Pedicle screw with anti-retreating function

Abstract

The utility model provides a pedicle screw with an anti-retreating function. The pedicle screw comprises an expansion sleeve and a screw body inserted into the expansion sleeve. The expansion sleeve comprises a head section, a middle section and a tail section which are connected in sequence; a plurality of expansion gaps extending in the axial direction are formed in the head section; the expansion gap extends to the end face of the head section; the tail section is provided with a plurality of hollow structures distributed in the circumferential direction. And anti-retreating structures are arranged on the outer walls of the head section, the middle section and the tail section. And during revision operation, the expansion sleeve is fixed, and only the nail body is operated, so that secondary injury is prevented. The utility model has an anti-retreating function, and the fixing effect is increased.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of spine surgery medical instrument technology, especially a pedicle screw with anti-retreating function. BACKGROUND

[0002] Screw fixation is a common surgical fixation system, and the fixation is poor for some osteoporosis patients, and there is a risk of screw retreatment, and if the operation fails, the ability of the original screw position to hold the screw is greatly reduced. A screw on the market can only expand at the inner end, and the entire body cannot be expanded and fixed. If only the end part is expanded and fixed, the fixed area is small, and the force is also small, which reduces the fixed effect. For example, the orthopedic intramedullary expansion nail with the announcement number CN204072295U can only expand and fix at the end part. Therefore, how to increase the fixed effect, effectively prevent retreatment, and eliminate the disadvantages of secondary revision surgery is a problem that needs to be solved by technical personnel in this field. SUMMARY

[0003] The utility model discloses a pedicle screw with anti-retreating function, has anti-retreating function, increased fixed effect.

[0004] A pedicle screw with anti-retreating function, comprising:

[0005] An expansion sleeve 1 and a nail body 2 inserted into the expansion sleeve 1, the nail body 2 is in interference fit with the expansion sleeve 1, the expansion sleeve 1 comprises: a head section, a middle section and a tail section connected in sequence;

[0006] A plurality of expansion slots 11 extending along the axial direction are formed on the head section; the expansion slots 11 extend to the end face of the head section;

[0007] A plurality of hollow structures 12 distributed in the circumferential direction are formed on the tail section; the outer walls of the head section, the middle section and the tail section are all provided with anti-retreating structures.

[0008] Preferably, the hollow structure on the tail section is a hollow window.

[0009] Preferably, the adjacent hollow structures 12 are communicated through expansion grooves 13, and the expansion grooves 13 are formed on the inner wall of the tail section.

[0010] Preferably, the anti-retreating structure on the tail section is a wedge-shaped block 14, and the anti-retreating structures on the head section and the middle section are all anti-retreating grooves.

[0011] Preferably, the wedge-shaped block 14 is integrally formed with the tail section.

[0012] Preferably, the anti-retreating face of the anti-retreating groove is away from the tail section, and the anti-retreating face is perpendicular to the axis of the expansion sleeve 1.

[0013] Preferably, the expansion sleeve 1 is made of non-metallic material.

[0014] Preferably, the expansion sleeve 1 has a thickness of 0.5-1.5mm.

[0015] Preferably, the nail body 2 is made of titanium alloy material.

[0016] Compared with the prior art, the utility model has the advantages of:

[0017] 1, after the nail body 2 is inserted into the expansion sleeve 1, the expansion slit 11 is opened, and the tail part expands radially. Therefore, the expansion sleeve expands as a whole, and the tail part and the head part cooperate to increase the extrusion degree on the periphery, which can prevent the retreat and thus improve the fixing effect.

[0018] The reason why the tail part expands radially is that the nail body 2 is in interference fit with the expansion sleeve 1, and the thickness of the tail part of the expansion sleeve 1 is reduced due to the existence of the hollow structure, so that the tail part is shortened in the axial direction under the extrusion of the nail body 2 and thus expands radially.

[0019] 2, the three sections of the expansion sleeve 1 are all provided with anti-retreat structures, which further improve the fixing effect. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a structure diagram of the pedicle screw with anti-retreat function.

[0021] Figures 2-3 It is a structure diagram of the expansion sleeve.

[0022] Figure 4 It is a structure diagram of the anti-retreat groove.

[0023] Among them, 1-expansion sleeve, 11-expansion slit, 12-hollow structure, 13-expansion groove, 14-wedge block, 15-first anti-retreat groove, 151-anti-retreat surface, 16-second anti-retreat groove; 2-nail body. DETAILED DESCRIPTION

[0024] The pedicle screw with anti-retreat function will be described in more detail below with reference to the accompanying drawings, wherein the preferred embodiments of the utility model are shown, and it should be understood that the utility model described herein can be modified by those skilled in the art, and the advantageous effects of the utility model can still be achieved. Therefore, the following description should be understood as extensive knowledge for those skilled in the art, and not as a limitation on the utility model.

[0025] As Figures 1-4 , a pedicle screw with anti-retreat function comprises an expansion sleeve 1 and a nail body 2 inserted into the expansion sleeve 1.

[0026] The nail body 2 is in interference fit with the expansion sleeve 1. That is, the nail body 2 is cut and extruded into the expansion sleeve 1.

[0027] The expansion sleeve 1 is made of non-metallic material.

[0028] The non-metallic material includes PEEK (polyether ether ketone), PEEK+carbon fiber, PEEK+calcium silicate, PEEK+HA (hydroxyapatite), PEKK (polyether ketone ketone), PEKK+carbon fiber, PEKK+calcium silicate, non-absorbable biological material such as polyethylene, and absorbable biological material such as levorotatory lactic acid, meso-lactic acid, glycolic acid and trimethylene carbonate.

[0029] In the embodiment, the expansion sleeve 1 is made of composite material, polyether ether ketone PEEK+30% cf (30% carbon fiber). The thickness of the expansion sleeve 1 is between 0.5-1.5 mm.

[0030] The nail body 2 is made of titanium alloy material.

[0031] The expansion sleeve 1 includes a head section, a middle section and a tail section connected in sequence. The outer walls of the head section, the middle section and the tail section are all provided with anti-backout structures.

[0032] The head section is provided with a plurality of expansion slots 11 extending along the axial direction; the expansion slots 11 extend to the end face of the head section.

[0033] The anti-backout structure on the head section is a first anti-backout groove 15. The anti-backout surface 151 of the first anti-backout groove 15 is away from the tail section, and the anti-backout surface 151 is perpendicular to the axis of the expansion sleeve 1.

[0034] The tail section is provided with a plurality of hollow structures 12 distributed in the circumferential direction.

[0035] The hollow structure on the tail section is a rectangular hollow window. Each hollow structure extends along the axial direction.

[0036] The adjacent hollow structures 12 are communicated through expansion grooves 13 provided on the inner wall of the tail section.

[0037] The anti-backout structure on the tail section is a wedge-shaped block 14; the wedge-shaped block 14 is integrally formed with the tail section.

[0038] The anti-backout structure on the middle section is a second anti-backout groove 16, which has the same structure as the first anti-backout groove 15.

[0039] The working principle of the pedicle screw is as follows:

[0040] During the operation, a hole is first drilled on the vertebral body, the expansion sleeve 1 is screwed in, and then the nail body 2 is screwed in. The expansion sleeve 1 expands as a whole, increases the extrusion force on the surrounding, and thus improves the fixing effect.

[0041] Meanwhile, the three sections of the expansion sleeve 1 are all provided with anti-backout structures, which further improves the fixing effect.

[0042] If the operation fails, the nail body 2 needs to be taken out, the expansion sleeve 1 is reserved, the nail body 2 is taken out by special operation tool, and the second injury is not caused to the human body when the nail is placed again.

[0043] The above are only preferred embodiments of the present application, and do not have any limiting effect on the present application. Any person skilled in the art, without departing from the technical scheme of the present application, makes any form of equivalent replacement or modification of the technical scheme and technical content disclosed by the present application, and the change belongs to the content of the technical scheme of the present application, and still belongs to the protection scope of the present application.

Claims

1. A pedicle screw with anti-retraction function, characterized in that, The utility model relates to a kind of expandable nail, including: Expansion sleeve (1) and the nail body (2) inserted into expansion sleeve (1); The expansion sleeve (1) includes: head section, middle section and tail section are connected in sequence; Several expansion slots (11) extending along the axial direction are opened on the head section;The expansion slot (11) extends to the end face of head section; Several hollow structures (12) distributed along the circumference are opened on the tail section;The outer wall of head section, middle section and tail section is all provided with anti-retreating structure.

2. The pedicle screw having a retreat prevention function according to claim 1, wherein The hollow structure on the tail section is hollow window.

3. The pedicle screw having a retreat prevention function according to claim 1, wherein Adjacent the hollow structure (12) is communicated by expansion groove (13), and the expansion groove (13) is opened on the inner wall of the tail section.

4. The pedicle screw having a prevention function according to claim 1, wherein, The anti-retreating structure on the tail section is wedge block (14);The anti-retreating structure on head section and middle section is all anti-retreating groove.

5. The pedicle screw having a prevention function according to claim 4, wherein, The wedge block (14) is integrally formed with tail section.

6. The pedicle screw having a prevention function according to claim 4, wherein, The anti-retreating face of the anti-retreating groove is away from tail section, and the anti-retreating face is perpendicular to the axial line of expansion sleeve (1).

7. The pedicle screw having a prevention function according to claim 1, wherein The expansion sleeve (1) is made of non-metallic material.

8. The pedicle screw having a prevention function according to claim 1, wherein, The thickness of the expansion sleeve (1) is between 0.5-1.5mm.

9. The pedicle screw having a prevention function according to claim 1, wherein, The nail body (2) is made of titanium alloy material.

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