The present invention relates to an apparatus and method for repositioning portions of bone relative to each other, and more particularly to an apparatus and method for externally repositioning portions of bone.
The percutaneous reduction of femur fractures in a patient often involves placement of the patient in a supine position on a fracture table having a peroneal post engaging the pelvis between the two legs of the patient. The legs of the patient extend from the fracture table and are typically supported by traction devices such as footplates or other tibial or femoral traction devices. An intramedullary rod or nail is often introduced into the femoral canal to properly align fractured segments of the femur. However, femoral and other muscular forces are sometimes difficult to overcome when reducing fractured femurs, particularly for fractures that occur near the proximal end of the femur where such femoral forces are particularly strong, resulting in continued malreduction or malpositioning of the fractured segments of the femur after the intramedullary rod or nail has been placed in the bone. Such malreduction or malpositioning is exacerbated when the outer diameter of the nail or rod is smaller than the inner diameter of the femur being reduced. Current methods for attempting to minimize such malreductions or malpositioning involve using an assistant to manually engage and retain the fractured segments of the femur before and during placement of the rod or nail. A percutaneous apparatus and method are needed that are not highly invasive for reducing and positioning fractured segments of a femur or other bone, yet still retain such fractured segments in a desired position during insertion of an intramedullary rod or nail into the bone.
A medical apparatus has been provided that includes first and second arms coupled to a fracture table. A first attachment mechanism is carried by the first arm for securing the first arm to a first portion of a bone of a mammalian body and a second attachment mechanism is carried by the second arm for securing the second arm to a second portion of the bone. The first and second arms permit respective adjustment of the first and second portions of the bone so as to desirably align the first and second portions of the bone relative to each other.
The present invention is direction to a medical apparatus and method to aid in bone fixation of a segmented bone such as, for example a fractured or osteotomised bone, as those skilled in the art will understand. An exemplary medical apparatus 31 according to the present invention is configured for attachment to an operating table on which a patient rests. The medical device 31 comprises first and second arms 53, 54 extending laterally from a central post 51. The arms 53, 54 are selectively positionable to permit alignment and subsequent attachment to first and second pins 251, 261 attached to target portions of each of two bone fragments. Once engaged, manipulation of the arms 53, 54 permits realignment of the bone fragments. The medical apparatus 31 according to the present invention thus facilitates proper alignment of fragments of a fractured bone and further maintains a stabilized position thereof until a bone fixation procedure has been performed, as those skilled in the art will understand. It is noted that although embodiments of the present invention will be described with respect to a particular bone and method, the present invention may be employed with a bone fixation procedure for any bone in a living body without deviating from the scope of the present invention. As used in this application, the term bottom refers to a direction approaching an operating table on which the medical apparatus is mounted and the term top refers to a direction facing away from the operating table. Furthermore, the term proximal, as used in this application refers to a direction radially approaching the central post 51 while the term distal refers to a direction extending radially outward therefrom.
As shows in
As shown in greater detail in
The central portion 61 of the central post 51 has a length ranging from 5 to 80 centimeters, preferably approximately 20 to 40 centimeters and more preferably approximately 27 centimeters and extends upwardly to a first shoulder 71 having a plurality of circumferentially spaced-apart upstanding registration elements in the form of teeth 72 provided thereon, as shown in
In one embodiment, the first arm 53 comprises a first proximal end portion 91 and a second distal end portion 92 and extends along a longitudinal axis 93, as shown in
The first arm 53 further comprises a clamping mechanism 102 at a distal end of the central segment 95 for selectively securing the central segment 95 within the proximal segment 94. In one embodiment, the proximal segment 94 has a slot 103 extending longitudinally along a side wall thereof to permit contraction of the proximal segment 94 about the central segment 95. The clamping mechanism 102 includes a first bossed element 104 on one side of slot 103 and a second bossed element 106 on the other side of the slot. The first bossed element 104 has a non-threaded bore 107 and the second bossed element 106 has a threaded bore 108 for receiving a threaded shaft 109 of a screw 111 made from any suitable material such as stainless steel. Head 112 of screw 111 has a shoulder 113 for engaging the first bossed element 104 and urging the first bossed element 104 towards the second bossed element 106 as the threaded shaft element 109 threadably engages the bore 108. In one preferred embodiment, screw head 112 includes a transversely-adjustable slide element 114 which travels within a transverse slot 116 of the screw head 112 and is engageable by the fingers of the operator for tightening and loosening screw 111 within the clamping mechanism 102. Slidable element 114 provides screw 111 with an adjustable torque arm.
Central segment 95 slidably receives distal segment 96 in a manner similar to which the proximal segment 94 slidably receives the central segment 95. In this regard, the central segment 95 includes a central bore 121 having a distal opening 122 though which the distal segment 96 longitudinally travels. Proximal and distal travel of distal segment 96 within central segment 95 is limited by the limiting mechanism of slot 99 provided, for example, in one of the side walls of the distal segment 96 and a screw 100 that extends through a threaded bore 101 provided in the corresponding side wall of the central segment 95 and which extends further into the slot 99. Central segment 95 is provided with a slot 103 and a clamping mechanism 102 that includes a screw 111 for selectively locking the distal segment 96 at a desired position within the central segment 95.
An annular first collar 131 is secured to first or proximal end portion 91 of the first arm for pivotably coupling the aim to post 51. The first collar 131 and the central post 51 are included within the first securement mechanism of the medical apparatus 31 for coupling the proximal end portion 91 of the first arm 53 to the fracture table 34. The collar 131 is provided with an internal bore 132 extending perpendicular to arm axis 93. An inwardly-extending flange 133 extends around a top surface of the first collar 131, forming an upper circular opening 134. An annular rim 136 forms the bottom of the first collar 131 at the lower opening of the internal bore 132. The rim 136 is provided with a plurality of circumferentially spaced-apart registration elements in the form of depending teeth 137. The first collar 131 is sized to extend around first neck 73 of the central post 51 with the upper opening 134 extending around a second shoulder 76 of the central post 51. Teeth 137 of the collar 131 are radially dimensioned to incrementally register with upstanding teeth 72 on the first shoulder 71 for pivotably locking the first arm 53 in a desired orientation relative to central post 51. An annular space (not shown) is provided between the first collar 131 and the first neck 73 for receiving a coil spring 138 having a lower end which seats on the first shoulder 71 radially inward of the teeth 72 with an upper end seated against the inside of the collar flange 133, as shown in greater detail in
The second arm 54 has a construction substantially similar to the first arm 53. In this regard, the second arm 54, as shown in
A proximal end of the proximal segment 151 is joined to a tubular second collar 166 that is substantially similar to the first collar 131 of the first arm 53. A second collar 131 and a central post 51 are included within the second securement mechanism of the apparatus 31 for coupling the proximal end portion 46 of the second arm 54 to the table 34. The collar 166 is circular in cross section and has an inwardly-extending flange 167 at the top end thereof that is flush with the top surface of the proximal segment 151. An internal bore 168 is provided in the collar 166 and communicates with a circular upper opening 169 provided in the flange 168. A circular rim 171 extends around the bottom of the collar 166 and is provided with a plurality of circumferentially spaced-apart depending registration elements in the form of teeth 172 sized and spaced to cooperatively engage upstanding teeth 77 on the second shoulder 76 of the post 51 in the same manner discussed above with respect to the collar 131 and the teeth 72 on the first shoulder 71. The teeth 172 are spaced radially inward of the outer edge of the rim 171, which has an annular lower surface 173 that extends radially outside the teeth and is substantially planar. As such, the second collar 166 is radially sized so that the teeth 172 thereof engage the teeth 77 of the post 51. The upper opening 169 is radially sized to extend around the second neck 78 of the post 51 and the annular wall forming the second collar 166 is spaced from the outer cylindrical surface of the second neck 78 to provide an annular space between the collar 166 and the neck 78 for receiving a second coil spring 174, as shown in
First and second arms 53 and 54 may be of substantially the same length, but in a preferred embodiment, one of the arms is shorter than the other. In this regard, when the apparatus 31 is used to treat a fractured femur, the shorter arm is particularly suited for use with an attachment mechanism coupled to the proximal portion of the femur (i.e., the portion of the femur closer to the post 51), while the longer arm is particularly suited for use with an attachment mechanism coupled to the distal portion of the femur (i.e., the portion further from the post 51), as those skilled in the art will understand. When the shorter arm 53 or 54 is contracted, the respective distal segment 96 or 153 is fully retracted into its respective central segment 95 or 152, which is further fully retracted into the proximal segment 94 or 151. In this position, the shorter arm has a length ranging from 6 to 30 centimeters and preferably approximately 8 centimeters. When the shorter arm is fully extended, as described in greater detail earlier, the arm has a length ranging from 12 to 60 centimeters and preferably approximately 20 centimeters. When the longer arm 53 or 54 is contracted, such arm has a length ranging from 26 to 40 centimeters and preferably approximately 30 centimeters. When the longer arm is fully extended, such arm has a length ranging from 26 to 80 centimeters and preferably approximately 40 centimeters.
A washer 181 and a knob 182 are provided in the apparatus 31 for retaining the first collar 131 of the first arm 53 and the second collar 166 of the second arm 154 on the central post 51. As shown in
A first attachment mechanism is carried by the distal end portion or free end 92 of the first arm 53 for securing the first arm 53 to one of the bone portions 32 and 33 and a second attachment mechanism is carried by the distal end portion or free end 147 of the second arm 54 for securing the second arm 54 to the other one of the bone portions 32 and 33. In this regard, a first adjustment mechanism 203 is provided for coupling the first attachment mechanism to the distal end portion 92 of the first arm 53, and a second adjustment mechanism 204 is provided for coupling the second attachment mechanism to the distal end portion 147 of the second arm 54. The first and second adjustment mechanisms 203 and 204 of this embodiment are substantially identical and include an insert 206, a pivot element 207, a disk 208 and a screw 111, as shown in
The pivot element 207 which allows the second pin 261 to be positioned as desired by rotation about 2 mutually perpendicular axes may be modified if desired to add a third mutually perpendicular axis of rotation to permit any desired positioning of the pin 261 as would be understood by those skilled in the art. The pivot element 207, as shown most clearly in
The disk 208 is formed with first and second opposite planar surfaces 231 and 232 and a cylindrical surface 233 extending between the planar surfaces 231 and 232. An upstanding cylindrical hub 234 protrudes perpendicularly from the center of the first planar surface 231. A bore 236 extends through the center of the hub 234 to the second planar surface 232. A slot 237 extends perpendicularly from the cylindrical surface 233 parallel to the surfaces 231 and 232, through at least half of the disk 208 to a side wall 238. The slot 237 is preferably midway between the surfaces 231 and 232. The portion 236a of the bore 236 extending through the hub 234 to slot 237 is threaded. A first bore 239 extends through the cylindrical surface 233 parallel to the surfaces 231 and 232 adjacent to the open end of the slot 237. An optional second bore 240 extends parallel to the first bore 239 near the end of the slot 237 adjacent to the side wall 238. The first and second bores 239 and 240 are preferably symmetrically disposed about the centerline or axis 241 of the disk 208. The section of the disk 208 that includes the hub 234 and the portion of the disk between the first planar surface 231 and the slot 237 serves as a clamping portion 242 that hinges about the side wall 238 relative to the portion of the disk 208 between the slot 237 and the second planar surface 232.
In use, the disk 208 is placed in juxtaposition to the base 224 of the insert 206, with the second planar surface 232 of the disk 208 disposed against the planar surface 227 of the base 224. The disk 208 is centered on the base 224 so that the bore 236 of the disk 208 is centered on the bore 226 of the base 224. The threaded shaft 109 of a pin element or screw, for example screw 111, extends through the bore 226 into the disk 208 threadedly engaging the threaded portion 236a of the bore 236. When the screw 111 is not fully tightened relative to the base 224, the disk 208 can rotate about its center line 241 relative to the base 224. Once the shoulder 113 of the screw 111 abuts the base 224 and the screw 111 is further rotated relative to the insert 208, the clamping portion 242 of the disk 208 is urged by the screw 111 toward the base 224. The optional second bore 240 enhances pivoting of the clamping portion of 242 relative to the remainder of disk 208 by providing a relief within the disk 208 so as to minimize stress at the side wall 238, the hinge point of the clamping portion 242
Each of the first and second adjustment mechanisms 203 and 204 can be in the form of an elongate pin, for example as shown in
The disk 208 is configured to receive the respective first or second adjustment mechanism 203 or 204, for example first or second pin 251 or 261. In this regard, at least the first bore 239 of the disk 208 is shaped to receive the proximal portion of the respective pin. When utilizing the first pin 251, the proximal portion 252 of the pin is inserted into the bore 239. As the threaded shaft 109 of the respective screw 111 is advanced through the threaded bore 236a of the disk 208, the slot 237 permits the disk 208 to clamp about the shaft of the pin 251 to fixedly secure the second pin 252 to the disk 208 of the second adjustment mechanism 204.
As shown in
Although medical apparatus 31 has been illustrated and described for use with attachment mechanisms in the form of elongate pins, it will be understood by those skilled in the art that any suitable attachment mechanism for coupling to a portion of a bone of a mammalian body can be utilized therewith. In this regard, the first attachment mechanism, for example for use with first arm 53, can alternatively be in the form of a wire, a screw, a hook or a clamp, each of any suitable type. Further, the second attachment mechanism, for example for use with second arm 54, can alternatively can be in a form of a wire, a crew, a hook or a clamp, each of any suitable type. The first attachment mechanism can be of a different type then the second attachment mechanism.
In operation and use of the apparatus 31 and the kit 271, a patient 38 is placed on an upper surface 37 of a fracture table 34 with the ends of legs 43 secured to respective arms 47 of the traction apparatus 42 by any suitable means, such as by coupling the feet of the patient into respective foot pieces 48. The bottom portion 62 of the central post 51 is secured to fracture table 34 by any suitable means, as discussed above, between legs 43 of the patient, and the patient's pelvis is urged against the cushion 267 of the apparatus 31.
In one suitable procedure, threaded section 254 of the first pin 251 is inserted into a first bone portion 32 and the threaded section 264 of the second pin 261 is threaded into a second portion 33 of the target bone to be treated. In one preferred procedure, the first and second pins 251 and 261 are introduced into the first and second bone portions 32 and 33 of a femur. The relatively long threaded section 254 of the first pin 251 is particularly desirous for placement in the compact bone of the upper portion of the femur, while the relatively short threaded section 264 of the second pin 261 is particularly advantageous for placement within the compact bone of the central portion or the lower portion of the femur. Preferably, such threaded sections are longitudinally sized so as to not extend fully through the respective bone portion into which the pin is secured.
As shown in
Once first and second pins 251 and 261 are secured to respective first and second arms 53 and 54, the arms can be moved relative to each other and to fracture table 34 so as to desirably reposition first and second bone portions 32 and 33 relative to each other. When moving bone portions 32 and 33, the appropriate screws 111 on first and second arms 53 and 54 and the knob 182 can be loosened or tightened to reposition the pins 251 and 261, and thus bone portions 31 and 32, relative to the fracture table.
Although the apparatus 31 has been described and shown as having arms coupled to a fracture table that telescope relative to each other, it is appreciated that one or both of such arms can have a plurality of segments that pivot relative to each or are otherwise moveable relative to each other so that the distal portion of such arm is translatable and/or rotatable relative to the proximal portion of such arm. Each of the arms of the apparatus of the invention can have any number of segments. In addition, the arms of the apparatus of the invention can be coupled to fracture table 34 by other than the peroneal post and be within the scope of the present invention. For example, the arms can be commonly coupled to another location on the fracture table, for example to another location on the bed 36 of the fracture table. The arms of the apparatus can also be coupled to distinct or separate locations on the fracture table, for example the first arm can be coupled to one location on the bed 36 and the second arm can be coupled to another location on the bed.
Additionally, it is appreciated that one or all of the arms of the apparatus and the post of the apparatus can be provided without teeth, that is like teeth 137 and 172 of the arms and like teeth 72 and 77 of the post, so that the pivotable adjustment of such arms relative to the post is not limited to positions dictated by registration of the teeth on the arms with the teeth on the post. In one such embodiment without teeth, shoulders 71 and 76 of the post would have planar or relatively smooth surfaces and rims 136 and 171 of the arms would have planar or relatively smooth end surfaces. It is further appreciated that a variety of other pin and socket or other mechanical arrangements can be provided for permitting an attachment mechanism to pivot about one or more pivot axes at the distal end of an arm coupled to a fracture table.
The apparatus of the present invention can have more than two arms for repositioning more than two bone portions with respect to a fracture table. Medical apparatus 286 illustrated in
In operation and use, medical apparatus 286 can be used with any suitable bone, such as the femur, having a first bone portion 306, a second bone portion 307 and a third bone portion 308. The first, second and third arms of medical apparatus 86 can be joined to the respective first, second and third bone portions in the manner described above to desirably position such bone portions relative to each other and to the fracture table during any suitable procedure to treat the fractured bone.
As can be seen from the foregoing, a percutaneous apparatus and method that is not highly invasive has been provided for reducing and positioning fractured segments of a femur or other bone, and retaining such fractured segments in such desired position, during insertion of an intramedullary rod or nail into the bone. Since the fractured segments of the bone are coupled to the fracture table by means of respective arms coupled to the fracture table, the fractured segments do not move and instead remain in a fixed position during placement of the rod or nail and any other treatment of the bone and adjoining tissue.
Although various representative embodiments of this invention have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of the inventive subject matter set forth in the specification and claims. All directional references (e.g., upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, x-axis, y-axis, and z-axis) are only used for identification purposes to aid the reader's understanding of the embodiments of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention unless specifically set forth in the claims. Joinder references (e.g., attached, coupled, connected) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other.
In some instances, components are described with reference to “ends” having a particular characteristic and/or being connected with another part. However, those skilled in the art will recognize that the present invention is not limited to components which terminate immediately beyond their points of connection with other parts. Thus, the term “end” should be interpreted broadly, in a manner that includes areas adjacent, rearward, forward of, or otherwise near the terminus of a particular element, link, component, part, member. In methodologies directly or indirectly set forth herein, various steps and operations are described in one possible order of operation, but those skilled in the art will recognize that steps and operations may be rearranged, replaced, or eliminated without necessarily departing from the spirit and scope of the present invention. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.
Although the present invention has been described with reference to preferred embodiments, it is submitted that various modifications can be made to the exemplary system and method without departing from the spirit and scope of the invention.
The present application claims priority to U.S. Provisional Application Ser. No. 61/045,500, entitled “Apparatus and Method for Use With Fracture Table to Reposition Bone Portions” filed on Apr. 16, 2008. The entire disclosure of the above-identified application is incorporated herewith by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US09/40212 | 4/10/2009 | WO | 00 | 8/30/2010 |
Number | Date | Country | |
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61045500 | Apr 2008 | US |