Children tibia intramedullary nail

Abstract

The utility model relates to the technical field of medical instruments, and provides a child tibia intramedullary nail which comprises a main nail and an interlocking screw. The main nail is a rigid piece, a hollow cavity is formed in the main nail, and the main nail comprises a near-end straight section, a first bent section, a second bent section and a far-end straight section; the near-end straight section, the first bent section, the second bent section and the far-end straight section are connected in sequence; the near-end straight section is provided with a first threaded hole, the far-end straight section is provided with a second threaded hole, and the first threaded hole and the second threaded hole are respectively in threaded connection with an interlocking screw; wherein the bending angle of the first bending section ranges from 15 degrees to 17 degrees, and the bending angle of the second bending section ranges from 4 degrees to 6 degrees. According to the child tibia intramedullary nail, on the premise that fracture healing of children is facilitated, normal development of the children is not affected, and the effect that the fracture ends of tibia are stably fixed while development of the children is not affected is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of medical devices, in particular to a pediatric tibial intramedullary nail. Background Art

[0002] When treating tibial fractures in children, intramedullary nailing is usually performed in the medullary cavity to assist fracture recovery. Generally, an intramedullary nail of appropriate length is selected and driven into the tibia, and the intramedullary nail is fixed to the tibia to prevent bone shortening and avoid axial and rotational deformities of the fracture. The intramedullary nail is removed after the fracture heals.

[0003] Currently, the treatment of tibial fractures in children usually involves placing an elastic intramedullary nail in the medullary cavity. Two elastic intramedullary nails are placed alternately and fixed from the distal end. This structure is unstable, and the mobility of children increases the risk of loosening of the intramedullary nails, which is not conducive to fracture healing. Utility Model Content

[0004] The utility model provides a pediatric tibial intramedullary nail, which is used to solve the problem that the pediatric tibial intramedullary nail in the prior art is unstable in structure and easy to loosen.

[0005] The utility model provides a pediatric tibial intramedullary nail, comprising: a main nail and an interlocking screw;

[0006] The main nail is a rigid part, and a hollow cavity is formed inside, including a proximal straight section, a first bent section, a second bent section and a distal straight section;

[0007] The proximal straight section, the first bent section, the second bent section and the distal straight section are connected in sequence;

[0008] The proximal straight section is provided with a first threaded hole, and the distal straight section is provided with a second threaded hole, and the first threaded hole and the second threaded hole are respectively threadedly connected with one of the interlocking screws;

[0009] Wherein, the bending angle of the first bending section is 15° to 17°, and the bending angle of the second bending section is 4° to 6°.

[0010] According to the pediatric tibial intramedullary nail provided by the utility model, the distance between the end of the proximal straight section away from the first bending section and the bending point of the first bending section is 30-40 mm.

[0011] According to the pediatric tibial intramedullary nail provided by the utility model, the distance between the end of the proximal straight section away from the first bending section and the bending point of the second bending section is 50 to 60 mm.

[0012] According to the pediatric tibial intramedullary nail provided by the utility model, the outer diameter of the main nail is 6-9 mm.

[0013] According to the pediatric tibial intramedullary nail provided by the utility model, two first threaded holes are provided, and the two first threaded holes are spaced apart along the axial direction of the proximal straight section;

[0014] And / or, two second threaded holes are provided, and the two second threaded holes are spaced apart along the axial direction of the distal straight section.

[0015] According to the pediatric tibial intramedullary nail provided by the utility model, the top end of the proximal straight section is provided with a threaded hole, and the side of the threaded hole is provided with a limiting groove;

[0016] The threaded hole is used to match with the holding thread on the holding device, and the limiting groove is used to match with the clamping block on the holding device.

[0017] According to the pediatric tibial intramedullary nail provided by the utility model, the top outer wall of the proximal straight section is provided with an inclined surface;

[0018] The inclined surface is spaced apart from the limiting groove, and the inclined surface is used for positioning the main nail when it is implanted into the medullary cavity.

[0019] According to the pediatric tibial intramedullary nail provided by the utility model, the top end of the distal straight section is a conical structure;

[0020] Along the axial direction of the distal straight section and away from the proximal straight section, the cross-sectional area of ​​the tapered structure gradually decreases.

[0021] According to the pediatric tibial intramedullary nail provided by the utility model, the side wall of the interlocking screw is provided with a cutting edge;

[0022] The cutting edge is used to make it easier for the locking screw to be screwed into the tibia.

[0023] According to the pediatric tibial intramedullary nail provided by the utility model, the interlocking screw is a titanium alloy piece;

[0024] And / or, the interface of the interlocking screw is a plum blossom interface.

[0025] The pediatric tibial intramedullary nail provided by the utility model has a proximal straight section, a first bent section, a second bent section and a distal straight section arranged in the main nail, and the bending angle of the first bent section is set to 15°-17°, and the bending angle of the second bent section is set to 4°-6°, so that the main nail can fit the physiological characteristics of the child's tibia. After the main nail is implanted in the child's medullary cavity, it can avoid the child's growth area, and the child's growth and development will not be affected by the reduction and fixation of the child's tibia. Moreover, after the interlocking screw is screwed in through the first threaded hole and the second threaded hole, the locking structure of the main nail and the interlocking screw can firmly fix the child's tibia, reduce the risk of loosening, shorten the time for the child's fracture healing, and, on the premise of being conducive to the child's fracture healing, it does not affect the child's normal development, thereby achieving the effect of stably fixing the tibial fracture end without affecting the child's development. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 It is a three-dimensional structural schematic diagram of the tibial intramedullary nail for children provided by the utility model;

[0028] Figure 2 This is one of the three-dimensional structural schematic diagrams of the main nail provided by the utility model;

[0029] Figure 3 This is the second three-dimensional structural schematic diagram of the main nail provided by the utility model;

[0030] Figure 4 This is the third schematic diagram of the three-dimensional structure of the main nail provided by the utility model;

[0031] Figure 5 It is a three-dimensional structural schematic diagram of the interlocking screw provided by the utility model.

[0032] Reference numerals:

[0033] 1. Main nail;

[0034] 11. proximal straight section; 12. first bending section; 13. second bending section; 14. distal straight section; 111. first threaded hole; 112. threaded hole; 113. inclined surface; 141. second threaded hole; 142. conical structure; 1121. limiting groove;

[0035] 2. Locking screw; 21. Cutting edge; 22. Interface. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0037] Combine the following Figures 1 to 5 The pediatric tibial intramedullary nail provided by the utility model embodiment is described in detail through specific embodiments and application scenarios.

[0038] In some embodiments, Figure 1 , Figure 2 and Figure 3 As shown, this embodiment provides a pediatric tibial intramedullary nail, comprising: a main nail 1 and a locking screw 2.

[0039] The main nail 1 is a rigid member, and a hollow cavity is formed inside, including a proximal straight section 11 , a first bent section 12 , a second bent section 13 and a distal straight section 14 .

[0040] The proximal straight section 11, the first bent section 12, the second bent section 13 and the distal straight section 14 are connected in sequence.

[0041] The proximal straight section 11 is provided with a first threaded hole 111 , and the distal straight section 14 is provided with a second threaded hole 141 . The first threaded hole 111 and the second threaded hole 141 are respectively threadedly connected to an interlocking screw 2 .

[0042] The bending angle of the first bending section 12 is 15° to 17°, and the bending angle of the second bending section 13 is 4° to 6°.

[0043] It is understandable that when the main nail 1 is implanted into the medullary cavity of a child, the distal straight section 14 is located at the distal end of the medullary cavity, and the proximal straight section 11 is located at the proximal end of the medullary cavity. In order to fit the bone characteristics of the child's tibia, the main nail 1 can avoid the child's growth area after implantation, and the main nail 1 is placed at a 45° approach to the anterior and medial side below the growth metaphysis. The proximal straight section 11 and the distal straight section 14 of this embodiment are connected in a spatial angle. In order to smoothly connect the proximal straight section 11 and the distal straight section 14, this embodiment is provided with a first bending section 12 and a second bending section 13, and the proximal straight section 11 and the distal straight section 14 are smoothly connected through transitions at different angles.

[0044] After the main nail 1 is implanted into the medullary cavity, multiple interlocking screws 2 are respectively inserted into the first threaded hole 111 and the second threaded hole 141 on the main nail 1 from the outside of the tibia, and the main nail 1 is fixed at the proximal straight section 11 and the distal straight section 14, thereby enhancing the structural stability of the tibial intramedullary nail for children. When children move more and with a large range of motion, the interlocking locking structure of the interlocking screws 2 and the main nail 1 can also firmly fix the fracture ends of the tibia, thereby promoting rapid healing of the tibial fracture.

[0045] Optionally, one first threaded hole 111 may be provided in the proximal straight section 11 and one second threaded hole 141 may be provided in the distal straight section 14 , or a plurality of first threaded holes 111 may be provided in the proximal straight section 11 and a plurality of second threaded holes 141 may be provided in the distal straight section 14 .

[0046] like Figure 2 As shown, the bending angle of the first bending section 12 is defined as α, and the range of α is 15° to 17°; Figure 3 As shown, the bending angle of the second bending section 13 is defined as β, and the range of β is 4° to 6°. Since the angle between the proximal straight section 11 and the distal straight section 14 is a spatial angle, α and β are not in the same plane. In clinical practice, the main nail 1 with α and β in this range is more suitable for the physiological characteristics of the tibia of children. Whether it is the approach stage of implantation into the medullary cavity of children or the fixation stage after implantation, the angle combination setting of α and β can avoid the growth area of ​​children.

[0047] The pediatric tibial intramedullary nail provided by the utility model has a proximal straight section 11, a first bent section 12, a second bent section 13 and a distal straight section 14 arranged in the main nail 1, and the bending angle of the first bent section 12 is set to 15°~17°, and the bending angle of the second bent section 13 is set to 4°~6°, so that the main nail 1 can fit the physiological characteristics of the child's tibia. After the main nail 1 is implanted in the child's medullary cavity, it can avoid the child's growth area, and the child's growth and development will not be affected by the reduction and fixation of the child's tibia. Moreover, after the interlocking screw 2 is screwed in through the first threaded hole 111 and the second threaded hole 141, the locking structure of the main nail 1 and the interlocking screw 2 can firmly fix the child's tibia, reduce the risk of loosening, shorten the time for the child's fracture healing, and on the premise of being conducive to the child's fracture healing, it does not affect the child's normal development, thereby achieving the effect of stably fixing the tibial fracture end without affecting the child's development.

[0048] In some embodiments, Figure 2 As shown, in this embodiment, the distance between the end of the proximal straight section 11 away from the first bending section 12 and the bending point of the first bending section 12 is 30-40 mm.

[0049] It is understandable that the distance from the end of the proximal straight section 11 away from the first bending section 12 to the bending point of the first bending section 12 is defined as L1, and the range of L1 is 30 to 40 mm. The distance of the L1 section is located at the proximal end of the child's tibia. If it is too long, it will penetrate into the growth zone, and if it is too short, it will not be conducive to the locking and fixation of the main nail 1. The length of 30 to 40 mm is more in line with the physiological characteristics of the child's tibia, and can also reduce the impact on the activity function of the knee joint.

[0050] In some embodiments, Figure 3 As shown, in this embodiment, the distance between the end of the proximal straight section 11 away from the first bending section 12 and the bending point of the second bending section 13 is 50 to 60 mm.

[0051] It is understandable that if Figure 3 As shown, the distance from the end of the proximal straight section 11 away from the first bending section 12 to the bending point of the second bending section 13 is defined as L2, and the range of L2 is 50 to 60 mm. The distance of L2 is related to the bending point of the distal straight section 14. If L2 is set too long or too short, it will affect the placement angle of the distal straight section 14 in the medullary cavity. The length of 50 to 60 mm is more in line with the physiological characteristics of children's tibia, and avoids the growth area of ​​children under the premise of fixing the fracture ends.

[0052] In some embodiments, Figure 1 , Figure 2 and Figure 3 As shown, the outer diameter of the main nail 1 in this embodiment is 6 to 9 mm.

[0053] It is understandable that, since the outer diameter of the tibia of a child is smaller, the inner diameter of the corresponding medullary cavity is also smaller. This embodiment uses a main nail 1 with an outer diameter of 6 to 9 mm, which is more in line with the geometric dimensions of the medullary cavity of a child and facilitates the implantation and fixation of the main nail 1.

[0054] In some embodiments, Figure 3 As shown, in this embodiment, two first threaded holes 111 are provided, and the two first threaded holes 111 are spaced apart along the axial direction of the proximal straight section 11 .

[0055] It is understandable that in order to ensure that the proximal straight section 11 can be firmly fixed and at the same time avoid causing excessive opening damage to the child's tibia, the present embodiment provides two first threaded holes 111 in the proximal straight section 11. After the main nail 1 is implanted into the child's medullary cavity, two interlocking screws 2 are screwed into the proximal straight section 11 for fixation. The two interlocking screws 2 are arranged in parallel to form a stable fixation for the proximal straight section 11.

[0056] In some embodiments, Figure 3 As shown, in this embodiment, two second threaded holes 141 are provided, and the two second threaded holes 141 are spaced apart along the axial direction of the distal straight section 14 .

[0057] It is understandable that in order to ensure that the distal straight section 14 can be firmly fixed and at the same time avoid causing excessive opening damage to the child's tibia, the present embodiment provides two second threaded holes 141 on the distal straight section 14. After the main nail 1 is implanted into the child's medullary cavity, two interlocking screws 2 are screwed into the distal straight section 14 for fixation. The two interlocking screws 2 are arranged in parallel to form a stable fixation of the distal straight section 14.

[0058] In some embodiments, Figure 3 and Figure 4 As shown, in this embodiment, a threaded hole 112 is provided at the top end of the proximal straight section 11 , and a limiting groove 1121 is provided at the side of the threaded hole 112 .

[0059] The threaded hole 112 is used to match with the holding thread on the holding device, and the limiting groove 1121 is used to match with the clamping block on the holding device.

[0060] It is understandable that when the main nail 1 is held, the threaded hole 112 forms a threaded connection with the holding thread, which reduces the possibility of the holding instrument falling off the main nail 1 and facilitates the holding, transfer and implantation of the main nail 1.

[0061] After the holding instrument is screwed to make the holding thread and the threaded hole 112 threadedly connected, the limiting groove 1121 is engaged with the clamping block of the holding instrument to achieve circumferential positioning of the main nail 1, ensuring the main nail 1 can be held stably by the holding instrument.

[0062] In some embodiments, Figure 3 and Figure 4 As shown, the top outer wall of the proximal straight section 11 of this embodiment is provided with an inclined surface 113 .

[0063] The inclined surface 113 is spaced apart from the limiting groove 1121 , and the inclined surface 113 is used for positioning the main nail 1 when implanting it into the medullary cavity.

[0064] It is understandable that, based on the structural characteristics of the child's tibia, the main nail 1 can only be implanted into the medullary cavity in a specific posture to effectively fix the broken end of the child's tibia while avoiding the growth area. The inclined surface 113 of the proximal straight section 11 is used as a reference point. During the implantation process, the inclined surface 113 is compared with the target position to ensure the accuracy of the position of the main nail 1 implanted into the child's medullary cavity, thereby improving the efficiency of the implantation. In addition, the inclined surface 113 is more convenient for identification and positioning and makes it easier to implant the main nail 1 into the child's medullary cavity.

[0065] In some embodiments, Figure 4 As shown, the top end of the distal straight section 14 of this embodiment is a tapered structure 142 .

[0066] Along the axial direction of the distal straight section 14 and away from the proximal straight section 11 , the cross-sectional area of ​​the tapered structure 142 gradually decreases.

[0067] It is understandable that when the main nail 1 is implanted into the child's medullary cavity, the distal straight section 14 first enters from the proximal end of the child's tibia and is pushed toward the distal end of the child's tibia. The conical structure at the top of the distal straight section 14 of this embodiment makes the contact surface between the distal straight section 14 and the child's medullary cavity change from small to large, which is more conducive to the advancement of the distal straight section 14 in the child's medullary cavity, and the resistance encountered is smaller, which is conducive to the implantation of the main nail 1.

[0068] In some embodiments, Figure 5 As shown, the side wall of the locking screw 2 of this embodiment is provided with a cutting edge 21.

[0069] The cutting edge 21 is more conducive to the implantation of the interlocking screw 2 , and is used to avoid bone chips generated when the interlocking screw 2 is screwed into the tibia.

[0070] It is understandable that the side wall of the locking screw 2 is provided with a full-length external thread structure, and a cutting edge 21 is provided at the top of the locking screw 2. When the locking screw 2 is screwed into the tibia, a drill bit with an outer diameter smaller than that of the locking screw 2 is first used to drill a hole, and then the locking screw 2 is screwed into the hole. The avoidance gap in the cutting edge 21 can avoid bone chips of the tibia and discharge them through the avoidance gap to avoid the accumulation of bone chips at the top when the locking screw 2 is screwed in, which is more conducive to the assembly of the locking screw 2 and the main nail 1.

[0071] In some embodiments, Figure 5 As shown, the interlocking screw 2 of this embodiment is a titanium alloy part.

[0072] It is understandable that the interlocking screw 2 is made of titanium alloy, which can withstand dynamic loads for a long time and achieve stable fixation of the main nail 1 due to its low density, high strength, good biocompatibility and fatigue resistance.

[0073] In some embodiments, the interface 22 of the locking screw 2 of this embodiment is a plum blossom interface.

[0074] It can be understood that the hole of the plum blossom interface is used to cooperate with the screwing tool to fix the locking screw 2 on the main nail 1. When medical personnel operate, they can firmly hold the locking screw 2 and screw it. After screwing it into place, the nut 22 of the locking screw 2 is fixed in the cortical bone area and does not sink into the bone surface.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A pediatric tibial intramedullary nail, characterized in that: include: primary nails and interlocking screws; The main nail is a rigid part, and a hollow cavity is formed inside, including a proximal straight section, a first bent section, a second bent section and a distal straight section; The proximal straight section, the first bent section, the second bent section and the distal straight section are connected in sequence; The proximal straight section is provided with a first threaded hole, and the distal straight section is provided with a second threaded hole, and the first threaded hole and the second threaded hole are respectively threadedly connected with one of the interlocking screws; Wherein, the bending angle of the first bending section is 15° to 17°, and the bending angle of the second bending section is 4° to 6°.

2. The pediatric tibial intramedullary nail according to claim 1, characterized in that: The distance between the end of the proximal straight section away from the first bending section and the bending point of the first bending section is 30-40 mm.

3. The pediatric tibial intramedullary nail according to claim 2, characterized in that: The distance between the end of the proximal straight section away from the first bending section and the bending point of the second bending section is 50 to 60 mm.

4. The pediatric tibial intramedullary nail according to claim 3, characterized in that: The outer diameter of the main nail is 6 to 9 mm.

5. The pediatric tibial intramedullary nail according to any one of claims 1 to 4, characterized in that: There are two first threaded holes, and the two first threaded holes are spaced apart along the axial direction of the proximal straight section; And / or, two second threaded holes are provided, and the two second threaded holes are spaced apart along the axial direction of the distal straight section.

6. The pediatric tibial intramedullary nail according to claim 1, characterized in that: A threaded hole is provided at the top of the proximal straight section, and a limiting groove is provided on the side of the threaded hole; The threaded hole is used to match with the holding thread on the holding device, and the limiting groove is used to match with the clamping block on the holding device.

7. The pediatric tibial intramedullary nail according to claim 6, characterized in that: The top outer wall of the proximal straight section is provided with an inclined surface; The inclined surface is spaced apart from the limiting groove, and the inclined surface is used for positioning the main nail when it is implanted into the medullary cavity.

8. The pediatric tibial intramedullary nail according to claim 1, characterized in that: The top end of the distal straight section is a conical structure; Along the axial direction of the distal straight section and away from the proximal straight section, the cross-sectional area of ​​the tapered structure gradually decreases.

9. The pediatric tibial intramedullary nail according to claim 1, characterized in that: The side wall of the interlocking screw is provided with a cutting edge; The cutting edge is used to make it easier for the locking screw to be screwed into the tibia.

10. The pediatric tibial intramedullary nail according to claim 1, characterized in that: The interlocking screw is a titanium alloy part; And / or, the interface of the interlocking screw is a plum blossom interface.

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