CN110613504B

CN110613504B - Follow-on side formula pedicle of vertebral arch nail

Info

Publication number: CN110613504B
Application number: CN201911002734.2A
Authority: CN
Inventors: 何静; 何伟义
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-10-21
Filing date: 2019-10-21
Publication date: 2022-09-27
Anticipated expiration: 2039-10-21
Also published as: CN110613504A

Abstract

The invention relates to an implant applied to bone surgery and neurosurgery, in particular to an improved side-mounted pedicle screw; the invention can effectively solve two technical problems of 'explosive wire' and 'high notch' which are most clinically and most seriously suffered from problems, and can further improve the 'dynamic nail' and the 'fixed nail' while carrying out reversible switching between the two, so that the notch is reduced, the components are simplified, and more importantly: the improved side-mounted pedicle screw can ensure accurate positioning of the connecting rod and effective restriction in operation.

Description

Follow-on side formula pedicle of vertebral arch nail

Technical Field

The invention relates to an implant applied to bone surgery and neurosurgery, in particular to an improved side-mounted pedicle screw; the invention improves the original side-mounted pedicle screw on the basis of the advantages of 'explosion-proof wire', 'low notch', 'switchable', 'easy stock', and the like, reduces the notch, simplifies the components, and more importantly: the improved side-mounted pedicle screw can ensure accurate positioning of the connecting rod and effective restriction in operation.

Technical Field

At present, in the field of bone surgery and neurosurgery, a plurality of implementation schemes are proposed in various academic schools for pedicle screws selected in surgical treatment schemes for treating protrusion of intervertebral disc and spinal stenosis, wherein the technical scheme of laterally arranging a connecting rod is adopted, so that the technical problems which are urgently and hopefully solved clinically, such as 'explosion-proof wire' and 'down incisure', as well as 'switchable' and 'easy stock', can be effectively solved, and the application number is as follows: 201910494047.0, entitled "a low-incisura dual-purpose pedicle screw for explosion-proof wire" is representative work in this application; however, with the deep study of academia and the discovery in the research and development process of obstetrics and researchers, there are still some points to be further improved and perfected: firstly, the method comprises the following steps: the 'notch' can be reduced; its "component" can be simplified; the matching can be more reasonable; the outer wall of the nail seat and the inner wall of the hook frame are provided with conical matching pairs, so that the nail seat can be accurately positioned in an ideal state, and a connecting rod is accurately constrained by the combination of a rod clamping groove on the nail seat and a rod pressing groove on the hook frame; however, when the trial-produced sample is used for clinical practice, the following results are found: in a complex environment on an operating table, due to the existence of tiny impurities such as blood clots and broken bones, the contact of the conical matching pair in an ideal state is easily obstructed, so that the positioning deviation occurs, and the constraint on the connecting rod is influenced.

How to keep the advantages of 'explosion-proof wire', 'falling notch', 'switchable' and 'easy stock' of the connecting rod side-mounted pedicle screw and the like, and then further perfecting, namely solving the found problem of 'positioning difficulty' in a complex environment in the tapered matching pair in actual specific operation and further efforts in aspects of 'falling notch', 'simplifying structure', 'saving cost' and the like, which is a technical problem which needs to be solved clinically urgently in the industry.

Disclosure of Invention

Aiming at the technical problem which needs to be solved urgently in clinic in the industry, the research and development group discloses the technical scheme for improving and perfecting the side-mounted pedicle screw developed in the early stage through multiple comparison tests and repeated demonstration as follows:

firstly, the conical matching pairs of the outer wall of the nail seat and the inner wall of the hook frame of the side-mounted pedicle nail (hereinafter referred to as a front nail) developed in the earlier stage are improved into cylindrical matching pairs, so that the problem that the conical matching pairs adopted by the front nail are blocked in the conical matching pairs to cause positioning deviation in complex clinical operations, namely the axes of arc surfaces formed by a clamping rod groove on the nail seat and a pressing rod groove on the hook frame are not coincident, and further the connection rod cannot be combined and accurately restrained is fundamentally solved.

Furthermore, when the tapered matching pair of the front nail is processed, strict requirements are required on the relative form and position tolerances of the taper, the center line and the cambered surfaces on the nail seat and the hook frame, otherwise, effective constraint on the connecting rod cannot be implemented, so that the processing difficulty and the processing cost are increased; the technical scheme of the improved side-mounted pedicle screw (hereinafter referred to as the screw) of the invention, namely the conical shape-changed column shape, can greatly reduce the processing difficulty, thereby saving the processing cost and ensuring that the invention has operability and reliable practicability.

And furthermore, a plane on the ball head in the nail body in the front nail is moved downwards to be only 1mm away from the spherical center of the front nail from a distance 2.5-3 mm higher than the spherical center, and a concave plane is processed on the plane and is used for directly supporting a spring for implementing flexible constraint, so that a pressing block adopted by the front nail is simplified, the nail is simplified in structure and saved in cost, the space is saved, and the possibility is provided for reducing the overall notch.

Furthermore, a blind hole specially used for a screwdriver is machined on the concave plane of the nail body of the nail, and the bottom of the blind hole is arranged to be hemispherical so as to be matched with the function of the control screw, so that reversible switching between a dynamic nail and a fixed nail is realized for the nail, and feasibility is provided.

Furthermore, a sunken annular groove is processed on the concave plane of the nail body of the nail, and an optional file capable of avoiding the consumption of the notch height is provided for the arrangement of the spring with the height increased by increasing the acting force of the spring.

Still further, the hook frame, the main part is a cylinder barrel-shaped body without conicity, one side of the cylinder barrel-shaped body is provided with a gap, a pressure bar arm extends outwards above the gap, the pressure bar arm is provided with a U-shaped groove with a downward opening, and when in clinical application, the clamping bar groove on the outer side of the nail seat exposed by the gap and the U-shaped groove on the pressure bar arm clamp and fix the connecting bar together.

Furthermore, the nail seat is a hollow cylinder, the outer surface of the nail seat is cylindrical with steps, and the outer surface of the nail seat is matched with the inner wall surface of the hook frame; the inner cavity of the nail seat is opened upwards and is provided with an internal thread; the lower opening is an incomplete hemispherical concave surface matched with the outer surface of the ball head on the nail body, and the center of the concave surface is provided with a through hole for the tail part of the nail body to penetrate out and be implanted into the diseased vertebra body.

Furthermore, the screw plug is provided with an inner thread and an outer thread which are coaxial with the axis of the screw plug and are respectively matched with the control screw which acts on the head of the screw body and plays a switching role and the internal thread of the screw seat which is opened upwards; the top end of the plug screw is provided with a flat upper cover extending outwards, the center of the flat upper cover is provided with a groove for a screwdriver, the flat upper cover can tightly press the hook frame sleeved on the screw seat, and the downward surface of the plug screw is processed into an inwards concave inner cavity.

Furthermore, the spring is a columnar compression spring, and the upper end surface and the lower end surface of the spring are respectively contacted with the concave inner cavity of the screw plug and the concave plane of the nail body, so that the flexible constraint on the nail body can still be realized after the pressing block of the front nail is simplified.

Furthermore, the head of the control screw is threaded, the end face of the tail of the control screw is a hemispherical surface, the control screw is matched with the nail body, and reversible conversion of switching the 'fixed nail' into the 'dynamic nail' can be realized if the control screw is inserted or not.

Furthermore, the connecting rod is a cylinder and is used for connecting adjacent pedicle screws; because the arc-shaped surface formed by the pressing rod groove on the hook frame and the clamping rod groove on the outer side of the nail seat coincides with the axis of the connecting rod when being designed and processed, the nail can ensure that the axis is not coincident due to the fact that the conical surface matching of the front nail is influenced by the interference of sundries existing in clinical operation through the technical improvement of 'conical-column changing', and the generated defect that the binding force of the connecting rod is weakened can be prevented in the nail.

Advantageous effects

The invention has the beneficial effects that on the basis of ensuring that the front nail solves the advantages of explosion-proof wire, low notch, switchable, easy stock, and the like, deep optimization and perfection are carried out continuously, and the problem of difficult positioning in a complex environment, which is found in actual specific operation, of the conical matching pair is solved through the cone-to-column method; the 'taper-to-column' and the pressing block are simplified, so that the processing difficulty and cost are reduced to a greater extent, and the processing cost is saved; in addition, the notch is also reduced.

In conclusion, the application of the invention has obvious novelty and creativity, also has strong practicability, can solve the difficult problem which needs to be solved urgently in clinic, and simultaneously makes beneficial attempts and exploration for advancing the development from the traditional 'rigid fixation fusion' theory to the practice of 'non-fusion fixation' and 'micro-dynamic promotion fusion' theory; the method comprises the steps of designing a corresponding product according to a new theory, developing a template, continuously improving and perfecting, realizing the rigorous scientific attitude of continuously improving and perfecting while repeatedly and mutually quoting the theory and the template through testing, providing practical and beneficial prospective attempts for every academic contest, and having and certainly generating great social benefits.

Drawings

The invention is further illustrated in the following description, with reference to the figures and the embodiments:

FIG. 1 is a two-dimensional graph and effect graph of the present application;

FIG. 2 is a schematic illustration of the explosion effect of a feature of the present application;

FIG. 3 is a schematic illustration of the unstable positioning that may result from the "taper fit" of the leading nail;

FIG. 4 is a schematic view of the screw plug, the screw seat and the hook frame of the present invention together forming a constraint on the connecting rod;

FIG. 5 is a two-dimensional diagram and effect diagram of the second embodiment of the present application;

FIG. 6 shows a third embodiment of the present invention, particularly showing the engagement between the ball stud and the spring;

FIG. 7 is a comparison of the present invention application with a conventional overhead connecting rod type pedicle screw in the process of incising and bursting;

wherein:

a plug screw 1; a plug external thread 11; a plug screw inner screw hole 12; a plug screw driver hole 13;

a plug screw cavity 14; a screw upper cover 15;

a hook frame 2; a hook frame inner wall 21; a hook frame notch 22; a plunger groove 23; a press bar arm 24; a lead-in arc angle 25;

a connecting rod 3; a spring 5; a control screw 6; control screw threads 61; a control screw tail end face 62;

a nail seat 4; a nail seat outer wall 41; a nail seat internal thread 42; nail holder bar groove 43;

a hemispherical surface 44 of the nail seat inner cavity; a compact (8) in the compacted front nail;

a nail body 7; a nail body head 71; a shank tail 72; a nail body upper plane 73; a nail body driver aperture 74;

the screw plug, the hook frame and the nail seat are matched with a gap g; a clinically likely-occurring obstacle k; the height difference of the incised marks h;

axial center O of the cambered surfaces of the press rod arm 24 and the clamping rod groove 43 ₂ And O ₄ (ii) a And the axial line O of the connecting rod 3 ₃ 。

Detailed Description

In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the following embodiments; it should be understood that in the description of the present application, the terms "left and right", "up and down", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present application, but do not require that the present application be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

FIG. 1 is a two-dimensional diagram and effect diagram of the present invention, as can be seen from FIG. 1; the pedicle screw is a basic structure form which continues to use a front screw, namely a conventional form of a central connection rod (shown in a middle drawing of a figure 7) of the traditional pedicle screw is abandoned, the side connection nail is improved into a side connection rod, the connection rod 3 is arranged on one side of the screw seat 4, feasibility is provided for the screw seat 4 to be in surrounding threaded fit with the screw plug 1, and therefore structural defects of the traditional pedicle screw due to a U-shaped open slot on the screw seat are fundamentally avoided, a phenomenon which is clinically commonly called 'wire explosion' possibly generated (shown in an effect drawing on the right side of the figure 7) is avoided, and meanwhile, a space is provided for effectively reducing 'cutting marks' of the height of the diameter of the connection rod occupied by the central connection rod.

FIG. 2 is a schematic illustration of the explosion effect of the present invention, i.e., the features of the nail; as shown in the figure, and with reference to the two-dimensional diagram of fig. 1, it can be seen that: the external thread 11 of the screw plug 1 is matched with the internal thread 42 in the cavity of the screw seat 4, and the hook frame 2 sleeved on the outer wall 41 of the screw seat is pressed tightly by the screw plug upper cover 15; one side of the hook frame 2, the main body of which is cylindrical and tubular, is provided with a notch 22, a nail holder clamping rod groove 43 exposed out of the notch 22 is combined with a downward opening pressing rod groove 23 on a pressing rod arm 24 extending outwards above the notch 22 to carry out constraint and fixation on the connecting rod 3; the plane 73 on the nail body 7 is reduced by about 2mm compared with the front nail until the height of the sphere center is close to the front nail, thereby reducing the incisure of the whole nail; the spring 5 is cylindrical, one end of the spring props against the downward concave cavity 14 of the plug screw 1, and the other end of the spring directly passes through the plane 73 to flexibly constrain the nail body 7, so that the nail body 7 can swing around the spherical center of the nail body only by utilizing the matching formed by the head 71 of the nail body and the hemispherical surface 44 of the inner cavity of the nail seat; in addition, the pressing block (8) for restraining the swing of the ball stud can be simplified by using the front stud, so that the possibility of reducing the notch is provided, the components are further simplified, and the manufacturing cost is saved.

When the operation is performed at the later stage, the operator can select the control screw 6 shown in fig. 2 to be screwed into the inner threaded hole 12 in the plug screw 1 by using the thread 61 at the upper end of the control screw, so that the tail end surface 62 of the control screw enters the screw body driver hole 74 and is pressed against the bottom of the control screw, as shown in the right side of the central line of the two-dimensional diagram in fig. 1, in this state, the screw body 7 cannot swing relative to the screw seat 4, and the screw is switched into a 'fixed screw' according with the 'rigid fixation fusion theory'; from this it can be seen that the control screw 6 has a switching function for the use of the entire nail, i.e. depending on whether the control screw 6 is inserted or not.

As shown in fig. 3, the working principle of the side pedicle screw is to utilize the rod clamping groove 43 on the screw seat 4 and the rod pressing groove 23 on the hook frame 2 to jointly constrain and fix the connecting rod 3; for the front nail, although the front nail has a higher positioning effect by utilizing the conical surface matching mode, the machining precision and the strict form and position tolerance grade are also required in the machining process; when in an ideal state, under the accurate positioning of the conical matching pairs of the two, the axis O of the cambered surfaces of the rod pressing groove 23 and the rod clamping groove 43 ₂ And O ₄ (ii) a And connectingAxial line O of rod 3 ₃ It should be coincident and only coincident, the restraint and fixation of the connecting rod 3 can be implemented, as illustrated in the upper left corner of fig. 3.

In clinical application, the operation process is as follows: as the nail body 7, the spring 5 and the nail seat 4 are assembled before operation, the tail 72 of the nail body is implanted into the vertebral body of a patient by using a special screwdriver through the screwdriver hole 74, after the adjacent vertebral bodies complete the same work, the connecting rod 3 and the hook frames 2 are alternately sleeved and placed on the corresponding nail seat 4, the connecting rod 3 is preliminarily fixed, and then the screw plugs 1 are sequentially placed and locked, so that the whole operation process is completed.

However, in practice, it is found that when the hook frame 2 is sleeved into the nail seat 4 in the current nail, because the hook frame and the nail seat are in conical fit, a large gap is formed between the hook frame and the nail seat when the nail is sleeved, and in clinical operation, fine impurities K such as blood clots, shredded meat, broken bones and the like often exist, the operation time is tight, the sight line is not good, and the fine impurities K are likely to be clamped between the two conical surfaces; when the screw plug 1 is pressed down by the screw thread pair of the external screw thread 11 and the internal screw thread 42 of the nail seat 4 by using a screwdriver, two conical surfaces cannot be completely matched due to the obstruction of the sundries K, two axial leads are relatively inclined, and then, the axial lead O is ₂ And O ₄ Misalignment, which does not cooperate to effectively constrain the connecting rod 3, results in instability of the nail and rod system, affecting the effectiveness of the operation, as shown in the upper right-hand diagram of fig. 3 (with exaggerated treatment of the inclination of the axis for better clarity).

The nail disclosed by the invention finds problems and improves the problems in clinical simulation operation of the front nail during observation, and the specific technical scheme is that the front nail is positioned by conical surface matching and is improved to be positioned by cylindrical matching surface; as shown in fig. 4.

The benefits of such improvements are: firstly, the problem of processing difficulty is reduced; since the cylindrical shape is easier to machine than the conical shape, and its surfaces are at the same distance from the axis, as long as the diameter of the cylindrical shape is ensured, and its axis is in line with the plunger grooves 23 andaxial center O of the arc surface of the clamping bar groove 43 ₂ And O ₄ The accuracy of the horizontal distance is sufficient, and when the connecting rod 3 is not inserted after the assembly of the two, the O-shaped distance is ₂ And O ₄ The position in the horizontal direction can be accurately determined, only the position in the vertical direction is not determined, and after the connecting rod 3 is placed, the position in the vertical direction is naturally adjusted to a proper position by the limitation of the cylindrical surface of the connecting rod 3, and O ₂ And O ₄ And O ₃ Must coincide; the distance from each surface to the axis is different in the up-down direction of the axis, which increases the taper and diameter of the cone and the axis O of the cambered surface when processing the cone ₂ And O ₄ The horizontal distance and the upper and lower heights of the connecting rod are required to be accurate, and once one of the four elements has an error, the constraint and the fixation of the connecting rod are necessarily influenced.

Secondly, the method comprises the following steps: the matching of the cylindrical surface can avoid the possibility that the matching of the conical surface is possibly interfered by impurities K in the operation; it can be known from the enlarged partial view of the cylindrical surface matching shown in fig. 4 that the leading-in arc angles 25 are respectively arranged on the cylindrical matching surfaces of the hook frame 2 and the nail seat 4, and it is the leading-in arc angle 25 specially designed for finding problems in the practical operation test of the front nail in the present invention that the inner wall 21 of the hook frame 2 can be effectively and conveniently led into the outer wall 41 of the nail seat 4 for assembly, and when the interference of the sundries K occurs during the assembly process, the sundries K cannot be hidden in the middle of the matching surfaces but can only be pushed into the matching gap g in the vertical direction of the two matching surfaces by the leading-in arc angles 25, so that the phenomenon that the sundries K are gradually clamped in the matching surfaces due to the gradual reduction of the contact surface distance during the conical surface matching process is avoided.

In addition, because the invention is applied to designing the nail, the specially designed free floating interval g can effectively treat the possibly existing impurities K and can also effectively digest and treat the axial line in the cylindrical matching surface and the axial center O of the cambered surfaces of the rod pressing groove 23 and the rod clamping groove 43 ₂ And O ₄ Tolerance build-up in the vertical direction, i.e. during setting of the connecting rod 3The connecting rod 3 is only required to be arranged on the cambered surface, O, of the clamping rod groove 43 ₄ And O ₃ Then coincidence is bound; as the screw plug 1 gradually presses down the rod pressing groove 23 on the hook frame 2 sleeved on the nail seat 4, the cambered surface of the rod pressing groove 23 is finally necessarily overlapped with the cylindrical surface of the connecting rod 3 and locks the connecting rod; therefore, the matching gap g of the nail can effectively reduce the processing difficulty of the nail seat 4 and the hook frame 2; the invention also proves that the invention has greater operability and practicability.

Fig. 5 shows an embodiment two of the present application, specifically, only the front nail is improved in the incisal trace and the simplified components: the pressing block (8) of the front nail is eliminated, the spring 5 is directly arranged between the downward plug screw cavity 14 of the plug screw 1 and the upper plane 73 of the nail body, the pressing block (8) is eliminated, the height of the head part 71 of the nail body is reduced, and the effect of reducing the notch can be realized.

In order to further reduce the notch and fully exert the elastic function of the spring 5, the invention discloses the third embodiment, as shown in fig. 6, that is, the upper plane 73 of the nail body is provided with an annular groove, and the spring 5 is sunk to the bottom, so that the height of the spring 5 can be properly increased, and more effective flexible constraint can be implemented on the nail body 7.

In conclusion, the technical scheme provided by the application of the invention not only can keep the advantages of explosion-proof wire, low notch, switchable performance, easy stock and the like of the front nail through the improvement of the front nail, but also can solve the technical problem of difficult positioning clinically through the technical measures of 'cone-to-column', and has obvious creativity and novelty; meanwhile, the notch is further reduced, the components are simplified, the effects of saving cost and improving efficiency are achieved, and the practicability is sufficient; further, the above-described embodiments are preferred embodiments of the present application, and are not intended to be exhaustive, and therefore, any modifications, equivalents, improvements, etc. made by using the contents of the specification and the drawings disclosed in the present application should be included in the scope of the present application.

Claims

1. An improved side-mounted pedicle screw comprises a screw plug, a hook frame, a connecting rod, a screw seat, a spring, a control screw and a screw body, wherein the hook frame main body is a cylindrical body without taper, one side of the cylindrical body is provided with a notch, a rod pressing arm extends outwards above the notch, and the rod pressing arm is provided with a U-shaped groove with a downward opening;

the nail seat is a hollow cylinder, and the outer surface of the nail seat is a cylindrical body with steps at the bottom; one side of the outer surface of the clamping rod is provided with a clamping rod groove; an upward opening of the inner cavity of the nail seat is provided with internal threads; an incomplete hemispherical concave surface is arranged at the downward opening, and a through hole is formed in the center of the concave surface;

the tail of the nail body is a nail-shaped body with external threads, and the nail-shaped body penetrates out of the downward through hole of the nail seat and is implanted into a pathological vertebral body; the head of the nail body is an incomplete spherical body and forms a swing pair with a hemispherical concave surface of a downward opening of the nail seat, a plane perpendicular to the axis of the tail part is processed at a position 1mm above the spherical center of the head of the nail body, an annular groove for the spring to sink is arranged on the plane, a blind hole for a screwdriver is processed in the center of the plane, and a hemispherical concave hole is further formed in the center of the blind hole;

the screw plug is provided with inner and outer threads which are coaxial with the axis of the screw plug and are respectively matched with the control screw and the inner threads at the upward opening of the screw seat; the top end of the screw plug is provided with a flat upper cover extending outwards, the center of the flat upper cover is provided with a groove used for matching with a screwdriver, the flat upper cover can tightly press the hook frame sleeved on the screw seat, and the downward surface of the screw plug is processed into an inwards concave inner cavity;

the spring is a cylindrical compression spring, the upper end of the spring is restrained and positioned by the inward concave inner cavity of the screw plug, and the lower end of the spring is directly pressed against the annular groove of the head of the nail body to implement flexible restraint on the nail body so as to ensure that the head of the nail body forms a swing pair in the nail seat;

the upper end of the control screw is provided with a small section of thread which is matched with an inner threaded hole in the center of the screw plug; the lower end of the nail body is a section of cylindrical body, and the end surface of the nail body is a semicircular head which can reach the end of a concave hole of the nail body directly and is used for controlling the swing of the nail body;

the method is characterized in that: the hook frame cup joints the surface of nail seat, the internal surface of hook frame and the surface cooperation of nail seat, the hook frame with the fitting surface of nail seat is cylindrical fitting surface, works as the hook frame cup joints when the surface of nail seat, the hook frame with it floats the interval to have between the step of nail seat, and works as the connective bar quilt U-shaped groove on the hook frame reaches when the clamping bar recess on the nail seat retrains jointly and fixes, presses the axle center of the U-shaped groove on the excellent arm and the axle center coincidence of the clamping bar recess on the nail seat.

2. The improved side pedicle screw as claimed in claim 1, wherein: the connecting rod is a cylindrical rod, is arranged on one side of the central line of the pedicle screw and is used for connecting the adjacent pedicle screws.