CN207734212U - A kind of orthopaedics internal fixation system - Google Patents
A kind of orthopaedics internal fixation system Download PDFInfo
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- CN207734212U CN207734212U CN201621427793.6U CN201621427793U CN207734212U CN 207734212 U CN207734212 U CN 207734212U CN 201621427793 U CN201621427793 U CN 201621427793U CN 207734212 U CN207734212 U CN 207734212U
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- screw
- biodegradable coating
- fixation system
- internal fixation
- bone plate
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Abstract
The utility model discloses a kind of orthopaedics internal fixation systems, including locking bone plate and lock screw, the female through-hole of tool is provided on the wherein described locking bone plate, the lock screw includes screw head, screw tail portion and the screw bar portion between screw head and screw tail portion, wherein, the screw head and screw tail portion are provided with is less than the central diameter of the screw head and screw tail portion with the matched external screw thread of through-hole internal thread, the diameter of the screw bar portion；The screw bar portion is coated with biodegradable coating, the thickness of the wherein described biodegradable coating is less than or equal to the difference of the diameter of the bar portion and the central diameter of the tail portion, and the rigidity of the lock screw is as the thickness of the biodegradable coating reduces and reduces, to which the gap gradually increased with screw bar portion between fracture of fracturing forms the stress stimulation of gradual change fine motion, poroma is promoted to form the healing in favor of fracture site.
Description
Technical field
The utility model is related to biomedical devices fields, more particularly to fixed in a kind of orthopaedics applied to fracture site
System.
Background technology
Orthopaedics internal fixation system is made of bone plate and bone screws, is a kind of embedded type for being widely used in treating orthopaedic disease
Medical instrument can be divided into common internal fixation system and locking internal fixation system, wherein solid in common internal fixation system and locking
Determining system maximum, difference lies in the ways of contact of bone plate and bone screws.
Bone plate is designed with a certain number of through-holes in common internal fixation system and locking internal fixation system, and bone screws pass through bone
Through-hole on plate is fixed with the bar portion for being threaded structure with human body bon e formation frame-type.And common internal fixation system bone plate leads to
Hole is contacted with bone screw head, either through-hole wall or bone screw head all non-threaded configurations, i.e. bone plate and murices ailhead
The contact in portion is Non-thread type contact, and each other without mutual restriction relation, therefore, fixation is tightened by screw thread in human body bone completely
When the torque that generates and axle power realize that clinically periosteum is concurrent because of congested insufficient necrosis frequent occurrence for this fixed form
Disease.And lock in internal fixation system, the through-hole of bone plate is equipped with internal thread, and the head of bone screws is equipped with external screw thread, with bone plate through-hole
Internal thread matching, realize the contact relation that mutually constrains, and the axial direction of bone plate through-hole can be with the horizontal direction shape of bone plate
It is at a certain angle, by the constraint of screw thread, can adjust bone screws into nail direction, conveniently adapt to various types of bone
Folding treatment.
In general, the bone plate for locking internal fixation system is known as locking bone plate, and bone screws are known as locking bone screws, and common
Bone plate and bone screws are distinguished.Locking internal fixation system has two-stage fixed mode when treating orthopaedic disease, that is, locks bone
Screw and the fixation of human body bone and the fixation of locking bone plate and locking bone screws.Bone plate may be implemented in this two-stage fixed mode
It detaches, is prevented because compressing of the bone plate to periostal surface blood vessel caused by torque and axle power, avoids periosteum with human body bone outer surface
The generation of necrosis.
Locking internal fixation system, common internal fixation system is insurmountable to ask because of with two-stage fixed mode, solving
Topic, therefore on clinical treatment, application is more and more extensive.However, locking internal fixation system is also the same in practical clinical
There are problems, and the severity of problem is no less than periosteum necrosis caused by common internal fixation system.It is wherein the most serious
Problem is, with the fracture of locking internal fixation system treatment, long-time disunion.It is found with clinical research by largely testing,
Fracture long-term disunion the reason of be to lack stress stimulation at fracture site, the formation of unfavorable poroma, and the formation of poroma is bone
Roll over the precondition of healing.The two-stage fixed mode that the reason of lacking stress stimulation is locked out internal fixation system is too strong, whole
The rigidity of body frame is too big, undertakes a large amount of stress, generates stress shielding to fracture and cannot get stress stimulation for a long time, to lead
Cause long-term disunion of fracturing.
Since the rigidity for locking internal fixation system general frame in the prior art is too big, stress shielding, bone are generated to fracture
It fractures and lacks stress stimulation at end, the formation of unfavorable poroma, so as to cause long-term disunion of fracturing.It is fixed in locking in order to reduce
The rigidity of system, reduces adverse effect of the stress shielding to union, and one kind being contralateral cortex bone lock-in techniques (FCL, Far
Cortical Locking) it comes into being.FCL technologies and the difference of general locking internal fixation system essentially consist in its bone screws
Structure.
As shown in Figure 1, the bar portion tail end of the locking bone screws in FCL is equipped with screw thread, between threaded portion and screw head
It is polished rod, and the diameter of polished rod is less than the central diameter of threaded portion, to when FCL is implanted to fracture, lock the light of bone screws
Bar part is since there are difference in diameter with threaded portion so that close between the polished rod and bone of screw head there are one it is small between
Gap, by this minim gap, when locking internal fixation system by axial force, human body bone is surveyed close to bone plate between bone screws
A small displacement is formed, moving toward one another for fracture site is driven by this small displacement, realizes stress stimulation bone
The formation of scab, this mode is fine motion.After the fixed operation of fracture, the parallel fine motion of fracture site can effectively facilitate poroma
It is formed, to improve the healing rate of fracture.FCL technologies can reduce under the intensity for ensureing general locking internal fixation system
80% rigidity.
However, although FCL technologies reduce the integral rigidity of locking internal fixation system well, effectively reduces fracture end and answer
Power is blocked, and fine motion is formed, and promotes poroma to be formed with accelerating union of bone fracture, but in clinical practice, discovery has due to enclosing art
The rigidity that phase locks internal fixation system is too low, lead to that fracture misplaces there is a situation where, and dislocation of once fracturing, often
Re-operation is needed, fracture is corrected again, this certainly will all bring huge shadow to the body of patient, spirit and economy
It rings.Therefore, it is also desirable to be improved to FCL technologies.
Utility model content
The purpose of the utility model is to overcome above-mentioned the deficiencies in the prior art, provide a kind of bone applied to fracture site
Section's internal fixation system can provide good rigidity in the perioperative of fracture site, and then rigidity continuously decreases, and realizes that fracture is disconnected
The stress stimulation of gradual change fine motion between end promotes poroma to be formed in the healing in favor of fracture site.
To realize the purpose of this utility model, the utility model discloses a kind of orthopaedics internal fixation system, locking bone plate and
Lock screw, wherein being provided with the female through-hole of tool on the locking bone plate；The lock screw includes screw head, spiral shell
Follow closely tail portion and the screw bar portion between screw head and screw tail portion, wherein the screw head and the setting of screw tail portion
Have and is less than the screw head and screw tail portion with the matched external screw thread of through-hole internal thread, the diameter of the screw bar portion
Central diameter；
The screw bar portion is coated with biodegradable coating, wherein the thickness of the biodegradable coating is less than or waits
In the difference of the central diameter of the diameter and tail portion of the bar portion, and the rigidity of the lock screw is with the biodegradable
The thickness of coating reduces and reduces.
Preferably, ranging from the 0 of the thickness d of the biodegradable coating<d<1mm；Alternatively, the biodegradable applies
Ranging from the 0.5 of the thickness d of layer<d<1mm.
Preferably, the screw head is cylinder；Alternatively, the screw head is cone, wherein the cone of cone
Spend ranging from 0 ° of 90 ° of ＜ Φ ＜ of Φ.
Preferably, the screw head and screw tail portion are provided with and the matched externally threaded screw pitch of the through-hole internal thread
For varying pitch P=P0 ± α；Wherein, ranging from 0.001~0.1mm of α values；Alternatively, ranging from 0.005~0.05mm of α values；
Alternatively, α values are 0.01mm.
Preferably, the screw pitch of internal thread is standard pitch P0 on the locking bone plate.
Preferably, the externally threaded screw thread cusp is equipped with 30 ° of inclined-planes, and correspondingly, the bottom of the internal thread is equipped with 30 °
Inclined-plane.
Preferably, when the screw head is screwed into the through-hole of locking bone plate, the externally threaded cusp and the interior spiral shell
The bottom bevel of line squeezes, and contact of the external screw thread with internal thread becomes spiral banding pattern from spiral linear, and varying pitch carries
For the mutual extruding between the externally threaded cusp and the bottom bevel of the internal thread, the external screw thread and internal thread are improved
Between frictional force.
Preferably, the axial horizontal direction shape with locking bone plate of through-hole of through-hole has a certain degree on the locking bone plate
The size of α, angle [alpha] are 0 °<α<90°.
Preferably, the locking bone plate is straight type, dynamic pressing or anatomical form.
The utility model has the beneficial effects that：
Compared to the prior art, the utility model is not the fracture breaking part for providing common internal fixation system merely
" fine motion " of the fracture breaking part of " fixation " and FCL, and the creative bar portion in lock screw is coated with biology and can drop
Electrolytic coating so that the protection that good rigidity is provided in perioperative, situations such as avoiding fracture breaking part dislocation, with the time fracture it is disconnected
The slowly healing for splitting place, rigidly continuously decreases, formed " gradual change fine motion ", until biodegradable coating degradation complete, fine motion
Stress stimulation promotes poroma to be formed to accelerate the healing of fracture breaking part, so as to avoid common internal fixation system due to whole frame
The rigidity of frame is too big, undertakes a large amount of stress, generates the case where fracturing long-term disunion caused by stress shielding to fracture, also keeps away
Exempted from FCL perioperative lock internal fixation system rigidity it is too low, cause fracture misplace there is a situation where correct again.And
And using biodegradable coating, the coating after degradation can be discharged by absorbing, and will not be damaged to body.
Description of the drawings
It, below will be to attached drawing needed in the embodiment in order to illustrate more clearly of the technical solution of the utility model
It is briefly described, it should be apparent that, the accompanying drawings in the following description is only some embodiments of the utility model, for ability
For the those of ordinary skill of domain, without creative efforts, it can also be obtained according to these attached drawings other attached
Figure.
Fig. 1 is the locking bone screws schematic diagram of FCL；
Fig. 2 is the schematic diagram of the orthopaedics internal fixation system of the utility model；
Fig. 3 is the schematic diagram of the locking bone screws with biodegradable coating of the utility model；
Fig. 4 is the schematic diagram of the helicitic texture of the utility model；
Fig. 5 is the schematic diagram of the rigidity test of the utility model；
Fig. 6 is the schematic diagram of the PDLA attenuation curves of the utility model；
Fig. 7 is the schematic diagram of the rigidity and PLDA degradation relationships of the utility model；
Fig. 8 is the schematic diagram of magnesium alloy attenuation curve in SBF of the utility model；
Fig. 9 is the schematic diagram of the rigidity and magnesium alloy degradation relationship of the utility model；
Figure 10 is the PLDA degradation rates of the utility model and the schematic diagram of thickness relationship；
Figure 11 is the magnesium alloy degradation rate of the utility model and the schematic diagram of thickness relationship.
Specific implementation mode
The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model
Clearly and completely describe.
The utility model embodiment provides one on the basis of existing common locking internal fixation system and FCL technologies
Orthopaedics internal fixation system of the kind applied to the gradual change fine motion of fracture site.
As shown in Fig. 2, the orthopaedics internal fixation system includes locking bone plate 1 and lock screw 2.It is arranged on the locking bone plate
There are the female through-hole of tool, the axial horizontal direction with locking bone plate of the through-hole that can form certain angle [alpha], angle [alpha]
Size can be 0 °<α<90°.The locking bone plate can be straight type, dynamic pressing and anatomical form, not limit specifically
System.
As shown in figure 3, the lock screw includes head 21, tail portion 22 and the bar portion 23 between head and tail portion,
Wherein, the head and tail portion are provided with is less than described with the matched external screw thread of through-hole internal thread, the diameter of the bar portion
The central diameter on head and tail portion.The size of the head and tail portion may be the same or different, and not be limited specifically.
In addition, as shown in figure 4, screw head is cylindrical or cone, conical taper is 0 ° of 90 ° of ＜ Φ ＜,
External screw thread screw pitch is varying pitch, i.e. P=P0 ± α, α values are 0.001~0.1mm, and more excellent is 0.005~0.05mm, most preferably
0.01mm.Screw thread cusp is equipped with 30 ° of inclined-planes.With the matched bone plate through-hole internal thread taper of screw head, internal thread screw pitch is
Standard pitch P0, the bottom of thread are equipped with 30 ° of inclined-planes, when screw head is screwed into Bone plate inner hole, externally threaded cusp and internal thread
Bottom bevel squeezes so that contact of the external screw thread with internal thread becomes spiral banding pattern from spiral linear, increases frictional force, to carry
High bone screws loosing prevention ability.And varying pitch then provides the mutual extruding between thread inclined-plane, further increases between screw thread
Frictional force.
Significantly, since existing common internal fixation system since the rigidity of general frame is too big, produces fracture
The long-term disunion of fracture and existing FCL caused by raw stress shielding lock interior solid in the perioperative that fracture site is performed the operation
Determine that the rigidity of system is too low to be likely to result in fracture dislocation, therefore, it is creative in the utility model embodiment will be described
Bar portion is coated with biodegradable coating 24.
The biodegradable coating of the bar portion coating has good biocompatibility, and for biodegradable work(
The active coating of energy so that the biodegradable coating enhances the rigid of the lock screw in the perioperative energy Enough of fracture site
Property, and as time stepping method is in the degradation process of the biodegradable coating, the biodegradable coating is gradually compatible,
So that the rigidity of the lock screw continuously decreases, bone forms the gap gradually increased with screw body part, to realize bone
Fracture end between gradual change fine motion stress stimulation, promote poroma formed in favor of fracture site healing.Wherein, perioperative is to enclose
Around an overall process of operation, since patient determines to be treated surgically, to operative treatment up to basic rehabilitation, including operation
Before, operation in and postoperative a period of time, the perioperative time be less than 14 days, it is preferable that be less than or equal to 7 days.
In specific embodiment of the utility model, before the biodegradable coating degradation and perioperative, spiral shell is locked
The rigidity of nail is 5.0~6.5KN/mm so that fixedly locked system maintains good rigidity in the orthopaedics of gradual change fine motion, substantially
It is similar with the common rigidity of locking nail internal fixation system (PL), it is good rigid so as to be provided in the perioperative of fracture site
Property, avoid perioperative locking internal fixation system rigidity it is too low, cause fracture misplace there is a situation where.
The stress stimulation of fine motion is the necessary condition of union.In the gradual compatible degradation of the biodegradable coating
In the process, lock screw rigidity with biodegradable coating thickness reduce and reduces, fracture be broken between with shank of screw
The gap that portion gradually increases forms the stress stimulation of gradual change fine motion, and poroma is promoted to form the healing in favor of fracture site.
After the biodegradable coating is degradable, the rigidity of the lock screw is 1.0~1.5KN/mm so that
The rigidity of fixedly locked system is similar with the rigidity of contralateral cortex bone lock-in techniques (FCL) in the orthopaedics of gradual change fine motion, to have
Effect reduces fracture end stress shielding, forms fine motion, and poroma is promoted to be formed with accelerating union of bone fracture.
It is tested repeatedly by utility model people, when the degradation rate (weight-loss ratio) 0 of the biodegradable coating<δ<=10%
When, the rigidity of the lock screw is 5.0~6.5KN/mm；When the degradation rate 10 of the biodegradable coating<δ<=30%
When, the rigidity of the lock screw is 4.0~5.5KN/mm；When the degradation rate 30 of the biodegradable coating<δ<=100%
When, the rigidity of the lock screw is 1.0~5.0KN/mm.
It is compared with FCL with existing common internal fixation system, the utility model is not that simple provide fixes system in common
" fixation " of the fracture breaking part of system and " fine motion " of the fracture breaking part of FCL, and the creative bar in lock screw
Portion is coated with biodegradable coating so that the protection that good rigidity is provided in perioperative avoids the feelings such as fracture breaking part dislocation
Condition is rigidly continuously decreased with the slowly healing of time fracture breaking part, is formed " gradual change fine motion ", until postoperative period biology
Biodegradable coating degradation is completed, and the stress stimulation of fine motion promotes poroma to be formed to accelerate the healing of fracture breaking part.
(1) material of biodegradable coating
In the present invention, the biodegradable coating material includes following one or more：Polylactic acid, biology
Degradation magnesium alloy, bio-vitric, degradable biological hydroxyapatite, bioactivity nacre, chitosan, hyaluronic acid
Sodium, chitin, collagen, gelatin, beta tricalcium phosphate.Certainly there can also be other biodegradable coating materials,
This is simultaneously not listed one by one.
In a specific embodiment, the biodegradable coating of the bar portion coating is polylactic acid coating.
Polylactic acid is the polymer using lactic acid as primary raw material, as one kind of biodegradable material, environmentally friendly,
Nonhazardous can be applied to the bio-medical materials such as medicament slow release.
In medical domain, after lock screw of the bar portion coated with polylactic acid coating implants, degradation reaction is just opened
Begin to carry out.It being compared slowly in initial period degradation reaction, the acid small molecule of generation can be metabolized and excrete, with
The passage of time, degradation reaction gradually accelerates the acid small molecule generated to have little time to be metabolized and accumulate, and causes part acid dense
Degree becomes larger, and accelerates the degradation of catalysis material, that is, autocatalytic effect occurs.Therefore, it can be seen that polylactic acid coating can be lacked in bone
The damage phase temporarily substitutes bone tissue, supports surrounding soft tissue, and with degradation reaction, polylactic acid coating is gradually degraded, absorbed, and polymerization is big
Molecule is gradually hydrolyzed into smaller polymer, and final cracking becomes lactic acid monomer, i.e. lock screw mechanical strength declines, and bone supports work(
It can gradually lose.
Such as in application example one, FCL screws use TC4ELI titanium alloys, polylactic acid to use poly- d- lactic acid (PDLA),
Molecular weight is 1.5-3 (ten thousand) Mw, viscosity 0.3-0.5dl/g.In this application example, polylactic acid coating preferably uses
PDLA, naturally it is also possible to be poly (l-lactic acid) (PLLA) and poly- dL- lactic acid (PDLLA), then this is not restricted.
PDLA coatings are coated to the smooth bar part of FLC screws, the bottom of thickness and threaded portion by injection molding
Diameter is concordant.The degradation of PDLA carries out in simulated body fluid, according to every one section when, measure its weightless quality number weigh,
Degradation rate is calculated according to the percentage calculation of residual mass and original quality, i.e. δ=W1/W0, and wherein W1 is residual mass, and W0 is
Original quality.The bone that frame structure is formed with locking internal fixation system uses polyurethane artificial bone, locking bone plate or so respectively to match 3 pieces
FCL screws, control group for no PDLA coatings FCL screws.
The test of rigidity carries out on universal tensile testing machine, as shown in figure 5, at the both ends of artificial bone, loads and presses to
Power detects under same pressure, the relative displacement size of fracture end, and direction shown in arrow is power loading direction.Contrast sample is
Common locking internal fixation system (PL) and FCL internal fixation systems.
By testing, PDLA attenuation curves figure as shown in FIG. 6, within the initial stage of immersion, about one week, the degradation of PDLA
Rate is slow, degradation 9%, and degradation speed improves after a week, reaches 85% when by 7 weeks, then postpones at any time, degradation rate obviously becomes
Slowly.
Specifically, the degradable cycle T of the polylactic acid coating is 49~70 days；When the biodegradable coating drops
Solve the time 0<T<At=7 days, the degradation rate δ is 0~10%；When the biodegradable coating degradation time 8<T<=24 days
When, the degradation rate δ is 10~50%；When the biodegradable coating degradation time 24<T<At=49 days, the degradation rate
δ is 50~85%；When the biodegradable coating degradation time 49<T<At=70 days, the degradation rate δ is 85~100%.
By experiment, rigidity as shown in Figure 7 and PLDA degradation relationships, with the degradation of PLDA, the orthopaedics of gradual change fine motion
The rigidity of interior fixedly locked system reduces.Early period occurs in degradation, fixedly locked system maintains in the orthopaedics of gradual change fine motion
Good rigidity, rigidity reach 5.4KN/mm, compared with the rigidity 6.2KN/mm of common locking nail internal fixation system (PL), slightly
It reduces, and compared with state in FCL determines the rigidity 1.2KN/mm of system, then big 4 times or more.The degradation of PLDA therewith, when by 7 weeks,
The rigidity of fixedly locked system will be as low as fixed in 1.5KN/mm, with FCL in the orthopaedics of gradual change fine motion provided by the utility model
System is close.
Specifically, when the degradation rate 0 of the biodegradable coating<δ<When=10%, the rigidity of the lock screw is
5.0~5.5KN/mm；When the degradation rate 10 of the biodegradable coating<δ<When=30%, the rigidity of the lock screw is
4.5~5.5KN/mm；When the degradation rate 30 of the biodegradable coating<δ<When=50%, the rigidity of the lock screw is
4.0~5.0KN/mm；When the degradation rate 50 of the biodegradable coating<δ<When=70%, the rigidity of the lock screw is
3.0~4.0KN/mm；When the degradation rate 70 of the biodegradable coating<δ<When=85%, the rigidity of the lock screw is
1.0~3.5KN/mm；When the degradation rate 85 of the biodegradable coating<δ<When=100%, the rigidity of the lock screw is
1.0~2.0KN/mm.
In another specific embodiment, the biodegradable coating of the bar portion coating is biodegradable magnesium alloy.Magnesium
Normal contents in human body are 25g or so, and half is present in bone, and magnesium alloy has ideal mechanical support power, well
Biocompatibility, and be easy degradation, catabolite participate in metabolism.Therefore, magnesium alloy, which is proper biology, to drop
Solve material.Certainly, the biodegradable coating of the bar portion coating can also be used with the biodegradable other materials become,
It is not limited herein.
Such as in application example two, it is AZ13B that FCL screws, which use TC4ELI titanium alloys, biodegradable magnesium alloy,
One layer of magnesium alloy coating is deposited on FCL polished rods, wherein coating production is plasma spraying, the screw thread of thickness and FCL screws
Central diameter is concordant.The test method of degradation and rigidity is similar with application example one, therefore will herein be described in detail.
By experiment, the magnesium alloy as shown in Figure 8 degradation rate figure in SBF, basic degradation in 240 hours finishes.Magnesium alloy
Degradation rate ratio PDLA it is fast very much, can degrade and finish substantially in 10 days.It is solid in the orthopaedics of the gradual change fine motion of magnesium alloy coating
Good rigidity can be provided at first 3 days by determining locking system.In the rigidity that can then provide lasting reduction, to the micro- of fracture end
The dynamic stress stimulation formed also has the function of stepping up.FCL system base of the fine motion amplitude substantially with inanimate object degradation coating
This is consistent.
Specifically, the degradable cycle T of the biodegradable magnesium alloy is 7~14 days；When the biodegradable applies
Layer degradation time 0<T<At=3 days, the degradation rate δ is 0~20%；When the biodegradable coating degradation time 3<T<=
At 10 days, the degradation rate δ is 20~95%；When the biodegradable coating degradation time 10<T<At=15 days, the drop
Solution rate δ is 95~100%.
By experiment, rigidity as shown in Figure 9 and magnesium alloy degradation relationship, with degradation of the magnesium alloy in SBF, gradual change
The reduction of the rigidity of fixedly locked system in the orthopaedics of fine motion.Early period occurs degrading, fixing lock in the orthopaedics of gradual change fine motion
Determine system and maintain good rigidity, rigidity reaches 6.1KN/mm, the rigidity with common locking nail internal fixation system (PL)
6.2KN/mm is compared, and is slightly reduced, and compared with state in FCL determines the rigidity 1.2KN/mm of system, then big 5 times or more.Magnesium therewith
The degradation of alloy, when by 10 days, the rigidity 1.3KN/ of fixedly locked system in the orthopaedics of gradual change fine motion provided by the utility model
Mm, it is close with FCL internal fixation systems.
Specifically, when the degradation rate 0 of the biodegradable coating<δ<When=10%, the rigidity of the lock screw is
5.5~6.5KN/mm；When the degradation rate 10 of the biodegradable coating<δ<When=30%, the rigidity of the lock screw is
4.5~5.0KN/mm；When the degradation rate 30 of the biodegradable coating<δ<When=50%, the rigidity of the lock screw is
3.0~4.0KN/mm；When the degradation rate 50 of the biodegradable coating<δ<When=85%, the rigidity of the lock screw is
1.0~2.5KN/mm；When the degradation rate 85 of the biodegradable coating<δ<When=100%, the rigidity of the lock screw is
1.0~2.0KN/mm.
In addition, the biodegradable coating of the bar portion coating is HA (hydroxyapatite) or the degradable material of other biological
Material, in the present invention and is not specifically limited.
(2) thickness of biodegradable coating
The thickness d of the biodegradable coating is less than or equal to the difference of the diameter of the bar portion and the central diameter of the tail portion
Value, it is preferable that the thickness d of the biodegradable coating is equal to the difference of the diameter of the bar portion and the central diameter of the tail portion.
In general, the difference of the central diameter of the diameter tail portion of bar portion is less than 1mm, therefore ranging from the 0 of the thickness d of the biodegradable coating
<d<1mm is tested repeatedly by utility model people, it is preferable that ranging from the 0.5 of the thickness d of the biodegradable coating<d<
1mm。
Such as in application example one, by experiment, the relational graph of PLDA degradation rates and thickness as shown in Figure 10.Thickness
Degradation speed is relatively slow when relatively thick；As thickness is reduced, degradation speed is opposite to be improved.
Specifically, when the thickness 0.8 of the biodegradable coating<d<When=1.0mm, the biodegradable coating
Degradation rate is 0~10%；When the thickness 0.7 of the biodegradable coating<d<When=0.8mm, the biodegradable coating
Degradation rate be 20~30%；When the thickness 0.5 of the biodegradable coating<d<When=0.7mm, the biodegradable applies
The degradation rate of layer is 30~60%；When the thickness 0.3 of the biodegradable coating<d<When=0.5mm, the biodegradable
The degradation rate of coating is 50~80%；When the thickness 0.1 of the biodegradable coating<d<When=0.3mm, the biology can drop
The degradation rate of electrolytic coating is 70~90%；When the thickness 0 of the biodegradable coating<d<When=0.1mm, the biology can drop
The degradation rate of electrolytic coating is 90~100%.
Such as in application example two, by experiment, the relational graph of magnesium alloy degradation rate and thickness as shown in figure 11.It is thick
Degradation speed is relatively slow when spending relatively thick；As thickness is reduced, degradation speed is opposite to be improved, when follow-up thickness very little of degrading
When, degradation speed significantly improves.
Specifically, when the thickness 0.8 of the biodegradable coating<d<When=1.0mm, the biodegradable coating
Degradation rate is 0~10%；When the thickness 0.7 of the biodegradable coating<d<When=0.8mm, the biodegradable coating
Degradation rate be 20~30%；When the thickness 0.5 of the biodegradable coating<d<When=0.7mm, the biodegradable applies
The degradation rate of layer is 30~40%；When the thickness 0.3 of the biodegradable coating<d<When=0.5mm, the biodegradable
The degradation rate of coating is 50~60%；When the thickness 0.1 of the biodegradable coating<d<When=0.3mm, the biology can drop
The degradation rate of electrolytic coating is 70~80%；When the thickness 0 of the biodegradable coating<d<When=0.1mm, the biology can drop
The degradation rate of electrolytic coating is 80~100%
(3) degradation cycle of biodegradable coating
It can be seen that based on above-mentioned biodegradable coating, the perioperative of fracture site locks internal fixation system in order to balance
Rigidity, and between fracture site within the surgery recovery phase gradual change fine motion stress stimulation, needing to control the biology can
The degradation cycle of degradation coating, the degradation cycle of the biodegradable coating and the material and biology of biodegradable coating can
The thickness of degradation coating is related.
It is worth noting that the degradation cycle of the biodegradable coating can be real by adjusting coating ingredients parameter
It is existing, such as adjust the molecular weight of polylactic acid or the molecular weight of biodegradable magnesium alloy.In addition, the biodegradable coating
Degradation cycle can be realized by adjusting the thickness of biodegradable coating.
It is tested repeatedly by utility model people, in order to provide good rigidity, the life in fracture fracture perioperative
The degradable cycle T of Biodegradable coating is less than or equal to 90 days, it is preferable that the degradable week of the biodegradable coating
Phase T is 7~30 days.For example, when biodegradable coating is polylactic acid coating, the degradation cycle of the biodegradable coating
It is 49~70 days；When biodegradable coating is biodegradable magnesium alloy, the degradation cycle of the biodegradable coating is 7~
14 days.Certainly the degradation cycle numerical value for also having other coating compositions, is not restricted herein.It, can for different fracture sites
To determine the biodegradable coating for being conducive to fracture site healing by the material and thickness that adjust biodegradable coating
Degradation cycle.
It can be seen that from the description above, compared to the prior art, the bar portion in lock screw of the utility model creativeness
Coated with biodegradable coating so that perioperative provide good rigidity protection, avoid fracture breaking part dislocation situations such as, with
The slowly healing for time fracture breaking part, rigidly continuously decreases, and is formed " gradual change fine motion ", until postoperative period biodegradable
Coating degradation is completed, and the stress stimulation of fine motion promotes poroma to be formed to accelerate the healing of fracture breaking part, so as to avoid common
Internal fixation system is too big by the rigidity of what general frame, undertakes a large amount of stress, generates to fracture and fractures caused by stress shielding
The case where long-term disunion, also avoid FCL perioperative lock internal fixation system rigidity it is too low, cause fracture misplace
There is a situation where correct again.Moreover, using biodegradable coating, the coating after degradation can be discharged by absorbing, will not be to body
Body damages.
Each embodiment in this specification is described in a progressive manner, identical similar between each embodiment
Just to refer each other for part, what each embodiment stressed is the difference with other embodiment.
Finally it should be noted that：The description of the various embodiments of the utility model is supplied to the purpose described above
Those skilled in the art.It is not intended to exhaustive or is not intended to and limits the invention to single disclosed embodiment party
Formula.As described above, the various replacements of the utility model and variation will be aobvious for above-mentioned technology one of ordinary skill in the art
And it is clear to.Therefore, although having specifically discussed some alternative embodiments, other embodiment will be aobvious and easy
See or those skilled in the art relatively easily obtain.The utility model is intended to be included in this this practicality crossed by discussion
Novel all replacements, modification and variation, and fall the other embodiment in the spirit and scope of above-mentioned application.
Claims (8)
1. a kind of orthopaedics internal fixation system, including locking bone plate and lock screw, wherein being provided on the locking bone plate has
The through-hole of internal thread, it is characterised in that：
The axial horizontal direction shape with locking bone plate of the through-hole of through-hole has a certain degree on the locking bone plate；
The lock screw includes screw head, screw tail portion and the screw bar portion between screw head and screw tail portion,
Wherein, the screw head and screw tail portion be provided with the matched external screw thread of through-hole internal thread, the screw bar portion
Diameter is less than the central diameter of the screw head and screw tail portion；
The screw bar portion is coated with biodegradable coating, wherein the thickness of the biodegradable coating is less than or equal to institute
The difference of the diameter of bar portion and the central diameter of the tail portion is stated, and the rigidity of the lock screw is with the biodegradable coating
Thickness reduce and reduce.
2. orthopaedics internal fixation system according to claim 1, which is characterized in that the thickness d of the biodegradable coating
Ranging from 0<d<1mm；Alternatively,
Ranging from the 0.5 of the thickness d of the biodegradable coating<d<1mm.
3. orthopaedics internal fixation system according to claim 1, which is characterized in that the screw head is cylinder；Alternatively,
The screw head is cone, wherein ranging from 0 ° of 90 ° of ＜ Φ ＜ of the taper Φ of cone.
4. orthopaedics internal fixation system according to claim 1, which is characterized in that the screw head and the setting of screw tail portion
It is varying pitch P=P0 ± α to have with the matched externally threaded screw pitch of the through-hole internal thread；
Wherein, ranging from 0.001~0.1mm of α values；Alternatively,
Ranging from 0.005~0.05mm of α values；Alternatively,
α values are 0.01mm.
5. orthopaedics internal fixation system according to claim 4, which is characterized in that the screw pitch of internal thread on the locking bone plate
For standard pitch P0.
6. orthopaedics internal fixation system according to claim 5, which is characterized in that the externally threaded screw thread cusp is equipped with
30 ° of inclined-planes, correspondingly, the bottom of the internal thread are equipped with 30 ° of inclined-planes.
7. orthopaedics internal fixation system according to claim 6, which is characterized in that when the screw head is screwed into locking bone plate
Through-hole when, the bottom bevel of the externally threaded cusp and the internal thread squeezes, contact of the external screw thread with internal thread
Become spiral banding pattern from spiral linear, and varying pitch provide the externally threaded cusp and the internal thread bottom bevel it
Between mutual extruding, improve the frictional force between the external screw thread and internal thread.
8. orthopaedics internal fixation system according to claim 1, which is characterized in that the locking bone plate is straight type, power adds
Die mould or anatomical form.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621427793.6U CN207734212U (en) | 2016-12-24 | 2016-12-24 | A kind of orthopaedics internal fixation system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621427793.6U CN207734212U (en) | 2016-12-24 | 2016-12-24 | A kind of orthopaedics internal fixation system |
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| Publication Number | Publication Date |
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| CN207734212U true CN207734212U (en) | 2018-08-17 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111407387A (en) * | 2020-03-10 | 2020-07-14 | 昶盛(物料应用制品)有限公司 | Screw assembly for bone fixation and bone fixation device |
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2016
- 2016-12-24 CN CN201621427793.6U patent/CN207734212U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111407387A (en) * | 2020-03-10 | 2020-07-14 | 昶盛(物料应用制品)有限公司 | Screw assembly for bone fixation and bone fixation device |
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