Growth rod and orthopedic fixation system

Abstract

The present application relates to a kind of growing rod and orthopedic fixation system, the growing rod includes first rod, second rod and check valve, the first end of first rod is provided with accommodating cavity, accommodating cavity has first chamber and second chamber, the first end of second rod is provided with sliding seat, sliding seat is arranged in accommodating cavity along the axial direction of first rod, first chamber and second chamber are respectively arranged in the axial direction of sliding seat Two sides, second chamber is closer to the second end of first rod compared with first chamber, check valve is provided on sliding seat, when one of first rod and second rod is subjected to greater than preset traction force Traction force away from the other, check valve can allow the medium in first chamber to flow towards second chamber. The growing rod of the present application can be extended accordingly with the growth of the patient's spine, which is advantageous to reduce the risk of complications caused by repeated open surgery, and the spine orthopedic effect is better.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a growing rod and an orthopedic fixation system. BACKGROUND

[0002] The growing rod technology is used for non-fusion correction surgery for early-onset scoliosis or juvenile idiopathic scoliosis in children, generally for patients in the growth and development stage, to maintain the balance of the coronal and sagittal planes of the spine while preserving the growth potential of the spine, and to allow the chest to continue to grow, improve chest volume and cardiopulmonary function. In the related art, the growing rod generally requires repeated open surgery to ensure normal growth of the spine, i.e., the patient needs to undergo a growing rod extension surgery every certain period of time, but the above surgical procedure greatly increases the risk of complications, etc. SUMMARY

[0003] The present application aims to at least partially solve one of the technical problems in the related art.

[0004] To this end, an embodiment of the present application proposes a growing rod which can be extended accordingly as the spine of a patient grows, thereby reducing the risk of complications caused by repeated open surgery and achieving better spinal orthopedic effect.

[0005] An embodiment of the present application also proposes an orthopedic fixation system.

[0006] The growing rod of the embodiment of the present application comprises: a first rod, a first end of the first rod being provided with a containing cavity, the containing cavity having a first chamber and a second chamber; a second rod, a first end of the second rod being provided with a sliding seat, the sliding seat being arranged in the containing cavity in the axial direction of the first rod, the first chamber and the second chamber being arranged on the two sides of the axial direction of the sliding seat respectively, the second chamber being closer to the second end of the first rod than the first chamber; and a one-way valve, the one-way valve being provided on the sliding seat, when one of the first rod and the second rod is subjected to a pulling force away from the other rod greater than a preset pulling force, the one-way valve can allow the medium in the first chamber to flow towards the second chamber.

[0007] When the growth rod is implanted on the spine of a patient and grows along with the spine or is pulled externally, one of the first rod and the second rod is pulled away from the other, and when the pulling force is greater than the preset pulling force, the one-way valve can allow the medium in the first chamber to flow into the second chamber, so that the space of the second chamber increases and the space of the first chamber decreases synchronously, so that the first rod and the second rod can move away from each other, so that the growth rod can be stretched along with the growth of the spine. Since the one-way valve has the characteristic of one-way conduction, the medium in the second chamber cannot flow back into the first chamber, thereby improving the stability of the support after the growth rod is stretched.

[0008] Therefore, the growth rod of the embodiment of the present application can be stretched along with the growth of the spine of the patient, which is beneficial to reduce the risk of complications caused by repeated open surgery, and the spine orthopedic effect is better.

[0009] In some embodiments, the sliding seat is provided with a first channel, two ends of the first channel are in communication with the first chamber and the second chamber respectively, the one-way valve comprises an elastic member and a valve core, the valve core is arranged in the first channel and connected with the elastic member, the elastic member has an elastic force for driving the valve core to close the first channel, the elastic force is equal to the preset pulling force, and when the pulling force is greater than the preset pulling force, the valve core makes the first channel conductive.

[0010] In some embodiments, a first port of the first channel is in communication with the first chamber, a second port of the first channel is in communication with the second chamber, the valve core has a first sealing surface, the first sealing surface is spaced apart from the first port when the pulling force is greater than the preset pulling force, and the first sealing surface abuts against the first port when the pulling force is less than or equal to the preset pulling force.

[0011] In some embodiments, the first sealing surface is a conical surface, the conical surface is arranged to be gradually tapered in the direction from the second port to the first port; and / or, the valve core comprises a core body and a first sealing ring, the first sealing ring is sleeved on the core body, and the first sealing surface is formed on the first sealing ring.

[0012] In some embodiments, the one-way valve further comprises a limiting member, the limiting member is arranged in the first channel and adjacent to the second port, one end of the elastic member is connected with the valve core, and the other end of the elastic member is connected with the limiting member.

[0013] In some embodiments, the outer wall surface of the limiting member is threadedly matched with the inner wall surface of the first channel; and / or, the limiting member is provided with a mounting groove adjacent to one end of the valve core, the other end of the elastic member is abutted in the mounting groove.

[0014] In some embodiments, the second rod is provided with a first hole and a second hole, the first hole extends along the radial direction of the second rod, the second hole extends along the axial direction of the second rod, the radially outer end of the first hole is communicated with the first chamber, the radially inner end of the first hole is communicated with the second hole, and the second hole is communicated with the first channel.

[0015] In some embodiments, the one-way valve further comprises a second sealing ring, the second sealing ring is sleeved on the outer peripheral wall of the sliding seat, and the outer peripheral wall of the second sealing ring is abutted with the inner peripheral wall of the accommodating cavity; and / or, the first chamber and the second chamber are both filled with a medium; and / or, in the cross section perpendicular to the first rod, the cross-sectional profiles of the accommodating cavity and the sliding seat are both polygons, and the sliding seat is rotationally matched with the accommodating cavity.

[0016] In some embodiments, the first rod comprises a first rod body, a fixing seat and a sealing cover, the fixing seat is arranged at the end of the first rod body, the sealing cover is detachably mounted at the end of the fixing seat away from the first rod body, and the sealing cover and the fixing seat enclose the accommodating cavity; and / or, the first rod comprises a fixing seat and a sealing cover, the sealing cover and the fixing seat enclose the accommodating cavity, the growth rod further comprises a third sealing ring, the third sealing ring is arranged in the accommodating cavity, the third sealing ring is clamped between the sealing cover and the fixing seat, and the third sealing ring is abutted with the inner peripheral wall of the second rod.

[0017] The orthopedic fixation system of another embodiment of the present application comprises: a growth rod, the growth rod is any one of the growth rods of the embodiments of the present application; at least two pedicle screws, at least one of the pedicle screws is connected to the first rod and the second rod.

[0018] When the growing rod is implanted on the spine of a patient and grows along with the spine or is pulled by an external force, one of the first rod and the second rod is pulled away from the other, and when the pulling force is greater than a preset pulling force, the one-way valve allows the medium in the first chamber to flow into the second chamber, so that the space of the second chamber increases and the space of the first chamber decreases synchronously, thereby enabling the first rod and the second rod to move away from each other, so that the growing rod can extend along with the growth of the spine. Since the one-way valve has the characteristic of one-way conduction, the medium in the second chamber cannot flow back into the first chamber, thereby improving the stability of the support of the growing rod after extension.

[0019] Therefore, the orthopedic fixation system of the embodiment of the present application can extend along with the growth of the spine of the patient, which is advantageous to reduce the risk of complications caused by repeated open surgery, and the spine orthopedic effect is better. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic view of the growing rod of the embodiment of the present application when the growing rod extends.

[0021] Figure 2 is a partial cross-sectional view of the growing rod (when not extended) of the embodiment of the present application.

[0022] Figure 3 is a partial cross-sectional view of the growing rod (during extension) of the embodiment of the present application.

[0023] Figure 4 is a partial cross-sectional view of the growing rod when the growing rod cooperates with the installation tool of the embodiment of the present application.

[0024] Figure 5 is a partial cross-sectional view of the second rod of the growing rod of the embodiment of the present application.

[0025] Figure 6 is a partial cross-sectional view of the first rod of the growing rod of the embodiment of the present application.

[0026] Figure 7 is a cross-sectional view of the valve core of the growing rod of the embodiment of the present application.

[0027] Figure 8 is a partial installation cross-sectional view of the sealing cover and the third sealing ring of the growing rod of the embodiment of the present application.

[0028] Figure 9 is a cross-sectional view of the limiting member of the growing rod of the embodiment of the present application.

[0029] REFERENCE SIGNS:

[0030] 1. First rod; 11. Receiving cavity; 111. First chamber; 112. Second chamber; 12. First rod body; 13. Fixing seat; 14. Sealing cover; 15. Third sealing ring;

[0031] 2. Second rod; 21. Sliding seat; 211. First channel; 2111. First port; 2112. Second port; 212. Second slot; 22. Second rod body; 221. First hole; 222. Second hole; 23. Second sealing ring;

[0032] 3. One-way valve; 31. Elastic element; 32. Valve core; 321. Core body; 3211. First slot; 322. First sealing ring; 3221. First sealing surface; 33. Limiting element; 331. Through hole; 332. Mounting groove;

[0033] 4. Pedicle screws;

[0034] 51. Airbag head; 52. Hose; 53. Air source. Detailed Implementation

[0035] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0036] The following is a reference appendix. Figures 1 to 9 The growth rod and orthopedic fixation system of the present invention are described in the embodiments of the present invention.

[0037] like Figures 1 to 4 As shown, the growth rod of this embodiment includes: a first rod 1, a second rod 2, and a one-way valve 3. The first rod 1 has a receiving cavity 11 at its first end, which has a first chamber 111 and a second chamber 112. The second rod 2 has a sliding seat 21 at its first end, which is slidably arranged within the receiving cavity 11 along the axial direction of the first rod 1. The first chamber 111 and the second chamber 112 are respectively arranged on both sides of the axial direction of the sliding seat 21. The second chamber 112 is closer to the second end of the first rod 1 than the first chamber 111. The one-way valve 3 is disposed on the sliding seat 21. When one of the first rod 1 and the second rod 2 is subjected to a traction force greater than a preset traction force away from the other, the one-way valve 3 allows the medium in the first chamber 111 to flow towards the second chamber 112.

[0038] It should be noted that the traction force can come from the normal growth of the patient's spine or from external traction on the patient.

[0039] When the traction force reaches a set threshold (i.e. the traction force is greater than the preset traction force), the one-way valve 3 allows the medium in the first chamber 111 to flow into the second chamber 112. In other words, when the traction force is greater than the set threshold, the one-way valve 3 is open, and when the traction force is less than or equal to the set threshold (i.e. the traction force is less than or equal to the preset traction force), the one-way valve 3 is closed. The set threshold can be selected according to the traction force generated by the normal growth of the human spine, and the present application does not limit this.

[0040] For example, the first rod 1 is connected to the vertebra below the one-way valve, and the second rod 2 is connected to the vertebra above the one-way valve. For another example, the first rod 1 is connected to the vertebra above the one-way valve, and the second rod 2 is connected to the vertebra below the one-way valve.

[0041] It can be understood that the first rod 1 and the second rod 2 are respectively connected to the vertebrae on different sides of the one-way valve. Thus, when the spine grows normally or is externally pulled, the first rod 1 and the second rod 2 can move away from each other to stretch synchronously with the spine.

[0042] According to the growth rod of the embodiment of the present application, when the growth rod is implanted on the spine of a patient and grows with the spine or is externally pulled, one of the first rod 1 and the second rod 2 will be subjected to a traction force away from the other, and when the traction force is greater than a preset traction force, the one-way valve 3 can allow the medium in the first chamber 111 to flow into the second chamber 112, so that the space of the second chamber 112 increases and the space of the first chamber 111 decreases synchronously, thereby allowing the first rod 1 and the second rod 2 to move away from each other, so that the growth rod can stretch synchronously with the growth of the spine. Since the one-way valve 3 has the characteristic of one-way conduction, the medium in the second chamber 112 will not flow back into the first chamber 111, thereby improving the stability of the support after the growth rod stretches.

[0043] It can be understood that the sliding seat 21 can act as a "sliding piston" in the accommodating cavity 11. When the first rod 1 and the second rod 2 move away from each other under the action of the traction force of the spine, the pressure in the first chamber 111 increases and the pressure in the second chamber 112 decreases, at which time the one-way valve 3 can open under the action of the pressure difference, i.e. the one-way valve 3 can allow the medium in the first chamber 111 to flow into the second chamber 112, so as to balance the pressure difference between the first chamber 111 and the second chamber 112.

[0044] When the growth rod is stretched by a certain distance, the traction force on the first rod 1 and the second rod 2 decreases until it is less than the preset traction force, at which time the pressure difference between the first chamber 111 and the second chamber 112 is substantially balanced, and the one-way valve 3 is closed, thereby limiting the exchange of the medium in the first chamber 111 and the second chamber 112, so as to avoid the problem of retraction of the growth rod.

[0045] The growth rod of the embodiment of the present application can be stretched accordingly with the growth of the spine of the patient, and can guarantee the support force after the growth rod is stretched, so that the distraction orthopedic purpose can be achieved, and the growth ability of the spine and the thoracic cavity can be retained, and the number of open surgeries is reduced.

[0046] Optionally, as shown in Figure 2 and Figure 5 , the sliding seat 21 is provided with a first channel 211, both ends of the first channel 211 are in communication with the first chamber 111 and the second chamber 112 respectively, the one-way valve 3 comprises an elastic member 31 and a valve core 32, the valve core 32 is arranged in the first channel 211 and connected with the elastic member 31, the elastic member 31 has an elastic force for driving the valve core 32 to close the first channel 211, and the elastic force is equal to the preset traction force.

[0047] When the traction force is greater than the preset traction force (elastic force), the valve core 32 makes the first channel 211 conductive. Correspondingly, when the traction force is less than or equal to the preset traction force (elastic force), the valve core 32 can close the first channel 211 under the action of the elastic force, so that the opening and closing of the one-way valve 3 can be realized.

[0048] As can be understood, as shown in Figure 3 , when the traction force is greater than the preset traction force (elastic force), the sliding seat 21 moves upward, the pressure of the first chamber 111 is greater than the pressure of the second chamber 112, so that the one-way valve 3 is opened, and the first chamber 111 is in communication with the second chamber 112 through the first channel 211. As shown in Figure 2 , when the pressure of the first chamber 111 and the pressure of the second chamber 112 are substantially equal, that is, the pressure difference is reduced or disappears, the traction force is less than or equal to the preset traction force (elastic force), at this time the valve core 32 can close the first channel 211 under the action of the elastic force.

[0049] The growth rod of the embodiment of the present application is designed as the above structure, so that the stretching of the growth rod needs to meet the condition that the traction force is greater than the elastic force. Therefore, the problem that the growth rod is also stretched synchronously when the patient's spine is bent or pulled daily can be avoided, which is beneficial to improve the reliability after the growth rod is implanted. And the structure of “elastic member 31 + valve core 32” of the one-way valve 3 can make the required parts of the one-way valve 3 less, and the structure design is simple and reliable.

[0050] As shown in Figure 3 and Figure 5As shown, the first port 2111 of the first channel 211 is in communication with the first chamber 111, and the second port 2112 of the first channel 211 is in communication with the second chamber 112. The valve core 32 has a first sealing surface 3221. When the traction force is greater than the preset traction force (elastic force), the first sealing surface 3221 is spaced apart from the first port 2111. When the traction force is less than or equal to the preset traction force (elastic force), the first sealing surface 3221 abuts against the first port 2111. Figure 2 and Figure 3 As shown, the first port 2111 is arranged adjacent to the first chamber 111, and the second port 2112 is arranged adjacent to the second chamber 112. The valve core 32 can be moved under the interaction of the pressure difference force of the containing cavity 11 and the elastic force of the elastic member 31 to close and open the first port 2111. When the traction force is less than or equal to the elastic force, the elastic member 31 can press the valve core 32 upward to make the first sealing surface 3221 in surface contact with the first port 2111, thereby improving the sealing effect when the one-way valve 3 is closed, so that the support of the growth rod is more stable.

[0051] Optionally, as shown in Figure 3 and Figure 7 The first sealing surface 3221 is a conical surface, which is arranged to be gradually tapered in the direction from the second port 2112 to the first port 2111. When the traction force is less than or equal to the elastic force, the conical structure on the upper side of the valve core 32 can block the first port 2111. When the traction force is greater than the elastic force, the conical structure on the upper side of the valve core 32 can be spaced apart from the first port 2111 to form a gap for the medium to flow through.

[0052] The growth rod of the embodiment of the present application adopts the above structure design for the first sealing surface 3221 (conical surface), which can axially limit the position of the valve core 32 to avoid the valve core 32 from being pulled out of the first port 2111 under the action of the elastic member 31. On the other hand, the sealing structure in the form of a conical surface can increase the contact area of the valve core 32 and the first port 2111 to ensure the sealing effect. When the valve core 32 is spaced apart from the first port 2111, the inclined flow gap formed can make the medium more smoothly flow into the first channel 211.

[0053] As shown in Figure 7 To further improve the sealing effect of the valve core 32 and the first port 2111, the valve core 32 includes a core body 321 and a first sealing ring 322. The first sealing ring 322 is sleeved on the core body 321, and the first sealing surface 3221 is formed on the first sealing ring 322. It can be understood that the core body 321 and the first sealing ring 322 are made of different materials. The first sealing ring 322 can be made of medical-grade silicone, which can not only ensure the sealing effect of the valve core 32 and the first port 2111, but also improve the safety of the growth rod after being implanted into the human body.

[0054] In an example, the first sealing ring 322 is clamped with the core body 321. As shown, the core body 321 is provided with a first clamping groove 3211, which is arranged around the outer peripheral wall of the core body 321, and the first sealing ring 322 is sleeved and clamped on the core body 321, so as to ensure the firmness of the connection between the first sealing ring 322 and the core body 321 and facilitate assembly. Figure 7

[0055] Optionally, as shown in Figures 2 to 4 and Figure 9 , the one-way valve 3 further comprises a limiting piece 33, which is arranged in the first channel 211 and adjacent to the second port 2112, one end of the elastic piece 31 is connected with the valve core 32, and the other end of the elastic piece 31 is connected with the limiting piece 33. The growth rod of the embodiment of the present application can limit the installation of the elastic piece 31 by arranging the limiting piece 33, so as to facilitate the assembly of the one-way valve 3.

[0056] As shown in Figure 2 , Figure 3 and Figure 9 , the limiting piece 33 is provided with a through hole 331, which penetrates the limiting piece 33 along the axial direction of the sliding seat 21. Thus, the through hole 331 in the limiting piece 33 can equalize the pressure difference between the first channel 211 and the second chamber 112, and will not interfere with the flow of the medium from the first channel 211 to the second chamber 112.

[0057] In an example, the outer wall surface of the limiting piece 33 is threadedly matched with the inner wall surface of the first channel 211. As shown in Figure 9 , the limiting piece 33 is a hollow plug structure, which can be screwed in the first channel 211 from bottom to top, so as to facilitate the assembly of the one-way valve 3 and have simple structure design and good stability.

[0058] As shown in Figure 2 , Figure 7 and Figure 9 , the limiting piece 33 is provided with a mounting groove 332 adjacent to one end of the valve core 32, and the other end of the elastic piece 31 abuts in the mounting groove 332. It can be understood that the mounting groove 332 can radially and axially limit the lower end of the elastic piece 31, and the valve core 32 can axially and radially limit the upper end of the elastic piece 31, so that the deformation of the elastic piece 31 is more stable when the elastic piece 31 is compressed, and the speed balance of the growth rod when stretched is improved, and the adjustment effect is better.

[0059] ​Exemplarily, the elastic member 31 can be a cylindrical coil spring, a disc spring or a leaf spring. In the example of the present application, the elastic member 31 is a cylindrical coil spring, which is a hollow coil structure. In addition, compared with the scheme of "disc spring or leaf spring", the cylindrical coil spring is more stable when deformed under force, which can make the speed of the growth rod stretching balanced, and the adjustment effect is better.

[0060] Optionally, as shown in Figure 2 and Figure 5 , the second rod 2 is provided with a first hole 221 and a second hole 222, the first hole 221 extends along the radial direction of the second rod 2, the second hole 222 extends along the axial direction of the second rod 2, the radial outer end of the first hole 221 is in communication with the first chamber 111, the radial inner end of the first hole 221 is in communication with the second hole 222, and the second hole 222 is in communication with the first channel 211. The growth rod of the embodiment of the present application can guide the medium in the first chamber 111 into the second hole 222 along the horizontal direction through the first hole 221, because the second hole 222 extends along the axial direction, so that the force of the medium on the valve core 32 when vertically extruding the valve core 32 is more uniform, which reduces the problem of lateral tilting and deviation of the valve core 32 when moving caused by the direct communication between the first hole 221 and the valve core 32, and improves the uniformity of the force on the valve core 32.

[0061] In an example, the first hole 221 is a plurality of first holes 221, and the plurality of first holes 221 are arranged at intervals along the circumferential direction of the second rod 2, that is, the plurality of first holes 221 can flow the medium at the same time, thereby improving the efficiency of the differential pressure adjustment of the first chamber 111 and the second chamber 112, and making the valve core 32 vertically uniformly stressed, and improving the length adjustment effect of the growth rod.

[0062] As shown in Figure 5 , the second rod 2 includes a second rod body 22 and a sliding seat 21, the sliding seat 21 is arranged at the first end of the second rod body 22, and the first hole 221 and the second hole 222 are arranged between the second rod body 22 and the sliding seat 21. The second hole 222 is coaxially arranged with the first channel 211, and the inner diameter of the second hole 222 is substantially the same as the inner diameter of the first port 2111. The first hole 221 is a plurality of first holes 221, and the plurality of first holes 221 are arranged in a radial manner, and the radial inner ends of the plurality of first holes 221 are in communication with the second hole 222.

[0063] Optionally, as shown in Figure 2 and Figure 5As shown, the one-way valve 3 further comprises a second sealing ring 23 sleeved on the outer circumferential wall of the sliding seat 21, and the outer circumferential wall of the second sealing ring 23 abuts against the inner circumferential wall of the accommodating cavity 11. It can be understood that the sliding seat 21 and the accommodating cavity 11 are sealingly connected through the second sealing ring 23, so that the flow of the medium at the gap position between the sliding seat 21 and the accommodating cavity 11 can be avoided, the sealing effect of the accommodating cavity 11 is improved, and the supporting effect of the growth rod is better.

[0064] As shown in Figure 5 , the outer circumferential wall of the sliding seat 21 is provided with a second clamping groove 212, and the second sealing ring 23 is sleeved and clamped in the second clamping groove 212. The outer side wall of the second sealing ring 23 and the outer side wall of the sliding seat 21 both abut against the inner circumferential wall of the accommodating cavity 11, so that the sealing effect between the sliding seat 21 and the inner wall of the accommodating cavity 11 can be further improved.

[0065] For example, as shown in Figure 5 , the second sealing ring 23 is a plurality of second sealing rings 23 arranged along the axial direction of the sliding seat 21. Figure 5 As shown in , the second clamping groove 212 is two second clamping grooves 212 arranged along the axial direction of the sliding seat 21, and the second sealing ring 23 is two second sealing rings 23 installed in the two second clamping grooves 212 one by one.

[0066] Optionally, the first chamber 111 and the second chamber 112 are both filled with a medium. The medium can be a lubricating liquid, which can be a medical-grade liquid silicone oil, paraffin oil, glycerol or other safer lubricating liquid. Since the medium is a lubricating liquid, the volume of the lubricating liquid remains basically unchanged under the action of pressure, which makes the sealing of the lubricating liquid relatively easy to control, thereby facilitating the reduction of the probability of medium leakage in the growth rod, and the lubricating liquid can lubricate the movement of the sliding seat 21, avoiding the problem of jamming of the sliding seat 21 in the accommodating cavity 11.

[0067] Optionally, in the cross section perpendicular to the first rod 1, the cross-sectional profiles of the accommodating cavity 11 and the sliding seat 21 are both polygons, and the sliding seat 21 is rotationally matched with the accommodating cavity 11. Thus, the relative rotation of the first rod 1 and the second rod 2 can be limited, and the stability of the growth rod after implantation is improved.

[0068] For example, the cross-sectional profiles of the accommodating cavity 11 and the sliding seat 21 are both regular hexagons.

[0069] Figure 2 Optionally, as shown in Figure 3 andAs shown, the first rod 1 comprises a first rod body 12, a fixing seat 13 arranged at an end of the first rod body 12, and a sealing cover 14 detachably mounted at an end of the fixing seat 13 away from the first rod body 12, the sealing cover 14 and the fixing seat 13 jointly defining a containing cavity 11. Since the sealing cover 14 is detachably connected with the fixing seat 13, the sealing cover 14 can be opened before the assembly of the growth rod, so that the operator can load the sliding seat 21, the one-way valve 3 and the lubricating liquid into the fixing seat 13, and then close the sealing cover 14, thereby improving the convenience of the assembly of the growth rod.

[0070] In an example, as shown in Figure 2 and Figure 3 The sealing cover 14 is connected with the fixing seat 13 in a threaded manner. Thus, the fixing seat 13 and the sealing cover 14 can be conveniently installed, and the structure is simple.

[0071] In order to further improve the sealing effect of the containing cavity 11, the growth rod further comprises a third sealing ring 15 arranged in the containing cavity 11, the third sealing ring 15 being clamped between the sealing cover 14 and the fixing seat 13, and the third sealing ring 15 abutting against the inner circumferential wall of the second rod 2. Thus, the probability of leakage of the lubricating liquid from the gap between the fixing seat 13 and the sealing cover 14, and the gap between the second rod body 22 and the sealing cover 14 can be reduced, so that the growth rod has a better sealing effect.

[0072] It can be understood that, during the assembly of the growth rod, the air in the second chamber 112 is not easy to be discharged along with the descent of the sliding seat 21 due to the small installation gap between the sliding seat 21 and the containing cavity 11, and the one-way conduction characteristic of the one-way valve 3. Therefore, the sliding seat 21 needs to be put into the bottom of the containing cavity 11 by means of an installation tool.

[0073] Specifically, as shown in Figure 4 The installation tool comprises an air bag head 51 and a hose 52, one end of the hose 52 being in communication with the air bag head 51, the other end of the hose 52 being in communication with an air source 53, the air bag head 51 being located between the second rod body 22 and the valve core 32, the air source 53 inflating the air bag head 51 through the hose 52, the valve core 32 being moved downward under the pressure of the air bag head 51 to open the first channel 211, so that the pressure of the first chamber 111 and the second chamber 112 is balanced, thereby facilitating the putting of the sliding seat 21 into the bottom of the containing cavity 11. After the sliding seat 21 is put into the bottom of the containing cavity 11, a medium is injected into the containing cavity 11, so that the medium can fill the first chamber 111 and the second chamber 112, then the air source 53 is controlled to deflate the air bag head 51, and the air bag head 51 and the hose 52 are removed from the containing cavity 11, and the sealing cover 14 is installed, thereby completing the assembly of the growth rod.

[0074] AsFigure 2 and Figure 3 As shown in FIG. 1, when the spine is subjected to growth force or external traction force, the second rod 2 is forced to move upward relative to the first rod 1, and in the accommodating cavity 11, the upper end surface of the sliding seat 21 is subjected to positive pressure generated by space compression, while the lower end surface of the sliding seat 21 is subjected to negative pressure, and when the pressure difference acting on the valve core 32 of the one-way valve 3 reaches the preset traction force, the valve core 32 is opened, and the lubricating liquid in the first chamber 111 flows into the second chamber 112 through the first hole 221, the second hole 222 and the first channel 211. As the growth force of the spine decreases or the external traction force stops, the pressure on the upper end surface of the sliding seat 21 and the pressure on the lower end surface of the sliding seat 21 reach balance. The one-way valve 3 is closed under the elastic force of the elastic member 31, and the second rod 2 is extended upward.

[0075] The second rod 2 can be extended "grown" infinitely within the maximum extension range, and the maximum extension "growth" range can be designed and manufactured according to actual needs. After the growth rod completes the extension "growth", it can also effectively support the stress of the upper vertebral body to the lower vertebral body of the spine. When the second rod 2 is subjected to downward force relative to the first rod 1, the lower end surface of the sliding seat 21 is subjected to positive pressure generated by space compression, while the upper end surface of the sliding seat 21 is subjected to negative pressure, and the valve core 32 of the one-way valve 3 cannot be opened due to this pressure difference, thereby realizing effective support after the extension "growth" of the growth rod.

[0076] As shown in FIG. 1, when the spine is subjected to growth force or external traction force, the second rod 2 is forced to move upward relative to the first rod 1, and in the accommodating cavity 11, the upper end surface of the sliding seat 21 is subjected to positive pressure generated by space compression, while the lower end surface of the sliding seat 21 is subjected to negative pressure, and when the pressure difference acting on the valve core 32 of the one-way valve 3 reaches the preset traction force, the valve core 32 is opened, and the lubricating liquid in the first chamber 111 flows into the second chamber 112 through the first hole 221, the second hole 222 and the first channel 211. As the growth force of the spine decreases or the external traction force stops, the pressure on the upper end surface of the sliding seat 21 and the pressure on the lower end surface of the sliding seat 21 reach balance. The one-way valve 3 is closed under the elastic force of the elastic member 31, and the second rod 2 is extended upward. Figure 1 As shown in FIG. 1, when the spine is subjected to growth force or external traction force, the second rod 2 is forced to move upward relative to the first rod 1, and in the accommodating cavity 11, the upper end surface of the sliding seat 21 is subjected to positive pressure generated by space compression, while the lower end surface of the sliding seat 21 is subjected to negative pressure, and when the pressure difference acting on the valve core 32 of the one-way valve 3 reaches the preset traction force, the valve core 32 is opened, and the lubricating liquid in the first chamber 111 flows into the second chamber 112 through the first hole 221, the second hole 222 and the first channel 211. As the growth force of the spine decreases or the external traction force stops, the pressure on the upper end surface of the sliding seat 21 and the pressure on the lower end surface of the sliding seat 21 reach balance. The one-way valve 3 is closed under the elastic force of the elastic member 31, and the second rod 2 is extended upward.

[0077] According to the embodiment of the present application, when the growth rod is implanted on the spine of a patient and accompanied by the growth of the spine or subjected to external traction, one of the first rod 1 and the second rod 2 will be subjected to traction force away from the other, and when the traction force is greater than the preset traction force, the one-way valve 3 can allow the medium in the first chamber 111 to flow into the second chamber 112, so that the space of the second chamber 112 increases and the space of the first chamber 111 decreases synchronously, thereby allowing the first rod 1 and the second rod 2 to move away from each other, so that the growth rod can be extended synchronously with the growth of the spine. Since the one-way valve 3 has the characteristic of one-way conduction, the medium in the second chamber 112 will not flow back to the first chamber 111, thereby improving the stability of the support after the extension of the growth rod. Therefore, the orthopedic fixation system of the embodiment of the present application can be extended accordingly with the growth of the spine of the patient, which is beneficial to reduce the risk of complications caused by repeated open surgery, and has good spine orthopedic effect.

[0078] In the description of the present application, it is to be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements indicated thereby must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0079] In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated thereby. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0080] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or in communication with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication or interaction relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0081] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0082] In this disclosure, the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" mean that a particular feature, structure, material, or characteristic is included in at least one embodiment or example of the present disclosure. The illustrative appearances of the above-mentioned terms in various places in the specification are not necessarily referred to the same embodiment or example. Moreover, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Furthermore, the terms "comprising", "containing", "having" or "including" and their derivatives, mean "including but not limited to". The terms "coupled" and "connected", along with their derivatives, mean "directly or indirectly connected".

[0083] Although the above-mentioned embodiments have been shown and described, it is to be understood that the above-mentioned embodiments are exemplary, and are not to be construed as limiting the present disclosure, and the changes, modifications, replacements and variations made by those skilled in the art to the above-mentioned embodiments are within the protection scope of the present disclosure.

Claims

1. A growth rod, characterized in that, The utility model relates to a kind of spinal traction device, including: First rod, the first end of the first rod is equipped with accommodating cavity, the accommodating cavity has first chamber and second chamber; Second rod, the first end of the second rod is equipped with sliding seat, the sliding seat is arranged in the accommodating cavity along the axial direction of the first rod, the first chamber and the second chamber are respectively arranged in the axial direction of the sliding seat, the second chamber is closer to the second end of the first rod compared with the first chamber; Check valve, the check valve is equipped on the sliding seat, when one of the first rod and the second rod is subjected to traction force greater than preset traction force away from another, the check valve can allow medium in the first chamber to flow towards the second chamber; First channel is equipped in the sliding seat, both ends of the first channel are communicated with the first chamber and the second chamber respectively, the check valve includes elastic member and valve core, the valve core is equipped in the first channel and is connected with the elastic member, the elastic member has the elastic force of driving the valve core to close the first channel, the elastic force is equal to the preset traction force, when the traction force is greater than the preset traction force, the valve core makes the first channel conductive, and the preset traction force is selected according to the traction force generated by normal growth of human spine; The valve core includes core body and first sealing ring, the first sealing ring is sleeved on the core body, first sealing surface is formed on the first sealing ring, the first sealing ring is made of medical grade silicone rubber; The first port of the first channel is communicated with the first chamber, the second port of the first channel is communicated with the second chamber, the valve core has first sealing surface, when the traction force is greater than the preset traction force, the first sealing surface is spaced apart from the first port, when the traction force is less than or equal to the preset traction force, the first sealing surface is abutted with the first port; The first sealing surface is conical surface, the conical surface is arranged gradually necked in the direction from the second port to the first port; The check valve further includes limiting piece, the limiting piece is arranged in the first channel and is adjacent to the second port, one end of the elastic member is connected with the valve core, the other end of the elastic member is connected with the limiting piece; The outer wall surface of the limiting piece is threadedly matched with the inner wall surface of the first channel; And / or, one end of the limiting piece adjacent to the valve core is equipped with mounting groove, the other end of the elastic member is abutted in the mounting groove; The limiting piece is hollow screw plug structure, the limiting piece is screwed in the first channel along the direction from bottom to top.

2. The grow rod of claim 1, wherein, Second rod is equipped with first hole and second hole in, the first hole extends along the radial direction of the second rod, the second hole extends along the axial direction of the second rod, the radial outer end of the first hole is communicated with the first chamber, the radial inner end of the first hole is communicated with the second hole, the second hole is communicated with the first channel.

3. The grow rod of claim 1, wherein, The check valve further includes second sealing ring, the second sealing ring is sleeved on the outer circumferential wall of the sliding seat, the outer circumferential wall of the second sealing ring is abutted with the inner circumferential wall of the accommodating cavity. And / or, the first chamber and the second chamber are filled with medium; And / or, in a cross section perpendicular to the first rod, the cross section profiles of the accommodating cavity and the sliding seat are both polygonal, and the sliding seat is rotationally engaged with the accommodating cavity.

4. The grow rod of claim 1, wherein, The first rod comprises a first rod body, a fixing seat arranged at an end of the first rod body, and a sealing cover detachably mounted at an end of the fixing seat away from the first rod body, the sealing cover and the fixing seat enclosing the accommodating cavity; And / or, the first rod comprises a fixing seat and a sealing cover, the sealing cover and the fixing seat enclosing the accommodating cavity, the growing rod further comprising a third sealing ring arranged in the accommodating cavity, the third sealing ring being clamped between the sealing cover and the fixing seat, and the third sealing ring abutting against an inner circumferential wall of the second rod.

5. An orthopedic fixation system comprising: Comprise: The growing rod is the growing rod according to any one of claims 1-4; At least two pedicle screws, at least one of which is connected to each of the first rod and the second rod.

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