CN102133132A - Dynamic screw implant for pedicle of vertebral arch - Google Patents

Abstract

The invention relates to a dynamic screw implant for pedicle of a vertebral arch. Specifically, the dynamic screw implant for the pedicle of the vertebral arch comprises a screw base, a compression ring, a screw, a connecting rod and a gland nut, wherein the screw comprises a screw body and a joint, the joint is accommodated in the screw base; the connecting rod is arranged in an open slot of the screw base and arranged between the compression ring and the gland nut; and the gland nut is screwed down the upper part of the screw base so as to compress the connecting rod. The dynamic screw implant for the pedicle of the vertebral arch is further provided with a screw head cover, the interior of the screw head cover is of a ball socket structure, the joint of the screw is of a spherical external structure so that the ball socket structure can be matched with the joint of the screw; therefore, the screw not only can swing in a traditional multiaxial angle way but also can swing in an additional angle way after being locked so as to ensure the stability of the vertebral column.

Description

Dynamic pedicle screw implant

Technical field

The present invention relates to technical field is orthopaedics implants technical field, relates to dynamic pedicle screw implant especially.

Background technology

When intervertebral disc degeneration or slippage of little joint or regression, cause intervertebral height to be lost, the rear structure shakiness, thereby cause intervertebral foramina and vertebral foramen narrow, and this narrow spinal nerves or the nerve root of can oppressing causes symptoms such as patient's lumbago and skelalgia, numbness, has a strong impact on patient's quality of life.

Known method is medical expectant treatment on addressing this problem, and this mode is intended to control disease, i.e. pain, numbness, but not correct to deal with problems.For some patients, this may need long periods of treatment, and this may need the life-time service analgesic, may cause patient's the mental status or other adverse side effects.

Another kind of known method is to merge between intervertebral fusion or spinous process, can keep intervertebral height like this, reduces the pressure of neuromechanism.Can adopt fusion device, various tabular devices and pedicle screw system are fixed.Yet two vertebral bodys grew into an integral body about fusion can make, and made patient lose mobility, because it has stoped the motion of spinal column in any direction of problem sections.And even more serious be that it has brought new problem, the regression of contiguous spinal segments.

The relative fixed that is known that the spinal fusion sections can cause stress to be concentrated to contiguous vertebral body, has especially increased the weight of the load of adjacent vertebral bodies.Simultaneously, the mobility forfeiture of merging sections causes the range of activity of adjacent segment to increase, and merges the mobility of sections with compensation, thereby causes the biomechanics environmental abnormality of neighbouring section, and the change of biomechanics environment has finally caused the neighbouring section regression.

Therefore, spinal surgeons and researcher discover that existing pedicle screw is stiff after implantation, though increased the stability of lumbar vertebra, have changed the biomechanics environment of lumbar vertebra, thereby cause the probability of neighbouring section regression.Though had the dynamic implant of some lumbar vertebras to occur now, their therapeutic effect is relatively poor, has related complications such as fracture of spinous process, implant be loosening, thereby cause the probability of performing the operation once more.On the other hand, these implants can not or be not suitable for treating comparatively serious degenerative lumbar symptom, cause the range of application of these implants very narrow.

Patent documentation CN200680020249 discloses a kind of interspinous vertebral and lumbosacral stabilization devices and using method, and particularly, it discloses the spinous process flexible spacer body of U-shaped, and a pair of lateral sidewall that is configured to the spinous process of engage vertebrae; Fixed cover can be set be fixed to the flexible spacer body with spinous process with vertebra; For the flexible spacer body is fixed between lumbar vertebra and the adjacent vertebrae, anchoring assembly is set; The method of using described implantable device to stablize patient's spinal column also is provided.

Patent documentation US 20100100137 discloses a kind of implant, and it comprises that a multiaxis is to anchoring piece and connector; Anchoring piece has a flexible apparatus, and joint motion can be provided, and allows certain movement at multiaxis to the fixing back of anchoring piece.But the structure less stable of the prior art, and can only provide limited dynamic moving degree; In addition, the assembly performance of the prior art is also not so good.

Patent documentation US 20050192571 discloses a kind of pedicle of vertebral arch flexible unit and method, and this assembly comprises that head of screw has the male ridge structure; The bone fixed structure has the semiglobe of female depression and forms a ball-and-socket joint; One locks fixator pins hold-down screw head and bone fixed structure; A block, be used to guarantee major axis to stable.

Patent documentation CN200480038132 discloses a kind of osseous anchoring element and has comprised the stabilising arrangement that is used for bone or vertebrae of such osseous anchoring element, wherein osseous anchoring element comprises that one is used for being anchored on the nail bar of bone, and described bar has one can be anchored on the second portion that first in the bone and an elasticity constitute; And comprise that an ailhead, described ailhead are configured for connecting one with at least two bars that osseous anchoring element is connected.The prior art is mainly laid a counterbore up to the screw cervical region at common pedicle of vertebral arch head end, cuts out the spiral groove on the wall in duct, and this measure meeting significantly reduces screw cervical region intensity, thereby its practical feasibility may be not high.

Summary of the invention

Defective in view of prior art, the objective of the invention is to develop a kind of dynamic pedicle screw implant, this dynamic pedicle screw implant make screw can provide traditional multiaxis to angle of oscillation, extra angle swinging can also be provided after locking and guarantee the stability of spinal column.

According to a first aspect of the invention, provide a kind of dynamic pedicle screw implant, having comprised: screw base; Pressure ring; Screw; Pitman; And clamp nut,

Wherein, described screw comprises screw body and union joint, and this union joint is contained in the described screw base; Described pitman is arranged in the fluting of described screw base, and between described pressure ring and described clamp nut; Described clamp nut is used to be screwed into the top of described screw base, thereby compresses described pitman,

It is characterized in that:

Described dynamic pedicle screw implant also is provided with the screw headgear, and the inside of this screw headgear is socket arrangement, and the union joint of described screw has spherical external structure, thereby this socket arrangement can match with the union joint of described screw.

According to above-mentioned structure, the screw headgear is provided, the main effect of this screw headgear is that the union joint with screw wraps, though make the head of screw of universal screw still can in the screw headgear, do after fixing multiaxis to the minute angle swing.Thereby, the existing traditional multiaxis of this screw to angle of oscillation, after locking, can also provide extra angle swinging, and can guarantee the stability of spinal column.Extra angle swinging can prevent neighbouring section because of the strong excessive load that fixedly causes, thereby has prevented the regression of neighbouring section.

Preferably, the bottom of described screw headgear has the procheilon structure, and this procheilon structure matches with the cervical region of described screw, and is arranged such that the inboard of this procheilon structure can limit the secondary angle of oscillation of screw, and the main angle of oscillation of screw can be controlled in the outside of this procheilon structure.

According to above-mentioned structure, the lip of screw headgear becomes the scope that can limit the screw pendulum angle with the neck portion design of screw.Thereby structure of the present invention can increase the small angle oscillation of screw, can improve the stress distribution of neighbouring section, reduces neighbouring section regression probability, keeps spinal column physiological activity scope, thereby realizes dynamic fixing.

Preferably, the inside of described pressure ring has inner concave, and described inner concave is spherical, so that match with the spherical outer wall of described screw headgear.

According to above-mentioned structure, the Internal Spherical Surface of pressure ring cooperates with the spherical outside surface of screw headgear, make the screw headgear encase screw and the screw base of packing into after have multiaxis to large angle pendulum, thereby realize traditional universal screw, carry out to implant from all angles to make things convenient for the doctor.Thus, the present invention can provide the requirement of screw wide-angle in the implantation process, and the little displacement swing after the implantation also can be provided.

Preferably, has stage portion on the spherical outer wall of described screw headgear, so that the inner concave of described pressure ring contacts with the stage portion of described screw headgear.

According to above-mentioned structure, the inner concave of described pressure ring contacts with the stage portion of described screw headgear and transmits pressure, thus can to the multiaxis of screw to large angle pendulum be better controlled.

Preferably, the periphery of described pressure ring cooperates with the inner chamber of described screw base, thereby described pressure ring can be along described screw base axially-movable.

According to above-mentioned structure, described pressure ring can be along described screw base axially-movable, thereby can realize the assembling of dynamic pedicle screw implant of the present invention better, and by clamp nut being screwed into from top, the screw headgear can be fixed in the screw base, be beneficial to the multiaxis of screw to the control of large angle pendulum.

Preferably, the periphery of described screw headgear has a plurality of bar shaped flutings.

According to above-mentioned structure, the bar shaped fluting provides the space of expansion in the time of can inserting the screw headgear at the union joint of screw, so that the insertion of screw.

Preferably, described dynamic pedicle screw implant comprises back-up ring, and described back-up ring is used for being embedded into the groove of bottom of the inner chamber of described screw base, contacts with described screw headgear simultaneously.

According to above-mentioned structure, the screw headgear can be fixed in the screw base, thereby restriction screw displacement in the axial direction, be beneficial to the multiaxis of screw to the control of large angle pendulum.

Preferably, be provided with opening in the described back-up ring.

According to above-mentioned structure, back-up ring is provided with opening, thereby can make things convenient for the embedding assembling of back-up ring.

In a word, according to technical scheme of the present invention, can be so that universal screw provides the performance of dynamic fixing; And, flexural center that can the self adaptation spinal column after can making screw implant; And can prevent the neighbouring section regression of spinal column.Thereby, can when recovering intervertebral height, reducing spinal nerves pressure, spinal stability is provided, keep the normal center of rotation of spinal column, the fine motion after the treatment is provided, reduce the probability of spinal column neighbouring section regression.

From below with reference to being readily appreciated that above-mentioned feature and advantage of the present invention the described preferred embodiment of accompanying drawing.

Description of drawings

Fig. 1 is the overall perspective of dynamic pedicle screw implant of the present invention.

Fig. 2 is the decomposition diagram of dynamic pedicle screw implant of the present invention.

Fig. 3 is the sectional elevation of dynamic pedicle screw implant of the present invention.

Fig. 4 is the sketch map of the screw of dynamic pedicle screw implant of the present invention, wherein Fig. 4

(a) be the perspective view of screw, Fig. 4 (b) is the sectional elevation of screw.

Fig. 5 is the perspective view of the back-up ring of dynamic pedicle screw implant of the present invention.

Fig. 6 is the sketch map of the screw headgear of dynamic pedicle screw implant of the present invention, wherein

Fig. 6 (a) is the sectional elevation of screw headgear, and Fig. 6 (b) is the perspective view of screw headgear, and Fig. 6 (c) is the front view of screw headgear, and Fig. 6 (d) is the top view of screw headgear.

Fig. 7 is the sketch map of the pressure ring of dynamic pedicle screw implant of the present invention, and wherein Fig. 7 (a) is the perspective view of pressure ring, and Fig. 7 (b) is the sectional elevation of pressure ring.

Fig. 8 is the sketch map of the screw base of dynamic pedicle screw implant of the present invention, and wherein Fig. 8 (a) is the perspective view of screw base, and Fig. 8 (b) is the sectional elevation of screw base.

The specific embodiment

Describe the preferred embodiments of the present invention in detail below with reference to accompanying drawing.

Fig. 1 is the overall perspective of dynamic pedicle screw implant of the present invention, and Fig. 2 is the decomposition diagram of dynamic pedicle screw implant of the present invention, and Fig. 3 is the sectional elevation of dynamic pedicle screw implant of the present invention.

Referring to Fig. 1-3, the dynamic pedicle screw implant that is used to be implanted among the vertebral body of the present invention comprises:screw base 1;Pressure ring 2;Screw headgear 3;Screw 4; Back-upring 5; Pitman 6; Andclamp nut 7.

Fig. 4 is the sketch map of thescrew 4 of dynamic pedicle screw implant of the present invention, and wherein Fig. 4 (a) is the perspective view of screw, and Fig. 4 (b) is the sectional elevation of screw.Find out that from Fig. 4 the screw of dynamic pedicle screw implant of the present invention comprisesscrew body 16 and union joint 8.Screw body 16 have be used for bone fix, especially for the helicitic texture of vertebra fixation.Union joint 8 has spheric profile substantially, and is positioned at an end ofscrew body 16 and links to each other integratedly with screw body 16.The union joint 8 ofscrew 4 can be inserted in thesocket arrangement 13 ofscrew headgear 3, thereby is connected with screw headgear 3.The top of union joint 8 is provided with is convenient to the interface 9 that apparatus connects.

Fig. 5 is the perspective view of the back-upring 5 of dynamic pedicle screw implant of the present invention.Back-upring 5 can be embedded in thegroove 17 ofscrew base 1 bottom, contact withscrew headgear 3 simultaneously, thereby it can limitscrew 4 and deviate from, and the pendulum angle ofscrew 4 is provided simultaneously.Preferably, back-upring 5 is provided with opening 18, so that the embedding of back-upring 5 assembling.

Fig. 6 is the sketch map of thescrew headgear 3 of dynamic pedicle screw implant of the present invention, wherein Fig. 6 (a) is the sectional elevation ofscrew headgear 3, Fig. 6 (b) is the perspective view ofscrew headgear 3, and Fig. 6 (c) is the front view ofscrew headgear 3, and Fig. 6 (d) is the top view of screw headgear 3.Particularly,screw headgear 3 is the structure of cardinal principle hollow ball on thewhole.Screw headgear 3 has top throughhole 10 at an upper portion thereof, has lower through-hole 11 in its underpart.The throughhole 10 convenient nail apparatuses of going up in top are screwed into, and lower through-hole 11 is the patchholes that are used to insert screw 4.The periphery ofscrew headgear 3 has a plurality of bar shapedflutings 12; Preferably, in the present embodiment, respectively there are three bar shapedflutings 12 both sides up and down of the periphery of screw headgear 3.These bar shapedflutings 12 provide the space of expansion in the time of can insertingscrew headgear 3 at the union joint 8 ofscrew 4, so that the insertion ofscrew 4.

As can be seen from Figure 6, the inside ofscrew headgear 3 issocket arrangement 13, and thissocket arrangement 13 is used for the union joint 8 ofattachment screw 4, thereby forms ball-and-socket joint.Havestage portion 14 on the spherical outer wall ofscrew headgear 3, thisstage portion 14 diameter on the short transverse ofscrew headgear 3 reduces gradually.Thisstage portion 14 can cooperate with the inner concave 19 ofpressure ring 2, to transmit pressure loading, so that the main angle of oscillation of lock screw.The bottom ofscrew headgear 3 hasprocheilon structure 15, and the secondary angle of oscillation of screw can be limited in the inboard of thisprocheilon structure 15, and the main pendulum angle of screw can be controlled in the outside of thisprocheilon structure 15.

Fig. 7 is the sketch map of thepressure ring 2 of dynamic pedicle screw implant of the present invention, and wherein Fig. 7 (a) is the perspective view ofpressure ring 2, and Fig. 7 (b) is the sectional elevation of pressure ring 2.Pressure ring 2 has the nail of going up apparatus patchhole 20.The periphery ofpressure ring 2 cooperates with the inner chamber ofscrew base 1, therebypressure ring 2 can be alongscrew base 1 axially-movable.The inside ofpressure ring 2 is spheric inner concave 19, and inner concave 19 contacts with thestage portion 14 of screw headgear 3.Pressure ring 2 relies on thepitman 6 of being located at top to provide pressure to screwheadgear 1.

Fig. 8 is the sketch map of thescrew base 1 of dynamic pedicle screw implant of the present invention, and wherein Fig. 8 (a) is the perspective view ofscrew base 1, and Fig. 8 (b) is the sectional elevation of screw base 1.Screw base 1 hasinner chamber 21, and describedinner chamber 21 comprises threaded top part and slick bottom part, and describedinner chamber 21 can hold union joint 8,screw headgear 3 and thepressure ring 2 of back-upring 5,screw 4, andpressure ring 2 is moved vertically guide effect is provided.Screwbase 1 also hasU type fluting 22, is used to place pitman 6.The medial surface on the top ofscrew base 1 has helicitic texture, so that be connected with a joggle with clamp nut 7.Be provided with agroove 17 along circumferencial direction in the bottom perisporium of the slick bottom part of theinner chamber 21 ofscrew base 1, back-upring 5 can be embedded in thisgroove 17 ofscrew base 1, being used for fixing back-upring 17, therebyrestriction screw 4 to bottom offset.

Pitman 6 is used to connect a plurality of screws, andpitman 6 is set in the U type fluting 22 ofscrew base 1, and betweenpressure ring 2 andclamp nut 7.

Clamp nut 7 can be screwed into the medial surface on the top ofscrew base 1, thereby is connected withscrew base 1, is used to compresspitman 6.

From above embodiment as can be known, according to dynamic pedicle screw implant of the present invention, on the basis of traditional pedicle screw, further be provided with the head of screw covering device and improved bolt structure.

As be known in the art the universal screw of traditional pedicle of vertebral arch is after fixing like that, and head of screw and screw base have certain angle and head of screw can not have any swing again, belongs to strong fixed form.But, according to the present invention, described dynamic pedicle screw implant also is provided with the screw headgear, and the inside of this screw headgear is socket arrangement, the union joint of described screw has spherical external structure, thereby this socket arrangement can match with the union joint of described screw.By above-mentioned setting, the present invention can prevent the neighbouring section regression of spinal column, preservation spinal mobility.That is, the invention provides the screw headgear, the main effect of this screw headgear is that the union joint with screw wraps, though make the head of screw of universal screw still can in the screw headgear, do after fixing multiaxis to the minute angle swing.

And, according to the present invention, the bottom of described screw headgear has the procheilon structure, and this procheilon structure matches with the cervical region of described screw, and the inboard that is arranged such that this procheilon structure can limit the secondary angle of oscillation of screw, and the main angle of oscillation of screw can be controlled in the outside of this procheilon structure.By above-mentioned setting, the lip of screw headgear becomes the scope that can limit the screw pendulum angle with the neck portion design of screw.This restricted small angle oscillation is an importance of the present invention, the advantage that provides thus is: the small angle oscillation that can increase screw, can improve the stress distribution of neighbouring section, reduce neighbouring section regression probability, keep spinal column physiological activity scope, realize dynamic fixing, more meet requirements for clinical application, the clinical effectiveness that obtains is better.

In addition, according to the present invention, the inside of described pressure ring has inner concave, and described inner concave is spherical, so that match with the spherical outer wall of described screw headgear.Thereby, the Internal Spherical Surface of pressure ring cooperates with the spherical outside surface of screw headgear, make the screw headgear encase screw and the screw base of packing into after have multiaxis to large angle pendulum (this point and the functional similarity of traditional universal screw, but the structure difference that realizes), thereby realize traditional universal screw, implant to make things convenient for the doctor to carry out from all angles.That is, the present invention can provide the requirement of screw wide-angle in the implantation process, and the little displacement swing after the implantation also can be provided.

The doctor can adjust head of screw and the angular range of following closely seat according to actual needs in the implant procedure process, make things convenient for the implantation of screw.When being implanted to the tram, compress clamp nut and make pressure ring and head of screw cover closely cooperate, thereby the multiaxis that has limited the screw headgear just having locked the implant angle of screw to swing.At this moment, the screw that is positioned at the screw ball cover can also have the swing of minute angle, and the size of controlling this swing is only relevant with the lip design of screw ball cover, and whether and lock with screw it doesn't matter.

In addition, dynamic pedicle screw implant of the present invention can be made by metal materials such as titanium alloy, cobalt-base alloys, Nitinols; In addition, the part-structure of implant of the present invention also can be made by macromolecules such as polyether-ether-ketone, PCU, reinforcement polyether-ether-ketone, ultra-high molecular weight polyethylene or composite.

For the ordinary skill in the art, can be easy to the details of embodiments of the invention is carried out various modification and improvement.These modification and improvement all drop within the scope of design of the present invention.

Claims (8)

1. a dynamic pedicle screw implant comprises: screw base (1); Pressure ring (2); Screw (4); Pitman (6); And clamp nut (7),

Wherein, described screw (4) comprises screw body (16) and union joint (8), and this union joint (8) is contained in the described screw base (1); Described pitman (6) is arranged in the fluting (22) of described screw base (1), and is positioned between described pressure ring (2) and the described clamp nut (7); Described clamp nut (7) is used to be screwed into the top of described screw base (1), thereby compresses described pitman (6),

It is characterized in that:

Described dynamic pedicle screw implant also is provided with screw headgear (3), the inside of this screw headgear (3) is socket arrangement (13), the union joint (8) of described screw (4) has spherical external structure, thereby this socket arrangement (13) can match with the union joint (8) of described screw (4).

2. dynamic pedicle screw implant according to claim 1, it is characterized in that, the bottom of described screw headgear (3) has procheilon structure (15), this procheilon structure (15) matches with the cervical region of described screw, and the inboard that is arranged such that this procheilon structure (15) can limit the secondary angle of oscillation of screw, and the main angle of oscillation of screw can be controlled in the outside of this procheilon structure (15).

3. dynamic pedicle screw implant according to claim 1 and 2 is characterized in that the inside of described pressure ring (2) has inner concave (19), and described inner concave (19) is spherical, so that match with the spherical outer wall of described screw headgear (3).

4. dynamic pedicle screw implant according to claim 3, it is characterized in that, has stage portion (14) on the spherical outer wall of described screw headgear (3), so that the inner concave (19) of described pressure ring (2) contacts with the stage portion (14) of described screw headgear (3).

5. dynamic pedicle screw implant according to claim 1 and 2 is characterized in that, the periphery of described pressure ring (2) cooperates with the inner chamber of described screw base (1), thereby described pressure ring (2) can be along described screw base (1) axially-movable.

6. dynamic pedicle screw implant according to claim 1 and 2 is characterized in that, the periphery of described screw headgear (3) has a plurality of bar shaped flutings (12).

7. dynamic pedicle screw implant according to claim 1 and 2, it is characterized in that, described dynamic pedicle screw implant comprises back-up ring (5), described back-up ring (5) is used for being embedded into the groove (17) of bottom of the inner chamber (21) of described screw base (1), contacts with described screw headgear (3) simultaneously.

8. dynamic pedicle screw implant according to claim 7 is characterized in that, is provided with opening (18) in the described back-up ring (5).

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