CN1003211B - external dynamic bone fixation device - Google Patents

Abstract

An external fixation device for fixation of a fractured joint. The device includes first and second fixation rods connected to a pin to be inserted into the bone and a movable portion connecting the two fixation rods. One of the two fixed rods is connected to a slider which can slide on a sliding surface with an imaginary axis in the fixed sleeve of the mobile part. The fixed sleeve of the movable part is provided with observation lines on the covering layer, and the observation lines are used for accurately observing the position of the rotation central shaft of the broken joint.

Description

External moving bone fixed apparatus

The present invention relates to a kind of medical apparatus and instruments, particularly a kind of bone anchoring device that allows bone in the joint motion that fractures.

For the present invention, will a kind ofly so fixedly be called a kind of bone fixation by means of pin, bar and external support device of " dynamic fixing " its expression, this external support utensil has a movable part by human or animal's geometric active relation.It can fix the bone fragments that can rotate, and the parts of fixture are rotated around joint shaft.

Bone outside fastening or fixedly be an ancient surgical technic that before a century, just uses first.Its application is confined to the complicated fracture wound on traumatology and the thing followed orthopedy for a long time, as the chronic healing of after-treatment, the infection of fracture wound, bone, pseudarthrosis and the rectification etc. of difficulty.Outside fasteningly be particularly suitable for being used in, scratch on the long bone bone, the elbow bone as femur, tibia, humerus.People also wish to produce small-sized clamp device, and this midget plant can be used on such as on Plantar bone and the so little bone of metacarpal bone and on the experimental surgery of maxillary surface surgery and toy.

The exterior bone fixture can be realized two types bone fixation:

Pierce through fixingly, pin is stretched over opposite side from a side of limbs;

Non-ly pierce through fixingly, pin inserts in the bone but does not pass across bone fully.

Mainly being used in piercing through on the lower limb fixes fixing more reliable than piercing through.Fix two bars or frame in the both sides of bone, and fix two groups of pins on bar or frame, pin is positioned in the both sides that bone fractures and locates.These two groups of framves or two bars interconnect by a support, and this support should stablize as far as possible and it also comprises several sliding bars or slider bar, and the length of sliding bar or rod can increase or reduce.

Like this, we have just known the fixed basic fundamental of exterior bone, and have considered how outside bone fixedly is generalized on the suture in fracture joint.This design is exactly, the GUSUIPIAN of the joint part that fractures is fixed on the contiguous bone by the hair(-)pin nail, fixing pin is inserted into (it may fracture in the another part in this joint that fractures, may also not fracture yet), and by movable connection method two parts of external device (ED) are linked up.This movable fixed purpose is as follows: usually the fixing bone that has fractureed for treatment of rigid bone should be a kind of method that is enough to satisfy.Yet, when fractured bone is joint a part of, the great risk of the joint stiffness after may occurring curing, and it is believed that the joint that patient the is fractureed exercise that moves as quickly as possible is indispensable.Such motion should increase angle of bend then gradually from angle and curved.Certainly, all these motions all should be carried out in the tolerance band of the external fixation device that is mounted, but rigid fixation means can not reach this requirement, for example at United States Patent (USP) NO.4, and the device of describing in 365,624.

The dynamic outer fixture is described (its application number is 2,551,650, and open day is on March 15th, 1) to some extent in the French Patent (FRP) of TerryA.Clyburn application.According to above-mentioned total thinking, this fixture comprises the first nearly branch and second branch far away, and these branches are suitable for installing and fixing regularly pin, with a universal joint (being typically a ball-and-socket joint) above-mentioned two branches are coupled together.

Certainly, in order to make fixture energy operate as normal, should strictly be applied in it under certain situation, soon moving point places on the carpal rotating shaft exactly between two branches of said apparatus; Otherwise, will produce excessive and pulling force or pressure that make people's pain when palmistry during for arm motion., when a new fracture fracture occurring, all surface all swelling gets up and the joint can not rotate, so in most of the cases can not be with the movable axis of sufficiently high accuracy detection to the joint.In addition, can not adjust the moving point position of said apparatus.

Primary and foremost purpose of the present invention provides a kind of new and practical dynamic outer bone anchoring device, and this device is used for the treatment of the fracture of joint part and makes articular surface no longer be subjected to the evil of above-named shortcoming.

Another object of the present invention provides a kind of fixture of narrating above, and this fixture allows injured joint under the situation that can progressively increase angle and with controlled resistance exercise.

Another object of the present invention provides a kind of fixture, this fixture can be by the surgeon with the turning cylinder location according to injured joints of method very accurately, even also can adjust this fixture according to the range of activity in joint later on installing fixing pin.

Further object of the present invention provides a kind of dynamic outer bone anchoring device of the joint that is used to fracture, and this fixture can also compress or extend in the fractures process, thereby all more satisfactory to the recovery situation of the recovery in joint and joint mobility.

All these purposes and other some purposes all realize by dynamic outer bone anchoring device of the present invention, this device comprises: (1) has first parts that are suitable for being connected to the fixed bar on the bone pin, and this bone pin is inserted in the bone of joint one side that fractures; (2) have second parts that are suitable for being connected to the fixed bar on the bone pin, this bone pin inserts in the joint that fractures of opposite side in said joint; (3) above-mentioned two movable parts that parts link together, this movable part has the slidingsurface of a bending, and slidingsurface has an imaginary axis, and said movable part also comprises the device of accurately determining the crooked slidingsurface imaginary axis.

In order to make the term and the notion in present technique field be more readily understood, referring to United States Patent (USP) NO.4,365,624, its detail can be with reference to the full text of this patent.

People are surprised to find, and device of the present invention can not only be used for wrist fracture, and can be used for such as knee joint, ankle, refer to, the fracture in elbow, shoulder even other joints such as pelvis and clavicle.

Dynamic outer bone anchoring device of the present invention develops out from above-mentioned basic thought, be that the mode that this device should not be positioned at said joint rotating shaft with the center of rotation of two fixed parts laterally is placed on the joint that fractures of health, place and should be approximately perpendicular to this joint.Promptly be placed on than on the higher plane, health plane.This will make an explanation and represent with accompanying drawing below.

The mobile enforcement state that has caused another kind of geometry of this fixture moving point is rotatablely moved and extends (or contraction) motion and substituted by what carry out simultaneously as simply rotatablely moving of universal joint known to preceding or ball-and-socket joint.Thereby the present invention also provides a kinematic coupling portion except the both sides of locating in the joint that fractures are fixed on two fixed parts in the bone.This kinematic coupling portion comprises crooked (preferably by cylindrical bending) slidingsurface.One in these surfaces is convex, and it is the part of what is called " sun " element that is connected to one of said fixed part, and another surface is a concavity, and it is the what is called " part of female element that is connected to another fixed part.When these surfaces slided over each other, the ordinary skill of this area readily appreciated that, was fixed on any one lip-deep parts and will produces an existing angular movement moving of lengthwise movement arranged again.

Convex surface is the part of slide block, and slide block can slide on the corresponding concave surface in fixed cover.This is fixed with a transverse baffle, and the axle of it and said curved surface meets at right angles.On baffle plate (another side surface that preferably also has fixed cover), many straight lines that intersect at a point in the fixed cover outside are arranged.Select this intersection point (therefore promptly having selected said collinear direction) to determine the said slidingsurface axis of curvature.This axle also is osteoarticular rotating shaft.When the surgeon was put into fixture of the present invention on the health, he can accurately determine the axle in joint by the mode of checking along said straight line.Even joint part swelling, the doctor also can be easy to find said axle.If possible, the doctor also can readjust fixture of the present invention, and this names a person for a particular job and makes an explanation below.

Slide block can be fixed by the screw that passes the slotted eye in the fixed cover.This slotted eye is crooked, and its curvature is consistent with the curvature of slidingsurface.Another screw that is stuck in the said slotted eye is to be used for limiting the active limit screw of slide block in the fixed cover.The angle indication can be provided near slotted eye.Slidingsurface can be topped by the rub resistance layer, as with polytetrafluoroethylene (PTFE) or nylon.

This fixture should be selected through adopting to such an extent that live the material that kills mattress repeatedly.The selection of this material is common technology for one of skill in the art.

For this reason, for can be for patient sets up a suitable exercise, or rehabilitation procedure, preferably the power that needs at moving slider is controlled the motion of the slide block in the fixed cover.In one group of embodiment, if the motion of slide block is the elastic force of distortion or the elastic force of rubber strap, then slide block is hampered by elastic force.In another embodiment, hinder the motion of said slide block with frictional force, the size of frictional force preferably can be controlled in and approach zero and arrive and lead between the prevention slide block movement.

In order to explain dynamic outer bone anchoring device of the present invention in more detail, we will contrast accompanying drawing and describe several optimum examples, in the accompanying drawing:

Fig. 1 is the side view of dynamic Connection Element, represents that when pitman pitman dots during in the centre position with solid line when the extreme position that allows among the figure.

Fig. 2 is the longitudinal sectional drawing that comprises Connection Element among Fig. 1 of first embodiment that stops patient's motion spring.

Fig. 3 and Fig. 4 are the part figures similar with Fig. 2.Represented among the figure that the angular force parts are respectively the embodiment of the frictional damping element of flexible member.

Fig. 5 is the perspective view of dynamic outer carpal joint fixture, and this device comprises every group of two groups that two pins are arranged, and these two groups are connected to again on two corresponding rods, and rod is linked on the dynamic Connection Element.

Fig. 6 is that the angle between pin becomes among 40 ° the embodiment cutaway view along VI among Fig. 5-VI line intercepting.

Fig. 7 is that this figure represents to be lockable the Connection Element of position along the partial sectional view of Fig. 1 VII-VII line intercepting.

Fig. 8 be Fig. 4 amplification detail drawing, this figure represents an embodiment who uses the frictional damping element to stop patient to move.

The dynamic outer bone anchoring device of representing in Fig. 1 and Fig. 2 comprises the movable part 1 of connecting rod 2 and 3.

Just as will be explained below like that, bar 2 is connected on the pin by the connected mode of 4 expressions, and dowel fixes is on patient's metacarpal bone; Same bar 3 is by being linked scratching on the bone of patient with the connected mode of 5 expressions.

Movable part 1 mainly is made up of fixed cover 6 and slide block 7, and the two can both slide with respect to slidingsurface 8.

With other term, fixed cover 6 has a convex slidingsurface 8, and slide block 7 has a corresponding concavity slidingsurface.These slidingsurfaces for example can be columniform surfaces, and corresponding cylinder axis is vertical with the sliding surface of movable part 1.This imaginary axis is represented with alphabetical A in the accompanying drawings, and it is corresponding with the carpal kinematic axis that fractures.

Since all parts of this device must pass through gas or steam hot-pressing processing, so fixed cover 6 or make with light-alloy or with holding out against the synthetic material that mattress extremely handles.Slip 7 for example can be made by rustless steel.

The slidingsurface 8 of the slidingsurface of fixed cover 6 and/or slide block 7 is formed (not showing in the drawings) by ganoid coating, for example nylon or poly-four polyethylene (PTFE).

Referring to Fig. 1 or Fig. 2, it should be noted that the general shape of fixed cover 6 has a bit crooked along slidingsurface 8.The bottom of fixed cover 6 is flexure planes 9.

Pin 10 is fixed on the termination of slide block 7 upper booms 2.The termination of an other bar 3 (not having screw thread) is assemblied on the threaded bar 11, and locatees with two knurled wheels 12 and 13, and this just allows to adjust the length of the device that comprises movable part 1, bar 2 and bar 3.Can avoid horizontal moving by extension component 14.Perhaps by directly being threaded or matching with fixed cover 6, as shown in Figure 2 by the other end of pin 15 with threaded rod 11.

Another part of movable part 1 is a side overcoat 16, and its overall shape is identical with the shape of fixed cover 6.

A graduated disc 17 is arranged on the visible face of side overcoat 16, and the relative angle of reading between slide block 7 and fixed cover 6 and the side overcoat 16 with it changes.For accurately definite imaginary axis A, some scale on the circular scale 17 is exaggerated and expands to form survey line 18.People also can observe the survey line that is set up that side of fixed cover on overcoat 16 opposites (can not as seen from the figure).

Graduated disc 17 and corresponding numerical value thereof also have survey line 18, can or be drawn in or are engraved on overcoat and the fixed cover.

Shown in Fig. 7 detailed cross sectional view, a side that faces toward the fixed cover 6 of side overcoat 16 has one and slide block 7 corresponding slits 19.As shown in Figure 2, slit 19 is garden shapes, this just allow to fix 6 and slide block 7 between relative motion is arranged.Equally, overcoat 16 also has a garden shape groove 20, and the center of groove also is A.

Among Fig. 1, two screws 21 and 22 are arranged in groove 20.First screw is a lock-screw 21, and it can stop any relative motion (referring to Fig. 7) that takes place between fixed cover 6 and the slide block 7.Second screw is a dog screw 22, and it can be adjusted on overcoat along graduated disc 17, and when screw 21 was not locked, screw 22 defined groove 20, therefore also just limits relative motion between sub-fixed cover 6 and the slide block 7.

Among first embodiment that represents among Fig. 2, the relative motion between fixed cover 6 and the slide block 7 has been subjected to the effect of the biasing force of spring 23, and an end of spring is fixed on the fixed cover 6 by pin 24, and the other end matches with slide block 7.In the present embodiment, slit 19 comprises extension 25, and spring 23 is arranged in the position that the extension is represented with solid line.

Though do not show in the drawings, can also utilize with any other curved spring (shape or arrangement position difference) to match with fixed cover 6 and slide block 7 directly or indirectly.

Parts or the rubber bar or the rubber strap 26 of 7 motions of fixed cover 6 internal resistance limited slip blocks, this rubber bar or band extend by fixed cover 6 and slide block, in the embodiment that Fig. 3 represents, the free end of rubber bar 26 is fixed by the metal clip 27 that lies on the plane 28, and the other end of rubber bar 26 directly is fixed on the fixed cover 6 from the outside by cone screw 29.

Can consider to use other rubber bar fixing means, but this does not exceed scope of the present invention yet.

Fig. 4 represents an embodiment who utilizes the frictional damping element, and the frictional force of braking member is controlled.This frictional damping element mainly is made up of following parts:

-fixed part 30, it is tightened to 6 li of fixed covers by spiral.

-seal cover screw 31, it is used to be screwed on the fixed part 30.

The piston rod 32 of-slip in filling box screw 31, its end extends through fixed part 30 and matches with slide block 7 by the pin 33 that enters in the corresponding slit that is provided by slide block 7.

Referring to more detailed Fig. 8, fixed part 30 and filling box screw 31 all have an extension, are respectively 34 and 35, and they are used to be connected with pressure ring 37 with a series of O type sealing rings 36, and these rings are arranged around piston rod 32.The transverse section of pressure ring 37 is interior V-arrangements, and its effect will be explained below.

Piston rod 32 is made by the rustless steel of polishing or the material of other fine polishing.Other parts of present embodiment all are to be made by the material that can stand mattress processing extremely.

Fixed part 30 and cartridge screw 31 all have graduated disc 38 and 39 respectively, read the size of frictional force with them.Graduated disc 38 and 39 reading can be drawn or be engraved.

After above several embodiments of the present invention were described, we explained location, installation question to such dynamic outer bone anchoring device now.

Referring to Fig. 5, label 1 expression movable part.Use foregoing identical reference number, bar 2 and bar 3 are fixed on ball-and-socket joint 4 and 5 places, and ball-and-socket joint 4 and 5 is installed in again on clamping device 40 and 41.

Clamping device 40 and 41 base plate 42 and 43 topped so that it can firmly fix a plurality of pins 44 and 45 by reinforcing fiber phenolic materials institute, pin 44 and 45 is positioned in metacarpal bone 46 respectively and scratches on the bone 47.We notice that the hole that is suitable for accurately installing pin 44 and 45 is arranged on the base plate 42 and 43.

Referring to Fig. 6, we notice in a step, and fixture is very near the position that fractures, and this is because reason pin 44 clinically described in detail below can only be fixed on second metacarpal bone 46 with the angle that is 45 ° to the maximum.

Referring to Fig. 5 in detail, the installation of fixture will be described in detail below.

According to technique known, to there be two pins 44 to be inserted into 46 li of second metacarpal bones at least.Successive screw thread is arranged on the pin 44, and the end 44 has the automatic drill vent needle.The other end of pin 44 is designed to and can inserts securely in the chuck, and chuck is not illustrated in the drawings.Self-tapping screw has maximum folder power.

On the other hand, also can use non-automatic boring pin, these pins are inserted in the locating hole by two cortexes.Certainly, we also can utilize a guider so that pin 44 obtains position accurately.

Two pins 44 on the metacarpal bone 46 are fixed on the base plate 42 of clamping device 40.

Rough alignment fractures behind the place, will have two pins 45 to stretch in the radius 47 in a similar fashion at least and is fixed on the base plate 43 of clamping device 41.

Clamping device 40 and 41 all is furnished with ball-and-socket joint 4 and 5, and the termination by wing nut 48 and 49 barres 2 and 3 is fixed in ball-and-socket joint 4 and 5.

When bone fracture restoration, the doctor at first finds out the center of survey line 18 on the rotating shaft of joint, then with wing nut 48 and 49 fixture is fixed up, and fixture can be placed on the correct position in this way.

Then, whether we can clap an X-ray sheet and confirm to fracture and accurately reset.If be necessary, can unclamp wing nut and do further operation.

Can do further to adjust by knurled wheel 12 and 13.At first knurled wheel 12 and 13 is aligned on the threaded rod 11, moves rolling wheel 12 and 13 then and exist with the elongation of guaranteeing to be necessary.Fixture is fixed (referring to Fig. 1 and Fig. 7) at the treatment initial stage by lock-screw 21.

As discussing in beginning part like that, be desirably in that the later injured pass of initial period (at this moment, fixture keep snap maintain static) is energy-conservation to obtain increasing motion.

Under the situation that does not provide complete program, people may advise controlling crooked numerical value according to following table:

Fracture one week of back is motionless

Fracture two weeks of back are motionless

Three week of fracture back maximum deflection to 10 °

Fracture back four stars phase maximum deflection to 20 °

Fracture back five-pointed star phase maximum deflection to 30 °

Six week of fracture back maximum deflection to 40 °

Allow crooked size to determine that by the doctor doctor is locked at dog screw 22 on the corresponding position.

For example in Fig. 1, rotation is limited to 20 °, thereby the relative motion of bar 2 and bar 3 occurs between centre position of representing with solid line and the extreme position that dots by screw 22.

Referring to Fig. 2, we further notice, in the centre position of representing with solid line, bar 2 and bar 3 not point-blank, they have formed one about 10 ° α angle.This is because the normal position of carpal joint when static determines.Therefore, change between 0 ° and 40 ° at the angle of rotation β that represents on Fig. 2.

As mentioned above, this relative motion during the treatment is to realize by the effect of power obviously.

This power is not linear usually in the embodiment that Fig. 2 and Fig. 3 represent, this is because be the retroaction that spring 23 or elastic component 26 all can not produce a valency force such as corresponding with its position.

For further improving this device, we have proposed embodiment as shown in Figure 4 (Fig. 8 is then more detailed).In the present embodiment, because counteracting force is because fricative between bar 32 and the sealing ring 36, so this relative motion all is subjected to the effect of same angular force on both direction.

In addition, this also can be obtained adjusting by rotating filling screw 31 by patient or doctor.When extension 34 and 35 was close together more tightly, sealing ring 36 had just been pushed down piston rod 32, and this is that the cross sectional shape of pressure ring 37 is the V-arrangements at sensing center because they are crushed between the pressure ring 37.On the contrary, when the extension separates, so also reduce because the pressure of sealing ring reduces above-mentioned counteracting force.

Scale on graduated disc 38 and 39 can be read the numerical value of frictional force.And graduated disc 38 also can be become a vernier cursor by scale with 39.

Claims (15)

1, the dynamic outer bone anchoring device that engages of a kind of ossa articularia that is used to fracture, this device comprises:

(1) have first parts that are suitable for being connected the fixed bar on the bone pin, this bone pin is inserted in the bone of joint one side that fractures;

(2) have second parts that are suitable for being connected the fixed bar on the bone pin, this bone pin is inserted in the bone of the joint opposite side that fractures; It is characterized in that this device also comprises the movable part with a crooked slidingsurface that (3) link together above-mentioned first parts and second parts, said slidingsurface has an imaginary axis, and said movable part also comprises the device of accurately determining the said crooked slidingsurface imaginary axis.

2, dynamic fixation device as claimed in claim 1, wherein said movable part have a fixed cover on of being fixed in said first fixed bar and second fixed bar, saidly are fixed with a convex slidingsurface; Movable part also has a slide block that is fixed on in said first fixed bar and second fixed bar another, and said slide block has a concavity slidingsurface that matches with above-mentioned convex slidingsurface; Movable part also has the side overcoat, and overcoat has a curved slot, and the curvature of this curved slot is corresponding with the curvature of said two slidingsurfaces.

3, dynamic fixation device as claimed in claim 2, wherein said slidingsurface is a cylindrical surface, and the sliding surface of corresponding cylindrical axis and said slide block is perpendicular.

4, dynamic fixation device as claimed in claim 1, wherein said being used for determines that accurately the device of the crooked slidingsurface imaginary axis comprises the survey line that is engraved in or is drawn on the overcoat of side.

5, dynamic fixation device as claimed in claim 2 has the indicated value of said slide block angular displacement on the overcoat of wherein said side.

6, dynamic fixation device as claimed in claim 2 further comprises the device of the angle that the said slide block of restriction slides in said fixed cover.

7, dynamic fixation device as claimed in claim 2 further comprises a device that can make said slide block be subjected to the angular force effect that the resting position in said fixed cover moves, in fixed cover said two fixed bars or on same straight line or therewith straight line become approximately ± 10 ° low-angle.

8, dynamic fixation device as claimed in claim 7, wherein said angular force device is made up of elastic strip, and an end of this elastic strip is fixed on the fixed cover, and its other end is fixed on the said slide block.

9, dynamic fixation device as claimed in claim 7, wherein said angular force device is made of a spring that is inserted between said slide block and the said fixed cover.

10, dynamic fixation device as claimed in claim 2 further comprises and can make the rubbing device of said slide block in controlled frictional force effect sliding block motion.

11, dynamic fixation device as claimed in claim 10, wherein said rubbing device comprises: an end is fixed on the piston rod on the said slide block; Be screwed into an axle bush in the said fixed cover; Be placed in the said axle bush and round the sealing ring of said piston rod; Be inserted into two pressure rings between the adjacent seals ring; And be suitable for being screwed into cartridge screw in the said axle bush with hands, said sealing ring can be compressed to greatlyyer or in various degree less thus, thereby promptly controlled the size of said frictional force.

12, dynamic fixation device as claimed in claim 11, wherein said axle bush and cartridge screw are furnished with a vernier cursor.

13, dynamic fixation device as claimed in claim 2 has at least one to have lubricious in the shoe surface of wherein said fixed cover and slide block.

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