Minimally invasive bone cement hollow screw injection assembly

Abstract

The minimally invasive bone cement hollow screw injection assembly comprises a hollow screw provided with a bone cement extrusion hole in a screw rod, and is characterized by further comprising an inner sleeve inserted into an inner cavity of the head of the hollow screw in a butt joint mode, an outer sleeve sleeved on the inner sleeve in a guiding fit mode and a core ejecting rod penetrating through the inner sleeve in a guiding fit mode and stretching into the hollow screw; the outer sleeve sleeves the head of the hollow screw in a threaded fit mode. The inner sleeve extends upwards from the inner cavity of the head of the hollow screw to be conveniently in butt joint with an injector, the inner sleeve is supported and positioned through the outer sleeve, stability and reliability of butt joint of the inner sleeve and the hollow screw in the bone cement injection process are guaranteed, and bone cement in the inner sleeve and the hollow screw is extruded out through the ejector core rod. The injection amount of bone cement is increased, the operability and convenience of bone cement injection are improved, the injection amount requirement of osteoporosis patients is met, and practicability is high.

Description

Technical Field

[0001] The utility model relates to a minimally invasive bone cement hollow screw injection component, belonging to the technical field of orthopedic surgical instruments. Background Art

[0002] Osteoporosis (OP) is a disease in which bone density decreases, resulting in decreased bone strength, increased brittleness, and increased fracture risk. Osteoporosis patients have reduced bone density, decreased bone mass, and bone structure degeneration, which significantly reduces the fixation effect of fixation screws. The risk of screw loosening, screw removal, and loss of structural stability after surgery is significantly increased, and even leads to internal fixation failure. In addition to meeting the pressurized internal fixation function of conventional hollow screws, hollow screws that can be injected with bone cement can also fill bone cement into loose bones through the implantation hole to promote the closure and recovery of fracture cracks, and are suitable for osteoporotic fracture patients. Ordinary medical hollow screws are generally made of titanium. The length of small hollow screws is 20mm-60mm, and the length of large hollow screws is 50mm-110mm. After the hollow screws are implanted in human bones, injecting bone cement into the hollow screws has the following problems:

[0003] 1. After the hollow screw is implanted, the inner diameter of the hollow screw head is small and located deep in the soft tissue, which often cannot be seen directly, and it is inconvenient to dock the syringe with the hollow screw head.

[0004] 2. The amount of bone cement injected, the injection pressure, the patient's bone density, and the degree of damage are closely related. Syringe injection alone sometimes cannot meet the injection volume requirements of osteoporotic fracture patients. Utility Model Content

[0005] The utility model provides a minimally invasive bone cement hollow screw injection component, which uses an inner sleeve to extend the inner cavity of the head of the hollow screw upward to facilitate docking with a syringe, and supports and positions the inner sleeve through the outer sleeve to ensure the stability and reliability of the docking between the inner sleeve and the hollow screw during bone cement injection. The bone cement in the inner sleeve and the hollow screw is squeezed out by a core rod, thereby increasing the injection amount of bone cement, improving the operability and convenience of bone cement injection, and meeting the injection amount requirements of osteoporosis patients, with high practicality.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] A minimally invasive bone cement hollow screw injection assembly includes a hollow screw with a bone cement extrusion hole on the screw rod, and is characterized in that it also includes an inner sleeve that is inserted into the inner cavity of the head of the hollow screw, an outer sleeve that is guided and fitted on the inner sleeve, and a guide that passes through the inner sleeve and extends into a core rod in the hollow screw, and the outer sleeve is threaded and fitted on the head of the hollow screw.

[0008] Preferably, the inner cavity of the head is an inner hexagonal cavity with a regular hexagonal cross-section, and the bottom of the inner sleeve has an outer hexagonal convex ring that cooperates with the inner cavity of the head. The outer hexagonal convex ring is inserted into the inner cavity of the head, and the inner cavity of the outer hexagonal convex ring is cylindrical. The inner diameter of the outer hexagonal convex ring, the inner diameter of the inner sleeve and the inner diameter of the screw of the hollow screw are all equal, and the height of the outer hexagonal convex ring is 2~3mm.

[0009] Preferably, the top of the inner sleeve extends out of the outer sleeve and has an operating handle, and the top surface of the inner sleeve has a docking convex ring that can dock with the syringe, and the inner diameter of the docking convex ring is equal to the inner diameter of the inner sleeve.

[0010] Preferably, the head of the hollow screw has an external thread, the bottom of the outer sleeve has an internal thread matching the external thread, and the height of the inner sleeve is greater than the height of the outer sleeve.

[0011] Preferably, the top of the outer sleeve is provided with a rotating handle, the height of the core rod is greater than the sum of the height of the inner sleeve and the height of the hollow screw, and the top of the core rod is provided with a pressing round handle.

[0012] The beneficial effects of the utility model are:

[0013] The minimally invasive bone cement hollow screw injection component of the utility model, when used, first inserts the hollow screw into the bone body, and sleeves the outer sleeve on the inner sleeve, then the inner sleeve and the outer sleeve are in contact with the head of the hollow screw and the inner sleeve is pushed to dock and inserted into the inner cavity of the head of the hollow screw, and then the outer sleeve is rotated to thread the outer sleeve and the head of the hollow screw, and then the syringe is docked with the inner sleeve, and bone cement is injected into the inner sleeve, and the bone cement flows into the hollow screw through the inner sleeve and is squeezed out from the bone cement extrusion hole under the action of pressure, and after the bone cement in the syringe is completely injected into the inner sleeve, the syringe is removed, and then the bone cement in the inner sleeve and the hollow screw is pressed down by a core rod, so that the inner sleeve and the hollow screw are The bone cement in the hollow screw is squeezed out from the bone cement extrusion hole. After the bone cement injection is completed, the core rod, the inner sleeve and the outer sleeve are removed in sequence; the inner sleeve is used to extend the inner cavity of the head of the hollow screw upward to facilitate docking with the syringe, thereby improving the convenience of the bone cement injection operation; the outer sleeve is connected to the thread of the head of the hollow screw to position the outer sleeve on the hollow screw; the inner sleeve is supported and positioned by the outer sleeve to ensure the stability and reliability of the docking between the inner sleeve and the hollow screw during the bone cement injection process; the core rod is used to squeeze out the bone cement in the inner sleeve and the hollow screw to increase the injection amount of bone cement; the operability and convenience of bone cement injection are improved, and the injection amount requirements of osteoporosis patients are met, and the practicality is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the minimally invasive bone cement cannulated screw injection assembly while extruding bone cement.

[0015] Figure 2Schematic diagram of a hollow screw.

[0016] Figure 3 It is a cross-sectional view of the inner sleeve.

[0017] Figure 4 It is the front view of the inner sleeve.

[0018] Figure 5 Schematic diagram of the outer sleeve. DETAILED DESCRIPTION

[0019] Combine the following Figures 1 to 5 The embodiments of the utility model are described in detail.

[0020] The minimally invasive bone cement hollow screw injection assembly comprises a hollow screw 1 with a bone cement extrusion hole A formed on the screw rod, and is characterized in that it also comprises an inner sleeve 2 that is butt-jointed and inserted into the inner cavity 11 of the head of the hollow screw 1, an outer sleeve 3 that is guide-fitted and sleeved on the inner sleeve, and a core rod 4 that passes through the inner sleeve 2 and extends into the hollow screw 1, and the outer sleeve 3 is threadedly fitted on the head of the hollow screw 1.

[0021] The above-mentioned minimally invasive bone cement hollow screw injection assembly, when used, first inserts the hollow screw 1 into the bone body, and sleeves the outer sleeve 3 on the inner sleeve 2, then the inner sleeve 2 and the outer sleeve 3 are in contact with the head of the hollow screw 1 and the inner sleeve 2 is pushed to connect and insert into the inner cavity 11 of the head of the hollow screw 1, and then the outer sleeve 3 is rotated to thread the outer sleeve 3 with the head of the hollow screw 1, and then the syringe is connected with the inner sleeve 2, and bone cement is injected into the inner sleeve 2. The bone cement flows into the hollow screw 1 through the inner sleeve 2 and is squeezed out from the bone cement extrusion hole A under the action of pressure. After the bone cement in the syringe is completely injected into the inner sleeve 2, the syringe is removed, and then the core rod 4 is used to press down the bone cement in the inner sleeve 2 and the hollow screw 4 so that the inner sleeve 2 and the hollow The bone cement in the screw 4 is squeezed out from the bone cement extrusion hole A. After the bone cement injection is completed, the core rod 4, the inner sleeve 5 and the outer sleeve 3 are removed in sequence; the inner sleeve is used to extend the head cavity 11 of the hollow screw 1 upward, which is convenient for docking with the syringe and improves the convenience of bone cement injection operation; the outer sleeve 3 is connected with the thread of the head of the hollow screw 1 to position the outer sleeve 3 on the hollow screw 1, and the inner sleeve 2 is supported and positioned by the outer sleeve 3 to ensure the stability and reliability of the docking between the inner sleeve 2 and the hollow screw 1 during the bone cement injection process; the core rod 4 is used to squeeze out the bone cement in the inner sleeve 2 and the hollow screw 1 to increase the injection amount of bone cement; the operability and convenience of bone cement injection are improved, and the injection amount requirements of osteoporosis patients are met, which is highly practical.

[0022] The head cavity 11 is a hexagonal cavity with a regular hexagonal cross section. The bottom of the inner sleeve 2 has an outer hexagonal convex ring 21 that matches the head cavity. The outer hexagonal convex ring 21 is inserted into the head cavity 11. The inner cavity of the outer hexagonal convex ring 21 is cylindrical. The inner diameter of the outer hexagonal convex ring 21, the inner diameter of the inner sleeve 2 and the inner diameter of the screw of the hollow screw 1 are all equal. The height H of the outer hexagonal convex ring 21 is 2-3 mm. The head cavity 11 is a hexagonal cavity to facilitate the insertion of the hollow screw. The outer hexagonal convex ring 21 at the bottom of the inner sleeve 2 is inserted into the head cavity 11 to form a docking. The insertion and matching of the inner and outer hexagons prompts the operator that the inner sleeve 2 and the head cavity 11 are docked in place, so that the inner sleeve 2 can quickly form a docking with the head cavity 11. The outer hexagonal convex ring 21 plays a role in docking and anastomosis, improving the convenience of the docking operation. After the inner sleeve 2 is docked with the inner cavity 1 of the head, it is equivalent to extending the hollow screw 1 upward, which is convenient for docking with the syringe.

[0023] The top of the inner sleeve 2 extends out of the outer sleeve and has an operating handle 23. The top surface of the inner sleeve 1 has a docking protrusion 22 that can dock with the syringe. The inner diameter of the docking protrusion 22 is equal to the inner diameter of the inner sleeve 1. The docking protrusion 22 docks with the syringe, so that the inner sleeve 2 can be quickly docked with the syringe, improving the convenience of bone cement injection operation. The operating handle 23 facilitates the docking and insertion of the inner sleeve 2 and the head cavity 11, as well as the removal of the inner sleeve 2 after the bone cement injection is completed.

[0024] The head of the hollow screw 1 has an external thread 12, the bottom of the outer sleeve 3 has an internal thread matched with the external thread, and the height of the inner sleeve 2 is greater than the height of the outer sleeve 3. The outer sleeve 3 is sleeved on the inner sleeve 2, and the inner sleeve 2 can move on the outer sleeve 3, so that the bottom of the inner sleeve 2 extends out of the outer sleeve 3; after the inner sleeve 2 and the outer sleeve 3 are in contact with the head of the hollow screw 1, the inner sleeve 2 is pushed to make the outer hexagonal convex ring 21 docked and inserted into the inner cavity 11 of the head of the hollow screw 1, and then the outer sleeve 3 is rotated to connect the outer sleeve 3 with the head of the hollow screw 1, so that the outer sleeve 3 is sleeved on the head of the hollow screw 1, and the inner sleeve 2 forms a guide for the connection between the outer sleeve 3 and the hollow screw 1, and the outer sleeve 3 is connected to the hollow screw 1 to form a support and positioning for the inner sleeve 2, ensuring that the inner sleeve 2 will not be separated from or tilted from the hollow screw 1, so that the inner sleeve 2 and the hollow screw 1 can maintain stable and reliable docking during the bone cement injection process.

[0025] The top of the outer sleeve 3 has a rotating handle 32, the height of the core rod 4 is greater than the sum of the height of the inner sleeve 2 and the height of the hollow screw 1, and the top of the core rod 4 has a pressing round handle 41, which is convenient for the core rod 4 to be pressed downward and extracted upward. The core rod 4 is guided and matched with the inner sleeve 2, and the inner diameter of the outer hexagonal convex ring 21, the inner diameter of the inner sleeve 2 and the inner diameter of the screw of the hollow screw 1 are equal, so that the core rod 4 can pass through the inner sleeve 2 and be guided and matched to be inserted into the hollow screw 1, and the bone cement in the inner sleeve 2 and the hollow screw 1 is squeezed out. The core rod 4 can squeeze the bone cement in the hollow screw 1 down to the screw tip cone, and the amount of bone cement extruded in the hollow screw 1 can be determined according to the amount of bone cement required. The bone cement in the head cavity 11 is squeezed out, which is also convenient for the connection between the head cavity 11 and the hexagonal wrench when the hollow screw needs to be removed.

[0026] The above is a complete description of the technical solutions of the embodiments of the utility model in combination with the accompanying drawings. It should be noted that the described embodiments are only part of the embodiments of the utility model. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

Claims

1. A minimally invasive bone cement hollow screw injection assembly, comprising a hollow screw with a bone cement extrusion hole formed on the screw rod, characterized in that: It also includes an inner sleeve that is inserted into the inner cavity of the head of the hollow screw, an outer sleeve that is guided and fitted on the inner sleeve, and a core rod that passes through the inner sleeve and extends into the hollow screw, and the outer sleeve threadedly fits on the head of the hollow screw.

2. The minimally invasive bone cement hollow screw injection assembly according to claim 1, characterized in that: The inner cavity of the head is an inner hexagonal cavity with a regular hexagonal cross-section. The bottom of the inner sleeve has an outer hexagonal convex ring that cooperates with the inner cavity of the head. The outer hexagonal convex ring is inserted into the inner cavity of the head. The inner cavity of the outer hexagonal convex ring is cylindrical. The inner diameter of the outer hexagonal convex ring, the inner diameter of the inner sleeve and the inner diameter of the screw of the hollow screw are all equal. The height of the outer hexagonal convex ring is 2~3mm.

3. The minimally invasive bone cement hollow screw injection assembly according to claim 2, characterized in that: The top of the inner sleeve extends out of the outer sleeve and is provided with an operating handle. The top surface of the inner sleeve is provided with a butt joint convex ring which can be butt jointed with a syringe. The inner diameter of the butt joint convex ring is equal to the inner diameter of the inner sleeve.

4. The minimally invasive bone cement hollow screw injection assembly according to claim 2, characterized in that: The head of the hollow screw has an external thread, the bottom of the outer sleeve has an internal thread matched with the external thread, and the height of the inner sleeve is greater than the height of the outer sleeve.

5. The minimally invasive bone cement hollow screw injection assembly according to claim 2, characterized in that: The top of the outer sleeve is provided with a rotating handle, the height of the core rod is greater than the sum of the height of the inner sleeve and the height of the hollow screw, and the top of the core rod is provided with a pressing round handle.

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