Subtalar joint brake

Abstract

The utility model discloses a subtalar joint brake, comprising: a head, a connecting part and a cone, wherein the head is connected to the cone through the connecting part, a plurality of bosses are arranged at equal intervals along the axial direction on the outer wall of the head, the bosses are arranged around the head, and a plurality of grooves are arranged at the outer periphery of the bosses. The subtalar joint brake provided by the utility model can avoid damage caused by excessive pressure during implantation, and can ensure sufficient axial extraction force.

Description

Technical Field

[0001] The utility model belongs to the field of medical instruments, and in particular relates to a subtalar joint brake. Background Art

[0002] Flatfoot is a common foot deformity that affects both children and adults. The main pathological feature of flatfoot is excessive eversion of the subtalar joint, which leads to collapse of the arch, causing foot pain and fatigue when walking. Subtalar joint brake is a minimally invasive surgery that corrects flatfoot foot deformity by placing a subtalar joint brake between the tarsal sinus formed by the talus and calcaneus. The specific steps are: after local anesthesia, an incision is made in the center of the outer side of the tarsal sinus, and a subtalar joint brake of appropriate size is selected and inserted into the tarsal canal. Intraoperative fluoroscopy shows that the implant is located in front of the subtalar joint, and the skin is sutured after the operation.

[0003] Currently, most subtalar joint brakes on the market are made of metal, which may cause secondary damage after being implanted in the human body and need to be removed a second time. There are also subtalar joint brakes made of absorbable materials, which can be degraded and absorbed in the human body and do not need to be removed a second time, but they have problems such as low strength, easy crushing during implantation, or too small axial pull-out force.

[0004] Therefore, providing a subtalar joint brake that can ensure sufficient strength and pull-out force and is made of absorbable material is a technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0005] The utility model provides a subtalar joint brake, which can avoid damage caused by excessive pressure during implantation.

[0006] In order to solve the above technical problems, the technical solution provided by the utility model is:

[0007] A subtalar joint brake comprises: a head, a connecting part and a cone, wherein the head is connected to the cone through the connecting part, a plurality of bosses are arranged at equal intervals along the axial direction on the outer wall of the head, the bosses are arranged around the head, and a plurality of grooves are arranged on the outer periphery of the bosses.

[0008] Preferably, the distribution positions of the grooves on every two adjacent bosses in the circumferential direction are different.

[0009] Preferably, the head includes a columnar proximal end and a distal end along the axial direction, the proximal end is connected to the connecting portion, and the diameter of the distal end is smaller than the diameter of the proximal end.

[0010] Preferably, the boss includes a first boss and a plurality of second bosses, the first boss is located at the distal end, the second bosses are uniformly distributed in sequence at the proximal end, and the outer diameter of the first boss is smaller than the outer diameter of the second boss.

[0011] Preferably, the height of the first boss and the second boss is 0.7-1.3 mm, the minimum distance between the outer peripheral edge of the second boss and the proximal outer wall is 0.7-1.3 mm, and the minimum distance between the outer peripheral edge of the second boss and the distal outer wall is 0.3-0.5 mm.

[0012] Preferably, the boss has a generatrix, and an acute angle α formed by the generatrix and the axis of the head satisfies: 45°<α≤55°.

[0013] Preferably, the groove has two side walls and a bottom surface, and the minimum distance d between the bottom surface and the outer peripheral edge of the boss satisfies 0.5 mm. <d≤0.8mm。

[0014] Preferably, a hollow cavity is provided through the head, the connecting portion and the conical body.

[0015] Preferably, the outer diameter of the first boss is 5-8 mm, and the outer diameter of the second boss is 7-9 mm.

[0016] Preferably, a mounting groove is provided at one end of the cone away from the connecting portion.

[0017] Preferably, a plurality of grooves are evenly distributed on each boss.

[0018] Preferably, the outer diameter of the first boss is 5-8 mm, and the outer diameter of the second boss is 7-9 mm.

[0019] Preferably, the cross section of the groove is triangular, quadrilateral or fan-shaped.

[0020] The beneficial effects of the utility model are as follows: the utility model provides a subtalar joint brake, which is made of absorbable material and can be degraded into substances absorbable by the human body without the need for secondary removal; at the same time, a groove structure is designed on the surface of the subtalar joint brake, which can cause deformation due to force compression during implantation, thereby sharing part of the stress, avoiding damage due to excessive pressure during implantation, and ensuring its axial pull-out force; the groove structure can promote the ingrowth of scar tissue in the subtalar joint brake, thereby reducing the probability of its dislocation or loosening. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the overall structural diagram of the subtalar joint brake of the utility model;

[0022] Figure 2It is an overall front view of the subtalar joint brake of the utility model;

[0023] Figure 3 It is an overall cross-sectional view of the subtalar joint brake of the utility model;

[0024] Figure 4 A cross-sectional view of a boss in one embodiment of the utility model;

[0025] Figure 5 is a cross-sectional view of a boss in another embodiment of the utility model;

[0026] Figure 6 is a cross-sectional view of a boss in another embodiment of the utility model;

[0027] Figure 7 A cross-sectional view of a boss in another embodiment of the utility model;

[0028] Figure 8 This is a cross-sectional view of a boss in yet another embodiment of the present utility model.

[0029] Reference numerals include:

[0030] 110 - cone 120 - connection part 130 - head

[0031] 131 - distal end 132 - proximal end 140 - boss

[0032] 141 - first boss 142 - second boss 150 - groove

[0033] 160—hollow cavity 111—installation slot DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0036] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0037] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0038] The utility model provides a subtalar joint brake, such as Figure 1-3 As shown, it mainly includes a head 130, a connecting portion 120 and a cone 110. The head 130 is connected to the cone 110 through the connecting portion 120, and the head 130, the connecting portion 120 and the cone 110 are integrally formed. The head 130 includes a columnar proximal end 132 and a distal end 131 along the axial direction. The proximal end 132 is connected to the connecting portion 120, and the diameter of the proximal end 132 is greater than the diameter of the distal end 131. The outer wall of the head 130 is arranged with a plurality of bosses 140 at equal intervals along the axial direction. The bosses 140 are arranged around the head 130. The bosses 140 are truncated cone-shaped, and a groove 150 is arranged at the outer peripheral edge of the boss 140. When the boss 140 is squeezed and implanted into the tarsal sinus, the boss 140 can be deformed toward the groove 150 when receiving the circumferential squeezing force, thereby reducing stress and preventing fragmentation.

[0039] like Figure 3As shown in the figure, the boss 140 includes a first boss 141 and a plurality of second bosses 142. The first boss 141 is disposed on the outer wall of the distal end 131, and the second bosses 142 are sequentially and evenly disposed on the outer wall of the proximal end 132. The outer diameter of the first boss 141 is smaller than that of the second boss 142. The outer diameter of the first boss 141 is 5-8 mm, and the outer diameter of the second boss 142 is 7-9 mm. The first boss 141 with a small outer diameter will result in less resistance during implantation. The first boss 141 and the second bosses 142 have the same height in the axial direction and are both 0.7-1.3 mm. The minimum distance between the outer peripheral edge of the second boss 142 and the outer wall of the proximal end 132 is 0.7-1.3 mm, and the minimum distance between the outer peripheral edge of the second boss 142 and the outer wall of the distal end 131 is 0.3-0.5 mm. The side surface of the frustum-shaped boss 140 has a generatrix, and the acute angle α formed by the intersection of the generatrix and the central axis of the head 130 satisfies: 45° < α ≤ 55°. The structural and dimensional design of the boss 140 of the subtalar joint brake can ensure that the subtalar joint brake is firmly fixed after being implanted into the sinus tarsi and is not easily dislodged.

[0040] Preferably, the subtalar joint brake of the present invention is made of a polymer absorbable material, which can be degraded and absorbed in the human body to avoid the harm caused by secondary removal. The subtalar joint brake of the present invention is implanted into the model sinus tarsi, and a pressurized cycle with a maximum load of 500 N and a frequency of 5 Hz is performed 1,000,000 times. Then, static and dynamic pull-out force tests are carried out to obtain that the static pull-out force of the subtalar joint brake implanted into the sinus tarsi is 220-290 N, and the dynamic pull-out force is 210-270 N. After calculation, the average static pull-out force is 263 N, and the average dynamic pull-out force is 253.5 N. The actual force borne by the sinus tarsi is very small (1-2 N). After the subtalar joint brake is implanted, it is not easily dislodged from the sinus tarsi.

[0041] As Figure 2 and Figure 3 shown in the figure, the groove 150 has two side walls and a bottom surface. The minimum distance d between the bottom surface and the outer peripheral edge of the boss 140 satisfies 0.5 mm < d ≤ 0.8 mm. Since the sinus tarsi is relatively narrow, it will generate a squeezing force on the subtalar joint brake during implantation, and the situation of being crushed may occur. The groove 150 structure of the present invention can cause the subtalar joint brake to be deformed by the applied pressure to share part of the stress, and can avoid being damaged due to excessive pressure during implantation. The circumferential distribution positions of the grooves 150 on every two adjacent bosses 140 are different (i.e., the grooves 150 on adjacent bosses 140 are staggeredly distributed), so that the grooves 150 do not form a through channel in the axial direction of the subtalar joint brake, ensuring its axial pull-out force.

[0042] Preferably, the peripheral edge of the boss 140 is processed into a rounded corner or a chamfered corner, so that when the interosseous ligament extends to both sides, a smooth curved surface can be provided to contact the interosseous ligament, thereby avoiding wear of the interosseous ligament.

[0043] As a preferred example, Figure 3 As shown, a hollow cavity 160 cooperating with the guide needle is provided inside the head 130, the connecting part 120 and the cone 110, and a mounting groove 111 is provided at one end of the cone 110 away from the connecting part 120. The mounting groove 111 is a hexagonal hole for cooperating with the implantation tool.

[0044] The number of grooves 150 provided on each boss 140 may be one (eg Figure 4 As shown), 2 (as Figure 5 As shown), 3 (as Figure 6 140) or more, and the number of grooves 150 on each boss 140 may also be different. When each boss 140 is provided with one groove 150, the grooves 150 on different bosses 140 are staggered, and the grooves 150 are not on the same axis. When the number of grooves 150 on each boss 140 is more than one, the grooves 150 on each boss 140 are evenly distributed (such as Figure 5 and Figure 6 shown).

[0045] As a preference, the cross section of the groove 150 may be fan-shaped (eg Figure 4 As shown), quadrilateral (as Figure 7 As shown), triangle (as Figure 8 As shown) or other shapes, and all are chamfered at the corners to avoid cutting of tissues.

[0046] Furthermore, the working principle of the subtalar joint brake of the present application is as follows: a boss 140 is provided on the outer wall of the head 130, and the head 130 includes a distal end 131 with a smaller diameter and a proximal end 132 with a larger diameter, so that the subtalar joint brake can be firmly fixed in the tarsal sinus and tarsal canal of the subtalar joint and is not easy to dislodge; a groove 150 is provided on the boss 140, which can effectively reduce the stress during implantation and prevent implantation failure. Compared with the subtalar joint brake made of absorbable materials of the existing design, the fixing effect is better. The subtalar joint brake of the present application is directly inserted through the guide needle during implantation, and the front head 130 can clamp the interosseous ligament of the calcaneus to prevent it from dislodging, and the cross section of the first boss 141 is smaller than the cross section of the second boss 142, so that the interosseous ligament is not easy to dislodge after being clamped, and the firmness is enhanced. At the same time, it can promote the inward growth of scar tissue, effectively reducing the probability of loosening or dislodging of the subtalar joint brake.

[0047] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, many changes can be made in the specific implementation methods and application scopes based on the ideas of the present invention. As long as these changes do not deviate from the concept of the present invention, they all belong to the protection scope of the present invention.

Claims

1. A subtalar joint brake, characterized in that: include: A head (130), a connecting portion (120) and a conical body (110), wherein the head (130) is connected to the conical body (110) via the connecting portion (120), a plurality of bosses (140) are arranged at equal intervals along the axial direction on the outer wall of the head (130), the bosses (140) are arranged around the head (130), and a plurality of grooves (150) are arranged on the outer periphery of the bosses (140).

2. The subtalar joint brake according to claim 1, characterized in that: The distribution positions of the grooves (150) on every two adjacent bosses (140) in the circumferential direction are different.

3. The subtalar joint brake according to claim 2, characterized in that: The head (130) includes a columnar proximal end (132) and a distal end (131) along the axial direction, the proximal end (132) is connected to the connecting portion (120), and the diameter of the distal end (131) is smaller than the diameter of the proximal end (132).

4. The subtalar joint brake according to claim 3, characterized in that: The boss (140) comprises a first boss (141) and a plurality of second bosses (142), wherein the first boss (141) is located at the distal end (131), and the plurality of second bosses (142) are uniformly distributed in sequence at the proximal end (132), and an outer diameter of the first boss (141) is smaller than an outer diameter of the second boss (142).

5. The subtalar joint brake according to claim 4, characterized in that: The heights of the first boss (141) and the second boss (142) are 0.7 to 1.3 mm, the minimum distance between the outer edge of the second boss (142) and the outer wall of the proximal end (132) is 0.7 to 1.3 mm, and the minimum distance between the outer edge of the second boss (142) and the outer wall of the distal end (131) is 0.3 to 0.5 mm.

6. The subtalar joint brake according to claim 5, characterized in that: The boss (140) has a generatrix, and the acute angle α formed by the generatrix and the axis of the head (130) satisfies: 45°<α≤55°.

7. The subtalar joint brake according to claim 6, characterized in that: The groove (150) has two side walls and a bottom surface, and the minimum distance d between the bottom surface and the outer peripheral edge of the boss (140) satisfies 0.5 mm. <d≤0.8mm。 8. The subtalar joint brake according to claim 7, characterized in that: A plurality of grooves (150) are evenly distributed on each boss (140).

9. The subtalar joint brake according to claim 8, characterized in that: The outer diameter of the first boss (141) is 5 to 8 mm, and the outer diameter of the second boss (142) is 7 to 9 mm.

10. The subtalar joint brake according to claim 9, characterized in that: The cross section of the groove (150) is triangular, quadrilateral or fan-shaped.

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