A device for reducing and fixing atlantoaxial dislocation

Abstract

The invention discloses a resetting and fixing device for atlantoaxial dislocation. The device has the dual functions of assisting atlantoaxial movement and resetting and screwing and fixing, and has the advantages of good surgical effect and short surgical time. The device includes a resetting mechanism for adjusting and resetting the position of the atlantoaxial, and a fixing mechanism for fixing the atlantoaxial after resetting. The resetting mechanism includes an atlas fitting, a base and a resetting rod; the fixing mechanism includes an axis fitting, a first pedicle screw, a second pedicle screw, a fixing rod and a positioning nut; the axis fitting and the atlas fitting are both formed by 3D printing combined with subtractive processing.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, in particular to a resetting and fixing device for atlantoaxial dislocation. Background Art

[0002] Atlantoaxial dislocation, also known as atlantoaxial dislocation, refers to the loss of normal apposition between the first segment (atlas) and the second segment (axis) of the cervical spine. Types of atlantoaxial dislocation include anterior dislocation, posterior dislocation, bilateral asymmetric dislocation and rotational dislocation.

[0003] Atlantoaxial dislocation can directly or indirectly stimulate and compress the spinal cord, nerves and blood vessels, causing a series of diseases, with typical symptoms: 1) occipital and neck pain; 2) torticollis and limited neck movement; 3) upper spinal cord damage can be manifested as whole body muscle tension, unstable or weak hand grip; weak walking; weak bowel and urination; limb muscle atrophy; severe cases may cause whole body paralysis; 4) dizziness, tinnitus, blurred vision, chest tightness, palpitations and high blood pressure. Atlantoaxial dislocation may even compress the upper cervical spinal cord due to minor head and neck injuries or excessive flexion and extension of the cervical spine. The patient may suddenly develop stiff paralysis or even respiratory muscle paralysis and death, which requires timely diagnosis and treatment.

[0004] To treat atlantoaxial dislocation, the atlantoaxial must first be repositioned to relieve spinal cord compression, and then the cervical joints must be stabilized to prevent further dislocation. Atlantoaxial dislocation can be repositioned surgically or by traction.

[0005] Since the atlas is close to the brain, surgical reduction is extremely risky and difficult to perform.

[0006] There are certain risks in using a traction device to pull the head to reposition the atlantoaxial joint, and the effect is not very ideal, and accurate repositioning cannot be achieved. The reason is that after traction repositioning, the atlantoaxial joint needs to be maintained in a repositioned state with the help of traction force or the doctor's manpower in order to perform pedicle screw placement for atlantoaxial fixation surgery. However, whether it is traction force or doctor's manpower, the repositioning state will be unstable due to the interference force generated during the fixation operation, thereby affecting the final effect. In addition, the traction repositioning and fixation are performed separately, which makes the operation time very long. Summary of the invention

[0007] In order to solve the problem of great surgical risks in existing surgical methods for reducing and fixing atlantoaxial dislocation, and the problem of inability to accurately reduce and fix atlantoaxial dislocation and long operation time when using traction to reduce and fix atlantoaxial dislocation, the present invention provides a reduction and fixation device for atlantoaxial dislocation.

[0008] The basic design idea of ​​the present invention is:

[0009] The reduction and fixation device for atlantoaxial dislocation provided by the present invention can perform the reduction process and the fixation process at one time, and the structure of the device is designed according to the individual characteristics of atlantoaxial dislocation of the patient and the biomechanical distribution of surrounding ligaments and muscles, in combination with digital medicine and simulation analysis, in order to achieve accurate reduction and fixation of the patient's atlantoaxial dislocation.

[0010] The specific technical solution of the present invention is:

[0011] The present invention provides a reduction and fixation device for atlantoaxial dislocation, comprising a reduction mechanism and a fixation mechanism;

[0012] The reduction mechanism is used to adjust the position of the atlas and axis, and includes an atlas fitting, a base, and a reduction rod;

[0013] The fixing mechanism is used to fix the atlas and axis after reduction, and includes an axis fitting piece, a first pedicle screw, a second pedicle screw, a fixing rod and a positioning nut;

[0014] The lower end surface of the atlas fitting piece is completely matched with the atlas bone surface, and a pressing hole is provided at the upper end of the atlas fitting part;

[0015] The lower end surface of the axis fitting piece is completely matched with the axis bone surface, the base is installed in the middle of the upper end of the axis fitting piece, and guide holes are arranged on both sides of the axis fitting piece;

[0016] The reduction rod is threadedly connected to the base, and one end of the reduction rod is inserted into the pressure hole and connected by a pin, a screw or a steel wire. The reduction rod is rotated to adjust the atlantoaxial vertebra to achieve the reduction of the two.

[0017] There are two first pedicle screws, which are respectively inserted into the axis through two guide holes; there are two second pedicle screws, which are respectively inserted into the atlas and located on both sides of the atlas fitting;

[0018] The first pedicle screw and the second pedicle screw located on the same side are fixedly connected by a fixing rod and a positioning nut;

[0019] The axis fitting part and the atlas fitting part are both formed by a 3D printing method combined with a subtractive processing method.

[0020] Furthermore, the above device also includes a locking nut; the screw of the first pedicle screw includes a smooth transition section, a standard thread section and a pedicle screw thread section arranged in sequence; the locking nut is connected to the standard thread section of the first pedicle screw to fix the position of the first pedicle screw.

[0021] Furthermore, the base includes a vertical portion and a horizontal portion; one end of the horizontal portion is threadedly connected to the reset rod, and the other end is fixedly connected to the upper end of the vertical portion; the lower end of the vertical portion is fixedly connected to the upper end of the axis fitting.

[0022] Furthermore, the vertical part is fixedly connected to the horizontal part and the axis fitting into a whole in sequence by screws.

[0023] Furthermore, the above-mentioned axis fitting is provided with a plurality of grooves for winding steel wires.

[0024] Furthermore, the atlas fitting, the axis fitting, the first pedicle screw, the second pedicle screw, the fixing rod, the positioning nut, the locking nut, the pin and the screw are all made of PEEK or PEKK or TC4 or pure titanium or tantalum metal.

[0025] Furthermore, a rotating handle is provided at the upper end of the reset rod.

[0026] The beneficial effects of the present invention are:

[0027] 1. The present invention adopts a reduction mechanism and a fixation mechanism for coordinated treatment, and has the dual functions of atlantoaxial reduction and pedicle screw fixation. The atlantoaxial mobile reduction and small-amplitude rotational reduction can be easily achieved by rotating the reduction rod and utilizing the lever principle. The reduction effect is good, and the internal fixation operation can be directly performed after the atlantoaxial reduction, which ensures the stability of the reduction state and greatly reduces the operation time.

[0028] 2. The atlas fitting and the axis fitting of the present invention are both processed and formed by 3D printing, which achieves complete fit with the human bone surface. The wide contact area makes the bone surface evenly and dispersedly stressed, greatly reducing the risk of damage due to uneven bone stress and excessive local stress.

[0029] 3. The screw rod of the first pedicle screw of the present invention adopts a three-stage design, and cooperates with a locking nut. After the atlantoaxial vertebra is reset by rotating the reduction rod in the application, the current reduction state is fixed by the locking nut, thereby ensuring the stability of the reduction state, providing favorable implementation conditions for the atlantoaxial fixation that can be implemented immediately, and greatly improving the safety of the treatment;

[0030] 4. Compared with the existing traction method, the device of the present invention does not occupy the peripheral space of the operating table and does not affect the normal surgical operations of clinicians.

[0031] 5. When the reduction rod of the present invention is rotated, the force direction of the atlas fitting is opposite to the dislocation direction. In the treatment of posterior atlantoaxial dislocation, the atlas fitting and the atlas do not need to be fixed with wires, which reduces the treatment steps and saves treatment time.

[0032] 6. The device of the present invention can be used in conjunction with a conventional head traction and reduction device to hopefully resolve the “irreducible type” atlantoaxial dislocation classification cases; BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of an embodiment;

[0034] Figure 2 It is a schematic diagram of the relationship between the reduction rod and the atlas fitting;

[0035] Figure 3 It is a schematic diagram of the structure of the first pedicle screw placement;

[0036] Figure 4 for Figure 1 Schematic diagram of the structure after removing the pedicle screws;

[0037] Figure 5 It is a structural schematic diagram of the use process of the present invention.

[0038] The reference numerals are as follows:

[0039] 1-atlas fitting, 2-base, 21-vertical part, 22-horizontal part, 3-reduction rod, 4-axis fitting, 5-first pedicle screw, 51-smooth transition section, 52-standard threaded section, 53-pedicle screw threaded section, 6-second pedicle screw, 7-fixing rod, 8-positioning nut, 9-atlas, 10-pressing hole, 11-axis, 12-guide hole. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be noted that the terms “first” and “second” are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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, a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] Embodiment Structure

[0044] like Figure 1 As shown, this embodiment provides a reduction and fixation device for atlantoaxial dislocation, including a reduction mechanism and a fixation mechanism;

[0045] The resetting mechanism is used to adjust the position of the atlas and axis, so as to achieve the resetting of the dislocated atlas and axis. When the resetting is completed, the mechanism can be completely removed. The mechanism includes an atlas fitting 1, a base 2 and a resetting rod 3;

[0046] The fixing mechanism is used to fix the atlas and axis after reduction. After fixation, it can be determined whether to remove it according to the length of recovery time. It includes an axis fitting 4, a first pedicle screw 5, a second pedicle screw 6, a fixing rod 7 and a positioning nut 8.

[0047] The lower end surface of the atlas fitting piece 1 is completely adapted to the bone surface of the atlas 9, and can be closely fitted to the bone surface of the atlas 9 when in use. The upper end of the atlas fitting piece 1 is provided with a pressing hole 10;

[0048] The lower end surface of the axis fitting piece 4 is completely adapted to the bone surface of the axis 11, and can be closely fitted to the bone surface of the axis 11 when in use. The base 2 is installed in the middle of the upper end of the axis fitting piece 4, and guide holes 12 are set on both sides of the axis fitting piece 4;

[0049] The reset rod 3 is threadedly connected to the base 2, and one end of the reset rod 3 is inserted into the pressure hole 10, and the atlas fitting 1 and the reset rod 3 are connected by a pin, a screw or a steel wire (such as Figure 2 As shown, the small holes at A and B in the figure are the connecting holes used to connect the atlas fitting 1 and the reduction rod 3), and the rotation reduction rod 3 is used to adjust the atlas and axis to achieve the reduction of the two;

[0050] There are two first pedicle screws 5, which are respectively inserted into the axis 11 through two guide holes 12; there are two second pedicle screws 6, which are respectively inserted into the atlas 9 and located on both sides of the atlas fitting 1;

[0051] The first pedicle screw 5 and the second pedicle screw 6 located on the same side are fixedly connected by a fixing rod 7 and a positioning nut 8;

[0052] The atlas fitter 1 and the axis fitter 4 are both formed by 3D printing combined with subtractive processing. Since the axis fitter 4 may remain in the human body for a long time and both the atlas fitter 1 and the axis fitter 4 need to withstand greater tension and pressure during the operation, the atlas fitter 1 and the axis fitter 4 can be made of PEEK or PEKK or TC4 or pure titanium or tantalum metal.

[0053] On this basis, this embodiment also makes the following optimized design:

[0054] 1. In order to prevent the atlantoaxial vertebra from loosening after being in a reduced state, the first pedicle screw 5 implanted in the axis 11 is specially designed in this embodiment (it should be noted that the screw head of the first pedicle screw is consistent with the commercially available pedicle screw, and only the screw rod is designed). Figure 3As shown, the screw rod of the first pedicle screw 5 includes a smooth transition section 51, a standard thread section 52 and a pedicle screw thread section 53 which are arranged in sequence; the screw rod is connected to the standard thread section 52 of the first pedicle screw 5 by a locking nut to fix the position of the first pedicle screw 5, thereby ensuring that the reset state does not change. The second pedicle screw 6 can adopt a commercially available product.

[0055] 2. The reduction mechanism adopts a rotating reduction rod 3 and utilizes the lever principle to easily achieve the mobile reduction and small-amplitude rotation reduction of the atlantoaxial vertebra, while ensuring the rationality of the structure. Figure 4 As shown, the base 2 of this embodiment is L-shaped, including a vertical portion 21 and a horizontal portion 22; one end of the horizontal portion 22 is threadedly connected to the reset rod 3, and the other end is fixedly connected to the upper end of the vertical portion 21, and the lower end of the vertical portion 21 is fixedly connected to the upper end of the axis fitting 4. Preferably, in this embodiment, the vertical portion is fixedly connected to the horizontal portion 22 and the axis fitting 4 in sequence as a whole by screws.

[0056] 3. In order to prevent the steel wire from slipping due to winding, the axis fitting 4 is provided with a plurality of grooves for winding the steel wire.

[0057] 4. Since the fixing mechanism may retain the human body, the first pedicle screw, the second pedicle screw, the fixing rod, the positioning nut, the locking nut, and the pin or screw in this embodiment are all made of PEEK or PEKK or TC4 or pure titanium or tantalum metal.

[0058] 5. For easy operation, a rotating handle is provided at the upper end of the reset rod 3 of this embodiment.

[0059] Based on the description of the structure of the embodiment, the manufacturing method and the use method of the device are introduced respectively:

[0060] Preparation method

[0061] Step A1, collecting medical image data (including but not limited to CT data) of the affected part of the patient with atlantoaxial dislocation, using medical image data processing software (including but not limited to Mimics software) to perform noise reduction, threshold segmentation, three-dimensional reconstruction and other operations on the collected medical image data, reconstructing a three-dimensional model of the patient's head and spine (including at least the atlas and axis), and restoring information such as the state and position of the atlantoaxial dislocation;

[0062] Step A2, importing the three-dimensional model reconstructed in step A1 into 3-matic software, and based on the skull and atlantoaxial bone surfaces, using a series of functions of the 3-matic software, designing personalized fitting parts that can perfectly fit with the atlantoaxial bone surfaces, namely, atlas fitting parts and axis fitting parts;

[0063] Step A3: Use turning, milling, planing, grinding or CNC machining techniques to process components other than the personalized parts, and use selective laser melting (SLM), selective laser sintering (SLS) or fused deposition modeling (FDM) to 3D print the atlas fittings and axis fittings in step 2, followed by post-processing such as drilling, surface polishing, and heat treatment.

[0064] How to use

[0065] like Figure 5 As shown, step B1, disinfecting and sterilizing the above-made parts to make them meet the relevant use standards of surgical instruments;

[0066] Step B2: First, the axis fitting member 4 is fixed by winding with a steel wire so that it is perfectly fitted and fixed with the axis 11;

[0067] Step B3, drilling a hole on the axis according to the guide hole on the axis fitting 4;

[0068] Step B4, install the locking nut on the first pedicle screw 5 in advance, then perform the pedicle screw surgery, and then tighten the locking nut to further strengthen the connection between the axis fitting 4 and the axis 11;

[0069] Step B5, installing the base 2 on the axis fitting 4 by screws;

[0070] Step B6, placing the atlas fitting 1 on the atlas 9;

[0071] Step B7, install the locking nut on the reset rod 3, and then install the reset rod 3 on the base 2;

[0072] Step B8, connecting the reduction rod 3 and the atlas fitting 1 through a pin, a screw or a steel wire;

[0073] Step B9, according to the patient's atlantoaxial dislocation condition, rotate the reduction rod 3 to perform reduction movement, and after the reduction is completed, tighten the nut on the reduction rod 3 to complete the reduction operation;

[0074] Step B10, drilling holes on the atlas 9 on both sides of the atlas fitting 1, and implanting two second pedicle screws 6 on both sides of the atlas 9;

[0075] Step B11, fixing the atlantoaxial vertebra after reduction by installing the fixing rod 7 and the positioning nut 8 on the nuts of the first pedicle screw 5 and the second pedicle screw 6 on the same side;

[0076] Step B12, remove the reduction rod 3, the base 2 and the atlas fitting plate 1 (ie, remove the reduction mechanism) to complete the operation.

Claims

1. A device for reducing and fixing atlantoaxial dislocation, characterized in that: including a resetting mechanism and a fixing mechanism; The reduction mechanism is used to adjust the position of the atlas and axis, and includes an atlas fitting, a base, and a reduction rod; The fixing mechanism is used to fix the atlas and axis after reduction, and includes an axis fitting piece, a first pedicle screw, a second pedicle screw, a fixing rod and a positioning nut; The lower end surface of the atlas fitting piece is completely matched with the atlas bone surface, and a pressing hole is provided at the upper end of the atlas fitting part; The lower end surface of the axis fitting piece is completely matched with the axis bone surface, the base is installed in the middle of the upper end of the axis fitting piece, and guide holes are arranged on both sides of the axis fitting piece; The reduction rod is threadedly connected to the base, and one end of the reduction rod is inserted into the pressure hole and connected by a pin, a screw or a steel wire. The reduction rod is rotated to adjust the atlantoaxial vertebra to achieve the reduction of the two. There are two first pedicle screws, which are respectively inserted into the axis through two guide holes; there are two second pedicle screws, which are respectively inserted into the atlas and located on both sides of the atlas fitting; The first pedicle screw and the second pedicle screw located on the same side are fixedly connected by a fixing rod and a positioning nut; The axis fitting part and the atlas fitting part are both formed by 3D printing combined with subtractive processing; The base includes a vertical portion and a horizontal portion; one end of the horizontal portion is threadedly connected to the reset rod, and the other end is fixedly connected to the upper end of the vertical portion; the lower end of the vertical portion is fixedly connected to the upper end of the axis fitting; The vertical part is fixedly connected to the horizontal part and the axis fitting part in sequence by screws into a whole; It also includes a locking nut; the screw of the first pedicle screw includes a smooth transition section, a standard thread section and a pedicle screw thread section which are arranged in sequence; the locking nut is connected to the standard thread section of the first pedicle screw to fix the position of the first pedicle screw; The axis fitting piece is provided with a plurality of grooves for winding steel wires.

2. The device for reducing and fixing atlantoaxial dislocation according to claim 1, characterized in that: The atlas fitting, the axis fitting, the first pedicle screw, the second pedicle screw, the fixing rod, the positioning nut, the locking nut, the pin and the screw are all made of PEEK or PEKK or TC4 or pure titanium or tantalum metal.

3. The device for reducing and fixing atlantoaxial dislocation according to claim 2, characterized in that: A rotating handle is arranged on the upper end of the reset rod.

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