1. Field of the Invention
The present invention relates to stabilizing fractures and aligning displaced fractured bone fragments in a manner that readily allows for multiplanar half-pin fixation without the need for cumbersome and awkward bar-to-pin and pin-to-pin clamps used in a conventional unilateral external fixation system or the use of tensioned wires as used with a conventional ring-to-ring external fixation system structure. The present invention relates, in particular, to an apparatus providing for the quick and highly accurate alignment of fractured bone segments through the placement and precise adjustment of half-pins and blunt pins secured to an external planar member.
2. Background and the prior art
Various methods are currently available and are widely used by orthopedic surgeons to stabilize acute fractures and reduce displaced fractured bone fragments. Various of these prior art methods utilize external fixation devices. The currently practiced methods using unilateral external fixation systems are awkward and cumbersome and the currently practiced methods using ring-to-ring external fixation systems are technically demanding.
Unilateral External Fixation Systems
A typical prior art method for stabilizing an acute fracture utilizing a unilateral external fixation system incorporates external bars that, together with clamps, form a linear framework that supports a broken limb. The prior art unilateral external fixation system must be constructed and specifically tailored to each individual patient and is preferably positioned so as to overlie the point of fracture. Half-pins (as known to those skilled in the art) are positioned within the bone above and below the point of fracture and are connected to external bars using so called bar-to-pin clamps. In order to augment stability, multiple bars may be used and are connected to one another using so called bar-to-bar clamps. Stability may also be augmented by positioning the half-pins within the bone at various angles and within various planes so that the half-pins converge and diverge. This arrangement of half-pins inserted and secured to the bone segments is the so-called delta configuration.
Typical prior art unilateral systems substantially limit the surgeon's choices in regards to where half-pins may be positioned within the bone segments and some only allow half-pins to be placed in a linear fashion such that they are all parallel to one another. Other systems which allow for independent half-pin placement require cumbersome and awkward bar-to-pin clamps and pin-to-pin clamps in order to achieve the desirable delta configuration. The method to achieve this construction is slow and tedious.
To reduce a fracture and align a broken bone using a unilateral external fixation system a surgeon typically has to manually hold the bone segments in an aligned position while at the same time applying the external fixator. Some prior art methods allow for the incorporation of hinges or ball joints in order to allow for deformity correction. These hinges and ball joints are typically located at a fixed predetermined location along the length of the external fixation apparatus away from the apex of the fracture deformity. When there is a mismatch between the level of the hinge/ball joint and the level of the deformity, incomplete or incorrect movement of the bone segments occurs. These systems also do not permit the movement and reduction of displaced bone fragments through the manipulation of the half-pins which are anchored within the bone segments.
Ring-to-Ring External Fixator Systems
A typical prior art method for treating a displaced fracture utilizes an external fixator system which incorporates a plurality of rings that together with supporting rods, brackets, nuts and bolts, form a framework surrounding and supporting a broken limb. The prior art external ring fixator must be constructed and specifically tailored to each individual patient and is preferably positioned so as to overlie the point of fracture. The rings are typically spaced apart and held together in a rigid assembly by a series of threaded rods which form the framework around the limb. Rings above and/or below the point of facture each typically support tensioned wires and half-pins that function to effectively secure the external ring framework to the upper and lower fractured bone fragments. Special techniques have been devised to permit the surgeon to reduce the fracture using the tensioned wires but no accurate methods for bone reduction are available in the typical prior art.
To reduce a fracture and align a broken bone a surgeon typically passes Olive Wires through the skin and bone at positions above and below the point of the fracture. Olive Wires are manually manipulated to pull facture fragments into alignment in order to correct frontal plane angular deformities. The arched wire technique is often used to correct sagital plane angular and translational deformities. In both cases it is often a cumbersome procedure to tension a wire and maintain the desired tension and position while securing the free ends of the wire to the ring.
It can be appreciated that the fractured bone fragments are moved into a desired aligned positioned with respect to one another by the force exerted on the bone by the wire. The surgeon's skill and experience determines where along the ring the wire should be affixed and how tight the wire needs to be drawn in order to move the bone fragment to a desired position.
An x-ray is taken to verify the position of the fractured bone fragments and the process is then repeated, sometimes again and again, until the desired position is achieved. The process is very tedious and time consuming. In fact, one significant disadvantage with this prior art method is that each successive repositioning step tends to displace the prior reduction with the surgeon adjusting one offset after another, sometimes never getting the fracture accurately reduced. In addition, oblique plane deformities which are neither purely in the frontal nor sagital plane are typically reduced by using these techniques executed in sequence, first reducing the fracture in the frontal plane and then reducing the fracture in the sagital plane.
Moreover, each adjustment requires that one or both ends of the wire be freed from its post such that tension on the wire is effectively released, notwithstanding the surgeon's attempt to maintain tension while making an adjustment. This prior art method is generally a gross reduction maneuver that lacks the necessary precision and accuracy to optimally correct a displaced fracture.
In addition, the surgeon is required to construct a cumbersome frame surrounding the broken limb.
Accordingly it is a desirable characteristic of the invention to provide for the precise reduction of a bone fracture and achieve precise alignment with a direct rigid connection to the bone and without the use of wires or requiring the assembly and use of a complex multi-piece external supporting structure.
It is a further characteristic of the present invention to provide for the precise reduction of a bone fracture in a quick and efficient manner which omits trial and error.
These and other characteristics of the present invention will become apparent to one of skill in the art having the present disclosure before them.
A system is disclosed for externally repairing fractured bones and facilitating alignment of displaced fractured bone segments without requiring use of an external ring fixator system and tension wires. In one embodiment the invention includes at least one panel member having a plurality of apertures therein, extending from a first side of the at least one panel member through to a second side of the at least one panel member. At least one pin carrier capable of being inserted into at least one of the plurality of apertures in the at least one panel member is provided. The at least one pin carrier, upon insertion into at least one of the plurality of apertures in the at least one panel member, is longitudinally fixed relative to the aperture, and capable of rotation within the aperture. At least two half-pins being capable of insertion into the at least one pin carrier, following insertion of the at least one pin carrier into one of the plurality of apertures provided in the panel member, provides securement to a fractured bone segment.
In one embodiment, the at least one panel member is further configured to accommodate at least one outrigger member capable of being removably affixed to the panel member, the outrigger member is capable of accepting receipt of a half-pin toward securing the outrigger member to a fractured bone segment. A second one of the at least two half-pins is capable of insertion into one of another pin carrier inserted into another one of the plurality of apertures in the at least one panel member and at least one outrigger affixable to the at least one panel member. The at least two half-pins serve, in part, to support the at least one panel member overlying the fractured bone segments. Rotation of a pin carrier causes an associated half-pin inserted therein to move longitudinally with respect to the at least one panel member to, in turn, reposition the fractured bone segment affixed to the half-pin, relative to the at least one panel member.
In a disclosed embodiment, wherein the plurality of apertures provided in the panel member are formed in a plurality of symmetrical rows and columns providing multiple points at which a half-pin can be inserted and positioned relative to the bone segments to be aligned. The at least one pin carrier is substantially cylindrical in shape and includes at least one annular ring formed on an outer facing surface thereof. The pin carrier includes a helical thread formed on an inner facing surface thereof which thread cooperates with threads formed on at least a portion of the at least one half-pin, and includes a control surface to facilitate rotation of the pin carrier, following insertion into one of the plurality of apertures in the panel member. In one embodiment, the control surface comprises a knob.
In a preferred embodiment, each of the plurality of apertures within the panel member is formed with at least one annular ring on an inner surface and operably configured for cooperation with an outer facing annular ring of the pin carrier. In one embodiment, the panel member may be further provided with apertures dimensioned and threaded to directly accept at least one half-pin, without insertion of an intervening pin carrier. In a preferred embodiment, the panel member is arc shaped, and is further operably configured to generally conform to the shape of a limb surrounding fractured bone segments. The panel member may further include a roller bearing joint positioned in at least one aperture and capable accepting a pin carrier permitting a pin carrier, and in turn, a half-pin to be secured to a fractured bone segment at an angle relative to the surface of the panel member.
In one illustrated embodiment, the present invention includes at least one outrigger member capable of being removably affixed to the a panel member and capable of accepting receipt of a half-pin toward securing the outrigger member to a fractured bone segment. The length of the outrigger, upon attachment to an upper or lower edge region of the at least one panel member, may be alternatively increased or decreased as necessary to position the panel member in an overlying orientation with respect to the fractured bone segment.
The panel member may further comprise two panel or more members, secured together to form a single reconfigurable composite panel member capable of supporting pin carriers and, in turn, half-pins in a manner that permit the half-pins to be secured to the fractured bone segments in a plurality of planes, such as in a delta configuration. A first panel member may incorporate a groove formed on a lower facing edge thereof and a second panel member may incorporates a tongue formed on an upper facing edge thereof, to thereby facilitate joining the first panel member to the second panel member. A first panel member segment may thus be rotated and secured relative to a second panel member segment.
The invention in one embodiment may include a first panel member incorporating a threaded aperture formed on a lower facing edge and a second panel member incorporating a threaded aperture formed on an upper facing edge to facilitate joining one panel member to the another panel member using a threaded rod.
In an alternative further embodiment of the present invention, the invention is disclosed as a system comprising at least one panel member having a plurality of apertures extending from a first side to through to a second side; at least two pin carriers, capable of being inserted into at least two of the plurality of apertures in the panel member and upon insertion into at least apertures in the panel member are longitudinally fixed relative to the aperture, but capable of rotation within the aperture; at least one half-pin and one blunt-pin each capable of insertion into the a pin carrier, whereupon rotation of a pin carrier causes an associated half-pin inserted therein to move longitudinally with respect to the panel member to, in turn, reposition a fractured bone segment, relative to the panel member.
A further embodiment of the present invention comprises an automated computer assisted system for aligning displaced fractured bone fragments including , a panel member having a plurality of apertures therein and affixable to the displaced fractured bone fragments by a plurality half-pins with at least a first half-pin positionable above the point fracture and a second half-pin positionable below the point of fracture, the panel member, in turn, secured to the upper and lower fractured bone fragments by half-pins passed through the skin and into underlying bone and at least one pin carrier positioned in an aperture and configured to accept telescopic receipt of a half-pin, the rotation of the pin-carrier serving to adjust the position of the half-pin with respect to the panel member toward facilitating alignment of the displaced fracture bone fragments. A computer controlled electronic servo motor is operably connected to each pin carrier for precisely and independently adjusting the position of a half-pin positioned therein. A computer controlled x-ray imaging and control system creates and analyzes an electronic image, determining the relative displacement of the fractured bone fragments and signaling the controlled electronic servo motors to adjust the position of each pin carrier toward aligning the displaced fractured bone fragments without manual intervention. The automated computer assisted system may further include reference wires inserted into the fractured bone fragments to enhance detection of the bone fragments by the x-ray imaging and control system and establish the initial position of the fractured bone fragments.
The computer controlled x-ray imaging and control system analyzes the initial position of the fractured bone fragments, computes the distance and sequence in which each bone fragment must be moved in order to properly restore alignment and signals the controlled electronic servo motors in a coordinated manner to move in the proper sequence toward articulating the fractured bone fragments into proper alignment. Back pressure sensors may be provided and associated with one or more pin carriers and/or half-pins toward monitoring the force exerted by the half-pin upon the limb and providing an alarm signal to the x-ray imaging and control system.
The present invention further is disclosed as a method for aligning displaced fractured bone fragments, the method comprising the steps of: providing a panel member for affixation to the fractured limb with at least a first half-pin positionable above the fracture and a second half-pin positionable below the fracture; affixing at least one pin carrier to the panel member positioned adjacent to the fracture; inserting at least one half-pin into at least one pin carrier and affixing the half-pin to a fractured bone fragment; adjusting the pin carrier to reposition the associated half-pin to reposition the underlying bone fragment affixed thereto to reduce the fracture and align the bone fragments; whereby the fracture is reduced and bone fragments aligned without the surgeon having to use external ring fixator system and tension wires to reposition misaligned bone fragments.
While the present invention is susceptible of embodiment in many different forms, there are shown in the drawings and will be described in detail, several specific embodiments, with the understanding that the disclosure herein is to be considered as an exemplification of the principles of the present invention and is not intended to limit the invention to the embodiments illustrated.
The present invention is illustrated in the context of a fractured leg bone with the understanding the present invention has application in many other situations. For example, the present invention may be used to move and align deformities in long bones, joints and other bone structures.
As illustrated in
Outrigger 60 is shown attached to the bottom facing edge of arc panel 50. Outrigger 60 may be removably affixed to panel 50 using a number of mechanisms.
As shown in relation to reference letter C, pin carrier 80 is inserted into an aperture 51 preformed into arc panel 50. Pin carrier 80 is illustrated in
As shown by reference C, pin carrier 80 is inserted into aperture 51 such that head 81 does not completely abut the outer facing surface of arc panel 50. Half-pin 70 is shown having a threaded end 73 which is inserted into the open end of head 81 of pin carrier 80. The purpose of threads 71 are to tap into bone fragment 90 and secure half-pin 70 thereto. It will be appreciated that the surgeon may use a drill guide to drill a pilot hole into bone fragment 90 along the longitudinal axis of pin carrier 80 to facilitate insertion of half-pin 70 into bone 90. Alternatively, self-tapping half-pins may be used.
It can be seen with reference to letter D that half-pin 70 has been rotated clockwise such that it has advanced through pin carrier member 80 to the degree that threads 73 at the distal end thereof engage with and begin to tap into bone fragment 90.
Reference E illustrates half-pin 70 fully inserted into bone fragment 90, such that it is completely set into the bone and retained within arc panel 50 by pin carrier 80. Accordingly, it can be appreciated with reference to letter F that clockwise rotation of pin carrier 80 will serve to cause half-pin 70 to be drawn outward from the panel 50 and, in turn, the fractured bone fragments such that the fractured bone fragment is displaced from its initial position. Conversely, as shown with respect to reference G, it can be appreciated that a counter-clockwise rotation of pin carrier 80 will cause half-pin 70 to advanced inwardly toward the limb with respect to the arc panel 50 such that the fractured bone fragment is displaced from its initial position.
It can be appreciated that
It can be appreciated that depending upon the location, muscle tone, tissue, nature of the injury, etc. rotation of the pin carrier may cause pin carrier to be pulled further inward together with half-pin 50, as opposed to remaining within aperture 51 and merely advancing the half-pin. Accordingly as shown in reference E, spacer 72 may be provided and positioned between the outer facing surface of panel 50 and shoulder 82 of pin carrier 80, thereby restricting any further inward movement of the pin carrier. Alternatively, annular rings 84 could be formed with no angle with respect to a corresponding cooperating series of rings, grooves and ridges such that inward and outward movement of pin carrier with respect to arc panel 50 is equally restricted.
It can be appreciated with respect to
It can be appreciated that the pin carriers 80 can be rotated as necessary to effect the required degree of translation of bone fragments. It is further envisioned that pin carriers 80 may be rotated through the manual rotation of heads 81 formed thereon configured to accept an external tool, such as a socket, which may be rotated manually or by motor-driven apparatus under the control of the attending surgeon. Moreover, the spacing of the threads formed on the inner surface of pin carriers 80 and outer surface of half-pin 70 may be of various configurations that provide finer or coarser degrees of movement with respect to each 360 degree rotation of pin carrier 80, such that greater or fewer turns are required to move a half-pin 70 a given distance and, in turn, the bone fragment affixed to the distal ender thereof. As described below, it can be further appreciated that the mechanized rotation of the pin carriers can automated and under control of a computer-driven system, which, together with a fluoroscopy system, can automate the process of reducing fractured bone fragments.
One advantage of the present invention is the ability to provide a highly stable fixator without the need for the surgeon to assemble a complex, multi-part external fixator as presently utilized in the prior art. As illustrated in
It is deemed further within the scope of the present invention that half-pins could be used to secure the bone fragments to arc panel 50 without use of pin carriers. Such an application would be dictated when a temporary repair is needed, such as in advance of impending surgery. In such case, larger diameter half-pins could be used which include self-tapping threads that can cut into and engage with apertures 51. Alternatively, arc panel 50 could be provided with additional or select apertures which are dimensioned and threaded to accept the same half-pins as used in association with pin carriers 80.
Two inner segments 50-2 and 50-3 are connected to one another via a tongue-and-groove arrangement. While different mechanisms are contemplated to join the two together, one may simply insert screws (not shown) into one or more apertures in the lower-most row, such that the screw pierces the groove and abuts against the underlying tongue to affix the two segments together. As appreciated in
The step of translating the two fractured bone segments into alignment is illustrated with respect to
It will be appreciated that the spherical shaped bearing joint permits a pin carrier and half-pin to be angled relative to the axis perpendicular to the surface of arc panel 50. As illustrated, and as further subject to the dimensions of the various components, a half-pin may be angled as much as approximately 30 degrees from perpendicular.
In a further embodiment one or more half-pins can be replaced with blunt end pins, as illustrated in
As illustrated in
As discussed, it is contemplated that a control system may be provided to synchronize the movement of a single or multiple pin carriers 80, and, in turn, associated half-pins 50 to provide uniform and/or automated control. For example as illustrated in
In a further embodiment of the present invention full (llizarov-type) rings can be attached to the upper and lower (most proximal and distal aspects) of arc fixator panel 50 to allow for the use of tensioned wires in the most proximal and distal parts of the fractured bone segments.
The foregoing description and drawings merely explain and illustrate the invention and the invention is not limited thereto, as those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.
This application claims priority of the filing date of U.S. provisional patent application 60/704,912, filed 3 Aug. 2005 and U.S. provisional patent application 60/725,864, filed 11 Oct. 2005, the complete disclosures of which are hereby expressly incorporated herein by reference.
Number | Date | Country | |
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60704912 | Aug 2005 | US | |
60725864 | Oct 2005 | US |