ, 18-locking block Ⅱ, 19-locking block Ⅲ, 20-fixed locking rod, 21-cross bar, 22-handle, 23-locking hole Ⅰ, 24-locking hole Ⅱ, 25-locking hole Ⅲ, 26-flat section Ⅰ, 27-concave section Ⅰ, 28-flat section Ⅱ, 29-concave section Ⅱ, 30-gripping part, 31-flat section Ⅰ, 32-convex section Ⅰ, 33-flat section Ⅱ, 34-convex section Ⅱ, 35-nail head section, 36-nail entry port Ⅱ, 37-nail exit port Ⅱ. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] A precise navigation device for locking the distal end of a femoral interlocking intramedullary nail comprises a navigation locking device I, a navigation locking device II, a fixed aiming device, an intramedullary nail and a control device. The navigation locking device I comprises a distraction fixing ring 1, a telescopic rod I2, a telescopic rod II3, a navigation locking head 4, an aiming rod I5 and an aiming rod II5; an imager is arranged at the front end of the aiming rod I and the aiming rod II, and the aiming rod I and the aiming rod II are electrically connected to an external computer, and the image of the distal end of the femur by the imager is transmitted to the computer through a signal; the distraction fixing ring 1 is in a circular ring shape, and moves along the surgical incision of the patient toward the medullary cavity of the distal end of the femur, and the incision is directed to the distal end of the femur. The opening is expanded to a certain extent, and one end of the telescopic rod Ⅰ2 and the telescopic rod Ⅱ3 are fixed on the upper and lower parts of the arc of the expanded fixed ring. The telescopic rod Ⅰ2 and the telescopic rod Ⅱ3 are connected to their own power devices, and the telescopic rod Ⅰ2 and the telescopic rod Ⅱ3 are driven by their own power devices to telescope respectively. The other ends of the telescopic rod Ⅰ2 and the telescopic rod Ⅱ3 are respectively fixedly connected to the navigation locking head 4, and the navigation locking head 4 is provided with an inlet section 9 and a slope section 7; the inlet section 9 is square, and a nail inlet opening Ⅰ11 is provided on one side of the square inlet section, and a trapezoidal slope section 7 is connected to the other side of the square inlet section 9, and the slope section 7 is away from the inlet A nail outlet port Ⅰ6 is provided on the side of one side of the mouth section 9, and an intramedullary nail passage passage Ⅰ corresponding in shape is formed from the nail inlet port Ⅰ11 to the nail outlet port Ⅰ6 by the inside of the square entrance section and the trapezoidal slope section. The intramedullary nail enters from the nail inlet port Ⅰ11 of the square entrance section and passes out from the nail outlet port Ⅰ6 of the trapezoidal slope section. A perforated block 10 is provided between the nail inlet port Ⅰ11 and the upper and lower top surfaces of the square entrance section, and the upper and lower perforated blocks 10 are both provided with the rod inlet ends of the sighting rod 5 through the hole, and the rod outlet ends of the sighting rod 5 through the hole are arranged on the upper and lower slopes of the trapezoidal slope section 7, and from the rod inlet end to the rod outlet end, the inside of the entrance section 9 and the slope end 7 Two rod passing-out channels are formed at the top and the bottom. The rod passes through the upper and lower perforated blocks 10 arranged on the square inlet section 9 and passes through the upper and lower slopes of the trapezoidal slope section 7. The aiming rod 5 can also be a fixed rod. The navigation locking device II includes a guide tube 13, a connecting rod 14, a locking rod 16, and a balancing rod 15. The guide tube 13 is connected to the balancing rod 15 through the connecting rod 14. The guide tube 13 passes through the surgical incision. The end of the guide tube 13 that remains outside the patient's body is fixedly connected with the locking rod 16. A locking block I 17, a locking block II 18, and a locking block III 19 are arranged from top to bottom along the upper and lower directions of the locking rod 16.The locking blocks I-III are all arranged in the through hole on the locking rod 16, and the locking blocks I-III are all connected to the control device and can be extended and retracted in the through hole under the control of the control device. The balance rod 15 is arranged outside the patient's body. The sizes of the locking blocks I-III are different. The volume of the locking block I17 is X0, the volume of the locking block II18 is X1, and the volume of the locking block III19 is X2. The guide tube 13 is hollow. One end of the guide tube 13 is provided with a nail entry port II36, and the other end of the guide tube is provided with a nail exit port II37. The interior of the guide tube forms an intramedullary nail passage II from the nail entry port II36 to the nail exit port II37. The outer wall of the guide tube 13 is a flat rectangular shape. The intramedullary nail passes through the passage II and forms a flat section I26, a concave section I27, a flat section II28, and a concave section II29 between the inner wall of the guide tube 13 and the outer wall of the guide tube; the flat section I26 is arranged at one end outside the patient's body; the concave section I27, the flat section II28, and the concave section II29 are arranged at one end outside the patient's body. The concave section Ⅱ28 and the concave section Ⅱ29 extend into the patient's body along the surgical incision. One end of the concave section Ⅰ27 is connected to the flat section Ⅰ26, the other end of the concave section Ⅰ27 is connected to the flat section Ⅱ29, the other end of the flat section Ⅱ28 is connected to the concave section Ⅱ29, the other end of the concave section Ⅱ29 abuts against the square inlet section 9 of the navigation locking device Ⅰ, and the nail outlet Ⅱ37 formed on the other side of the concave section Ⅱ30 is connected to the nail inlet Ⅰ11 on the square inlet section and the size is The intramedullary nail 12 passes through the channel II between the inner wall of the guide tube and the outer wall of the guide rod to form a flat section I 26, a concave section I 27, a flat section II 29 and a concave section II 30, all of which are made of rubber, the outer wall of the guide tube is made of inelastic material, the concave sections I 27 and II 30 are both arc-shaped, and the intramedullary nail includes a gripping portion 30 at the bottom, a flat section I 31, a convex section I 32, a flat section II 33, a convex section II 34, and a nail head section 35;The gripping portion 30 is outside the guide tube 13 when the intramedullary nail is inserted into the guide tube, one end of the gripping portion 30 is connected to the flat section I 31, the other end of the flat section I 31 is connected to one end of the convex section I 32, the other end of the convex section I 32 is connected to the flat section II 33, the other end of the flat section II 33 is connected to the convex section II 34, the other end of the convex section II 34 is connected to the nail head section 35, the length of the intramedullary nail 12 is longer than the length of the guide tube 13, the intramedullary nail 12 completely passes through the guide tube 13 when inserted into the distal medullary cavity of the femur, and when the intramedullary nail 12 is in a completely passed state, the flat section I 31, the convex section I 32, the flat section II 33, the convex section II 34 The overall length of segment II 34 is equal to the overall length of flat segment I 26, concave segment I 27, flat segment II 28, and concave segment II 29. When the intramedullary nail 12 is in a completely passed state, the positions of flat segment I 31, convex segment I 32, flat segment II 33, convex segment II 34, and flat segment I 26, concave segment I 27, flat segment II 28, and concave segment II 29 correspond one to one. The positions corresponding to the convex segment I 32 and the concave segment I 27 form the intramedullary nail clamping segment I, the positions corresponding to the convex segment II 34 and the concave segment II 29 form the intramedullary nail clamping segment II, the positions corresponding to the flat segment I and the flat segment I form the intramedullary nail passing segment I, and the flat segment II and The position corresponding to the flat section II forms an intramedullary nail passing section II, the concave section I 27 and the concave section II 29 have the same inward concave arc, and are both lower than the height of the flat section I-II, the convex section I 32 and the convex section II 34 have the same outward convex arc, and are both higher than the height of the flat section I-II, when the intramedullary nail 12 is in a completely passed state, the nail head section 35 passes through the intramedullary nail passing channel I inside the navigation locking device I and enters the distal femoral medullary cavity, the nail head section 35 is conical, and the conical section of the nail head section 35 fits with the inner walls of the upper and lower slopes of the trapezoidal slope section in the intramedullary nail passing channel I inside the navigation locking device I, and the fixed aiming device includes a fixed Locking rod 20, cross bar 21, handle 22; the interior of the locking rod 20 is hollow, the upper end of the locking rod 20 is fixedly connected to the cross bar 21, and the other end of the cross bar 21 is connected to the handle 22 through a hole. The side wall of the locking rod 20 is provided with three locking holes I-III that penetrate the entire internal cavity. The locking rod is inserted into the cavity of the locking rod when locked. The three locking blocks I-III correspond to the three locking holes I-III one by one. The volume of the locking block I17 is X0, which is completely compatible with the size of the locking hole I23. The volume of the locking block II18 is X1, which is completely compatible with the size of the locking hole II24. The size of the locking hole III25 is larger than the volume X2 of the locking block III19. ;

[0040] The working process of the present invention is as follows: after the surgical site of the patient is incised, the navigation locking device I is first inserted through the incision, the aiming rod I and the aiming rod II are inserted through the aiming rod through-hole, the other end of the aiming rod is left outside the patient's body, the aiming rod is operated to make the navigation locking device I enter the distal end of the femur, the distal end of the femur is expanded by expanding the fixing ring, and the operator scans and images the position of the distal end of the femur through the aiming rod, and the photo of the distal end of the femur is transmitted to an external computer for observation by the doctor. When it is observed that the distal end of the femur is in a suitable position, Operate the navigation locking device II, and place the guide tube into the patient's body through the incision along the path of the navigation locking device I until the nail outlet II of the guide tube and the nail entry I on the navigation locking device I are connected. At this time, the three locking blocks I-III are controlled by the control device to lock on the three locking holes I-III. After the nail outlet II and the nail entry I on the navigation locking device I are connected, the locking of the entire navigation device is completed. Then the intramedullary nail is inserted into the guide tube and penetrates the guide tube all the way to the navigation locking head of the navigation locking device I. The nail head section of the intramedullary nail is accurately inserted into the fixed position at the distal end of the femur through the slope section of the navigation locking head on the navigation locking device I. After insertion, the locking blocks I-II are controlled by the control device to disengage from the locking holes I-II. Since the size of the locking hole III is larger than the size of the locking block III, the two sides do not match. If the intramedullary nail is inserted into the inaccurate position and shakes, the balance bar outside the patient's body connected to the guide tube will also shake. At this time, the external operator can directly observe it. If shaking occurs, scan and observe again through the aiming rod immediately. After observing the appropriate position, the control device controls the expansion of the fixing ring The internal telescopic rods Ⅰ-Ⅱ are respectively extended and retracted, thereby changing the position of the navigation locking head, thereby driving the change of the position of the intramedullary nail. The flat section Ⅰ, convex section Ⅰ, flat section Ⅱ, and convex section Ⅱ of the intramedullary nail correspond one to one with the flat section Ⅰ, concave section Ⅰ, flat section Ⅱ, and concave section Ⅱ in the guide tube. Due to the change in the position of the intramedullary nail, the rubber-like concave section Ⅰ and concave section Ⅱ are squeezed. After reaching the accurate position of the distal end of the femur again, the navigation locking device Ⅱ is locked again, and the aiming rod is changed into a fixed rod to lock the navigation locking device Ⅰ.

Claims

1. A precise navigation device for locking the distal end of a femoral interlocking intramedullary nail, comprising a navigation locking device I, a navigation locking device II, a fixed aiming device, an intramedullary nail, and a control device, wherein the navigation locking device I comprises a distraction fixing ring, a telescopic rod I, a telescopic rod II, a navigation locking head, an aiming rod I, and an aiming rod II; an imager is arranged at the front end of the aiming rod I and the aiming rod II, and the aiming rod I and the aiming rod II are electrically connected to an external computer, and the image of the distal end of the femur by the imager is transmitted to the computer through a signal; the distraction fixing ring is in the shape of a ring, and moves along the surgical incision of the patient toward the distal medullary cavity of the femur, and distracts the incision to a certain extent, and a telescopic rod I and a telescopic rod II are fixed on the upper and lower parts of the circular arc of the distraction fixing ring The telescopic rod I and the telescopic rod II are connected to their own power devices, and the telescopic rod I and the telescopic rod II are driven by their own power devices to telescope respectively. The other ends of the telescopic rod I and the telescopic rod II are respectively fixedly connected to the navigation locking head, and the navigation locking head is provided with an entrance section and a slope section; the entrance section is square, and a nail entry opening I is opened on one side of the square entrance section, and a trapezoidal slope section is connected to the other side of the square entrance section, and a nail exit opening I is arranged on the side of the slope section away from the entrance section. From the nail entry opening to the top exit, an intramedullary nail passing channel I with a corresponding shape is formed inside the square entrance section and the trapezoidal slope section, and the intramedullary nail enters from the nail entry opening I of the square entrance section and passes out from the nail exit opening I of the trapezoidal slope section.

2. The precise navigation device for distal locking of a femoral interlocking intramedullary nail according to claim 1, characterized in that: A perforated block is arranged between the nail inlet and the upper and lower top surfaces of the square inlet section, and the upper and lower perforated blocks are both provided with rod entry ends for the aiming rod exit hole, and the rod exit ends of the aiming rod exit hole are arranged on the upper and lower slopes of the trapezoidal slope section. From the rod entry end to the rod exit end, two rod exit channels are formed from the upper and lower perforated blocks arranged on the square inlet section, and the rod passes through the upper and lower slopes of the trapezoidal slope section.

3. The precise navigation device for distal locking of a femoral interlocking intramedullary nail according to claim 2, characterized in that: The navigation locking device II includes a guide tube, a connecting rod, a locking rod, and a balance rod; the guide tube is connected to the balance rod through the connecting rod, the guide tube is inserted through the surgical incision, and the end of the guide tube remaining outside the patient's body is fixedly connected to the locking rod, and locking blocks I, II and III are arranged from top to bottom along the upper and lower directions of the locking rod; locking blocks I-III are all arranged in the through hole on the locking rod, and locking blocks I-III are all connected to the control device, and can be extended and retracted in the through hole under the control of the control device.

4. The precise navigation device for distal locking of a femoral interlocking intramedullary nail according to claim 3, characterized in that: The guide tube is hollow, with a nail entry port II provided at one end and a nail exit port II provided at the other end. An intramedullary nail passage channel II is formed inside the guide tube from the nail entry port II to the nail exit port II. The outer wall of the guide tube is a flat rectangular shape. A flat section I, a concave section I, a flat section II and a concave section II are formed inside the intramedullary nail passage channel II between the inner wall of the guide tube and the outer wall of the guide tube; the flat section I is provided at one end outside the patient's body; the concave section I, the flat section II and the concave section II extend into the patient's body along the surgical incision, one end of the concave section I is connected to the flat section I, the other end of the concave section I is connected to the flat section II, the other end of the flat section II is connected to the concave section II, and the other end of the concave section II abuts against the square entrance section of the navigation locking device I.

5. The precise navigation device for distal locking of a femoral interlocking intramedullary nail according to claim 4, characterized in that: The nail outlet II formed on the other side of the concave section II is connected to the nail inlet I on the square inlet section and has the same size. The intramedullary nail passes through the channel II to form a flat section I between the inner wall of the guide tube and the outer wall of the guide rod. The materials of the flat section I, concave section I, and concave section II are all rubber, the outer wall of the guide tube is made of inelastic material, and the concave section I and the concave section II are both arc-shaped.

6. The precise navigation device for distal locking of a femoral interlocking intramedullary nail according to claim 5, characterized in that: The intramedullary nail includes a gripping portion at the bottom, a flat section I, a convex section I, a flat section II, a convex section II, and a nail head section; the gripping portion is outside the guide tube when the intramedullary nail is inserted into the guide tube, one end of the gripping portion is connected to the flat section I, the other end of the flat section I is connected to one end of the convex section I, the other end of the convex section I is connected to the flat section II, the other end of the flat section II is connected to the convex section II, and the other end of the convex section II is connected to the nail head section.

7. The precise navigation device for distal locking of a femoral interlocking intramedullary nail according to claim 6, characterized in that: The intramedullary nail completely passes through the guide tube when inserted into the distal femoral medullary cavity. When the intramedullary nail is completely passed through, the overall length of the flat section I, the convex section I, the flat section II, and the convex section II is equal to the overall length of the flat section I, the concave section I, the flat section II, and the concave section II.

8. The precise navigation device for distal locking of a femoral interlocking intramedullary nail according to claim 7, characterized in that: When the intramedullary nail is in a completely penetrated state, the positions of the flat section I, the convex section I, the flat section II, the convex section II and the flat section I, the concave section I, the flat section II and the concave section II correspond to each other. The corresponding positions of the convex section I and the concave section I form the intramedullary nail clamping section I, and the corresponding positions of the convex section II and the concave section II form the intramedullary nail clamping section II. The corresponding positions of the flat section I and the flat section I form the intramedullary nail passing section I, and the corresponding positions of the flat section II and the flat section II form the intramedullary nail passing section II. The concave sections I and II have the same inward concave arc, and are both lower than the height of the flat sections I-II. The convex sections I and the convex sections II have the same outward convex arc, and are both higher than the height of the flat sections I-II.

9. The precise navigation device for distal locking of a femoral interlocking intramedullary nail according to claim 8, characterized in that: When the intramedullary nail is in a fully penetrated state, the nail head section passes through the intramedullary nail inside the navigation locking device I through channel I and enters the distal femoral medullary cavity. The nail head section is conical in shape, and the conical section of the nail head section and the intramedullary nail inside the navigation locking device I fit together with the inner walls of the upper and lower slopes of the trapezoidal slope section in channel I. The fixed aiming device includes a locking rod, a cross bar, and a handle. The interior of the locking rod is hollow, and the upper end of the locking rod is fixedly connected to the cross bar, and the other end of the cross bar is connected to the handle through a hole. Three locking holes I-III that pass through the entire internal cavity are provided on the side wall of the locking rod.

10. The precise navigation device for distal locking of a femoral interlocking intramedullary nail according to claim 9, characterized in that: When locking, the locking rod is inserted into the cavity of the locking rod. The three locking blocks Ⅰ-Ⅲ correspond to the three locking holes Ⅰ-Ⅲ one by one. The volume of locking block Ⅰ is X0, which is completely matched with the size of locking hole Ⅰ. The volume of locking block Ⅱ is X1, which is completely matched with the size of locking hole Ⅱ. The size of locking hole Ⅲ is larger than the volume X2 of locking block Ⅲ.

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