Abstract:
A device for bone fixation is comprised of an expansion part and a covering part. The expansion part has a fixing end and a top end and provides an expandable structure for being adjusted in a state of expansion or contraction. The covering part has a front end and a joining end, wherein the front end thereof is joined to the top end of the expansion part, and the joining end thereof is attached to the fixing end of the expansion part. The covering part is employed to cover the expandable structure. After the expansion part and the covering part being added to the bone, the covering part is unfurled to spread to the expansion state, and the medical filler is stuffed or poured into the covering part.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a device for bone fixation device, particularly a bone fixation device which is comprised of an expansion part as well as a covering part. 
       BACKGROUND OF THE INVENTION 
       [0002]    Currently, surgery commonly applied for injecting or filling medical fillers into bones has following ways: 
         [0003]    The mechanical-type hole expansion device, which is disclosed in such as U.S. Patent Application Publication Nos. 20110196494, 2011018447, 20100076426, 20070067034, 20060009689, 20050143827, and 20220052623, and U.S. Pat. Nos. 6,354,995, and 6,676,665, is utilized to expand a hole in the bone and create a space, where the hole expansion device is removed after the hole has been bored; a covering device is then inserted before the process of pouring or stuffing medical fillers takes place. This type of surgery has the following shortcoming: The cancellous bone fragments that are crushed by the mechanical-type hole expansion device often falls into the mechanical-type hole expansion device, causing the device to jam and its components unable to be retrieved, i.e., unable to restore to a state of contraction, which in turn causes the entire mechanical-type hole expansion device to become stuck at the location of the hole and unable to be removed. 
         [0004]    The filling-type hole expansion device, which is disclosed in such as U.S. Pat. Nos.  5 , 972 , 015 ,  6 , 066 , 152 ,  6 , 235 , 043 ,  6 , 423 , 083 ,  6 , 607 , 544 ,  6 , 623 , 505 ,  6 , 663 , 646 , and 6,716,216, also bores a hole in the bone to create a space, where the hole expansion device is removed after the hole is bored, and a covering device is placed therein, and then the surgery with the pouring or stuffing of the medical filler takes place. Mostly, the filling-type hole expansion device has a balloon (the type of balloon used depends on what is needed) disposed inside the bone with liquid, such as water, poured into the balloon with high pressure, causing the balloon to expand and push away the cancellous bone, achieving the effect of hole expansion. The filling-type hole expansion device also has shortcomings, for example, the balloons used in the process must be attached to a nozzle, which creates the possibility that the balloon may be detached from the nozzle during the high-pressure insertion of liquid into said balloon. There can even be cases where the balloon ruptures. 
         [0005]    In the case that a hole expansion process is not done beforehand, and a covering device is placed directly into the bone for the insertion of medical fillers, the hole expansion is instead achieved through the pressure created when medical fillers are inserted into the covering device. In this case the covering device acts as both a hole expansion device and a fixation device as it is disclosed in, such as Taiwan patent No. 1321467, Taiwan Patent application publication No. 20112995, and U.S. Pat. No. 6,248,110. It is also possible to exclude a covering device entirely, instead using a perfusion device to directly pour medical filler at the surgery location such as U.S. Pat. No. 5,514,137 discloses to reinforce fixation at the surgery location. The surgical way has following shortcomings: due to the lack of a hole bored before surgery, the area for pouring the medical filler cannot be controlled accurately to cause the direction of the poured medical filler differing from what doctors originally predicted; there even can also be that, after the medical filler has been poured in, the bone is found not completely held up by the covering device, or the medical filler spreads out all over in the bone, or even seeping out of the bone; it is perhaps to occur that the concentration of slurry-type medical filler could be too dilute, or the grains of the medical filler are too fine such that it results in the bone to be unsuccessfully held up during the pouring of medical filler to greatly decrease the originally expected effectiveness. 
         [0006]    The mechanical-type hole expansion device, which is utilized as the bone fixation device as it is disclosed in such as U.S. patent Application Publication Nos. 20120071977, 20110046739, 20100069913, 20100217335, 20090234395, and 20090005821 is implanted into and props up the bone with the medical filler being poured immediately afterward to surround the mechanical-type hole expansion device. After pouring, the hole expansion device is left inside the body along with the medical filler. Due to the lack of a covering device, it is not possible to effectively control the flow direction of the medical filler, and the medical filler can therefore spread out in all directions or even flow out of the bone. Besides, the medical filler also cannot effectively and fully cover the mechanical-type hole expansion device, and it may leads that mechanical-type hole expansion device gradually contract to a state of partly expanding instead of the state of completely expanding. That in turn causes that the bone is not fully propped up to lose the original purpose of bone fixation. 
         [0007]    The present invention is a bone fixation device which uses a covering part to cover its expansion part. During the hole expansion process, the covering part can effectively prevent any falling of cancellous bone into the expansion part, which allows the expansion part to expand and contract smoothly and repeatedly in the bone to adjust the direction and extent of the hole expansion. In addition, when the medical filler is poured in, the area which poured by the medical filler can be controlled effectively to avoid the medical filler spreading all over in the bone. After pouring being completed, the medical filler can completely cover the expansion part to avoid the expansion part contracting. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention relates to use of a covering part to cover the expansion part, preventing cancellous bone fragments from falling into the expansion part. The covering part allows the expandable structure to expand and contract smoothly, which is crucial for the expandable structure to repeatedly expand and contract within the bone for hole expansion, in order to control the direction and extent of the hole expansion. The covering part can also effectively control the extent of medical filler pouring, avoiding the medical filler to spread out within the bone. After completion of medical filler pouring, the medical filler can fully cover the expansion part, avoiding the possibility of said expansion part from contracting. 
         [0009]    An object of the present invention is to provide a device for bone fixation. 
         [0010]    Another object of the present invention is to provide a device for bone fixation with a covering part. 
         [0011]    A further object of the present invention is to provide a device for bone fixation with a covering part and an expansion part. 
         [0012]    A further object of the present invention is to provide a device for bone fixation with which the medical filler can be stuffed or poured via a tube. 
         [0013]    A further object of the present invention is to provide a device for bone fixation which has the capability to prop up a bone. 
         [0014]    A further object of the present invention is to provide a device for bone fixation which can prevent bone fragments from jamming the expansion part. 
         [0015]    A further object of the present invention is to provide a device for bone fixation with which the medical fillers can fully cover the expansion part. 
         [0016]    A further object of the present invention is to provide a device for bone fixation which can cover the expansion part and expand and contract repeatedly. 
         [0017]    A further object of the present invention is to provide a device for bone fixation with a pressing device. 
         [0018]    A further object of the present invention is to provide a device for bone fixation which has a hollow fixing device. 
         [0019]    A further object of the present invention is to provide a device for bone fixation which has limited control over the extent of medical filler pouring. 
         [0020]    A device for bone fixation according to the present invention is comprised of:
       an expansion part having an end being a fixing end, and the other end being a top end, and providing an expandable structure for being adjusted in a state of expansion or contraction;   a covering part having a front end, and a joining end, wherein the front end thereof is joined to the top end of the expansion part, and the joining end thereof is fixedly attached to the fixing end of the expansion part, and the covering part is employed to cover the expandable structure;   wherein after the expansion part and the covering part are placed in a bone, the covering part is propped up by the expansible structure in a state of expansion, and the medical filler is stuffed or poured into the covering part via the fixing end of the expansion part during the expansible structure being in a state of expansion.       
 
         [0024]    The aforementioned expandable structure in the expansion part can be any conventional expandable structure disclosed in such as U.S. patent Application publication Nos. 20110196494, 20110184447, 20100076426, 20070067034, 20060009689, 20050143827, 20220052623, 6354995, 6676665, 20120071977, 20110046739, 20100069913, 20100217335, 20090234398, and 20090005821, and Taiwan Patent Nos. 585091, and 1318110, wherein it is preferable that the expandable structure is lantern-shape (shown in  FIGS. 2   a ,  2   b ,  2   c , and  2   d ), or strip shape (shown in  2   g,    2   h,  and  2   i ). 
         [0025]    The aforementioned expansion part is provided with the expandable structure to prop up the covering part in a state of expansion, thereafter the medical filler is inserted instead of pressure resulting from the medical filler being poured or stuffed into the covering part being used to prop up the covering part. This method avoids the situation that insufficient pressure caused by either slurry medical filler being excessively dilute and seeping out via clearances of the covering part, or the grains of the medical filler being too fine and falling out via clearances of the covering part is incapable of successfully propping up the expandable structure and the covering part and greatly reduces the required function of the expansion part. 
         [0026]    The aforementioned covering part can effectively prevent crushed cancellous bone fragments from jamming in the expandable structure during hole expansion, allowing the expandable structure to repeatedly and smoothly expand and contract, and effectively control the extent of the medical filler pouring to avoid the medical filler spreading out all over within the bone so as not to hurt the patient due to uneven poured medical filler and the medical filler flowing out of the bone. Moreover, after being poured in, the medical filler completely covers the expandable structure to avoid the possibility of the expansion structure to contract. 
         [0027]    The front end of the aforementioned covering part can be cylinder-shaped, cone-shaped, sphere-shaped, sphere-like, gourd-shaped, cube-shaped, cube-like or any other conventional shapes. 
         [0028]    The aforementioned covering part can be any conventional covering device, such as elastic covering device, web-shaped covering device, or porous covering device. The web-shaped covering device or porous covering device is preferable. Additionally, the covering part can be one single or multiple covering devices. 
         [0029]    The aforementioned covering part is made of biocompatible material, preferably biocompatible material that are flexible, such as: PU (poly-urethane), silicone rubber, or nylon. The covering part can also be a covering device described in other similar devices, such as disclosed in U.S. Patent Application Publication Nos. 20040122455, 200040210297, 20040073308, 20060149379, and U.S. Pat. No. 6,719,773. 
         [0030]    The aforementioned web-shaped covering part can be made of flexible compatible materials, or biocompatible surgery sutures such as catgut and chrome catgut which are made of naturally absorbable sutures, silk and cotton threads which are non-naturally-absorbable sutures, polyglycolic acid threads and poly(lacticacid-co-glycolicacid) ethanol threads which are composite absorbable threads, and nylon threads, polyester fiber threads, polyethelene threads, Polypropylene threads, polydioxanone threads, or polytetrafluoroethylene threads which are composite non-absorbable sutures. 
         [0031]    The aforementioned web-shaped covering device can also be made of biocompatible metal wires, such as titanium, titanium alloy, or stainless steel wires. 
         [0032]    The top end of the aforementioned expansion part can have a protrusion that holds against the front end of the covering part to protect the covering part from being damaged if the top end of the expansion part is too sharp. 
         [0033]    The front end of the aforementioned covering part can also have a protrusion to hold up the projection of the expansion part. The protrusion of the covering part can be slightly thicker than other areas of the covering part to withstand the pressure from the expansion part. 
         [0034]    The aforementioned covering part can further include a fixing device joining the protrusion of the expansion part for connection between the expansion part and the covering part being firmer. Said fixing device can be a collar as shown in  FIGS. 5   c , and  5   d  or any other conventional fixing device. The connection between the fixing device and the protrusion of the expansion part can also be any conventional connection way such as engaging, locking, or binding. 
         [0035]    The fixing end of the aforementioned expansion part and the joining end of the covering end can be connected by any conventional connection way, such as riveting, with a retainer ring, locking, adhering, buckling, engaging, or binding. The fixing end of the expansion part can further have a ring-shaped groove, where the covering part can be connected to via riveting, with a retainer ring, locking, adhering or binding. The preferably connection way is the riveting, with a retainer ring, or locking. 
         [0036]    The aforementioned device for bone fixation can further include a blocking part which is connected with the fixing end of the expansion part after medical filler has been poured or stuffed inside the bone. This blocking part is used to prevent medical filler from flowing or falling out at the fixing end of said expansion part. The connection between said blocking part and the fixing end of said expansion part can be any conventional connection way, such as screw threading, engaging, locking, a retainer ring. The preferable connection way is screw threading or engaging. 
         [0037]    The aforementioned medical filler can be any conventional medical filler, such as bone grafts, bone substitutes, bone cement, and/or a mixture, composition and composite of the bone grafts, the bone substitutes and the bone cement; Taiwan Patent Application No. 097141700, Taiwan Patent No. 1227146, and U.S. Patent Application Publication No. 20070088436 can be referred and referenced. Generally, the aforementioned medical filler can be simply filled medical filler, such as auto-grafts or allografts which are implanted bone grafts, but the simply filled medical filler has poorer solidifying effects. Therefore, it is preferable that the medical filler is a medical filler paste capable of at least solidifying such as slurry type medical filler or the transplanted bone grafts being stuffed and then slurry capable of solidifying is poured, allowing the slurry to fill up the entire covering part. Generally it is best to use only the slurry medical filler. The slurry type medical filler stated here refers that the slurry can be prepared prior to using or during using, and can then solidify within a proper time period after being poured into the covering part. Such medical filler can be bone substitutes, bone cement, and/or a mixture, composition, or composite of both mentioned above. It is preferable that the aforementioned medical filler is osteo-conductive and/or osteo-inductive. Osteo-conductive medical filler can be conventional HA bone filler, while osteo-inductive medical filler can be conventional SrHA medical filler, wherein the osteo-inductive medical filler is preferable, and it can be referred to Taiwan Patent Application No. 097141700. The medical fillers mentioned above are known by persons familiar with the art, and aside from conventional medical fillers, a combination of conventional medical fillers or modified medical fillers can be used. The medical filler can even be any new developed medical filler which have the same effect as described above. 
         [0038]    A bone fixation system according the present invention comprises:
       a device for bone fixation which further comprises:   an expansion part having an end being a fixing end and another end being a top end, and having an expansible structure which is adjustable in a state of expansion or a state of contraction; and   a covering part having an end being a front end and another end being a joining end, wherein the front end of the covering part is joined to the top end of the expansion part, the joining end of the covering part is connected to the fixing end of the expansion part, and the covering part covers the expansion part;   a hollow joining tube having a front end and a rear end, wherein the front end of the hollow joining tube is detachably joined to the fixing end of the expansion part;   an auxiliary expansion part having an end being a coupling end and another end being an operating end, wherein the coupling end is detachably joined to the rear end of said hollow joining tube;   an operation lever having an end being a front end, and another end being a rear end, wherein the front end of the operation lever is detachably joined to said expansion part, the rear end of the operation lever is joined to the operating end of the auxiliary expansion part, and the operation lever is capable of being operated to allow the auxiliary expansion part to adjust the expansion part in a state of expansion or a state of contraction;   an injection tool being joined to the rear end of the joining tube or the rear end of the operation lever to inject or push a medial filler into the covering part via the joining tube or the operation lever;   wherein the auxiliary expansion part is detached and the syringe is attached after the auxiliary expansion part expands the expansion part with the operation lever to fill up the medical filler.       
 
         [0047]    The description of the expansion part, covering part and medical filler are similar to those previously mentioned. 
         [0048]    The aforementioned hollow joining tube can be any conventional hollow joining tube. 
         [0049]    The aforementioned auxiliary expansion part connecting with the operation lever with the operation lever connecting with the expansion part is capable of adjusting the expandable structure of the expansion part in a state of expansion or contraction; after the expansion part has been expanded, the auxiliary expansion part can be detached and the injection tool is attached in its place for the insertion of medical filler. 
         [0050]    The aforementioned detachable connection can be any conventional detachable connection (as shown in  FIGS. 6   a , and  6   b ), such as engaging, locking, or screw threading. 
         [0051]    The detachable connection between the front end of the aforementioned operation lever and the expansion part can be any conventional detachable connection (as shown in  FIGS. 7   a ,  7   b ,  7   c ,  7   d , and  7   e ), such as engaging, locking, or screw threading. The operation lever can be detached and removed from the expansion part through the detachable connection. 
         [0052]    The aforementioned operation lever can adjust the expandable structure to a state of expansion or contraction by relative motions of pushing, pulling, or turning (as shown in  FIGS. 3   a  to  3   h ,  7   b ,  7   c ). 
         [0053]    The aforementioned operation lever can further be a hollow operation lever which is detached but not completely removed from the expansion part after expanding the expandable structure of the expansion part such that the medical filler is poured or stuffed into the covering part through the hollow operation lever (as shown in  FIG. 7   e ). 
         [0054]    The aforementioned hollow operation lever can further be a hollow operation lever with a hole at the front end thereof (as shown in  FIGS. 2   e , and  2   f ). After the hollow operation lever has been used to expand the expandable structure, the hole thereof can be used to pour or stuff the medical filler into the covering part, after which it is detached via the detachable connection and removed from the expansion part. 
         [0055]    The aforementioned injection tool can be used after the auxiliary expansion part and the operation lever have been detached, wherein the injection tool is attached to the joining tube for injection (as shown in  FIG. 1   c ). 
         [0056]    The aforementioned injection tool can, after the removal of the auxiliary expansion part, also be connected with the hollow operation lever for the insertion of medical filler. 
         [0057]    The aforementioned bone fixation system can further include one extension tube (as shown in  FIG. 1   c ). The extension tube is used alongside the injection tool to connect to both the rear end of the hollow joint tube and the injection tool. The connection way can be any conventional connection way, such as engaging, locking, or screw threading. 
         [0058]    The aforementioned extension tube can be any conventional extension tube. 
         [0059]    The aforementioned injection tool can be any conventional injection tool. 
         [0060]    The aforementioned bone fixation device can further include a blocking part which is used after the completion of medical filler insertion. The blocking part is connected to the fixing end of the expansion part, and prevents the medical filler from flowing or falling out through the fixing end of the expansion part. The connection way used to connect the blocking part and the expansion part can be any conventional connection way, such as screw threading, engaging, locking, or with a retainer ring. Screw threading or engaging is preferable. 
         [0061]    The aforementioned bone fixation system can further include a connection device which can be an engaging groove, a spinal rod, bone hook, bone plate or a combination of these components, as shown in FIGS. 4 a , 4 b , 4 c , 4 d , 4 e  and 15 of Taiwan patent application No. 201039796. 
         [0062]    A method of surgery for bone fixation is comprised of following steps:
       placing a contracted mechanical expansion part into a vertebra with the mechanical expansion part covered by a covering part;   expanding the mechanical expansion device in a state of expansion to prop up the covering part as well as the vertebra;   pouring or stuffing a medical filler into the propped open covering part;   leaving the covering part containing the medical filler and the mechanical expansion part in the vertebra.       
 
         [0067]    Wherein the expansion part, covering part, and medical filler are similar to those described previously. 
         [0068]    The aforementioned method of bone fixation surgery can further include an auxiliary expansion part, an hollow joining tube, an operation lever, and an injection tool. 
         [0069]    The aforementioned device for bone fixation can further include an extension tube. 
         [0070]    The auxiliary expansion part, the hollow joining tube, the operation lever, the injection tool and the extension tube are similar to those described previously. 
         [0071]    A bone fixation system is comprised of:
       a device for bone fixation which further comprises:
           an expansion part having an end being a fixing end and another end being a top end, and having an expansible structure which is adjustable in a state of expansion or a state of contraction; and   a covering part having an end being a front end and another end being a joining end, wherein the front end of the covering part is joined to the top end of the expansion part, the joining end of the covering part is secured to the fixing end of the expansion part, and the covering part covers the expansion part;   wherein the expansion part and the covering part are placed in a bone, and the covering part is propped up by said expansible structure to be the state of expansion;   
               
 
         [0076]    a hollow fixing device having an end being an injecting end and another end being a connecting end, wherein the connecting end of the hollow fixing device is joined to the fixing end of the expansion part; 
         [0077]    a pressing device being joined to the injecting end of the hollow fixing device; 
         [0078]    an auxiliary expansion part having an end being a coupling end and another end being an operating end, wherein the coupling end is detachably joined to the injecting end of the hollow fixing device; 
         [0079]    an operation lever having an end being a front end, and another end being a rear end, wherein the front end of the operation lever is detachably joined to the expansion part, the rear end of the operation lever is joined to the operating end of the auxiliary expansion part, and the operation lever is capable of being operated to allow the auxiliary expansion part to adjust the expansion part in a state of expansion or the state of contraction;
       an injection tool with an end thereof being joined to the injecting end of the hollow fixing device or the rear end of the operation lever to inject or push a medial filler into the covering part via the hollow fixing device or the operation lever;   wherein the auxiliary expansion part is capable of being detached with the injection tool being attached instead after the auxiliary expansion part expands the expansion part with the operation lever to fill up the medical filler, and the pressing device is set up after completing filling up the medical filler to press the device for bone fixation toward a bone disposed at a surgery site.       
 
         [0082]    The expansion part, the covering part, the medical filler and operation lever are similar to those described previously. 
         [0083]    The aforementioned pressing device can be any conventional pressing device (as shown in  FIG. 11 ), which allows the device for bone fixation to be pressed at the location of the surgery after insertion of the medical filler to reinforce fixing capability of the bone fixation system. 
         [0084]    The connection way between the pouring end of the hollow fixing device and the pressing device can be any conventional connection way, such as locking, engaging, or screw threading. 
         [0085]    The stem of the aforementioned hollow fixing device between the pouring end and connecting end can be various patterns of embossments thereon, such as ring-shaped embossments, stripe-shaped embossments, spot-shaped embossments, or web-shaped embossments. The embossments increase friction between the hollow fixing device and the bone such that it is not easy for the hollow fixing device to slide after surgery. The stem between the pouring end and the connecting end of the hollow fixing device can be provided with holes for the medical filler capable of partially flowing out to combine the bone, or for the bone cells capable of growing through the holes to combine the medical filler to enhance the stability between the hollow fixation device and the bone. 
         [0086]    The connection way between the connecting end of the hollow fixing device and the fixing end of the expansion part can be any conventional connection way, such as riveting, screw threading, engaging, with retainer rings, or locking. 
         [0087]    The aforementioned bone fixation system can further include an auxiliary fixing part (as shown in  FIGS. 14 , and  15 ) to increase the stability of the bone fixation system. The auxiliary fixing part can be a bone plate, connecting rods, bone screws, screws, rods, or bone hooks. 
         [0088]    The connection between the auxiliary fixing part and the pressing device can be any conventional connection way, such as joint replacement-screw connection (as shown in  FIG. 14 ), bone plate-bone screw connection, or bone plate-screw connection (as shown in FIGS. 7 a , and 7 b  in Taiwan patent Application No. 2011112996). 
         [0089]    The aforementioned auxiliary expansion part connecting with the operation lever with the operation lever connecting with the expansion part adjusts the expandable structure of the expansion part in a state of expansion or contraction; after the expansion part has been expanded, the auxiliary expansion part can be detached and the injection tool is attached in its place for the insertion of medical filler. 
         [0090]    The connection way between the connecting end of the auxiliary expansion part and the connecting end of the hollow fixing device can be any conventional detachable connection way, such as engaging, locking, or screw threading. 
         [0091]    The aforementioned injection tool can be connected to the hollow fixing device for injection after the auxiliary expansion part and the operation lever have been detached. 
         [0092]    The aforementioned injection tool also can be connected to the hollow operation lever for insertion of the medical filler after the auxiliary expansion part being detached. 
         [0093]    The aforementioned bone fixation system can further include an extension tube which is used alongside the injection tool, where the extension tube is connected to the rear end of the hollow joining tube and the injection tool. The connection way can be any conventional connection way, such as engaging, locking, or screw threading. 
         [0094]    The aforementioned extension tube can be any conventional extension tube. 
         [0095]    The aforementioned injection tool can be any conventional injection tool. 
         [0096]    A method of surgery for bone fixation is comprised of following steps:
       placing a contracted mechanical expansion part and a hollow fixing device into a bone, wherein the mechanical expansion part is covered by a covering part;   expanding the mechanical expansion device in a state of expansion to prop up the covering part;   pouring or stuffing a medical filler into the propped open covering part;   leaving the covering part containing the medical filler, the mechanical expansion part, and the hollow fixing device in the bone;   utilizing a pressing device to allows the hollow fixing device to be pressed at the location of the surgery.       
 
         [0102]    Wherein the expansion part, the covering part, the medical filler, the hollow fixing device, and the pressing device are similar to those described previously. 
         [0103]    The aforementioned method for bone fixation surgery can further include an auxiliary expansion part, an operation lever, and an injection tool. 
         [0104]    The descriptions of the auxiliary expansion part, the operation lever and the injection tool are similar to those described previously. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0105]    The present invention can be more fully understood by reference to the following description and accompanying drawings, in which: 
           [0106]      FIG. 1   a  is a perspective view of a preferred embodiment of a device for bone fixation according to the present invention; 
           [0107]      FIG. 1   b  is a perspective view of a preferred embodiment of a device for bone fixation according to the present invention in a state of expansion; 
           [0108]      FIG. 1   c  is a perspective view of a preferred embodiment of a device for bone fixation according to the present invention in a state of injection; 
           [0109]      FIGS. 2   a ,  2   b ,  2   c ,  2   d ,  2   e ,  2   f ,  2   g ,  2   h ,  2   i ,  2   j ,  2   k ,  2   l ,  2   m ,  2   n , and  2   o  are perspective views showing preferred embodiments of the expansion part of the device for bone fixation according to the present invention; 
           [0110]      FIGS. 3   a ,  3   b ,  3   c ,  3   d ,  3   e ,  3   f ,  3   g , and  3   h  are perspective views illustrating four different expansion ways of the device for bone fixation according to the present invention; 
           [0111]      FIGS. 4   a ,  4   b ,  4   c , and  4   d  are perspective views illustrating four embodiments of joining ways between the expansion part and the covering part of the device for bone fixation according to the present invention; 
           [0112]      FIGS. 5   a ,  5   b ,  5   c , and  5   d  are perspective views illustrating two embodiments for the expansion part joining with the covering part of the device for bone fixation according to the present invention; 
           [0113]      FIGS. 6   a , and  6   b  are perspective views illustrating two embodiments of joining structure between the expansion part and an auxiliary expansion part of the device for bone fixation according to the present invention; 
           [0114]      FIG. 7   a  is a perspective view, and  FIGS. 7   b ,  7   c ,  7   d  and  7   e  are plan views to illustrate two examples of joining structures between the expansion part and an operating shaft of an auxiliary expansion part of the device for bone fixation according to the present invention; 
           [0115]      FIG. 8   a  is a perspective view of a preferred embodiment of a system for bone fixation according to the present invention; 
           [0116]      FIG. 8   b  is a perspective view of the preferred embodiment of a bone fixation system in a state of expansion according to the present invention; 
           [0117]      FIG. 8   c  is a perspective view of the preferred embodiment of a bone fixation system in a state of completing injection according to the present invention; 
           [0118]      FIGS. 9   a ,  9   b ,  9   c ,  9   d , and  9   e  are perspective views of five preferred embodiments of the hollow fixation device of a bone fixation system according to the present invention without or with embossed outer surface on the hollow fixing device; 
           [0119]      FIGS. 10   a , and  10   b  are perspective views illustrating two types of engaging parts joining the hollow fixing device of a bone fixation system according to the present invention; 
           [0120]      FIG. 11  is a perspective view illustrating a bone fixation system according to the present invention applied to a hip joint; 
           [0121]      FIG. 12  is a perspective view illustrating a bone fixation device according to the present invention applied to a long bone; 
           [0122]      FIG. 13  is another perspective view illustrating a bone fixation system according to the present invention applied to a long bone; 
           [0123]      FIG. 14  is a perspective view illustrating a bone fixation system with an auxiliary fixing device according to the present invention applied to a long bone; 
           [0124]      FIG. 15  is a perspective view illustrating a bone fixation system with the auxiliary fixing device according to the present invention applied to a hip joint; 
           [0125]      FIGS. 16   a  to  16   k  are perspective views illustrating surgery steps of a bone fixation system with the auxiliary fixing device according to the present invention; 
           [0126]      FIGS. 17   a ,  17   b ,  17   c , and  17   d  are perspective views illustrating surgery steps of a device for bone fixation according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0127]    Referring to  FIG. 1   a  illustrates a preferred embodiment of a device for bone fixation according to the present invention. A covering part  200  covers an expansion part  100  with a sphere-like component  210 , and, meanwhile, the covering part  200  is capable of blocking off bone fragments in a vertebra to prevent the expansion part  100  from getting stuck caused by the bone fragments in the vertebra and result in the expansion part  100  incapable of contracting to the original state. The covering part  200  is attached to the expansion part  100  with rivets at the joining end  220  thereof. A fixing end  120  of the expansion part  100  and the front end  341  of a joining tube are provided with screw threads to detachably join with each other; an auxiliary expansion part  300  has a joining end  320  to detachably engage with the rear end  342  of the joining tube to facilitate the auxiliary expansion part  300  to be replaced with an injection tool for injecting medical filler afterward. An operation lever  310  has an end to detachably join with the front end of the expansion part  100 , and another end of the operating lever  310  is joined to an operating end  330  of the auxiliary expansion part  300 ; the operating end  330  of the auxiliary expansion part  300  is manipulated to move the operation lever  310  so as to allow the operation lever  310  capable of controlling expansion or contraction of the expansion structure  110 . A fitting piece  140  is employed to reinforce connection between the covering part  200  and the expansion part  100 . 
         [0128]      FIG. 1   b  is a perspective view illustrating the expansion part  100  in a state of expansion. 
         [0129]      FIG. 1   c  is a perspective view of the preferred embodiment of a device for bone fixation according to the present invention in a state of injection. The fixing end of the expansion part  100  has been connected to an extension tube  510 , and the expansion part  100  is detachably connected to the extension tube  510 . The expansion part  100  can be detached from the extension tube  510  after the medical filler  800  is completely injected via the injection tool  500  and the extension tube  510 . 
         [0130]      FIGS. 2   a ,  2   b ,  2   c ,  2   d ,  2   e ,  2   f ,  2   g ,  2   h ,  2   i ,  2   j ,  2   k ,  2   l ,  2   m ,  2   n , and  2   o  are perspective views illustrating preferred embodiments of the expansion part of the device for bone fixation according to the present invention.  FIG. 2   a  shows a lantern-shaped expansion structure  111  with four flaps in a state of contraction.  FIG. 2   b  shows a lantern-shaped expansion structure  111  with four flaps in a state of expansion.  FIG. 2   c  shows another lantern-shaped expansion structure  111  with four flaps in a state of contraction.  FIG. 2   d  shows the lantern-shaped expansion structure  111  shown in  FIG. 2   c  with four flaps in a state of expansion wherein slits  112  and grooves  113  are utilized.  FIG. 2   e  shows a lantern-shaped expansion structure  111  with two flaps in a state of contraction wherein the operating lever  310  has an injecting hole  150  for the medical filler being injected through.  FIG. 2   f  shows a lantern-shaped expansion structure  111  with two flaps in a state of expansion wherein the operating lever  310  has an injecting hole  150  for injecting the medical filler.  FIG. 2   g  shows an expansion structure  114  with strips in a state of contraction.  FIG. 2   h  shows the expansion structure  114  with strips in a state of expansion.  FIG. 2   i  shows the expansion structure  114  with strips made of shape memory metal forming a gourd shape.  FIG. 2   j  shows an expansion structure  115  with plates in a state of contraction.  FIG. 2   k  shows the expansion structure  115  with plates in a state of expansion wherein expansion rods  116  are employed to prop up the expansion structure  115  to the expansion state.  FIG. 2   l  shows a leaf-shaped expansion structure  117  in a state of contraction.  FIG. 2   m  shows the leaf-shaped expansion structure in a state of expansion.  FIG. 2   n  shows an expansion structure  110  in a state of contraction.  FIG. 2   o  shows the expansion structure  110  is propped up to a state of expansion with rod members  118 . 
         [0131]      FIGS. 3   a ,  3   b ,  3   c ,  3   d ,  3   e ,  3   f ,  3   g , and  3   h  illustrate four different expansion ways of the device for bone fixation according to the present invention.  FIGS. 3   a  and  3   b  show that the operation lever  310  is pushed to change the expansion structure  110  from the contraction position to the expansion position.  FIGS. 3   c  and  3   d  show that the operation lever  310  is pulled to change the expansion structure  110  from the contraction position to the expansion position.  FIGS. 3   e  and  3   f  show that the operation lever  310  is rotated and screw threads  119  are utilized to extend the expansion rods  116  so as to change the plate-shaped expansion structure from the contraction position to the expansion position.  FIGS. 3   g  and  3   h  show that the operation lever  310  is rotated to change the leaf-shaped expansion structure  117  from the contraction position to expansion position. 
         [0132]      FIGS. 4   a ,  4   b ,  4   c , and  4   d  illustrate four embodiments of joining ways between the expansion part and the covering part of the device for bone fixation according to the present invention.  FIG. 4   a  shows that the fixing end of the expansion part  120  is joined to the joining end  220  of the covering part  220  with riveting.  FIG. 4   b  shows that the fixing end of the expansion part  120  is joined to the joining end  220  of the covering part  220  with locking.  FIG. 4   c  shows that the fixing end of the expansion part  120  is joined to the joining end  220  of the covering part  220  with fitting.  FIG. 4   d  shows that the fixing end of the expansion part  120  is joined to the joining end  220  of the covering part  220  with binding. 
         [0133]      FIGS. 5   a ,  5   b ,  5   c , and  5   d  illustrate two embodiments for the expansion part joining with the covering part of the device for bone fixation according to the present invention.  FIGS. 5   a  and  5   b  show that a sphere-like double-layer covering member  210  is fixed to a protrusion  130  of the expansion part with binding of a fixing member  211 .  FIGS. 5   c  and  5   d  show that a sphere-like double-layer covering member  210  is fixed to a protrusion  130  of the expansion part with a fixing member  211 . 
         [0134]      FIGS. 6   a  and  6   b  illustrate two embodiments of joining structure between the expansion part and an auxiliary expansion part of the device for bone fixation according to the present invention.  FIG. 6   a  shows the fixing end  120  of the expansion part is detachably to engage with the joining end  320  of the auxiliary expansion part with screw threads.  FIG. 6   b  shows the fixing end  120  of the expansion part is detachably to join with the joining end  320  of the auxiliary expansion part with locking. 
         [0135]      FIGS. 7   a ,  7   b ,  7   c  and  7   d  illustrate two embodiments of joining structures between the expansion part and an operating shaft of the auxiliary expansion part of the device for bone fixation according to the present invention.  FIG. 7   a  shows a locking groove  131  disposed at the top of the expansion part and a locking protrusion piece  311  of the operating lever  310  form detachable engagement; the operation lever  310  is detached and replaced with the injection tool after the expansion part is expanded by the operation lever  310 . The stem  340  of the auxiliary expansion part also has a locking protrusion piece  321  to detachably lock with the retaining groove  121  of the expansion part as well.  FIGS. 7   b  to  7   e  show that with an upper screw threads  312  engaging with screw threads  132  at the top end of the expansion structure  110 , the operation lever  310  is capable of being controlled to expand the expansion structure  110 ; the operation lever  310  is withdrawn from the expansion structure  110  after the manipulation of expansion is completed. The operation lever  310  shown in  FIG. 7   e  has a hollow passage  313  for injecting the medical filler. 
         [0136]      FIG. 8   a  illustrates a preferred embodiment of a bone fixation system according to the present invention. A hollow fixing device  400  is joined to the expansion part with rivets, and the stem  420  of the hollow fixing device  400  is embossed thereon to enhance friction between the hollow fixing device  400  and the bone such that it is not easy for the hollow fixing device  400  to slide after surgery, wherein there is an injection passage  411  in the hollow fixing device  400  for the medical filler, and a pressing device  430  is attached to the hollow fixing device  400  for the expansion part capable of pressing the bone located at the surgery site after the medical filler is injected completely. 
         [0137]      FIG. 8   b  illustrates the expansion structure in  FIG. 8   a  in a state of expansion. 
         [0138]      FIG. 8   c  illustrates the expansion structure shown in  FIG. 8   b  after the medical filler is injected completely. 
         [0139]      FIGS. 9   a ,  9   b ,  9   c ,  9   d , and  9   e  illustrate five preferred embodiments for embossment on the stem  420  of the hollow fixing device of a bone fixation system according to the present invention.  FIG. 9   a  shows that there is no embossment on the stem  420  of the hollow fixing device.  FIG. 9   b  shows that the stem  420  of the hollow fixing device has ring-shaped embossments.  FIG. 9   c  shows that the stem  420  of the hollow fixing device has stripe-shaped embossments.  FIG. 9   d  shows that the stem  420  of the hollow fixing device has spot-shaped embossments.  FIG. 9   e  shows that the stem  420  of the hollow fixing device has net-shaped embossments. 
         [0140]      FIGS. 10   a  and  10   b  illustrate two embodiments for the pressing device joining the hollow fixing device of a bone fixation system according to the present invention.  FIG. 10   a  shows that the joining end  431  of the pressing device is joined to the injection end  410  of the hollow fixing device  400  with screw threads.  FIG. 10   b  shows that the joining end  431  of the pressing part fits with the injection end  410  of the hollow fixing device  400 . 
         [0141]      FIG. 11  illustrates a preferred embodiment of a bone fixation system according to the present invention applied to a hip joint. The hollow fixing device  400 , the expansion part  100 , and the covering part  200  pass through a rear broken bone  620 , a crack  630 , and a front broken bone  610 , and the front broken bone  610  and the rear broken bone  620  are joined to each other via injection of the medical filler  800 ; further, the pressing device  430  is utilized to unite the front broken bone  610 , the rear broken bone  620 , and the hollow fixing device  400  more closely to enhance firmness thereof. Steps of surgery for bone fixation are shown in  FIGS. 16   a  to  16   k.    
         [0142]      FIG. 12  illustrates a preferred embodiment of a system for bone fixation according to the present invention applied to a long bone. The hollow fixing device  400 , the expansion part  100 , and the covering part  200  pass through a rear broken bone  620 , a crack  630 , and a front broken bone  610 , and the front broken bone  610  and the rear broken bone  620  are joined to each other via injection of the medical filler  800 ; further, the pressing device  430  is utilized to unite the front broken bone  610 , the rear broken bone  620 , and the hollow fixation device  400  more closely to enhance firmness thereof. Steps of surgery for bone fixation can be seen in  FIGS. 16   a  to  16   k.    
         [0143]      FIG. 13  is another embodiment for a bone fixation system according to the present invention applied to a long bone. The hollow fixing device  400 , the expansion part  100 , and the covering part  200  pass through a rear broken bone  620 , a crack  630 , and a front broken bone  610 , and the front broken bone  610  and the rear broken bone  620  are joined to each other via injection of the medical filler  800 ; further, the pressing device  430  is utilized to unite the front broken bone  610 , the rear broken bone  620 , and the hollow fixing device  400  more closely to enhance firmness thereof. Steps of surgery for bone fixation can be seen in  FIGS. 16   a  to  16   k.    
         [0144]      FIG. 14  illustrates a bone fixation system with an auxiliary fixing device according to the present invention applied to a long bone. The hollow fixing device  400 , the expansion part  100 , and the covering part  200  pass through a rear broken bone  620 , a crack  630 , a front broken bone  610  and an auxiliary fixing part  440 . The front broken bone  610  and the rear broken bone  620  are joined to each other via injection of the medical filler  800 ; further, the pressing device  430  is utilized to unite the front broken bone  610 , the rear broken bone  620 , the hollow fixing device  400  and the auxiliary fixing device  440  more closely to enhance firmness thereof. Steps of surgery for bone fixation can be seen in  FIGS. 16   a  to  16   k.    
         [0145]      FIG. 15  illustrates an embodiment for a bone fixation system with an auxiliary fixing device according to the present invention applied to a hip joint. The hollow fixing device  400 , the expansion part  100 , and the covering part  200  pass through a rear broken bone  620 , a crack  630 , a front broken bone  610  and an auxiliary fixing device  440 . The front broken bone  610  and the rear broken bone  620  are joined to each other via injection of the medical filler  800 ; further, the pressing device  430  is utilized to unite the front broken bone  610 , the rear broken bone  620 , the hollow fixation device  400  and the auxiliary fixing device  440  more closely to enhance firmness thereof. Steps of surgery for bone fixation can be seen in  FIGS. 16   a  to  16   k.    
         [0146]      FIGS. 16   a  to  16   k  illustrate steps of surgery for a bone fixation system according to the present invention.  FIG. 16   a  shows that a drill  710  drills into a rear broken bone  620 .  FIG. 16   b  shows that the drill  710  passes through the rear broken bone  620  and a crack  630  and enters a front broken bone  610 .  FIG. 16   c  shows that a hole  900  is generated after the drill  710  passes through the rear broken bone  620  and a crack  630  and enters a front broken bone  610 .  FIG. 16   d  shows that the hollow fixing device  400 , the covering part  200  and the expansion part  100  are placed in the hole  900 .  FIG. 16   e  shows that the hollow fixing device  400 , the covering part  200  and the expansion part  100  have been placed in the hole  900  completely.  FIG. 16   f  shows that the expansion part  100  is in a state of expansion with the aid of the auxiliary expansion part  300 .  FIG. 16   g  shows that the auxiliary expansion part  300  has been replaced with an injection tool  500  and an extension tube  510  so as to inject the medical filler  800 .  FIG. 16   h  shows that the injection of the medical filler  800  is completed.  FIG. 16   i  shows that the extension tube  510  is withdrawn from the hollow fixing device  400 .  FIG. 16   j  shows that a locking member  432  is employed to lock the pressing device  430  into the hollow fixing device  400 .  FIG. 16   k  shows that the pressing device  430  locked in the hollow fixation device to press the connection between the front broken bone  610 , the rear broken bone  620  and the hollow fixing device  400  closely. 
         [0147]      FIGS. 17   a ,  17   b ,  17   c , and  17   d  illustrate steps of surgery for a device for bone fixation according to the present invention.  FIG. 17   a  shows that the covering part  200  and the expansion part  100  are placed in a vertebra  600  via a tube  700 .  FIG. 17   b  shows that an auxiliary expansion part  300  is utilized to expand the expansion structure  110 , and the expansion structure  110  prop up the sphere-like covering member  210 .  FIG. 17   c  shows that the auxiliary expansion part  300  is replaced with an extension tube  500  and an injection tool  500  to perform injection of the medical filler  800 .  FIG. 17   d  shows that the device for bone fixation supports the vertebra  600  effectively after the injection of the medical filler  800  is completed.