Internal fixation nail applied to patella fracture closed reduction internal fixation

Abstract

The utility model provides an internal fixation nail applied to patella fracture closed reduction internal fixation, relates to the technical field of patella fracture surgical instruments, and solves the technical problem that a tension band is difficult to construct after nail placement. The internal fixation nail applied to patella fracture closed reduction internal fixation penetrates through patella from the coronal plane position to form patella internal fixation of fracture, and the internal fixation nail is of a segmented structure and comprises a head section, a middle section and a tail section which are detachably connected; and the head section and the tail section are respectively provided with a cavity for accommodating a high-strength cable, and the middle section is of a whole-section hollow structure, so that the high-strength cable can penetrate through the middle section conveniently. By adopting the segmented structure, the length of the middle section matched with the specification of the patella can be selected during use, and then the head section and the tail section are detached after the inner fixing nail penetrates through the patella, so that the cost of the inner fixing nail is saved, a tension band can be conveniently led out from a needle inlet position and a needle outlet position, and the operation process is greatly simplified.

Description

Technical Field

[0001] The utility model relates to the technical field of surgical instruments for patellar fractures, in particular to an internal fixation nail used for closed reduction and internal fixation of patellar fractures. Background Art

[0002] The patella is the largest sesamoid bone in the human body. It is located in front of the knee joint and has the function of protecting the knee joint. The quadriceps muscle is attached to the upper edge of the patella, and part of the fascia continues through the front of the patella as the patellar ligament, ending at the tibial tubercle. The patella plays a vital role in the movement of the human knee. For example, as the intermediate structure of the knee extensor, it transmits the tension generated by the quadriceps muscle to the patellar tendon; the patella acts as a lever when the knee is extended, which can effectively increase the lever arm of the knee extensor for the knee flexion and extension axis; the sliding of the patella on the femoral trochlear surface can also reduce the friction of the quadriceps muscle on the front of the lower end of the femur.

[0003] Patellar fracture is a common intra-articular fracture in clinical practice, which is more common in young and middle-aged people. It is often caused by violent contraction of the quadriceps femoris or direct impact. Patellar fracture involves the articular surface, and is often accompanied by tearing of the expanded part of the quadriceps femoris and intra-articular hematoma. It is prone to knee joint dysfunction and traumatic arthritis. The treatment of patellar fracture requires anatomical reduction, secure fixation and early functional exercise.

[0004] Minimally invasive surgery, represented by closed reduction and internal fixation, is the mainstream direction of surgical development today. Compared with traditional open surgery, closed reduction and internal fixation of patellar fractures causes less trauma to patients, less bleeding during surgery, faster recovery of knee joint function after surgery, and avoids the risk of poor wound healing or even infection caused by extensive stripping and destruction of soft tissue.

[0005] Tension band fixation is a classic principle of internal fixation of patellar fractures. By constructing a tension band, the tensile stress between the fracture ends can be converted into compressive stress, which is beneficial to increase the stability of the fracture ends and promote fracture healing. At present, the internal fixation nails used in clinical internal fixation of patellar fractures are mainly divided into two categories. One is a solid nail, including Kirschner wires, cortical bone screws, and breakable nails with threading holes at the tail end; the other is a hollow nail. After the solid nail is placed, the cable can be wrapped around the head and tail ends of the nail to complete the construction of the tension band. The hollow nail is to pass the cable through the cavity in the middle of the nail body to complete the construction of the tension band. However, whether it is a solid nail or a hollow nail, it is difficult to construct a tension band after the nail is placed. Either the skin flap on the back of the patella needs to be opened, or the soft tissue needs to be cut repeatedly during the closed reduction process to place the two ends of the cable in the ideal position to construct the tension band. Therefore, there is currently a lack of a simple and efficient means to conveniently construct a tension band while placing the nail. Utility Model Content

[0006] The utility model aims to provide an internal fixation nail used for closed reduction and internal fixation of patellar fractures, so as to solve the technical problem that it is difficult to construct a tension band after nail placement in the prior art.

[0007] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0008] The utility model provides an internal fixation nail for closed reduction and internal fixation of patellar fractures, which penetrates the patella from the coronal plane to form internal fixation of the fractured patella. The internal fixation nail is a segmented structure, including a head segment, a middle segment and a tail segment, wherein:

[0009] The head section, the middle section and the tail section are connected in a detachable manner.

[0010] Furthermore, the detachable connection between the head section, the middle section and the tail section is a threaded connection.

[0011] Furthermore, the number of the head section is one, the side facing the middle section is a hollow structure, a threaded section is arranged on the inner wall, and the side away from the middle section is a nail tip.

[0012] Furthermore, there is one tail section, the side facing the middle section is a hollow structure, a threaded section is provided on the outer wall of the tail section, and the side away from the middle section is a clamping section, the outer wall of which has a flat-angle cross-section design for easy clamping by a power drill.

[0013] Furthermore, the middle section is a completely hollow structure, and has a protruding section on the side of the middle section facing the head section, and a threaded section is arranged on the outer wall of the protruding section; a threaded section is arranged on the inner cavity wall of the middle section on the side facing the tail section.

[0014] Furthermore, there are several intermediate sections, and the length of each intermediate section is different.

[0015] Furthermore, the inner side of the threaded section in the inner cavity of the middle section has an inner hexagonal groove.

[0016] Furthermore, the rotation direction of the threads between the head section, the middle section and the tail section is the same as the rotation direction of the internal fixation nail when it is drilled.

[0017] Furthermore, the outer wall at the inner side of the protruding section of the middle section and the outer wall at the left end are respectively provided with thread sections with different pitches.

[0018] Furthermore, the pitch of the threaded section at the inner side of the protruding section of the middle section is greater than the pitch of the threaded section at the left end of the middle section.

[0019] The internal fixation nail used for closed reduction and internal fixation of patellar fractures provided by the utility model adopts a segmented structure. When in use, the length of the middle section that is compatible with the specifications of the patella can be selected. Then, after the internal fixation nail is passed through the patella, the head section and the tail section can be disassembled, which not only saves the cost of the internal fixation nail, but also makes it convenient to lead out the tension band from the needle entry and exit positions, greatly simplifying the surgical process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of the exploded structure of the internal fixation nail used for closed reduction and internal fixation of patellar fractures according to the utility model;

[0022] Figure 2 It is a cross-sectional view of one end of the middle section of an internal fixation nail used for closed reduction and internal fixation of patellar fractures according to the utility model.

[0023] In the figure, 3, internal fixing nail; 31, head section; 32, middle section; 33, tail section; 34, clamping section; 35, internal hexagonal groove; 4, high-strength cable. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the utility model.

[0025] like Figure 1 As shown, the utility model provides an internal fixation nail used for closed reduction and internal fixation of patellar fractures, which penetrates the patella from the coronal plane to form internal fixation of the fractured patella. In order to simplify the surgical procedure, a high-strength cable 4 is preset inside the internal fixation nail 3 to form a tension band structure under the skin of the dorsal side of the patella, so that the tensile stress on the dorsal side of the patella is converted into compressive stress between the fracture ends when the patient flexes the knee after surgery, thereby enhancing the fixation effect;

[0026] The internal fixation nail 3 can be drilled into the patella through the guide sleeve using a power drill to achieve internal fixation of the patella; specifically, the internal fixation nail 3 is a combined segmented structure, including a head segment 31, a middle segment 32 and a tail segment 33, and the head segment 31, the middle segment 32 and the tail segment 33 are connected in a detachable manner.

[0027] It should be noted here that the detachable connection methods include threaded connection methods, plug-in connection methods, snap-on connection methods, etc. In order to facilitate operation and ensure the connection strength, in this embodiment, the detachable connection method between the head section 31, the middle section 32 and the tail section 33 is a threaded connection method.

[0028] By adopting the threaded connection method, when the internal fixation nail 3 penetrates into the patella, the head section 31 and the tail section 33 are exposed to the outside of the patella and can be unscrewed and then wait for the next use, while the middle section 32 remains in the patella to fix the fracture fragment. Moreover, since the length of the middle section 32 matches the specifications of the patella, raw materials are saved and the surgical procedure is simplified.

[0029] In this embodiment, in order to save costs and increase the scope of application of the internal fixation nail 3, the number of removable head section 31 and tail section 33 is only one, while the number of middle sections 32 built into the patella is several, and the lengths of the several middle sections 32 can be different, so as to be suitable for fixation of patellas of different specifications for different people.

[0030] Specifically, the side of a head section 31 facing the middle section 32 is a hollow structure, with a threaded section on the inner wall, and the side away from the middle section 32 is a nail tip; it should be noted here that the hollow structure of the head section 31 can be a concave cavity with a certain depth, in which case the thickness of the head section 31 corresponding to the concave cavity is slightly larger; or a length of the head section 31 is a thin-walled hollow structure, in which case the thickness of the head section 31 corresponding to the thin-walled hollow structure is smaller. As for the form to be adopted, no specific limitation is made here, as long as the threaded section of the hollow structure can be threadedly connected with the middle section 32 and can be used to store one end of the high-strength cable 4, the depth of the hollow structure is not specifically limited.

[0031] The side of a tail section 33 facing the middle section 32 is a hollow structure, and a threaded section is provided on the outer wall of the tail section 33. The side away from the middle section 32 is a clamping section 34, and the outer wall of the cross section is a flat angle design to facilitate clamping of a power drill; the clamping section 34 has a groove structure.

[0032] It should be noted here that the hollow structure on the tail section 33 has a similar function to the hollow structure on the head section 31, and both need to accommodate the head end of the high-strength cable 4, but the hollow structure of the tail section 33 does not need to be provided with a threaded section, so its depth can be smaller than the depth of the hollow structure of the head section 31, but its form can adopt the structural form of the head section 31, which will not be repeated here.

[0033] Each intermediate section 32 is a whole hollow structure, and each intermediate section 32 has a protruding section on the side facing the head section 31, and the specifications of the protruding section are smaller than those of the intermediate section 32, thereby forming a step structure at the protruding section, and a threaded section is provided on the protruding section; the threaded section is used to be screwed with the threaded section on the inner wall of the hollow structure of the head section 31; that is, after the intermediate section 32 is connected to the head section 31, the protruding section of the intermediate section 32 is screwed into the hollow structure of the head section 31; a threaded section is provided on the inner cavity wall on the side of the intermediate section 32 facing the tail section, and the intermediate section 32 is screwed with the threaded section in the hollow structure on the tail section 33 through the threaded section in the inner cavity on this side.

[0034] It should be noted here that the hollow structure of the head section 31 and the hollow structure of the tail section 33 are a one-end cavity structure, and the cavity structure has two functions. One is to set the internal thread section to facilitate the threaded connection with the middle section 32, and the other is to accommodate the two ends of the high-strength cable 4, so that after the internal fixation nail 3 penetrates the patella, when the head section 31 and the tail section 33 are removed, the two ends of the cable can be exposed.

[0035] like Figure 2 As shown, in order to facilitate the removal of the middle section 32 using existing tools, the inner side of the threaded section in the inner cavity of the middle section 33 is provided with an inner hexagonal groove 35, through which the surgeon can use a universal hollow outer hexagonal screwdriver to further adjust the depth of the middle section of the internal fixation nail in the bone canal and remove the internal fixation nail after the fracture heals in the later stage.

[0036] In order to prevent the three sections from being separated during the drilling process of the internal fixing nail 3, in this embodiment, the rotation direction of the threads between the head section 31, the middle section 32 and the tail section 33 is the same as the rotation direction of the internal fixing nail 3 during the drilling process;

[0037] Furthermore, in order to pressurize the bone segments during the drilling process of the internal fixation nail 3, the outer wall of the inner side of the protruding section of the middle section 32 and the outer wall of the left end are respectively provided with thread segments with different pitches, so as to use the thread segments with different pitches to pressurize the fracture ends.

[0038] Specifically, the pitch of the threaded section on the outer wall at the left end of the middle section is smaller than the pitch of the threaded section on the outer wall on the inner side of the protruding section of the middle section 32, that is, the threaded section on the side of the middle section 32 close to the tail section 33 is a dense threaded section, while the threaded section on the side close to the head section 31 is a sparse threaded section.

[0039] The high-strength cable 4 is pre-set in the internal fixation nail 3, and both ends can be exposed outside the nail hole after the internal fixation nail 3 penetrates the patella;

[0040] The three parts of the head section 31, the middle section 32 and the tail section of the utility model can be connected by threads with the same direction, which we call matching threads. The tip of the head section 31 is similar to the Kirschner wire currently used in orthopedic operating rooms. The tail of the head section 31 of the internal fixation nail 3 (the side facing the middle section 32) is hollow, and has a matching thread matching the middle section 32 built in. The middle section 32 of the internal fixation nail 3 is also a hollow nail body, in which 1-2 high-strength cables of sufficient length are pre-installed for fixing the tension band 4 after the internal fixation nail 3 is implanted. The surface of the middle section 32 also has two sections of external threads distributed at the proximal end (the side facing the tail section 33) and the distal end (the side facing the head section 32) of the matching thread, and the pitch of the distal end is greater than the pitch of the proximal end, so that after being screwed into the bone channel, the nail body can apply pressure to the fracture end. The proximal inner wall of the middle section 32 (the inner cavity on the side of the middle section 32 facing the tail section 33) also has a section of matching thread that matches the matching thread of the tail section 33, such as Figure 1 As shown, an inner hexagonal groove is also provided on the inner side of the matching thread, so that the operator can use a universal hollow outer hexagonal screwdriver to further adjust the depth of the middle section of the internal fixation nail in the bone canal and remove the internal fixation nail after the fracture heals in the later stage. The tail section 33 of the internal fixation nail 3 is mainly the force-carrying part of the power drill, and its proximal end (the side away from the middle section 32) is solid, and the distal end (the side facing the middle section 32) is hollow. The inner wall of the distal end has a matching thread corresponding to the middle section 32, and the outer wall of the proximal end has a groove that is convenient for the power drill to clamp. The middle section 32 of the internal fixation nail 3 can be divided into multiple models according to different lengths, and the length can be selected and assembled according to the actual measured length during surgery.

[0041] When in use, the middle section of the internal fixation nail is selected according to the measured length of the patellar bone canal, and a complete internal fixation nail is assembled by matching threaded connection groups. During assembly, the high-strength cable is passed through the middle section, and then the two ends are respectively placed in the cavities of the head section and the tail section; then the assembled internal fixation nail is drilled along the guide sleeve of the coronal plane guide, and the drilling depth is determined by monitoring with a fluoroscopic machine; another internal fixation nail is inserted in parallel in the same way, and the spacing between the two internal fixation nails is 2-3cm; finally, the head section and tail section of the two internal fixation nails are reversely unscrewed, and the two ends of the tension band are pulled out of the skin incision. If necessary, the tail end of the high-strength cable is passed through a matching hollow external hexagonal screwdriver, and the hollow external hexagonal screwdriver is inserted into the internal hexagonal groove on the tail side of the middle section and rotated clockwise or counterclockwise, so that the middle section of the internal fixation nail is at an ideal depth in the bone canal.

[0042] The internal fixation nail used for closed reduction and internal fixation of patellar fractures provided by the utility model adopts a segmented structure. When in use, the length of the middle section that is compatible with the specifications of the patella can be selected. Then, after the internal fixation nail is passed through the patella, the head section and the tail section can be disassembled, which not only saves the cost of the internal fixation nail, but also makes it convenient to lead out the tension band from the needle entry and exit positions, greatly simplifying the surgical process.

[0043] First of all, it should be explained here that “inward” refers to the direction toward the center of the accommodating space, and “outward” refers to the direction away from the center of the accommodating space.

[0044] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate directions or positional relationships based on the attached Figure 1 The orientation or positional relationship shown is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0045] 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 at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0046] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0049] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. An internal fixation nail for closed reduction and internal fixation of patellar fractures, characterized in that: The patella is penetrated from the coronal plane to form an internal fixation of the fractured patella. The internal fixation nail is a segmented structure, including a head segment, a middle segment and a tail segment, wherein: The head section, the middle section and the tail section are connected in a detachable manner.

2. The internal fixation nail for closed reduction and internal fixation of patellar fracture according to claim 1, characterized in that: The detachable connection between the head section, the middle section and the tail section is a threaded connection.

3. The internal fixation nail for closed reduction and internal fixation of patellar fracture according to claim 2, characterized in that: The number of the head section is one, and the side facing the middle section is a hollow structure, a threaded section is arranged on the inner wall, and the side away from the middle section is a nail tip.

4. The internal fixation nail for closed reduction and internal fixation of patellar fracture according to claim 3, characterized in that: There is one tail section, and the side facing the middle section is a hollow structure. A threaded section is arranged on the outer wall of the tail section, and the side away from the middle section is a clamping section, and the outer wall of the cross section is a flat angle design, which is convenient for clamping with a power drill.

5. The internal fixation nail for closed reduction and internal fixation of patellar fracture according to claim 4, characterized in that: The middle section is a completely hollow structure, and has a protruding section on the side facing the head section, and a threaded section is arranged on the outer wall of the protruding section; a threaded section is arranged on the inner cavity wall on the side facing the tail section of the middle section.

6. The internal fixation nail for closed reduction and internal fixation of patellar fracture according to claim 5, characterized in that: There are several middle sections, and the length of each middle section is different.

7. The internal fixation nail for closed reduction and internal fixation of patellar fracture according to claim 5, characterized in that: The inner side of the threaded section in the inner cavity of the middle section is provided with an inner hexagonal groove.

8. The internal fixation nail for closed reduction and internal fixation of patellar fracture according to claim 2, characterized in that: The rotation direction of the threads between the head section, the middle section and the tail section is the same as the rotation direction of the internal fixation nail when it is drilled.

9. The internal fixation nail for closed reduction and internal fixation of patellar fracture according to claim 5, characterized in that: The outer wall at the inner side of the protruding section of the middle section and the outer wall at the left end are respectively provided with thread sections with different pitches.

10. The internal fixation nail for closed reduction and internal fixation of patellar fracture according to claim 9, characterized in that: The pitch of the threaded section at the inner side of the protruding section of the middle section is greater than the pitch of the threaded section at the left end of the middle section.

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