Fixing screw capable of being implanted into lumbosacroiliac joint

Abstract

The utility model discloses an implantable lumbosacroiliac joint fixing screw, and relates to the technical field of medical instruments. In order to solve the problem that no special internal fixing device for recovering the stability of the pelvic posterior ring and the lumbar iliac area of a patient exists in the prior art, the following technical scheme is provided: the internal fixing device comprises a screw body and a joint locking piece movably connected to the screw body, and a first external thread is arranged at the front end of the screw body; a plurality of self-tapping grooves are formed in the outer end of the first external thread in the circumferential direction, a bone grafting cavity penetrating through the screw body is formed in the middle of the screw body, and the joint locking piece is arranged in the bone grafting cavity. The joint locking piece comprises a base, supporting rods and locking ends, the base is connected to the rear end of the bone grafting cavity, the supporting rods are symmetrically arranged on the base, and the locking ends are arranged at the tops of the supporting rods and extend towards the two ends of the supporting rods. The utility model has the advantages of small trauma, small intraoperative bleeding, short operation time, relatively simple operation, fast postoperative recovery and satisfactory biomechanical strength.

Description

Technical Field

[0001] The utility model relates to the technical field of medical instruments, in particular to an implantable lumbar sacroiliac joint fixing screw. Background Art

[0002] The sacrum and the area around the sacroiliac joint are the most common sites of bone and soft tissue tumors. Among sacral tumors, metastatic tumors and giant cell tumors of bone are the most common, followed by neurogenic tumors and chordomas. For malignant tumors involving the area around the sacroiliac joint, extensive resection or marginal resection is the most important principle to reduce the recurrence rate of the disease, while thorough curettage is the principle of surgical treatment for invasive tumors or metastatic cancer. However, whether the sacroiliac joint is removed in one piece or by curettage, it will inevitably cause the integrity of the posterior pelvic ring to be destroyed, affecting the pelvic load-bearing arch to transfer the weight of the trunk when standing or sitting, and then affecting the stability of the pelvic ring, causing serious limb dysfunction or even disability in patients with sacral tumors. Since sacral tumor patients involve a variety of populations, including children, young adults and elderly patients, this also brings great mental and economic burdens to their families and society.

[0003] In addition to sacral tumors, another important disease that affects pelvic stability is pelvic fractures and sacroiliac joint separation caused by high-energy violence. Common high-energy violent injuries include traffic injuries, earthquake injuries, and mining accidents. Pelvic fractures caused by high-energy traffic injuries, especially sacroiliac joint separation or pubic symphysis separation, are important factors in pelvic fractures leading to death and disability. Pelvic fractures caused by high-energy violence often cause hemorrhagic shock in patients, and unstable pelvic rings form "open book" or "closed book" injuries. The resulting changes in pelvic volume will aggravate changes in pelvic pressure and increase the risk of death from hemorrhagic shock. In addition to traffic injuries, earthquake injuries are another common and important cause of high-energy pelvic injuries. Even if the patient is rescued, the limb dysfunction or severe pain caused by the instability of the sacroiliac joints in the future life often affects the patient's quality of life. However, there is no internal fixation device specifically designed to restore the stability of the patient's posterior pelvic ring and lumbar iliac region in the prior art. Utility Model Content

[0004] The utility model aims to provide an implantable lumbar sacroiliac joint fixation screw to solve the problem that there is no internal fixation device specifically for restoring the postoperative stability of the patient's posterior pelvic ring and lumbar iliac region in the prior art.

[0005] The technical solution of the utility model to solve the above technical problems is as follows:

[0006] An implantable lumbar sacroiliac joint fixation screw comprises: a screw body and a joint locking piece movably connected to the screw body, a first external thread is arranged at the front end of the screw body, a plurality of self-tapping grooves are circumferentially arranged at the outer end of the first external thread, a bone grafting chamber penetrating the interior of the screw body is arranged at the middle part of the screw body, and the joint locking piece is arranged in the bone grafting chamber.

[0007] Preferably, the joint locking member includes a base, a support rod and a locking end, the base is connected to the rear end of the bone graft chamber, the support rod is symmetrically arranged on the base, the locking end is arranged on the top of the support rod, and the locking end extends to both ends of the support rod.

[0008] Preferably, the locking end comprises an arc-shaped locking end connected to the top of the support rod and a locking tip connected to the top of the arc-shaped locking end.

[0009] Preferably, the joint locking member is a titanium alloy anchor bolt.

[0010] Preferably, a second external thread is provided at the rear end of the screw body.

[0011] Preferably, the second external thread is threadedly connected with a plum blossom-shaped bolt, which is convenient for the doctor to hold and screw in during surgery.

[0012] Preferably, a hydroxyapatite layer is provided on the surface of the screw body.

[0013] The utility model has the following beneficial effects:

[0014] Enhanced fixation effect: Through the first external thread and self-tapping groove design at the front end, the screw can pass through the sacroiliac joint and enter the sacrum more firmly. At the same time, the locking end design of the joint locking piece ensures the tight combination of the screw with the ilium and sacrum, effectively preventing the screw from loosening and displacement.

[0015] Promote bone healing: The design of the bone graft chamber allows it to be filled with autologous bone or allogeneic bone materials during surgery. These materials can fuse with the surrounding bone tissue, promote bone healing, and improve the success rate of surgery.

[0016] Reduce complications: Compared with traditional sacroiliac joint fixation methods, the screw implantation method of this invention has less trauma, less intraoperative bleeding, and shorter operation time, and can significantly reduce the incidence of complications such as poor fracture healing, lumbar sacral deformity, unequal length of lower limbs, and neurological damage.

[0017] Easy to operate: The design of the plum blossom bolt allows the doctor to easily hold and rotate the screw during surgery, simplifying the surgical operation and improving surgical efficiency.

[0018] High biomechanical strength: The whole is made of titanium alloy material, which ensures the high strength and excellent biocompatibility of the screw and can meet complex biomechanical requirements.

[0019] High safety: The 15° medial convergence angle design of the titanium alloy anchor ensures the safety of the implantation process and avoids damage to surrounding tissues caused by excessive expansion of the anchor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the utility model;

[0021] Figure 2 It is a structural schematic diagram of the screw body;

[0022] Figure 3 is a side view of the screw body;

[0023] Figure 4 is a front view of a joint locking member;

[0024] Figure 5 It is the front view of the plum blossom bolt;

[0025] Figures 1 to 5 The reference numerals shown in the figure represent respectively: screw body 1, first external thread 11, self-tapping groove 12, bone grafting chamber 13, second external thread 14, joint locking member 2, base 21, support rod 22, arc-shaped locking end 23, locking tip 24, plum blossom bolt 3. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solution of the utility model in conjunction with the accompanying drawings. 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 embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0027] Please refer to Figure 1 The utility model provides an implantable lumbar sacroiliac joint fixation screw, the structure of which includes:

[0028] Screw body design: Figure 2-3 As shown, the screw body 1 is made of high-strength titanium alloy material to ensure its biocompatibility and sufficient mechanical strength. The front end of the screw body 1 is provided with a first external thread 11, which is used to form a threaded connection with the bone tissue during the implantation process to enhance the fixation effect. At the outer end of the first external thread 11, three self-tapping grooves 12 are circumferentially provided. These self-tapping grooves are designed to cut the bone tissue during the screwing process, so that the screw can smoothly pass through the sacroiliac joint and enter the sacrum. The middle part of the screw body 1 is provided with a bone grafting chamber 13 running through it, which is used to fill autologous bone or allogeneic bone material to promote bone healing.

[0029] Joint locking design: Figure 4As shown, the joint locking member 2 is also made of titanium alloy material, specifically a titanium alloy anchor bolt structure. The locking member includes a base 21, a support rod 22 and a locking end. The base 21 is fixedly connected to the rear end of the bone graft chamber 13, and the support rod 22 is symmetrically arranged on the base 21 and extends upward. The locking end is composed of an arc-shaped locking end 23 connected to the top of the support rod 22 and a locking tip 24 that further extends upward. This design allows the two wings of the locking end to be able to open and lock toward the cortical walls of the ilium and sacrum respectively after the screw body 1 passes through the sacroiliac joint, thereby achieving compression fixation of the joint.

[0030] Auxiliary structure: The rear end of the screw body 1 is provided with a second external thread 14, which is threadedly connected to the plum blossom bolt 3. The design of the plum blossom bolt makes it easier for the doctor to hold and rotate the screw during the operation, so that it can be accurately and quickly implanted in the target position. In addition, the surface of the screw body 1 is also coated with a layer of hydroxyapatite to improve its biological activity and bone integration ability.

[0031] The screw body 1 is made of medical grade titanium alloy material (such as Ti-6Al-4V ELI), which has good biocompatibility, corrosion resistance and sufficient mechanical strength, and is suitable for long-term implantation in the human body. The first external thread 11 is designed as a full thread form with sufficient depth to ensure a close connection with the bone tissue. The tooth angle, pitch and depth of the thread are precisely calculated to balance the cutting force during screwing in and the stability after fixation. In addition, the thread surface is specially treated (such as sandblasting) to increase the bone tissue attachment area. The number, distribution and depth of the self-tapping grooves 12 are optimized to ensure that the bone tissue can be cut evenly and effectively during the screwing in process. These self-tapping grooves also have a certain guiding effect, helping the screws to smoothly pass through the complex structure of the sacroiliac joint. The size and shape of the bone grafting chamber 13 can be adjusted according to the needs of the bone filling material. The inner wall of the chamber is smooth to reduce friction damage to the filling material. The rear end of the screw body 1 is provided with a second external thread 14, which is connected to the plum blossom bolt 3 ( Figure 5 In order to increase the rotation stability, the tooth angle of the second external thread 14 can be appropriately reduced and the tooth pitch can be increased.

[0032] The base 21 is seamlessly connected to the rear end of the bone graft chamber 13 through precision machining to ensure the stability and reliability of the locking member during the implantation process. The base and the chamber can be connected by welding, threaded connection or snap-on connection. The support rod 22 is designed to have a structure with sufficient rigidity and toughness to withstand bending and torsion during the implantation process. The number, length and cross-sectional shape of the support rod 22 can be adjusted according to actual needs. The arc-shaped locking end 23 is designed to be an arc-shaped structure that matches the shape of the cortical wall of the ilium and sacrum to increase the contact area and locking effect. The locking tip 24 is designed to be a sharp structure with a certain hardness to penetrate the bone cortex and form a stable locking point during the implantation process. At the same time, the surface of the locking end can be covered with a layer of bioactive coating (such as hydroxyapatite) to promote bone integration.

[0033] Surgical procedure:

[0034] Preoperative preparation: Choose the appropriate screw size and model according to the patient's specific situation. Prepare autologous bone or allogeneic bone material as filler. And thoroughly disinfect and anesthetize the surgical area.

[0035] Implantation process: First, use a guide or positioning pin to determine the implantation position and angle of the screw. Then, align the front end of the screw body 1 with the entry point of the sacroiliac joint and slowly rotate it for implantation. During the implantation process, the self-tapping groove 12 will cut the bone tissue and guide the screw forward. When the screw completely passes through the sacroiliac joint and enters the sacrum, stop rotating.

[0036] Filling bone graft material: Autologous bone or allogeneic bone material is filled into the bone graft cavity 13 through the opening of the cavity. During the filling process, care should be taken to avoid material leakage and blockage.

[0037] Install the joint locking member: Connect the base 21 of the joint locking member 2 to the rear end of the bone graft chamber 13. Then, rotate the plum-shaped bolt 3 to push the locking end forward and lock it on the cortical wall of the ilium and sacrum. During the locking process, attention should be paid to controlling the force and angle to avoid damaging the surrounding tissues.

[0038] Postoperative treatment: Clean and suture the surgical area. Perform postoperative care and rehabilitation training according to the doctor's instructions.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An implantable lumbar sacroiliac joint fixation screw, characterized in that: include: A screw body (1) and a joint locking member (2) movably connected to the screw body (1), wherein a first external thread (11) is arranged at the front end of the screw body (1), a plurality of self-tapping grooves (12) are circumferentially arranged at the outer end of the first external thread (11), a bone grafting chamber (13) penetrating the middle portion of the screw body (1) is arranged, and the joint locking member (2) is arranged in the bone grafting chamber (13).

2. The implantable lumbar sacroiliac joint fixation screw according to claim 1, characterized in that: The joint locking member (2) comprises a base (21), a support rod (22) and a locking end, wherein the base (21) is connected to the rear end of the bone graft chamber (13), the support rod (22) is symmetrically arranged on the base (21), the locking end is arranged at the top of the support rod (22), and the locking end extends to both ends of the support rod (22).

3. The implantable lumbar sacroiliac joint fixation screw according to claim 2, characterized in that: The locking end comprises an arc-shaped locking end (23) connected to the top of the support rod (22) and a locking tip (24) connected to the top of the arc-shaped locking end.

4. The implantable lumbar sacroiliac joint fixation screw according to claim 1, characterized in that: The joint locking member (2) is a titanium alloy anchor bolt.

5. The implantable lumbar sacroiliac joint fixation screw according to claim 1, characterized in that: The rear end of the screw body (1) is provided with a second external thread (14).

6. The implantable lumbar sacroiliac joint fixation screw according to claim 5, characterized in that: The second external thread (14) is threadedly connected with a plum blossom-shaped bolt (3), which is convenient for a doctor to hold and screw in during surgery.

7. The implantable lumbar sacroiliac joint fixation screw according to claim 1, characterized in that: A hydroxyapatite layer is provided on the surface of the screw body (1).

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