Tooling gauge and detection method for spinal pedicle screw

Abstract

The application discloses a tool gauge and detection method for a spinal pedicle screw, and belongs to the technical field of medical devices. The tool gauge for the spinal pedicle screw comprises an inner ball diameter measuring gauge, which is used for detecting the diameter of an inner ball surface of a pedicle screw seat matched with a gasket or a ball screw. The inner ball diameter measuring gauge comprises a middle shaft rod, a lower large circular plate is fixedly arranged at the front end of the middle shaft rod, an upper small circular plate parallel to the lower large circular plate is sleeved on the middle shaft rod above the lower large circular plate, an elastic member is arranged between the lower large circular plate and the upper small circular plate to keep the two plates in an open state, the diameter of the lower large circular plate is larger than that of the upper small circular plate, and the diameters of the lower large circular plate and the upper small circular plate are both between the maximum cross-sectional circular diameter of the inner ball surface and the minimum cross-sectional circular diameter of the inner ball surface. The tool gauge and detection method for the spinal pedicle screw have low detection cost, high efficiency and high detection accuracy.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a tooling and testing method for spinal pedicle screws. Background Technology

[0002] Rod-pedicle screw fixation is a common internal fixation technique in spinal surgery for spinal correction. During the procedure, pedicle screws and connecting rods are used to connect and fix the diseased vertebrae to restore the patient's spinal curvature and reconstruct spinal height. Therefore, the quality of the pedicle screws is crucial to the success of rod-pedicle screw fixation surgery.

[0003] like Figure 1-3 As shown, a typical pedicle screw fixation system includes a pedicle screw 1', a connecting rod 2', and a plug 3'. The pedicle screw 1' includes a ball screw 11', a screw seat 12', and a washer 13'. During the processing and assembly of the pedicle screw, the size and position of the inner spherical surface 14' within the screw seat 12' that mates with the washer 13' or the ball screw 11' are crucial. If the inner spherical surface 14' is too small or positioned too high, it will reduce the swing angle of the ball screw 11', thus deviating from the original design intent. If the inner spherical surface 14' is too large or positioned too low, it will reduce the strength of the pedicle screw and increase the risk of the ball screw 11' dislodging from the screw seat 12'. Therefore, the size and position of the inner spherical surface of the pedicle screw seat is an important and critical inspection dimension.

[0004] With the increasing diversity of clinical surgeries, modular (split-type) screws are being used more and more widely for easier observation. When using modular screws, the ball screw needs to be placed in the appropriate position on the vertebral body first, and then the screw seat is placed on the ball head of the screw. This requires the diameter of the inner spherical surface of the screw seat to be larger than the diameter of the internal thread at the tail of the screw seat. Conventional internal spherical surface gauges cannot accurately measure the size and position of the inner spherical surface of the screw seat. Current technology requires the use of a profilometer or dissection of the screw seat for imaging, which has the following disadvantages:

[0005] 1. Contour measuring instruments and imaging instruments are usually expensive. Using contour measuring instruments and imaging instruments requires professional quality inspection personnel to operate them, which will significantly increase the processing and inspection costs of pedicle screw seats and reduce efficiency.

[0006] 2. The method of dissecting the staple seat is called "destructive measurement" in actual production. It adds extra steps and raw materials for testing, which increases the cost of processing personnel and raw materials. Furthermore, dissecting the staple seat for testing is not suitable for the factory inspection of medical device products. In the medical device production process, subsequent processing such as magnetic grinding and anodizing may cause the medical device to exceed the dimensional tolerance if excessive or repeated. More importantly, dissecting the staple seat may go beyond the center position of the staple seat, resulting in larger measurement errors and posing safety hazards to the operation. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a tooling and inspection method for detecting pedicle screws of the spine that is low in cost, high in efficiency and accurate in detection.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0009] On one hand, a tooling fixture for spinal pedicle screws is provided, including an inner ball diameter measuring fixture for measuring the diameter of the inner spherical surface that mates with a washer or ball screw within the screw seat of the pedicle screw. The inner ball diameter measuring fixture includes a central shaft, with a lower large circular plate fixed to the front end of the central shaft. An upper small circular plate, parallel to the lower large circular plate, is sleeved on the central shaft above the lower large circular plate. An elastic element is provided between the lower large circular plate and the upper small circular plate to keep them in an open state. The diameter of the lower large circular plate is larger than the diameter of the upper small circular plate, and both the diameters of the lower large circular plate and the upper small circular plate are between the maximum cross-sectional circle diameter and the minimum cross-sectional circle diameter of the inner spherical surface.

[0010] Furthermore, both sides of the lower large circular piece and the upper small circular piece are provided with flat surfaces;

[0011] And / or, the elastic element is a disc spring sleeved on the central shaft.

[0012] Furthermore, the tooling fixture also includes a fixing fixture, which can fix the inner ball diameter measuring fixture at the inner ball surface. The fixing fixture includes an operating rod, the front end of which is provided with abutment surface, the front part of which is provided with a drive thread that mates with the internal thread of the pedicle screw seat, and the rear end of which is provided with an operating part.

[0013] Furthermore, the abutting surface is spherical;

[0014] And / or, the diameter of the operating rod is smaller than the diameter of the internal thread of the pedicle screw seat;

[0015] And / or, the operating part is a knob.

[0016] Furthermore, the tooling fixture also includes a first inner ball position measuring fixture, used when the diameter of the hole on the inner spherical side of the pedicle screw seat is larger than the diameter of the hole on the inner thread side of the seat. The first inner ball position measuring fixture includes a first ball head, a connecting rod, and a handle connected in sequence, and the radius of the first ball head is the same as the radius of the inner spherical surface.

[0017] Furthermore, the first ball head has a flat surface on both sides of the direction in which the connecting rod passes through the pedicle screw seat;

[0018] And / or, the first ball head is provided with a plane in the direction of the opening toward the pedicle screw seat;

[0019] And / or, the connecting rod is inclined.

[0020] Furthermore, the tooling fixture also includes a second inner ball position measuring fixture, used when the diameter of the hole on the inner spherical side of the pedicle screw seat is smaller than the diameter of the hole on the inner thread side of the screw seat. The second inner ball position measuring fixture includes a fixture rod, and the front end of the fixture rod is provided with a second ball head. The radius of the second ball head is the same as the radius of the inner spherical surface. The distance from the center of the second ball head to its front end face is less than the distance from the center of the inner spherical surface to the end face of the inner spherical side of the screw seat.

[0021] On the other hand, a method for detecting the diameter of an inner spherical surface using the aforementioned tooling and fixture is provided, comprising:

[0022] Step 1: Insert the lower large circular piece and the upper small circular piece of the inner sphere diameter measuring gauge into the inner sphere surface through the side hole of the inner sphere surface of the pedicle screw seat;

[0023] Step 2: Screw the operating rod of the fixing fixture into the internal thread of the pedicle screw seat. As the operating rod is screwed in, the front end of the operating rod finally contacts and presses against the lower end face of the lower large circular plate of the inner ball diameter measuring gauge.

[0024] Step 3: Measure the distance from the upper end face of the central shaft of the inner ball diameter measuring fixture to the upper end face of the upper small circular piece;

[0025] Step 4: Calculate the radius of the inner sphere based on the distance from the upper end face of the central shaft to the upper end face of the upper small circular piece, the known distance from the upper end face of the central shaft to the upper end face of the lower large circular piece, the diameter of the lower large circular piece, and the diameter of the upper small circular piece.

[0026] Furthermore, a method for detecting the position of an inner spherical surface using the aforementioned tooling and fixture is provided, comprising:

[0027] Step 1: Insert the first ball head of the first inner ball position measuring gauge into the inner ball surface through the side hole of the inner ball surface of the pedicle screw seat;

[0028] Step 2: Screw the operating rod of the fixing fixture into the threaded hole of the nail seat. As the operating rod is screwed in, the front end of the operating rod finally contacts and presses against the bottom surface of the first ball head of the first inner ball position measuring gauge.

[0029] Step 3: Measure the height of the first inner ball head of the measuring instrument protruding from the inner spherical side surface of the pedicle screw seat;

[0030] Step 4: Based on the height of the first ball head protruding from the inner spherical side end of the pedicle screw seat and the known radius of the first ball head, calculate the distance from the center of the inner spherical surface to the inner spherical side end of the pedicle screw seat, and determine whether the product is qualified based on this distance.

[0031] On another front, a method for detecting the position of an inner spherical surface using the aforementioned tooling and fixture is provided, comprising:

[0032] Step 1: Insert the second ball head of the second inner ball position measuring gauge into the pedicle screw seat along the internal thread side of the pedicle screw seat until the spherical surface of the second ball head is in contact with the inner ball surface;

[0033] Step 2: Measure the distance from the inner spherical end face of the pedicle screw seat to the rear end face of the measuring rod of the measuring instrument at the position of the second inner sphere;

[0034] Step 3: Calculate the distance from the inner spherical end face of the pedicle screw seat to the rear end face of the gauge rod based on the distance from the inner spherical end face of the pedicle screw seat to the position of the second inner ball, and the known distance from the center of the second ball head to the rear end face of the gauge rod. Then, determine whether the product is qualified based on this distance.

[0035] The present invention has the following beneficial effects:

[0036] The tooling and testing method for spinal pedicle screws of this invention has a simple structure and is easy to operate. It can replace the use of contour measuring instruments and imaging instruments for testing, eliminating the need for manufacturing companies to purchase expensive equipment such as contour measuring instruments and imaging instruments specifically for testing the spherical surface of the pedicle screw seat. This saves companies unnecessary large expenses, reduces testing costs, avoids "destructive measurement" by dissecting the screw seat, reduces processes, saves raw materials, and lowers labor and processing costs. Moreover, it does not require professional quality inspection personnel to operate, is highly efficient, and provides accurate testing. It can be applied to all on-site points in the process of pedicle screw seat processing, subsequent procedures, and factory inspection, thereby achieving comprehensive testing and control of the quality of the pedicle screw seat, improving the overall quality of pedicle screws, and providing more reliable and safer protection for surgeons and patients. Attached Figure Description

[0037] Figure 1 This is a structural diagram of a prior art nail-bar fixing system;

[0038] Figure 2 This is a schematic diagram of the structure of a pedicle screw in the prior art;

[0039] Figure 3 This is a schematic diagram of the structure of the pedicle screw socket in the prior art, where (a) is a cross-sectional view of one socket and (b) is a cross-sectional view of another socket.

[0040] Figure 4 This is a schematic diagram of the inner ball diameter measuring fixture in the tooling fixture for spinal pedicle screws of the present invention, wherein (a) is a front view, (b) is a side view of (a), and (c) is a top view of (a).

[0041] Figure 5 This is a schematic diagram of the fixing fixture in the tooling and inspection fixture for the spinal pedicle screw of the present invention, wherein (a) is a front view and (b) is a bottom view of (a);

[0042] Figure 6 This is a schematic diagram illustrating the working principle of the inner ball diameter measuring fixture and the fixing fixture in the tooling and fixture for the spinal pedicle screw of the present invention.

[0043] Figure 7 The diagram shows the inspection status of the inner ball diameter measuring fixture and the fixing fixture in the tooling fixture for the spinal pedicle screw of the present invention, wherein (a) is a front view, (b) is a side view, and (c) is a sectional view.

[0044] Figure 8 This is a schematic diagram illustrating the calculation principle of the inner spherical diameter of the pedicle screw seat in the tooling fixture for the spinal pedicle screw of the present invention.

[0045] Figure 9 This is a schematic diagram of the structure of the first inner ball position measuring fixture in the tooling fixture for the spinal pedicle screw of the present invention, wherein (a) is a front view, (b) is a left view of (a), and (c) is a top view of (a).

[0046] Figure 10 This is a schematic diagram illustrating the working principle of the first inner ball position measuring fixture and the fixing fixture in the tooling fixture for the spinal pedicle screw of the present invention.

[0047] Figure 11 The diagram shows the inspection status of the first inner ball position measuring fixture and the fixing fixture in the tooling fixture for the spinal pedicle screw of the present invention, wherein (a) is a front view, (b) is a side view, and (c) is a sectional view.

[0048] Figure 12 This is a schematic diagram of the second inner ball position measuring fixture in the tooling fixture for spinal pedicle screws of the present invention.

[0049] Figure 13This is a diagram showing the detection state of the second inner ball position measuring fixture in the tooling fixture for the spinal pedicle screw of the present invention, wherein (a) is a front view and (b) is a sectional view. Detailed Implementation

[0050] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0051] On the one hand, the present invention provides a tooling fixture for spinal pedicle screws, such as... Figure 4-8 As shown, the device includes an inner sphere diameter measuring instrument 1, used to measure the diameter of the inner sphere 14' that mates with the washer 13' or the ball screw 11' within the screw seat 12' of the pedicle screw 1'. The inner sphere diameter measuring instrument 1 includes a central shaft 11. A lower large circular plate (flat circular plate) 12 is fixed to the front end of the central shaft 11 (which can be an integral structure). An upper small circular plate 13, parallel to the lower large circular plate 12, is sleeved on the central shaft 11 above the lower large circular plate 12 (specifically, the center of the upper small circular plate 13 has a central hole 131 that is clearance-fitted with the central shaft 11). An elastic element 14 is provided between the lower large circular plate 12 and the upper small circular plate 13 to keep them in an open state. The diameter d2 of the lower large circular plate 12 is greater than the diameter d1 of the upper small circular plate 13. The diameters d2 of the lower large circular plate 12 and d1 of the upper small circular plate 13 are both between the maximum cross-sectional circle diameter and the minimum cross-sectional circle diameter of the inner sphere 14'.

[0052] The tooling and inspection fixture for spinal pedicle screws of this invention can replace the use of contour measuring instruments and imaging instruments for inspection. This eliminates the need for manufacturing companies to purchase expensive equipment such as contour measuring instruments and imaging instruments specifically for inspecting the spherical surface of the pedicle screw seat, saving unnecessary and substantial expenses. The inspection cost is low, and it avoids "destructive measurement" by dissecting the screw seat, reducing processes, saving raw materials, and lowering labor and processing costs. Furthermore, its simple structure and convenient operation require no specialized quality inspection personnel, resulting in high efficiency and accurate inspection. It can be applied to various on-site points in the pedicle screw seat process, from machining to subsequent procedures and factory inspection, thereby achieving comprehensive inspection and control of the pedicle screw seat quality, improving the overall quality of pedicle screws, and providing more reliable and safer protection for surgeons and patients. This invention is mainly applicable when the diameter of the spherical side hole of the screw seat is larger than the diameter of the threaded side hole.

[0053] like Figure 4 As shown in (c), both sides of the lower large circular plate 12 and the upper small circular plate 13 can be provided with flat surfaces so that the two circular plates are in the shape of a racetrack, which facilitates the insertion of the two circular plates into the inner spherical surface 14' side hole of the pedicle screw 1' base 12' to the inner spherical surface 14'. The elastic element 14 is preferably a disc spring sleeved on the central shaft 11.

[0054] like Figure 5-7As shown, to facilitate fixing the inner sphere diameter measuring fixture 1 and the first inner sphere position measuring fixture 3 (described later) at the inner sphere surface 14', the tooling fixture of the present invention may further include a fixing fixture 2. The fixing fixture 2 can fix the inner sphere diameter measuring fixture 1 at the inner sphere surface 14'. The fixing fixture 2 includes an operating lever 21. The front end of the operating lever 21 is provided with a contact surface 22. The front part of the operating lever 21 is provided with a drive thread 23 that mates with the internal thread 15' of the pedicle screw 1' seat 12'. The rear end of the operating lever 21 is provided with an operating part 24. The operating part 24 can be a knob for easy operation.

[0055] Furthermore, the abutment surface 22 is preferably spherical, so that regardless of whether the lower end face of the lower large circular piece 12 / the bottom face of the first ball head 31 is horizontal, the abutment surface 22 can slowly contact and begin to bear force with the lower end face of the lower large circular piece 12 / the bottom face of the first ball head 31 until it finally contacts and presses together, so that the outer spherical surfaces of the lower large circular piece 12 and the upper small circular piece 13 / the first ball head 31 are completely flush with the inner spherical surface 14' of the nail seat 12'. The diameter of the operating rod 21 of the fixing fixture 2 in this invention does not need to be confirmed in a specific dimension, it is only necessary to ensure that the bare part of the operating rod 21 can pass through the small diameter of the internal thread 15' of the pedicle screw 1' nail seat 12', that is, the diameter of the operating rod 21 is preferably smaller than the diameter of the internal thread 15' of the pedicle screw 1' nail seat 12'.

[0056] On the other hand, the present invention provides a method for detecting the diameter of the inner spherical surface 14' using the above-mentioned tooling fixture (inner sphere diameter measuring fixture 1), comprising:

[0057] Step 1: Insert the lower large circular piece 12 and the upper small circular piece 13 of the inner sphere diameter measuring gauge 1 into the inner sphere 14' side hole along the inner sphere 14' side hole of the pedicle screw 1' base 12';

[0058] Step 2: Screw the operating rod 21 of the fixing fixture 2 into the internal thread 15' of the pedicle screw 1' and the base 12'. As the operating rod 21 is screwed in, the front end of the operating rod 21 finally contacts and presses against the lower end face of the lower large circular plate 12 of the inner ball diameter measuring gauge 1.

[0059] In this step, the distance between the front end (abutment surface) of the operating rod 21 of the fixed fixture 2 and the drive thread 23 needs to be ensured. The operating rod 21 is inserted into the side hole of the internal thread 15' of the nail seat 12. When the drive thread 23 contacts the internal thread 15' of the nail seat 12, the abutment surface 22 has not yet contacted the lower end face of the lower large circular piece 12. Thus, as the knob 24 is rotated, from the initial contact of the drive thread 23 and the internal thread 15' of the nail seat 12 to the thread engagement process, the abutment surface 22 finally contacts and presses against the lower end face of the lower large circular piece 12. During this process, the lower end face of the lower large circular piece 12 should be kept as horizontal as possible, but it is not required that the lower end face of the lower large circular piece 12 must be kept horizontal.

[0060] Step 3: Measure the distance y from the upper end face of the central shaft 11 of the inner sphere diameter measuring fixture 1 to the upper end face of the upper small circular piece 13 (see...). Figure 4 );

[0061] In this step, calipers or height gauges can be used to measure the distance y from the upper end face of the central shaft 11 of the inner ball diameter measuring fixture 1 to the upper end face of the upper small circular piece 13.

[0062] Step 4: Calculate the radius SR of the inner sphere 14' based on the distance y from the upper end face of the central shaft 11 to the upper end face of the upper small circular piece 13, the known distance x from the upper end face of the central shaft 11 to the upper end face of the lower large circular piece 12, the known diameter d2 of the lower large circular piece 12, and the known diameter d1 of the upper small circular piece 13.

[0063] In this step, the distance z from the upper end face of the upper small circular piece 13 to the upper end face of the lower large circular piece 12 can be calculated based on the distance y from the upper end face of the central shaft 11 to the upper end face of the upper small circular piece 13, and the known distance x from the upper end face of the central shaft 11 to the upper end face of the lower large circular piece 12. The formula for calculating the distance z is z = xy.

[0064] From this, we obtain the lengths d1 and d2 of the two parallel chords on the inner sphere 14' (where d1 < d2), and the distance z between the two parallel chords, and then calculate the diameter of the circle, as follows. Figure 8 As shown.

[0065] Assuming the distance from the upper surface of the lower large circular plate 12 to the center of the inner sphere 14' is m, the Pythagorean theorem formula formed by the radius SR of the inner sphere 14', half the chord length, and the distance m from the center of the inner sphere 14' to the upper surface of the lower large circular plate 12 is as follows:

[0066] SR 2 =(d1 / 2) 2 +m 2 ①

[0067] SR 2 =(d2 / 2) 2 +(m+z) 2 ②

[0068] ②-①:(d1 / 2) 2 +m 2 =(d2 / 2) 2 +(m+z) 2

[0069] (d1 / 2) 2 +m 2 =(d2 / 2) 2 +m 2 +z 2+2mz

[0070] We obtain: m = [d1 / 2) 2 -(d2 / 2) 2 -z 2 ] / 2z

[0071] Substitute the value of m into formula ① to obtain the radius SR of the inner sphere 14'.

[0072] After determining the radius SR of the inner spherical surface 14' of the nail seat 12', if the diameter of the inner spherical surface 14' side hole of the nail seat 12' is larger than the diameter of the inner thread 15' side hole of the nail seat 12' ( Figure 3 In (a)), the inner ball position can be detected by means of the first inner ball position measuring gauge 3 described below; if the diameter of the inner ball surface 14' side hole of the nail seat 12' is smaller than the diameter of the inner thread 15' side hole of the nail seat 12' ( Figure 3 In (b)), the inner sphere position can be detected using the second inner sphere position measuring fixture 4 described below.

[0073] First Inner Ball Position Measuring Fixture 3

[0074] like Figure 9-11 As shown, to facilitate the measurement of the position of the inner spherical surface 14' of the pedicle screw 1' seat 12', the tooling fixture of the present invention may further include a first inner spherical position measuring fixture 3, which is used when the diameter of the hole on the inner spherical surface 14' side of the pedicle screw 1' seat 12' is larger than the diameter of the hole on the inner thread 15' side of the seat 12'. The first inner spherical position measuring fixture 3 includes a first ball head 31, a connecting rod 32, and a handle 33 connected in sequence (the three can be an integral structure, wherein the connecting rod 32 and the first ball head 31 can be integrated by means of threaded connection or welding, etc.). The radius of the first ball head 31 is the same as the radius SR of the inner spherical surface 14'; the handle 33 is convenient for the inspector to hold and for marking the fixture.

[0075] Furthermore, the first ball head 31 may have flat surfaces on both sides in the direction through which the connecting rod 2' passes the pedicle screw 1' base 12'. This facilitates the insertion of the first ball head 31 into the inner spherical surface 14' of the pedicle screw 1' base 12' via the side hole. The distance between the two flat surfaces of the first ball head 31 should be as large as possible to ensure it can pass through the side hole of the inner spherical surface 14' of the base 12'. The first ball head 31 may also have a flat surface in the direction facing the opening of the pedicle screw 1' base 12'. The first ball head 31 is created by cutting a complete ball head to facilitate its insertion into the inner spherical surface 14' from the side hole of the base 12'. In this embodiment, the first ball head 31 is semi-circular. The bottom surface of the first ball head 31 may or may not be located at the center of the outer spherical surface of the first ball head 31. The connecting rod 32 can be inclined, that is, the connecting rod 32 is not perpendicular to the bottom surface of the first ball head 31 and forms a certain angle, so as to prevent interference with the field of vision and facilitate the measurement of the height of the first ball head 31 exposed on the inner spherical surface 14' side end face of the pedicle screw 1' and the base 12'.

[0076] Furthermore, the present invention provides a method for detecting the position of the inner spherical surface 14' using the aforementioned tooling fixture (first inner spherical position measuring fixture 3), comprising:

[0077] Step 1: Insert the first ball head 31 of the first inner ball position measuring gauge 3 into the inner ball surface 14' side hole along the inner ball surface 14' of the pedicle screw 1' base 12';

[0078] In this step, after the first ball head 31 is inserted into the inner spherical surface 14', adjust the first inner ball position measuring gauge 3 so that the outer spherical surface of the first ball head 31 is in contact with the inner spherical surface 14' of the nail seat 12'. The bottom surface of the first ball head 31 should be kept as horizontal as possible, but it is not required that the bottom surface of the first ball head 31 must be kept horizontal. It is only necessary to ensure that the outer spherical surface of the first ball head 31 protrudes from the side end face of the inner spherical surface 14' of the nail seat 12' so that it is convenient to use calipers or height gauges for measurement.

[0079] Step 2: Screw the operating rod 21 of the fixing fixture 2 into the internal thread 15' of the pedicle screw 1' and the screw seat 12'. As the operating rod 21 is screwed in, the front end of the operating rod 21 finally contacts and presses against the bottom surface of the first ball head 31 of the first inner ball position measuring gauge 3.

[0080] In this step, the distance between the front end (abutment surface 22) of the operating rod 21 of the fixing fixture 2 and the drive thread 23 needs to be ensured. The operating rod 21 of the fixing fixture 2 is inserted into the side hole of the pedicle screw 1's pedicle seat 12's internal thread 15'. When the drive thread 23 contacts the pedicle seat 12's internal thread 15', the abutment surface 22 has not yet contacted the bottom surface of the first ball head 31. Thus, as the knob 24 is rotated, from the initial contact of the drive thread 23 and the pedicle seat 12's internal thread 15' to the thread engagement process, the abutment surface 22 finally contacts and presses against the bottom surface of the first ball head 31.

[0081] Step 3: Measure the position of the first inner ball. Measure the height H of the first ball head 31 of the measuring instrument 3, which exposes the inner spherical surface 14' of the pedicle screw 1', the screw seat 12', and the side end face (see...). Figure 11 );

[0082] In this step, calipers or a height gauge can be used to measure the height H of the first ball head 31 exposed on the inner spherical surface 14' of the pedicle screw 1' and the base 12'.

[0083] Step 4: Based on the height H of the first ball head 31 protruding from the inner spherical surface 14' of the pedicle screw 1' and the known radius SR of the first ball head 31, calculate the distance L' from the center of the inner spherical surface 14' to the inner spherical surface 14' of the pedicle screw 1' and the known radius SR of the first ball head 31, and determine whether the product is qualified based on this distance L'.

[0084] In this step, the formula for calculating distance L' is L' = SR - H. It is determined whether the dimension of distance L' is within the dimension and tolerance range of distance L2 from the center of the inner sphere 14' to the side end face of the inner sphere 14' of the nail seat 12'. If it is, it is qualified; otherwise, it is unqualified.

[0085] Second Inner Ball Position Measuring Fixture 4

[0086] like Figure 12-13 As shown, to facilitate the measurement of the position of the inner spherical surface 14' of the pedicle screw 1' base 12', the tooling fixture of the present invention may further include a second inner spherical position measuring fixture 4, which is used when the diameter of the hole on the inner spherical surface 14' side of the pedicle screw 1' base 12' is smaller than the diameter of the hole on the inner thread 15' side of the base 12'. The second inner spherical position measuring fixture 4 includes a fixture rod 41, and a second ball head 42 is provided at the front end of the fixture rod 41. The radius of the second ball head 42 is the same as the radius SR of the inner spherical surface 14'. The distance L3 from the center of the second ball head 42 to its front end face is less than the distance from the center of the inner spherical surface 14' to the end face of the inner spherical surface side of the base 12', so as to meet the detection conditions.

[0087] Furthermore, the inspection rod 41 may include a first rod portion 411 located at the front and a second rod portion 412 located at the rear. The diameter of the second rod portion 412 is larger than the diameter of the first rod portion 411. The second ball head 42 is located at the front end of the first rod portion 411 to facilitate the insertion of the first rod portion 411 into the hole on the side of the internal thread 15' of the pedicle screw 1' seat 12', while also taking into account the strength of the inspection rod 41.

[0088] In another aspect, the present invention provides a method for detecting the position of the inner spherical surface 14' using the aforementioned tooling fixture (second inner spherical position measuring fixture 4), comprising:

[0089] Step 1: Insert the second ball head 42 of the second inner ball position measuring gauge 4 into the pedicle screw 1's base 12' along the internal thread 15' side of the pedicle screw 1's base 12' until the spherical surface of the second ball head 42 is in contact with the inner ball surface 14';

[0090] Step 2: Measure the distance L from the end face of the inner spherical surface 14' of the pedicle screw 1' base 12' to the rear end face of the gauge rod 41 of the gauge 4 at the position of the second inner spherical surface (see...). Figure 13 );

[0091] In this step, at the production or quality inspection point, calipers or height gauges can be used to measure the distance L from the side end face of the inner spherical surface 14' of the pedicle screw 1 seat 12' to the rear end face of the gauge rod 41 of the gauge 4 to the second inner spherical position.

[0092] Step 3: Based on the distance L from the side end face of the inner spherical surface 14' of the pedicle screw 1' base 12' to the position of the second inner ball, measure the distance L from the rear end face of the gauge rod 41 of the gauge 4, and the known distance L1 from the center of the second ball head 42 to the rear end face of the gauge rod 41, calculate the distance L2' from the center of the inner spherical surface 14' to the side end face of the inner spherical surface 14' of the pedicle screw 1' base 12', and determine whether the product is qualified based on this distance L2';

[0093] In this step, the formula for calculating distance L2' is L2' = L - L1. It is determined whether the dimension of distance L2' is within the tolerance range of the distance L2 from the center of the inner sphere 14' to the side end face of the inner sphere 14' of the nail seat 12'. If it is, it is qualified; otherwise, it is unqualified.

[0094] In summary, the tooling and testing method for spinal pedicle screws of the present invention can quickly detect the size and position of the spherical surface inside the pedicle screw seat. It can replace the use of profilometers and imaging instruments, eliminating the need for manufacturing companies to purchase expensive equipment such as profilometers and imaging instruments specifically for testing the spherical surface inside the pedicle screw seat, thus saving unnecessary large expenses. The testing cost is low, and it avoids "destructive measurement" by dissecting the screw seat, reducing processes, saving raw materials, and lowering labor and processing costs. Furthermore, the structure is simple, easy to operate, requires no professional quality inspection personnel, is highly efficient, and provides accurate testing. It can be applied to various on-site points in the pedicle screw seat process, from machining to subsequent procedures and factory inspection, thereby achieving comprehensive testing and control of the pedicle screw seat quality, improving the overall quality of pedicle screws, and providing more reliable and safer protection for surgeons and patients.

[0095] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A tooling fixture for spinal pedicle screws, characterized in that, The device includes an inner sphere diameter measuring instrument for measuring the diameter of the inner sphere surface that mates with a washer or ball screw within the seat of a pedicle screw. The instrument includes a central shaft with a lower large circular plate fixed to its front end. An upper small circular plate, parallel to the lower large circular plate, is fitted on the central shaft above the lower large circular plate. An elastic element is provided between the lower large circular plate and the upper small circular plate to keep them in an open state. The diameter of the lower large circular plate is larger than the diameter of the upper small circular plate, and both the diameters of the lower large circular plate and the upper small circular plate are between the maximum and minimum cross-sectional diameters of the inner sphere surface. The tooling fixture also includes a fixing fixture, which can fix the inner ball diameter measuring fixture at the inner ball surface. The fixing fixture includes an operating rod, the front end of which is provided with abutment surface, the front part of which is provided with a drive thread that mates with the internal thread of the pedicle screw seat, and the rear end of which is provided with an operating part.

2. The tooling and inspection fixture according to claim 1, characterized in that, Both sides of the lower large circular piece and the upper small circular piece are provided with flat surfaces; And / or, the elastic element is a disc spring sleeved on the central shaft.

3. The tooling and inspection fixture according to claim 1, characterized in that, The contact surface is spherical; And / or, the diameter of the operating rod is smaller than the diameter of the internal thread of the pedicle screw seat; And / or, the operating part is a knob.

4. The tooling and inspection fixture according to claim 1, characterized in that, The tooling fixture also includes a first inner ball position measuring fixture, used when the diameter of the hole on the inner spherical side of the pedicle screw seat is larger than the diameter of the hole on the inner thread side of the seat. The first inner ball position measuring fixture includes a first ball head, a connecting rod, and a handle connected in sequence, and the radius of the first ball head is the same as the radius of the inner spherical surface.

5. The tooling and inspection fixture according to claim 4, characterized in that, The first ball head has a flat surface on both sides in the direction in which the connecting rod passes through the pedicle screw seat; And / or, the first ball head is provided with a plane in the direction of the opening toward the pedicle screw seat; And / or, the connecting rod is inclined.

6. The tooling and inspection fixture according to claim 1, characterized in that, The tooling fixture also includes a second inner ball position measuring fixture, used when the diameter of the hole on the inner spherical side of the pedicle screw seat is smaller than the diameter of the hole on the inner thread side of the screw seat. The second inner ball position measuring fixture includes a fixture rod, and the front end of the fixture rod is provided with a second ball head. The radius of the second ball head is the same as the radius of the inner spherical surface. The distance from the center of the second ball head to its front end face is less than the distance from the center of the inner spherical surface to the end face of the inner spherical side of the screw seat.

7. A method for detecting the diameter of an inner spherical surface using the tooling fixture described in claim 1 or 3, characterized in that, include: Step 1: Insert the lower large circular piece and the upper small circular piece of the inner sphere diameter measuring gauge into the inner sphere surface through the side hole of the inner sphere of the pedicle screw seat; Step 2: Screw the operating rod of the fixing fixture into the internal thread of the pedicle screw seat. As the operating rod is screwed in, the front end of the operating rod finally contacts and presses against the lower end face of the lower large circular plate of the inner ball diameter measuring gauge. Step 3: Measure the distance from the upper end face of the central shaft of the inner ball diameter measuring fixture to the upper end face of the upper small circular piece; Step 4: Calculate the radius of the inner sphere based on the distance from the upper end face of the central shaft to the upper end face of the upper small circular piece, the known distance from the upper end face of the central shaft to the upper end face of the lower large circular piece, the diameter of the lower large circular piece, and the diameter of the upper small circular piece.

8. A method for detecting the position of an inner spherical surface using the tooling fixture described in claim 4 or 5, characterized in that, include: Step 1: Insert the first ball head of the first inner ball position measuring gauge into the inner ball surface through the side hole of the inner ball surface of the pedicle screw seat; Step 2: Screw the operating rod of the fixing fixture into the threaded hole of the nail seat. As the operating rod is screwed in, the front end of the operating rod finally contacts and presses against the bottom surface of the first ball head of the first inner ball position measuring gauge. Step 3: Measure the height of the first inner ball head of the measuring instrument protruding from the inner spherical side surface of the pedicle screw seat; Step 4: Based on the height of the first ball head protruding from the inner spherical side end of the pedicle screw seat and the known radius of the first ball head, calculate the distance from the center of the inner spherical surface to the inner spherical side end of the pedicle screw seat, and determine whether the product is qualified based on this distance.

9. A method for detecting the position of an inner spherical surface using the tooling fixture described in claim 6, characterized in that, include: Step 1: Insert the second ball head of the second inner ball position measuring gauge into the pedicle screw seat along the internal thread side of the pedicle screw seat until the spherical surface of the second ball head is in contact with the inner ball surface; Step 2: Measure the distance from the inner spherical end face of the pedicle screw seat to the rear end face of the measuring rod of the measuring instrument at the position of the second inner sphere; Step 3: Calculate the distance from the inner spherical end face of the pedicle screw seat to the rear end face of the gauge rod based on the distance from the inner spherical end face of the pedicle screw seat to the position of the second inner ball, and the known distance from the center of the second ball head to the rear end face of the gauge rod. Then, determine whether the product is qualified based on this distance.

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