Progressive self-guiding pedicle screw path builder

Abstract

The utility model discloses a progressive self-guiding pedicle screw path builder which comprises a handle, a connecting rod, a cortical bone thread part, a cancellous bone thread part and a blunt end. The handle is fixedly installed at the tail end of the connecting rod, the cortical bone thread part is fixedly installed on the outer side wall of the front end of the connecting rod, the front end of the cortical bone thread part is connected with the cancellous bone thread part, and the front end of the cancellous bone thread part is fixedly connected with the blunt end; the blunt end is inserted into the cancellous bone by bare hands, the handle rotates to generate trace advancing force (so that the cancellous bone is prevented from penetrating through the cortical bone to be steerable) through the threads of the cancellous bone, and the built preset bone tunnel is destroyed and expanded through intermittent front-and-back movement of the thread part of the cortical bone. The fixation of the preset bone tunnel on the advancing direction of the pedicle screw path builder is relieved, and automatic steering of the blunt end at the front end is facilitated.

Description

Technical Field

[0001] This utility model belongs to the field of medical device technology, specifically relating to a progressive self-guided pedicle screw tunnel creator. Background Technology

[0002] Pedicle screw fixation is a routine and core technique in spinal surgery, providing 360-degree mechanical fixation of the spine. It represents a milestone in the history of spinal surgery. The pedicle is a narrow tubular structure located between the vertebral body and the lamina. Ideally, pedicle screws should be placed within the medullary canal (i.e., cancellous bone) of the pedicle. However, in actual surgical procedures, due to poor (or incorrect) control of the entry point or angle, the screw may penetrate directly through the cortical bone surrounding the pedicle canal, causing direct damage to the surrounding nerve tissue.

[0003] The current manual process for creating a pedicle screw track involves first manually identifying the entry point, then removing the entry point and surrounding cortical bone using instruments, and finally pushing a hand conical tool (a cone-shaped or L-shaped instrument that is smaller at the front and larger at the back) into the cancellous bone of the pedicle to pre-create the pedicle screw track. Feedback during this manual track creation process comes solely from the surgeon's perception of force (commonly known as "feel"), relying entirely on personal experience. Because the existing hand conical tool maintains close contact and encircles the bone after insertion, it does not actively change direction during track creation. Furthermore, this cone-shaped structure provides resistance to the hand conical tool's advance, often lacking a clear sense of resistance even when penetrating the cortical bone. In patients with particularly osteoporotic bone, excessive force, especially at poor entry points and angles, may cause the instrument to penetrate the cortical bone, potentially damaging nerve tissue.

[0004] Therefore, how to safely and effectively establish pedicle screw channels in advance during surgery and improve the accuracy of screw placement is an urgent problem to be solved in clinical practice. Utility Model Content

[0005] To address the aforementioned technical issues, this invention presents a progressive self-guided pedicle screw tract creator. This pedicle screw tract creator allows the surgeon to easily perceive the resistance (pressure) at the tip of the pedicle screw tract and provide real-time feedback. Furthermore, by using different thread settings, it can pre-disrupt the pedicle channel and progressively change the direction of the channel tip. Additionally, the blunt tip design ensures that the tip can only disrupt brittle cancellous bone without penetrating the harder cortical bone.

[0006] To achieve the aforementioned technical effects, this utility model discloses a progressive self-guided pedicle screw track creator, comprising: a handle, a connecting rod, a cortical bone threaded portion, a cancellous bone threaded portion, and a blunt head; the handle is fixedly installed at the end of the connecting rod, the cortical bone threaded portion is fixedly installed on the outer side wall of the front end of the connecting rod, the front end of the cortical bone threaded portion connects to the cancellous bone threaded portion, and the front end of the cancellous bone threaded portion is fixedly connected to the blunt head; by rotating the control handle, the blunt head and the cancellous bone threaded portion advance along the cancellous bone without damaging the cortical bone, while the progressive back-and-forth movement of the cortical bone threaded portion slightly widens the posterior screw track, releasing the fixation of the posterior channel on the direction of the instrument's advance, facilitating the front end to turn;

[0007] Furthermore, the diameter of the connecting rod is larger than the diameter of the blunt end, and the diameter of the threaded portion of the cancellous bone decreases linearly towards the blunt end and matches the blunt end;

[0008] Furthermore, the cancellous bone threaded portion and the cortical bone threaded portion are threaded structures, and the cancellous bone threaded portion has a large and sparse pitch and deep threads, while the cortical bone threaded portion has a small and dense pitch and shallow threads.

[0009] Furthermore, the cancellous bone threaded portion has a threaded structure and the pitch of the cancellous bone threaded portion is large and sparse, while the cortical bone threaded portion has a linear array of ring-shaped structures and a wedge-shaped structure at the end.

[0010] Furthermore, the diameter of the blunt tip is between 1.5mm and 2mm, and the length is between 2mm and 3mm;

[0011] Furthermore, the length of the threaded portion of the cancellous bone is between 3mm and 4mm, and the diameter is between 3mm and 4mm; the length of the threaded portion of the cortical bone is between 40mm and 60mm, and the diameter is between 3mm and 4mm; the diameter of the connecting rod is between 2.5mm and 3mm.

[0012] Furthermore, a switch is fixedly installed on the side of the handle, and a display screen is fixedly installed on the rear end of the handle; the connecting rod is hollow inside, and an internal rod is fixedly installed inside. A pressure sensor is fixedly installed on the rear end of the internal rod, and the pressure sensor is fixedly installed inside the handle. A power supply is provided inside the handle and on the rear end of the sensor.

[0013] The beneficial effects of this utility model are:

[0014] This utility model discloses a progressive self-guided pedicle screw tunnel creator, comprising: a handle, a connecting rod, a cortical bone threaded portion, a cancellous bone threaded portion, and a blunt tip. The handle is fixedly installed at the end of the connecting rod, and the cortical bone threaded portion is fixedly installed on the outer side of the front end of the connecting rod. The front end of the cortical bone threaded portion connects to the cancellous bone threaded portion, and the front end of the cancellous bone threaded portion is fixedly connected to the blunt tip. The blunt tip is inserted into the cancellous bone by hand, and the handle is rotated to generate a small forward force using the cancellous bone thread (thus avoiding penetration of the cortical bone and allowing for steering). The intermittent back-and-forth movement of the cortical bone threaded portion destroys and expands the pre-established bone tunnel, releasing the pre-established bone tunnel from fixing the forward direction of the pedicle screw tunnel creator, facilitating the automatic steering of the blunt tip. The design of the cortical bone threaded portion and the cancellous bone threaded portion allows the channel to be formed gradually during creation. At the same time, the cortical bone threaded portion further expands the diameter of the channel, facilitating the steering of the blunt tip. Furthermore, the blunt tip replaces the traditional pointed tip, which can destroy the internal cancellous bone without penetrating the adjacent cortical bone.

[0015] In addition, this invention uses a progressive approach to eliminate the situation where the posterior structure tightly grips the condyle. During the establishment of the nail channel, only a small amount of cancellous bone strength at the front end is used to obtain a small forward force, which can effectively avoid the situation of manual forceful insertion. If it encounters cortical bone with a strength higher than cancellous bone, it can slide towards the cortical bone, thereby achieving automatic guidance and avoiding direct penetration of the cortical bone, which would cause nerve tissue damage.

[0016] In addition, this invention has an internal rod inside the connecting rod, which is connected to a pressure sensor. The pressure sensor can display the pressure value in real time, which can replace the traditional method of relying entirely on the doctor's experience and feel, making the establishment of the channel more accurate and more user-friendly for novice doctors. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0018] Figure 1 This is a schematic diagram of the overall structure of a progressive self-guided pedicle screw tunnel creator;

[0019] Figure 2 This is another overall structure and a partially enlarged schematic diagram of a progressive self-guided pedicle screw tunnel creator;

[0020] Figure 3 This is a front view of a progressive self-guided pedicle screw track creator;

[0021] Figure 4 This is a cross-sectional view of a progressive self-guided pedicle screw track creator.

[0022] The attached diagram lists the components represented by each number as follows:

[0023] 1-Handle, 11-Switch, 12-Display, 2-Connecting rod, 3-Cortical bone threaded part, 4-Cancellous bone threaded part, 5-Blunt head, 6-Built-in rod, 7-Pressure sensor, 8-Power supply. Detailed Implementation

[0024] Example 1

[0025] A progressive self-guided pedicle screw channel creator includes: a handle 1, a connecting rod 2, a cortical bone threaded portion 3, a cancellous bone threaded portion 4, and a blunt tip 5. The handle 1 is fixedly mounted at the end of the connecting rod 2, and the cortical bone threaded portion 3 is fixedly mounted on the outer wall of the front end of the connecting rod 2. The front end of the cortical bone threaded portion 3 connects to the cancellous bone threaded portion 4, and the front end of the cancellous bone threaded portion 4 is fixedly connected to the blunt tip 5. The handle 1 controls the forward and backward movement to insert the blunt tip 5 into the cancellous bone. The rotation of the handle 1 causes the cancellous bone threaded portion to engage with the cancellous bone, providing a small forward force. The intermittent forward and backward movement of the handle 1 utilizes the cortical bone threaded portion to widen the channel for easier turning. The design of the cortical bone threaded portion 3 and the cancellous bone threaded portion 4 allows for gradual channel formation during creation. The cortical bone threaded portion 3 further widens the diameter of the channel, facilitating the turning of the blunt tip 5. Furthermore, the blunt tip 5 replaces the traditional pointed tip, allowing for the destruction of the internal cancellous bone without penetrating the cortical bone.

[0026] In addition, in this embodiment, the diameter of the connecting rod 2 is larger than the diameter of the blunt tip 5, and the diameter of the cancellous bone threaded portion 4 decreases linearly towards the central axis of the blunt tip 5 and matches the blunt tip 5; the diameter of the blunt tip 5 is between 1.5mm and 2mm, and the length is between 2mm and 3mm. If the diameter of the blunt tip 5 is too small, it is easy to puncture the bone cortex, and when a certain force is applied, it will quickly penetrate the bone cortex, causing damage to the internal nerve tissue. If the diameter of the blunt tip 5 is too large, the force required to destroy the bone will increase, consuming more effort from medical personnel. Therefore, according to actual... It is more suitable to control the diameter of the blunt tip 5 between 1.5mm and 2mm; at the same time, the diameter of the connecting rod 2 should be between 2.5mm and 3mm. Since the length and diameter of the blunt tip 5 need to be controlled within a certain range, and the diameter of the connecting rod 2 is suitable to be between 2.5mm and 3mm, the linear change relationship (or the angle change relationship is determined by its length) of the cancellous bone threaded part 4 can be selected according to actual needs. The optimal angle in clinical trials is 15° (the angle formed by the cancellous bone threaded part 4 and the axis of the connecting rod 2).

[0027] Example 2

[0028] In this embodiment, the cancellous bone threaded portion 4 and cortical bone threaded portion 3 described in Embodiment 1 can be divided into the following forms: The first form is that the cancellous bone threaded portion 4 and cortical bone threaded portion 3 are threaded structures, with the cancellous bone threaded portion 4 having a large and sparse pitch, and the cortical bone threaded portion 3 having a small and dense pitch. This method directly uses the threads to establish and open the channel. This method can effectively expand the nail channel through the threads of the cortical bone threaded portion 3. However, this method still has a problem: when expanding the channel using threads, the threaded teeth are used to open the channel, but the tips of the threads are flat, which brings problems during expansion. The resistance is relatively large, and the flat opening is not conducive to rapid destruction of cortical bone; therefore, this embodiment provides another method for destroying cortical bone. Specifically, the cancellous bone threaded portion 4 is a threaded structure with a large and sparse pitch, and the cortical bone threaded portion 3 is a linear array of ring-shaped structures with a wedge-shaped end. The main feature is the ring-shaped structure of the cortical bone threaded portion, which is different from ordinary threads. The upper and lower ring-shaped structures are not directly connected, and the end is a wedge-shaped structure (a symmetrical wedge shape, which makes the contact part a point, which is more conducive to destroying bone, and can move back and forth and rotate to destroy, making destruction easier).

[0029] In this embodiment, the length of the cancellous bone portion is between 3mm and 4mm, and the diameter is between 3mm and 4mm. The length of the cortical bone threaded portion 3 is between 40mm and 60mm, and the diameter is between 3mm and 4mm. Since the length of the pedicle screw channel is determined based on the diameter of the patient's vertebrae, it can be selected according to actual needs in this embodiment. Too long a channel is inconvenient for medical staff to operate and also wastes materials; too short a channel will not meet the requirements for establishment.

[0030] Example 3

[0031] In this embodiment, a switch 11 is fixedly installed on the side of the handle 1, and a display screen 12 is fixedly installed at the rear end of the handle 1. The display screen 12 can display the pressure in real time. The connecting rod 2 is hollow inside, and an internal rod 6 is fixedly installed inside. A pressure sensor 7 is fixedly installed at the rear end of the internal rod 6. The pressure sensor 7 is fixedly installed inside the handle 1, and a power supply 8 is provided inside the handle 1 at the rear end of the sensor. The pressure sensor 7 is connected to the internal rod 6. The pressure sensor 7 can display the pressure value in real time, which can replace the traditional method of relying entirely on the doctor's experience and feel, making the channel establishment more accurate and more user-friendly for novice doctors. The working principle of the sensor and its connection relationship with the display screen 12 (or control unit) are existing technologies and will not be described in detail here. At the same time, the sensor is placed inside the handle 1. The size of the handle 1 can be controlled or appropriately expanded according to actual needs. The pressure sensor 7 can be a piezoresistive pressure sensor, such as the SBT760F micro sensor or the JTW-D08 micro sensor.

[0032] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to the specific implementation methods described.

Claims

1. A progressive self-guided pedicle screw track creator, comprising: The device comprises a handle, a connecting rod, a cortical bone threaded portion, a cancellous bone threaded portion, and a blunt tip. The handle is fixedly mounted at the end of the connecting rod, and the cortical bone threaded portion is fixedly mounted on the outer side wall of the front end of the connecting rod. The front end of the cortical bone threaded portion connects to the cancellous bone threaded portion, and the front end of the cancellous bone threaded portion is fixedly connected to the blunt tip. By rotating the handle, the blunt tip and the cancellous bone threaded portion advance along the cancellous bone without damaging the cortical bone. At the same time, the progressive back-and-forth movement of the cortical bone threaded portion slightly widens the posterior pin channel, releasing the posterior channel from fixing the direction of the instrument's advance and facilitating turning.

2. The progressive self-guided pedicle screw track establisher according to claim 1, characterized in that, The diameter of the connecting rod is larger than the diameter of the blunt end, and the diameter of the threaded portion of the cancellous bone decreases linearly towards the blunt end and matches the blunt end.

3. The progressive self-guided pedicle screw track creator according to claim 1, characterized in that, The cancellous bone threaded portion and the cortical bone threaded portion are threaded structures, with the cancellous bone threaded portion having a large and sparse pitch and deep threads, while the cortical bone threaded portion has a small and dense pitch and shallow threads.

4. The progressive self-guided pedicle screw track establisher according to claim 1, characterized in that, The cancellous bone threaded portion has a threaded structure with a large and sparse pitch, while the cortical bone threaded portion has a linear array of ring-shaped structures with wedge-shaped ends.

5. The progressive self-guided pedicle screw track establisher according to claim 1, characterized in that, The diameter of the blunt tip is between 1.5mm and 2mm, and the length is between 2mm and 3mm.

6. The progressive self-guided pedicle screw track establisher according to claim 1, characterized in that, The length of the threaded portion of the cancellous bone is between 3mm and 4mm, and the diameter is between 3mm and 4mm; the length of the threaded portion of the cortical bone is between 40mm and 60mm, and the diameter is between 3mm and 4mm; the diameter of the connecting rod is between 2.5mm and 3mm.

7. The progressive self-guided pedicle screw track establisher according to claim 1, characterized in that, A switch is fixedly installed on the side of the handle, and a display screen is fixedly installed on the rear end of the handle; the connecting rod is hollow inside, and an internal rod is fixedly installed inside. A pressure sensor is fixedly installed on the rear end of the internal rod. The pressure sensor is fixedly installed inside the handle, and a power supply is provided inside the handle at the rear end of the sensor.

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