Injectable screw fixation system for femoral neck fractures

Abstract

The application relates to an injectable screw fixing system for femoral neck fracture, which comprises a screw, a hollow guide rod and a double-channel high-pressure injection device. The screw comprises a screw body and a screw seat. A central through hole is arranged in the screw body. An outer screw thread is arranged on the outer wall of the front section or the whole section of the screw body. A side hole communicating with the central through hole is arranged on the side wall of the front section of the screw body. The screw seat is integrally connected to the tail end of the screw body. A polygonal hole is arranged in the screw seat. An outer screw thread is arranged on the outer periphery of the screw seat. The front end of the hollow guide rod is provided with an inner guide rod thread. The rear end of the hollow guide rod is provided with an outer guide rod thread. The double-channel high-pressure injection device comprises a three-way connector and two high-pressure injectors. The three-way connector has two inlets and one outlet. The two inlets are respectively connected to the two high-pressure injectors. A control valve is arranged on the three-way connector. The outlet is used for being connected to the rear end of the hollow guide rod. The application can effectively inject therapeutic liquid into the fracture site, practically solves the clinical technical obstacles and improves the operation effect.

Description

TECHNICAL FIELD

[0001] The present application relates to orthopedic instruments, in particular to an injectable screw fixation system for femoral neck fracture, and belongs to the technical field of medical instruments. BACKGROUND

[0002] Femoral neck fracture is a common injury in orthopedic clinic. The mechanical characteristics of femoral neck and the anatomical particularity of blood supply of femoral head lead to the occurrence of femoral head necrosis and nonunion after femoral neck fracture surgery. During surgery, doctors often choose appropriate implants according to the type of fracture and individual conditions of patients. The commonly used fixation methods include the use of multiple cannulated screws, compression screws, dynamic hip screws and lateral plate complexes.

[0003] However, no matter what method is used for treatment, the occurrence of nonunion and avascular necrosis of the femoral head after surgery has always plagued clinicians. Studies have reported that the incidence of avascular necrosis of the femoral head is as high as 10% to 43%. Once avascular necrosis of the femoral head occurs, it will cause hip pain and dysfunction, and in some cases, a second joint replacement surgery is required, which brings heavy burden to the patient's psychology and economy. So far, scholars have tried to use new means to reduce the occurrence of complications such as femoral head necrosis, but the actual effect is not good.

[0004] Through research and analysis, the root cause of femoral head necrosis after femoral neck fracture surgery is the loss of blood supply to the femoral head, so the key to treatment is how to improve the blood supply. Some scholars use blood-supplied periosteal transplantation to reconstruct the blood supply system of the femoral head to improve the blood supply of the femoral head. The introduction of blood-supplied periosteal transplantation to the necrotic area of the femoral head has the dual effects of osteogenesis and vascular reconstruction. In recent years, two types of technologies, assisted autologous stem cell transplantation and assisted platelet-rich plasma, have been proven to have certain efficacy in reducing postoperative femoral head necrosis. The healing of fracture is mainly due to the role of bone marrow stromal stem cells in bone marrow, but the content of bone marrow stromal stem cells in bone marrow is very low, and a large amount of bone marrow is needed to obtain sufficient cell amount. Platelet-rich plasma is a concentrated platelet material obtained by centrifugation of autologous whole blood. After activation by thrombin, platelet-rich plasma can activate and release platelet-derived growth factor, transforming growth factor beta, vascular endothelial growth factor, insulin-like growth factor and epidermal growth factor, etc., and plays an important role in the repair of soft tissue and bone diseases. However, the difficulty in the clinical treatment process of these two types of technology is that the obtained stem cells or platelet-rich plasma cannot be effectively injected into the fracture site to directly and fully exert the repair effect. SUMMARY

[0005] The present application aims to overcome the clinical treatment problems in the prior art, and provides an injectable screw fixing system for femoral neck fracture, which is ingenious in structure, reasonable in design, can effectively inject a treatment liquid (stem cells or platelet-rich plasma) into a fracture site, practically solves the clinical technical obstacles, and improves the operation effect.

[0006] According to the technical scheme provided by the present application, the injectable screw fixing system for femoral neck fracture comprises a screw, a hollow guide rod and a double-channel high-pressure injection device, the screw comprises a screw body and a screw seat, the screw body is arranged in a bone, a central through hole is arranged in the screw body, an outer thread is arranged on the outer wall of the front section or the whole section of the screw body, and a side hole communicating with the central through hole is arranged on the side wall of the front section of the screw body; the screw seat is integrally connected to the tail end of the screw body, a polygonal hole for connecting a screwdriver is arranged in the screw seat, and an outer thread for connecting the hollow guide rod is arranged on the outer periphery of the screw seat; the front end of the hollow guide rod is provided with a guide rod inner thread matched with the screw seat outer thread, and the rear end of the hollow guide rod is provided with a guide rod outer thread; the double-channel high-pressure injection device comprises a three-way connector and two high-pressure syringes, the three-way connector has two inlets and one outlet, the two inlets are respectively connected to the two high-pressure syringes, a control valve for controlling the flow direction of the liquid is arranged on the three-way connector, and the outlet is used for threadedly connecting with the rear end of the hollow guide rod.

[0007] As a further improvement of the present application, the front end of the hollow guide rod is provided with a protruding extension rod, and the outer diameter of the extension rod is matched with the inner diameter of the central through hole.

[0008] As a further improvement of the present application, the polygonal hole in the screw seat is a hexagonal hole or a square hole.

[0009] As a further improvement of the present application, the inlet of the three-way connector is provided with a butt joint pipe for extending into the hose end of the high-pressure syringe and a locking nut for locking the hose end.

[0010] As a further improvement of the present application, the outlet of the three-way connector is provided with a locking nut which can rotate but cannot fall off from the outlet, and the inner peripheral wall of the locking nut is provided with a connecting inner thread matched with the guide rod outer thread of the rear end of the hollow guide rod.

[0011] Compared with the prior art, the present application has the following advantages:

[0012] 1) This invention has an ingenious structure and reasonable design. Through the connection and cooperation of the screw, hollow guide rod and dual-channel high-pressure injection device, the therapeutic liquid can be injected from the side hole at the front of the screw. After injection, the therapeutic liquid spreads evenly in all directions, and the amount of injected liquid can be controlled sequentially and precisely. It is particularly suitable for the surgical treatment of femoral neck fractures. After the liquid bone wax or polymethyl methacrylate enters the central through hole of the screw, it changes from liquid to solid in a short time, which can seal the screw hole and prevent the therapeutic liquid from flowing out. It has excellent clinical application performance, can effectively solve clinical technical obstacles, improve surgical efficacy and reduce the incidence of femoral head necrosis.

[0013] 2) The screws, hollow guide rods and three-way connectors in this invention are all connected by threads, which can ensure that no leakage occurs when liquid is injected under high pressure, and has good reliability.

[0014] 3) The hollow guide rod in this invention has a protruding extension rod at the front end. The outer diameter of the extension rod matches the inner diameter of the central through hole. When the rear end of the screw is connected to the front end of the hollow guide rod, the extension rod is first inserted into the central through hole, which facilitates the precise connection between the hollow guide rod and the screw. In addition, it also helps to improve the sealing of the connection between the two, further ensuring that no leakage occurs when high-pressure liquid is injected. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention.

[0016] Figure 2 This is an enlarged schematic diagram of the screw structure in an embodiment of the present invention.

[0017] Figure 3 This is an enlarged schematic diagram of the hollow guide rod in an embodiment of the present invention.

[0018] Figure 4 This is an enlarged schematic diagram of the three-way connector in an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached diagram: 1-Screw, 1a-Nail body, 1b-Nail seat, 1c-Central through hole, 1d-Nail external thread, 1e-Side hole, 1f-Polygonal hole, 1g-Nail seat external thread, 2-Hollow guide rod, 2a-Guide rod internal thread, 2b-Guide rod external thread, 2c-Extension rod, 3-T-connector, 3a-Inlet, 3b-Outlet, 3c-Control valve, 3d-Connecting pipe, 3e-Locking nut, 3f-Locking nut, 4-High-pressure injector. Detailed Implementation

[0020] The present invention will be further described below with reference to specific accompanying drawings and embodiments.

[0021] like Figure 1As shown, the embodiment discloses an injectable screw fixing system for femoral neck fracture, which comprises a screw 1, a hollow guide rod 2 and a double-channel high-pressure injection device. The screw 1 comprises a shank 1a and a seat 1b. The shank 1a is arranged to be inserted into a bone. A central through hole 1c is arranged in the shank 1a. An outer thread 1d is arranged on the outer wall of the shank 1a. A side hole 1e is arranged on the side wall of the front section of the shank 1a and is in communication with the central through hole 1c. The seat 1b is integrally connected to the tail end of the shank 1a. A polygonal hole 1f is arranged in the seat 1b for connecting a screwdriver. An outer thread 1g is arranged on the outer periphery of the seat 1b for connecting the hollow guide rod 2. The front end of the hollow guide rod 2 is provided with a guide rod inner thread 2a matched with the seat outer thread 1g. The rear end of the hollow guide rod 2 is provided with a guide rod outer thread 2b. The double-channel high-pressure injection device comprises a three-way connector 3 and two high-pressure syringes 4. The three-way connector 3 has two inlets 3a and one outlet 3b. The two inlets 3a are respectively connected to the two high-pressure syringes 4. A control valve 3c is arranged on the three-way connector 3 for controlling the flow direction of the liquid. The outlet 3b is used for threaded connection with the rear end of the hollow guide rod 2.

[0022] During surgery, the screw 1 is screwed into the fixed fracture site by using a screwdriver. Then, the front end of the hollow guide rod 2 is tightly connected to the seat 1b of the screw 1 through the cooperation of the seat outer thread 1g and the guide rod inner thread 2a. The rear end of the guide rod is tightly connected to the outlet 3b end of the three-way connector 3 through the guide rod outer thread 2b. The two inlets 3a of the three-way connector 3 are respectively connected to the two high-pressure syringes 4. One of the high-pressure syringes 4 contains a therapeutic liquid (stem cells or platelet-rich plasma), and the other high-pressure syringe 4 contains liquid bone wax or polymethyl methacrylate. During use, one of the high-pressure syringes 4 is used to pump in the therapeutic liquid, and then the other high-pressure syringe 4 is used to pump in the liquid bone wax or polymethyl methacrylate. After the therapeutic liquid enters the internally hollow screw 1, it can be uniformly diffused to the surrounding area through the side hole 1e. The sequential and precise control of the liquid volume can be achieved, which is particularly suitable for the surgical treatment of femoral neck fracture and has excellent clinical application performance. After the liquid bone wax or polymethyl methacrylate enters the central through hole 1c of the screw 1, it changes from liquid to solid in a short time, which plays a role in plugging the screw hole and preventing the therapeutic liquid from flowing out. The control valve 3c on the three-way connector 3 controls the flow direction of the liquid during treatment. Since the screw 1, the hollow guide rod 2 and the three-way connector 3 are connected through threads, it can be ensured that there is no leakage when high-pressure injection of the liquid is performed, and the reliability is good.

[0023] As shown in the figure, Figure 1 , Figure 3As shown, in this embodiment, the hollow guide rod 2 has a protruding extension rod 2c at its front end, and the outer diameter of the extension rod 2c matches the inner diameter of the central through hole 1c. With this configuration, when the rear end of the screw 1 is connected to the front end of the hollow guide rod 2, the extension rod 2c is first inserted into the central through hole 1c, facilitating precise connection between the hollow guide rod 2 and the screw 1. Furthermore, this configuration improves the sealing of the connection, further ensuring no leakage occurs during high-pressure liquid injection.

[0024] like Figure 1 , Figure 2 As shown, in this embodiment, the polygonal hole 1f inside the screw base 1b is an internal hexagonal hole, which facilitates connection with a screwdriver during surgery, making it convenient to insert the screw 1 to fix the fracture site during the operation. Of course, the polygonal hole 1f can also be set as a square hole, etc., as long as it can match the front end of the screwdriver. In addition, the screw body 1a in this embodiment has a fully threaded structure [the entire outer wall has an external screw thread 1d]. In actual use, the screw body 1a can also be a semi-threaded structure [only the outer wall of the front section has an external screw thread 1d].

[0025] like Figure 1 , Figure 4 As shown, in this embodiment, the inlet 3a of the three-way connector 3 is provided with a connecting tube 3d for inserting into the end of the hose 5 of the high-pressure injector 4 and a locking nut 3e for locking the end of the hose 5. With this configuration, during use, the end of the hose 5 of the high-pressure injector 4 is first sleeved onto the connecting tube 3d and pushed inward into the locking nut 3e, and then the locking nut 3e is tightened. This ensures a safe and reliable sealed connection between the hose 5 of the high-pressure injector 4 and the three-way connector 3.

[0026] like Figure 1 , Figure 4 As shown, in this embodiment, the outlet 3b of the three-way connector 3 is provided with a locking nut 3f that can rotate freely but cannot be dislodged from the outlet 3b. The inner circumferential wall of the locking nut 3f is provided with a connecting internal thread that matches the external thread 2b of the guide rod at the rear end of the hollow guide rod 2. With this configuration, since the locking nut 3f can rotate freely, it is only necessary to tighten the locking nut 3f to achieve a sealed connection with the rear end of the hollow guide rod 2, without needing to flip the three-way connector 3, making the operation very convenient.

[0027] In addition, the high-pressure injector 4 in this invention can be a conventional product in the prior art, as long as it has the ability to output liquid at high pressure, which will not be described in detail here.

[0028] The above description is merely a preferred embodiment of the present invention, and the specific embodiments described above are not intended to limit the present invention. Various modifications and variations can be made within the scope of the technical concept of the present invention. All refinements, modifications, or equivalent substitutions made by those skilled in the art based on the above description are within the scope of protection of the present invention.

Claims

1. An injectable screw fixation system for femoral neck fractures, comprising a screw (1) and a hollow guide rod (2), wherein the screw (1) comprises a screw body (1a) and a screw seat (1b), the screw body (1a) being inserted into the bone, the screw body (1a) having a central through hole (1c) inside, the outer wall of the front section or the entire section of the screw body (1a) having an external screw thread (1d), and the side wall of the front section of the screw body (1a) having a side hole (1e) communicating with the central through hole (1c); the screw seat (1b) being integrally connected to the tail end of the screw body (1a), the screw seat (1b) having a polygonal hole (1f) inside for connecting a screwdriver, and the outer periphery of the screw seat (1b) having an external screw seat thread (1g) for connecting the hollow guide rod (2); the front end of the hollow guide rod (2) having a guide rod internal thread (2a) matching the external screw seat thread (1g), characterized in that: The injectable screw fixing system also includes a dual-channel high-pressure injection device, which includes a three-way connector (3) and two high-pressure injectors (4). The three-way connector (3) has two inlets (3a) and one outlet (3b). The two inlets (3a) are respectively connected to the two high-pressure injectors (4). The three-way connector (3) is provided with a control valve (3c) to control the flow of liquid. One of the high-pressure injectors (4) contains therapeutic stem cells or platelet-rich plasma, and the other high-pressure injector (4) contains liquid bone wax or polymethyl methacrylate. When in use, one of the high-pressure injectors (4) first pumps in the therapeutic liquid, and then the other high-pressure injector (4) pumps in the liquid bone wax or polymethyl methacrylate. The liquid bone wax or polymethyl methacrylate is used to seal the central through hole (1c) of the screw (1) to prevent the therapeutic liquid from flowing out. The hollow guide rod (2) has an external thread (2b) at its rear end. The outlet (3b) is used to connect with the threaded rear end of the hollow guide rod (2).

2. The injectable screw fixation system for femoral neck fractures as described in claim 1, characterized in that: The hollow guide rod (2) has a protruding extension rod (2c) at its front end, and the outer diameter of the extension rod (2c) matches the inner diameter of the central through hole (1c).

3. The injectable screw fixation system for femoral neck fractures as described in claim 1, characterized in that: The polygonal hole (1f) inside the nail seat (1b) is an internal hexagonal hole or a square hole.

4. The injectable screw fixation system for femoral neck fractures as described in claim 1, characterized in that: The inlet (3a) of the three-way connector (3) is provided with a connecting tube (3d) for inserting into the end of the hose (5) of the high-pressure injector (4) and a locking nut (3e) for locking the end of the hose (5).

5. The injectable screw fixation system for femoral neck fractures as described in claim 1, characterized in that: The outlet (3b) of the three-way connector (3) is provided with a locking nut (3f) that can rotate freely but cannot be dislodged from the outlet (3b). The inner circumferential wall of the locking nut (3f) is provided with a connecting internal thread that matches the guide rod external thread (2b) at the rear end of the hollow guide rod (2).

Images