CN101966098A - Perfusion type pedicle screw - Google Patents

Abstract

The invention belongs to a medical appliance. The invention provides a perfusion type pedicle screw for solving the problems that the existing pedicle screw has insufficient fixation strength and insufficient stability after implantation, which comprises a hollow screw body, that is a cavity is arranged in the screw body, the cavity is communicated with an injection port arranged on a screw head, an exsudation port communicated with the cavity is further arranged on the screw body, and the exsudation port is completely positioned in the range of being contact with pedicle of vertebral arch after the perfusion type pedicle screw is implanted into spine for positioning of the screw body. The perfusion type pedicle screw can be applied in the transpedicular internal fixation method.

Description

The filling type pedicle screw

Technical field

The present invention relates to the fixing screw, particularly fixing screw on vertebra that use in a kind of bone surgery.

Background technology

In spinal surgery, use the existing history for many years of pedicle screw fixation technology, the main effect of vertebra internal fixation is to stablize the power sections of vertebra to promote its fusion.The pedicle internal fixation method makes vertebra have best mechanical stability, so this technology is able to extensive use, particularly in the fixing operation of breast lumbar segment.

The pedicle internal fixation method is with the screw implantation vertebra, and screw contacts with vertebral body with pedicle of vertebral arch successively.The key of pedicle screw fixation technology is that the screw that implantation is put in place is stable.Clinical practice shows, even with correct position and direction pedicle screw, still screw loosening might occur, extract or phenomenon such as fracture, this mainly is because not enough the causing of bond strength of screw and bone contact interface, particularly cause under osteoporosis or the ruined situation of sclerotin in patients with osteoporosis or canceration, screw loosening appears, extract or the probability of phenomenon such as fracture bigger.The appearance of the problems referred to above, making fixing failure needs second operation, and this will increase the misery of the spirit and the human body to the patient.

Implant strength of fixation after the pedicle of vertebral arch in order to increase screw, especially improve the bond strength of pedicle screw and bone under osteoporosis or the ruined situation of sclerotin, a kind of processing means of normal employing are: pour into bone cement in the nail road that pedicle screw is implanted.In order better to realize the fixed effect of bone cement, existing specially designed screw is used, (patent No. is: 200520070998.9) disclosed a kind of pedicle screw as Chinese utility model patent, this screw has the nail body of hollow, nail also is provided with bleed opening on one's body, bone cement is circulated in the nail road from bleed opening by the nail body of hollow, and bone cement is an one in bone cement after bone cement solidifies in the nail body and the nail road, has strengthened the constant intensity and the stability of screw.Because bleed opening is positioned at the middle part and the afterbody of nail body, this just makes the position of screw hold that bone cement plays after implantation at the middle part and the afterbody of nail body, and the part of the corresponding vertebra in this position interior spongy bone part that is vertebral body.Can know by top analysis, formed the fastening impetus of screw at the bleed opening place, and there is following problem in impetus in such position: the one, and the external force that pedicle screw is subjected to after implantation mainly puts on the ailhead position, so just cause external force distance between the main fixing point of the point of application on the screw and screw bigger, just the arm of force is longer, and this has caused pedicle screw to implant the back constant intensity and stability is not enough; The 2nd, be the vertebral body spongy bone around the impetus, bearing capacity is low, and particularly under situations such as osteoporosis, bearing capacity is lower, and this has also reduced the constant intensity of screw; The 3rd, bone cement causes toxic reaction in disperse generation leakage easily in the vertebral body spongy bone under the liquid state; The 4th, if desired the screw of having implanted to be overhauled, the in bulk that condenses because bone cement disperse in the vertebral body spongy bone distributes usually causes bone destruction greatlyyer, is unfavorable for pedicle screw once more.

Summary of the invention

For constant intensity and stable insufficient problem after the implantation that solves existing pedicle screw existence, the invention provides a kind of filling type pedicle screw, solve this problem pointedly, improved constant intensity and stability after pedicle screw is implanted.

Technical scheme of the present invention is as follows:

The filling type pedicle screw, the nail body that comprises hollow, promptly follow closely and be provided with cavity in the body, the inlet that is provided with on cavity and the ailhead is communicated with, also be provided with the bleed opening that is communicated with described cavity on one's body at nail, described bleed opening all is positioned at the scope that nail contacts with pedicle of vertebral arch behind implantation vertebra and location.

The no screw thread in nail body surface of contiguous described bleed opening.

Another preferred version is the circumferential no screw thread on the nail body surface at described bleed opening place.

The diameter of described bleed opening place nail body part is less than the screw thread nominal diameter.

Described bleed opening is the long groove shape opening at the opening on nail body surface, and the axis of described groove is parallel with the axis of screw.

Described filling type pedicle screw also comprises the ascending pipe of hollow tubular structure, an end of ascending pipe be provided with described ailhead on inlet be complementary pour into mouth, promptly pour into mouthful with described inlet between can form not have to leak and dock, pour into docking of forming between mouth and the described inlet in other words and guarantee that bone cement does not have leakage; The described mouth that pours into is communicated with the hollow space of ascending pipe.

Technique effect of the present invention:

The present invention is arranged on the position of nail body near ailhead with bleed opening, and the particular location scope is the scope that nail contacts with pedicle of vertebral arch in back, implantation vertebra location.Pedicle screw order touches in the implantation vertebra process pedicle of vertebral arch and vertebral body.The solution of the present invention makes bone cement be circulated in the nail road from bleed opening by the nail body of hollow, and bone cement is an one in bone cement after bone cement solidifies in the nail body and the nail road, has strengthened the constant intensity and the stability of screw.The position of bleed opening is arranged on the scope that the nail body contacts with pedicle of vertebral arch, also just make the nail body by the more close ailhead of bone cement and the fixed position of sclerotin (impetus), make that than prior art screw of the present invention external force distance between the main fixing point of the point of application on the screw and screw is shorter in other words, improved constant intensity and stability after pedicle screw is implanted.

In addition, the characteristics of pedicle of vertebral arch anatomical structure are that cortical bone (has fine and close sclerotin, intensity is big) in (have loose sclerotin for spongy bone, intensity is low), cortical bone surrounds spongy bone and forms a narrow space, pedicle screw of the present invention is behind the implantation vertebra location, and bleed opening is positioned at cortical bone just and surrounds the formed space of spongy bone.Bone cement distributes by bleed opening disperse in cortical bone surrounds the formed space of spongy bone, and (bone cement is easy flow dispersion in spongy bone, can not penetrate cortical bone), bone cement solidifies the back and forms and the close body of the cortical bone encirclement formed spatial form of spongy bone, this body and cortical bone have very large contact surface, cortical bone gives these body all directions maximized mechanics support in other words, when pedicle screw is subjected to external force to produce mobile trends such as twisting, cortical bone can effectively stop this trend, and this makes the present invention more help improving the constant intensity after screw is implanted.

Adopt pedicle screw of the present invention, can avoid bone cement in the vertebral body spongy bone, to reveal the toxic reaction that causes.Simultaneously,, can not cause big destruction in the time of need overhauling yet, help overhauling and pedicle screw once more the vertebral body sclerotin because bone cement is distributed in the pedicle of vertebral arch.

Pedicle screw of the present invention can be widely used in from the operation of pedicle of vertebral arch pedicle screw.Especially cause using pedicle screw of the present invention under osteoporosis or the ruined situation of sclerotin in patients with osteoporosis or canceration, effect is more excellent.

Description of drawings

Fig. 1 is the structure chart of one embodiment of the present of invention, and left end is an ailhead, and right-hand member is the afterbody of nail.

Fig. 2 is the vertical view of Fig. 1, also is cutaway view simultaneously.

Fig. 3 is the cutaway view of ascending pipe of the present invention.

Fig. 4 is the axonometric chart that the ascending pipe of filling type pedicle screw and coupling is assembled together.

Sign is described as follows among the figure:

1, nail body; 2, bleed opening; 3, inlet; 4, cavity; 5, pour into mouth.

The specific embodiment

Below technical scheme of the present invention is elaborated.

Fig. 1 and Fig. 2 have shown the structure of filling type pedicle screw of the present invention.Left-hand end is the ailhead of pedicle screw among Fig. 1 and Fig. 2, and the ailhead right side is provided with the screw thread place and begins to benail body 1 to the right-hand end of pedicle screw thatnail body 1 is implanted the main body of sclerotin for pediclescrew.Nail body 1 be a hollow structure, and nail has cavity 4 in thebody 1, and theinlet 3 that is provided with on cavity 4 and the ailhead is communicated with, while cavity 4 also with follow closelybody 1 on thebleed opening 2 of setting be communicated with.Bleed opening in the position of nail on thebody 1 in following scope:nail body 1 is in implantation vertebra and back, location and scope that pedicle of vertebral arch contacts.This scope also can be with being described as mode: after being meant thatnail body 1 is implanted pedicle of vertebral arch and put in place, the length from the implantable port surface to pedicle of vertebral arch end is exactly the length range that bleed opening 2 can be provided with.This length is smaller or equal to 2 centimetres.Analyzed in the summary of the invention part as described above, this scope is positioned at the position ofnail body 1 contiguous ailhead, becausenail body 1 is behind implantation vertebra, bleed opening 2 places are impetus of bone cement hold-down screw, therefore, the loosening external force of pedicle screw that causes that is applied on the ailhead arrives the arm of force weak point of this impetus, helps the stability of pediclescrew.Bleed opening 2 is the strip mouth, and the major axis of this strip is parallel with the axis of pedicle screw, and the length ofbleed opening 2 described long axis directions is 0.3-1 centimetre, in the present embodiment preferred 0.5 centimetre.

Bleedopening 2 is not provided with screw thread in the contiguous part innail body 1 surface, and level and smooth nail body surface is beneficial to bone cement wider distribution in the nail road of liquid, strengthens the fixedly power of filling type pedicle screw.

Another preferred scheme is that the nail body peripheral surface of bleed opening 2 innail body 1 surperficial position is not provided with screw thread, and identical with aforementioned reason, this scheme makes bone cement circumferentially to distribute aroundnail body 1, further strengthens the fixedly power of filling type pedicle screw.Can be provided with on this basis bleedopening 2 at the diameter of the nail body part ofnail body 1 surperficial position less than the screw thread nominal diameter, as depicted in figs. 1 and 2, this set makes that other are provided with the threaded portion depression to bleed opening 2places nails body 1 part with respect tonail body 1, this part is recessed in and forms a stratiform space that distributes aroundnail body 1 between filling type pedicle screw and the sclerotin (being cortical bone in the present invention), more helps bone cement and circumferentially distributes around nail body 1.Because the pedicle of vertebral arch volume is little, pedicle screw of the present invention can reach and use less bone cement to reach higher constant intensity, because the bone cement consumption is few, and the corresponding hidden danger of having avoided the bone cement consumption too much to cause.The bone cement consumption too much causes leakage easily, and the bone cement of leakage enters into vein can cause the arteries and veins thromboembolism.Another benefit that the bone cement consumption is few is to overhaul if desired, can be easier when taking out pedicle screw, and it is few to destroy sclerotin.

As depicted in figs. 1 and 2, bleedopening 2 is shaped as long groove shape opening (this opening meets this requirement in the nail body that the present invention limits and the scope that cortical bone contacts certainly) atnail body 1 surface opening, and the axis of groove is parallel with the axis of screw.Bigger bleed opening helps flowing of bone cement, is difficult for forming stopping up.

Fig. 3 has shown another part accessory---the ascending pipe of filling type pedicle screw of the present invention.Ascending pipe is a hollow tubular structure, and an end of ascending pipe is provided with and pours intomouthfuls 5, pours intomouthfuls 5 and is communicated with the ascending pipe hollow space.Theinlet 3 that pours onmouth 5 and the screw ailhead is complementary.This be complementary be meant: pour intomouthfuls 5 with the profile phase coupling ofinlet 3, the outline coupling that pours intomouthfuls 5 outline and the depression ofinlet 3 of vertebra shape as shown in Figure 3 makes that pouring intomouth 5 can form tight the connection by concavo-convex cooperation withinlet 3; Pour intomouthfuls 5 and be complementary, make the bone cement of liquid can not have big difference during withinlet 3 intersections and cause revealing owing to both bores by pouring intomouthfuls 5 with the bore ofinlet 3.

The effect of ascending pipe be by dock the bone cement that in screw, pours into liquid withinlet 3, finish pour into the back ascending pipe separate with screw.

Fig. 4 is the state diagram that ascending pipe of the present invention and screw link together, and both pour intomouth 5 and inlet 3 couplings except above-mentioned, also further strengthen connecting by internal and external threads.

Claims (7)

1. filling type pedicle screw, the nail body that comprises hollow, promptly follow closely and be provided with cavity in the body, the inlet that is provided with on cavity and the ailhead is communicated with, also be provided with the bleed opening that is communicated with described cavity on one's body at nail, it is characterized in that described bleed opening all is positioned at the scope that nail contacts with pedicle of vertebral arch behind implantation vertebra and location.

2. according to the described filling type pedicle screw of claim 1, it is characterized in that the no screw thread in nail body surface of contiguous described bleed opening.

3. according to the described filling type pedicle screw of claim 1, it is characterized in that circumferential no screw thread on the nail body surface at described bleed opening place.

4. according to the described filling type pedicle screw of claim 3, the diameter that it is characterized in that described bleed opening place nail body part is less than the screw thread nominal diameter.

5. according to the described filling type pedicle screw of one of claim 1 to 4, it is characterized in that described bleed opening is the long groove shape opening at the opening on nail body surface, the axis of described groove is parallel with the axis of screw.

6. according to the described filling type pedicle screw of one of claim 1 to 4, it is characterized in that also comprising the ascending pipe of hollow tubular structure, an end of ascending pipe be provided with described ailhead on inlet be complementary pour into mouth; The described mouth that pours into is communicated with the hollow space of ascending pipe.

7. according to the described filling type pedicle screw of claim 5, it is characterized in that also comprising the ascending pipe of hollow tubular structure, an end of ascending pipe be provided with described ailhead on inlet be complementary pour into mouth; The described mouth that pours into is communicated with the hollow space of ascending pipe.

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