Nail rod fixing device for thoracolumbar posterior approach

Abstract

The utility model discloses a nail rod fixing device for thoracolumbar posterior approach, relates to the thoracolumbar surgery technical field, including connecting nail and nail rod, the nail rod is used for connecting a plurality of connecting nail together, including connecting nail including screw body, screw cap, expansion compression ring and expansion nail, the head of screw body is spherically articulated with the screw cap, and the screw rod is connected with the expansion nail. A circular groove is formed in the end, away from the screw body, of the screw cap, a mounting groove is formed in the side wall of the screw cap in a penetrating mode, the screw rod penetrates through the mounting groove, the expansion pressing ring is arranged in the circular groove and tightly presses the screw rod, the expansion screw penetrates into the expansion pressing ring, the expansion screw is used for making the expansion pressing ring expand to abut against the inner wall of the circular groove, and the fixing strength of the screw rod is enhanced; and the situations of loosening and sliding are not easy to occur.

Description

Technical Field

[0001] The utility model relates to the technical field of thoracolumbar vertebrae surgery, in particular to a nail-rod fixing device for posterior thoracolumbar vertebrae. Background Art

[0002] Thoracolumbar injuries primarily involve damage to structures such as bones, ligaments, and intervertebral discs, and the resulting damage to the spinal cord and nerves. Due to anatomical changes, T11 and T12 lack the manubrium in front of the sternum and are flanked by free ribs, making them less stable than other thoracic vertebrae. Furthermore, the thoracic spine exhibits a kyphotic curve, while the lumbar spine exhibits a lordotic curve, which can easily cause downward transmission of spinal forces. Generally speaking, fractures between T12 and L2 account for 60% of spinal fractures, while fractures between T11 and L4 account for 90%. Therefore, thoracic and lumbar fractures generally refer to fractures between T11 and L4. Severe thoracic and lumbar injuries require fixation with a fixation device driven into the bone. Current fixation devices utilize multiple screws driven into the bone, connected by rods to maintain screw position and correct the injury. However, these rods are currently attached to the screws using only crimping. Postoperative movement can lead to loosening or slipping of the rods, compromising fixation effectiveness and, in severe cases, causing injury to the patient. Utility Model Content

[0003] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a nail-rod fixing device for the posterior thoracic and lumbar spine, which strengthens the fixing strength of the nail-rod and is less likely to loosen or slide.

[0004] The purpose of the utility model is achieved through the following technical solutions: A nail-rod fixing device for the posterior thoracic and lumbar spine, comprising a connecting nail and a nail rod, the nail rod being used to connect multiple connecting nails together, comprising a connecting nail including a screw body, a nail cap, an expansion pressure ring and an expansion nail, the head of the screw body being spherically hinged to the nail cap, a circular groove being provided at one end of the nail cap away from the screw body, a mounting groove being provided through the side wall of the nail cap, the nail rod passing through the mounting groove, the expansion pressure ring being arranged in the circular groove and pressing the nail rod, the expansion nail being inserted into the expansion pressure ring, and the expansion nail being used to cause the expansion pressure ring to expand and press against the inner wall of the circular groove.

[0005] Furthermore, the outer wall of the expansion pressure ring is provided with an external thread, the inner wall of the circular groove is provided with an internal thread, and the expansion pressure ring thread is adapted to fit within the circular groove.

[0006] Furthermore, a plurality of expansion slots are formed on the side wall of the expansion pressure ring along its circumferential direction. The expansion slots extend in the axial direction of the expansion pressure ring, and one end of the expansion slots extends to the bottom of the expansion pressure ring.

[0007] Furthermore, a hexagonal inner groove is formed at one end of the expansion pressure ring away from the screw body.

[0008] Furthermore, a threaded hole and an expansion hole are sequentially opened in the hexagonal groove along the axial direction of the expansion pressure ring, the diameter of the expansion hole gradually decreases in the direction away from the threaded hole, the maximum diameter of the expansion hole is equal to the diameter of the threaded hole, the expansion nail thread is adapted to the threaded hole, and the tail of the expansion nail is inserted into the expansion hole to cause the expansion pressure ring to expand.

[0009] Furthermore, a spherical groove is formed through the nail cap, the spherical groove is coaxially arranged with the circular groove, a sphere is fixed to the head of the screw body, and the sphere is movably adapted to the spherical groove.

[0010] Furthermore, a cross-shaped groove is formed at one end of the sphere away from the screw body.

[0011] The beneficial effects of the utility model are:

[0012] The nail rod is pressed into the circular groove by the expansion pressure ring, and then the expansion nail is screwed into the expansion pressure ring. The expansion nail causes the expansion pressure ring to expand, so that the expansion pressure ring is pressed tightly into the circular groove, thereby strengthening the connection strength between the expansion pressure ring and the nail cap. When the nail rod moves, the expansion pressure ring is squeezed to move. When the connection strength of the expansion pressure ring is improved, the restriction strength of the nail rod is indirectly improved, so that the nail rod is not easy to slide, and has better fixing strength and safety in use. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the internal structure of a connecting nail in a nail-rod fixation device for posterior thoracic and lumbar spine according to the present invention;

[0014] Figure 2 This is a schematic structural diagram of an expansion pressure ring in a nail-rod fixation device for posterior thoracic and lumbar spine according to the present invention;

[0015] Figure 3 This is a schematic diagram of the connection of a nail-rod fixation device for the posterior thoracic and lumbar spine according to the present invention;

[0016] In the figure, 1-connecting nail, 2-nail rod, 3-screw body, 4-nail cap, 5-expansion pressure ring, 6-expansion nail, 7-circular groove, 8-expansion joint, 9-hexagonal groove, 10-threaded hole, 11-expansion hole, 12-spherical groove, 13-sphere. DETAILED DESCRIPTION

[0017] like Figures 1 to 3The nut 1 is screwed in place by the screw cap 4 and the screw cap 4 is screwed in place by the screw cap 4. The nail cap 4 and the screw body 3 are designed to be spherically hinged, which can arbitrarily deflect the angle of the nail cap 4, and then the nail rod 2 is bent accordingly at the positions corresponding to multiple nail caps 4, so that the nail rod 2 can pass through the installation grooves of multiple nail caps 4 at the same time, and then the expansion pressure ring 5 is screwed into the circular groove 7, and the nail rod 2 is pressed into the circular groove 7 by the expansion pressure ring 5. The threaded method is used to facilitate the connection between the expansion pressure ring 5 and the nail cap 4. However, the threaded method easily causes the expansion pressure ring 5 to loosen, thereby causing the nail rod 2 to slide. Therefore, the expansion nail 6 is screwed into the expansion pressure ring 5, and the expansion pressure ring 5 is expanded by the expansion nail 6, so that the expansion pressure ring 5 is pressed against the circular groove 7, thereby strengthening the connection strength between the expansion pressure ring 5 and the nail cap 4. When the nail rod 2 moves, the expansion pressure ring 5 is squeezed to move. When the connection strength of the expansion pressure ring 5 is improved, the restriction strength on the nail rod 2 is indirectly improved, making the nail rod 2 less likely to slide, and having good fixing strength and safety in use.

[0018] Furthermore, an inner hexagonal slot 9 is provided at one end of the expansion pressure ring 5 away from the screw body 3. The expansion pressure ring 5 can be screwed into the nail cap 4 by using a hexagonal wrench to act on the inner hexagonal slot 9, which facilitates operation and disassembly.

[0019] Furthermore, if Figure 1 and Figure 2As shown, the side wall of the expansion pressure ring 5 is provided with a plurality of expansion seams 8 along its own circumferential direction, the expansion seams 8 extending toward the axial direction of the expansion pressure ring 5, and one end of the expansion seam 8 extending to the bottom of the expansion pressure ring 5, the inner hexagonal groove 9 is provided with a threaded hole 10 and an expansion hole 11 in sequence along the axial direction of the expansion pressure ring 5, the diameter of the expansion hole 11 gradually decreases in the direction away from the threaded hole 10, the maximum diameter of the expansion hole 11 is equal to the diameter of the threaded hole 10, the expansion nail 6 is threadedly adapted to the threaded hole 10, and the tail of the expansion nail 6 penetrates the expansion hole 11 The expansion pressure ring 5 expands, and the expansion nail 6 is gradually screwed into the threaded hole 10. The tail of the expansion nail 6 penetrates into the expansion hole 11. Since the diameter of the expansion hole 11 is smaller than the diameter of the expansion nail 6, the expansion nail 6 squeezes the expansion pressure ring 5 to cause deformation, so that the expansion pressure ring 5 is pressed tightly against the circular groove, strengthening the engagement of the thread, improving the connection strength, and preventing the expansion pressure ring 5 from loosening, thereby strengthening the clamping effect on the nail rod 2; the setting of the expansion joint 8 weakens the strength of the expansion pressure ring 5, making the expansion pressure ring 5 easily squeezed and deformed.

[0020] Furthermore, if Figure 1 As shown, a spherical groove 12 is provided on the nail cap 4, and the spherical groove 12 is coaxially arranged with the circular groove 7. A sphere 13 is fixed to the head of the screw body 3, and the sphere 13 is movably adapted to the spherical groove 12. A cross groove is provided on the end of the sphere 13 away from the screw body 3. The tail of the screw body 3 is passed through the circular groove 7 and out of the spherical groove 12, so that the sphere 13 is adapted to the spherical groove 12 to form a spherical hinge. The screw body 3 is then rotated through the cross groove to screw the screw body 3 into the bone. Then, the nail rod 2 passes through the circular groove 7 through the mounting groove, and finally, the expansion pressure ring 5 is screwed in. Under the action of the expansion pressure ring 5, the nail rod 2 is pressed between the sphere 13 and the expansion pressure ring 5. Finally, the expansion nail 6 is used to expand the expansion pressure ring 5 to strengthen the connection strength, thereby effectively avoiding the nail rod from sliding in the later stage.

Claims

1. A nail-rod fixation device for posterior thoracic and lumbar spine, comprising a connecting nail (1) and a nail rod (2), wherein the nail rod (2) is used to connect a plurality of the connecting nails (1) together, and is characterized in that: The invention comprises a connecting nail (1) comprising a screw body (3), a nail cap (4), an expansion pressure ring (5) and an expansion nail (6), wherein the head of the screw body (3) is spherically hinged to the nail cap (4), a circular groove (7) is provided at one end of the nail cap (4) away from the screw body (3), a mounting groove is provided through the side wall of the nail cap (4), the nail rod (2) passes through the mounting groove, the expansion pressure ring (5) is arranged in the circular groove (7) and presses the nail rod (2), the expansion nail (6) penetrates into the expansion pressure ring (5), and the expansion nail (6) is used to make the expansion pressure ring (5) expand and press against the inner wall of the circular groove (7).

2. A nail-rod fixation device for posterior thoracic and lumbar spine according to claim 1, characterized in that: The outer wall of the expansion pressure ring (5) is provided with an external thread, the inner wall of the circular groove (7) is provided with an internal thread, and the thread of the expansion pressure ring (5) is adapted to fit within the circular groove (7).

3. The nail-rod fixation device for posterior thoracic and lumbar spine according to claim 1, characterized in that: The side wall of the expansion pressure ring (5) is provided with a plurality of expansion slits (8) along its own circumferential direction, the expansion slits (8) extending in the axial direction of the expansion pressure ring (5), and one end of the expansion slit (8) extending to the bottom of the expansion pressure ring (5).

4. The nail-rod fixation device for posterior thoracic and lumbar spine according to claim 1, characterized in that: An inner hexagonal groove (9) is formed on one end of the expansion pressure ring (5) away from the screw body (3).

5. The nail-rod fixation device for posterior thoracic and lumbar spine according to claim 4, characterized in that: A threaded hole (10) and an expansion hole (11) are sequentially provided in the hexagonal inner groove (9) along the axial direction of the expansion pressure ring (5). The diameter of the expansion hole (11) gradually decreases in a direction away from the threaded hole (10). The maximum diameter of the expansion hole (11) is equal to the diameter of the threaded hole (10). The thread of the expansion nail (6) is adapted to the threaded hole (10), and the tail of the expansion nail (6) penetrates into the expansion hole (11) to cause the expansion pressure ring (5) to expand.

6. The nail-rod fixation device for posterior thoracic and lumbar spine according to claim 1, characterized in that: A spherical groove (12) is formed through the nail cap (4), and the spherical groove (12) is coaxially arranged with the circular groove (7). A sphere (13) is fixed to the head of the screw body (3), and the sphere (13) is movably adapted to fit in the spherical groove (12).

7. The nail-rod fixation device for posterior thoracic and lumbar spine according to claim 6, characterized in that: A cross-shaped groove is formed at one end of the sphere (13) away from the screw body (3).

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