Abstract:
Described herein are external fixation systems for correcting bone deformities in adjacent bones or fragments thereof. The systems herein include first and second elongate rods that translate with respect to one another via rotation of an actuation member at an end of one of the rods. At least one housing is coupled along a length of one of the rods. The at least one housing includes at least one pin clamping member for clamping an end of a fixation pin therein. When the at least one pin clamping member is in an unlocked state, the fixation pin can rotate in polyaxial directions. When in a locked state, the angle of fixation wire with respect to the rods is set. The locked and unlocked state of the at least one pin clamping member is determined by the positing of a fixation member with respect to the housing it is coupled to.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. patent application Ser. No. 13/786,748, filed on Mar. 6, 2013, the disclosure of which is hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to external fixation systems and methods, and in particular relates to a telescoping body having coupled thereto a ball and socket type pin clamp that allows pin members to have independent trajectories when engaged to both the pin clamp of the external fixation system and a bone of a patient. 
     BACKGROUND OF THE INVENTION 
     Many different types of bone deformities can be corrected using external fixation systems. Such systems generally use rings, fixation plates, threaded rods or struts for manipulation, angulation, and translation of the deformities of bones. 
     Existing fixation systems on the market have many components thereof that are static and do not allow for certain adjustment and/or pivoting. Lack of flexibility in a system may restrict attachment to certain bone areas at certain angles as well as restrict motion of the portion of the body that the external fixation system is being attached to in order to correct. Because of such lack of flexibility, such systems may make it more difficult for the physician to achieve an optimal clinical outcome. 
     Mini-rails are external fixation systems known in the art that are used to control distraction and compression during lengthening or deformity correction procedures. The primary use of these systems are in the hand, foot and craniomaxillofacial (“CMF”) regions. Existing mini-rail systems are generally bulky, unnecessarily complex in procedure, and utilize pin configurations that generally flex during correction of bone fragments. 
     Further, prior art mini-rails generally consist of exposed threaded rods or “cages” which pin clamps translate on. In other prior art systems, the pin clamps may allow for some polyaxial rotation of the pins that are coupled thereto; however, other degrees of freedom are generally restricted between the pin clamp and the fixation rod that the pin clamp is coupled to. Further, many systems are not configured such that other fixation devices could attach to it unless such other fixation devices are specifically designed to interface with the threaded rod or cage thereof, for example. 
     There exists a need for a dynamic mini-rail system that is not bulky and allows a pin to be angled with respect to the bone that it is coupled to in almost any translational or rotational degree of freedom such that a physician may target ideal bone for the best pin purchase. 
     SUMMARY OF THE INVENTION 
     The present invention improves upon existing mini-rails by allowing for greater flexibility in pin placement. This function allows the physician to target the best bone possible for ideal pin placement and thread purchase. The systems described herein also provide cross platform compatibility by way of a standard 8 mm diameter compression/distraction tube that can easily be coupled to other external fixation devices if desired. Further, the mini-rails of the present invention have a built-in thread such that the mini-rails may be used in other external fixation constructs, such as circular and conventional ex-fix systems, for example. 
     The mini-rail systems disclosed herein further utilize a ball and socket type pin clamp that allows for independent pin trajectories within a mini-rail construct. The pin clamps are rotatably coupled to a telescoping rod of the mini-rail. This rotation about a longitudinal axis of the telescoping rod may be either in a free or locked state. When the pin clamps are in a locked state, the trajectories of the pins engaged to the pin clamps are preferably fixed. 
     A first aspect of the present invention is an external fixation device comprising a first elongate rod, a first fixation pin housing, at least one pin clamp member and a locking post member. The first fixation pin housing has at least one vertical bore therethrough and is coupled to the first elongate rod. The at least one pin clamping member is housed at least partially within the at least one vertical bore of the first fixation pin housing and is able to rotate and angulate independently of the first fixation pin housing when in an unlocked state. The first locking post member has a stopper portion and an actuator portion and is coupled to the first fixation pin housing. Movement of the first locking post member in a proximal direction causes compression of the at least one pin clamping member such that the at least one pin clamping member is in a locked state and cannot rotate and angulate independently of the first fixation pin housing. 
     In accordance with one embodiment of the first aspect of the present invention, the first fixation pin housing preferably has a central longitudinal bore and is coupled to the first elongate rod when at least a portion of the first elongate rod is located within the central longitudinal bore of the first fixation pin housing. 
     In another embodiment of the first aspect, the first locking post member is preferably coupled to the first fixation pin housing when at least a portion of the stopper portion of the first locking post member is located within a bore of the first fixation pin housing. 
     In still yet another embodiment of the first aspect, the bore of the first fixation pin housing at least partially cooperates with the central longitudinal bore and the at least one vertical bore of the first fixation pin housing. 
     In another embodiment of the first aspect, the at least one pin clamping member has a vertical bore adapted to receive at least a portion of a length of a fixation pin there through. 
     In another embodiment of the first aspect, the at least one pin clamping member is olive shaped with a slit running along a longitudinal length thereof, the at least one pin clamping member having first and second side ends adjacent the slit. The slit preferably has a first width when the at least one pin clamping member is in the unlocked state and a second width less than the first width when the at least one pin clamping member is in the locked state. 
     In another embodiment of the first aspect, the first fixation pin housing is preferably rotatably coupled to the first elongate rod, and wherein when the at least one pin clamping member is compressed the first fixation pin housing cannot rotate about a longitudinal axis of the first elongate rod. 
     In another embodiment of the first aspect, a second elongate rod has a longitudinal axis coaxial with a longitudinal axis of the first elongate rod when the first and second elongate rods are coupled, and wherein the first and second elongate rods translate with respect to one another along the longitudinal axes thereof. A second fixation pin housing has at least one vertical bore therethrough and is coupled to the second elongate rod. At least one pin clamping member is housed at least partially within the at least one vertical bore of the second fixation pin housing, the at least one pin clamping member being able to rotate and angulate independently of the second pin housing when in an unlocked state. A second locking post member has a stopper portion and an actuator portion, the second locking post member coupled to the second fixation pin housing, wherein movement of the second locking post member in a proximal direction causes compression of the at least one pin clamping member such that the at least one pin clamping member is in a locked state and cannot rotate and angulate independently of the second fixation pin housing. 
     In yet another embodiment of the first aspect, an actuation member is rotatably coupled to the first elongate rod such that rotation of the actuation member in a first rotational direction causes the first and second elongate rods to translate along the longitudinal axis thereof away from one another and rotation of the actuation member in a second rotational direction opposite the first rotational direction causes the first and second elongate rods to translate along the longitudinal axis thereof toward one another. 
     In accordance with a second aspect of the present invention, an external fixation device comprises first and second elongate rods, first and second fixation pin housing, at least one pin clamping member, and first and second locking post members. The first and second elongate rods coupled to one another such that the first and second elongate rods translate with respect to one another along longitudinal axes thereof. The first and second fixation pin housings each have at least one vertical bore therethrough and are coupled to the first and second elongate rods respectively. The at least one pin clamping member housed at least partially within the at least one vertical bore of each of the first and second fixation pin housings is able to rotate and angulate independently of each of the first and second fixation pin housing when in an unlocked state. The first and second locking post members have a stopper portion and an actuator portion and are coupled to each of the first and second fixation pin housings respectively. The at least one pin clamping member housed at least partially within the at least one vertical bore of each of the first and second fixation pin housings is in a locked state when at least a portion of the stopper portion of the first and second locking post members contact the at least one pin clamping member such that the at least one pin clamping member cannot rotate and angulate independently of the first and second fixation pin housings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the subject matter of the present invention and the various advantages thereof can be realized by reference to the following detailed description in which reference is made to the accompanying drawings in which: 
         FIG. 1  is a perspective view of one embodiment of an external fixation system of the present invention. 
         FIG. 2A  is a perspective view of a telescoping rod of the external fixation system of  FIG. 1 . 
         FIG. 2B  is a cross-section view of the telescoping rod of  FIG. 2A  taken along line  2 B- 2 B. 
         FIG. 2C  is an exploded perspective view of the telescoping rod of  FIG. 2A . 
         FIG. 3  is a perspective view of a first embodiment of a housing of the external fixation system of  FIG. 1 . 
         FIG. 4A  is a perspective view of a second embodiment of a housing of the external fixation system of  FIG. 1 . 
         FIG. 4B  is a cross-section view of the second embodiment of a housing of  FIG. 3B  taken along line  4 B- 4 B. 
         FIG. 5  is a perspective view of a pin clamp of the external fixation system of  FIG. 1 . 
         FIG. 6  is a plan view of the pin clamp of  FIG. 5 . 
         FIG. 7  is a perspective view of a third embodiment of a housing of the present invention that can be coupled to a telescoping rod such as shown in  FIG. 2A . 
         FIG. 8  is a perspective view of another embodiment of an external fixation system of the present invention including two of the third housings shown in  FIG. 7  each coupled to the telescoping rod shown in  FIG. 2A . 
         FIG. 9  is a perspective view of yet another embodiment of an external fixation system of the present invention including the first housing shown in  FIG. 3A  and two of the second housings shown in  FIG. 3B  with each of the first and second housings coupled to the telescoping rod shown in  FIG. 2A . 
         FIG. 10  is a perspective view of yet another embodiment of an external fixation system of the present invention including the first, second and third housings shown in  FIGS. 3, 4A, and 7 , respectively, each coupled to the telescoping rod shown in  FIG. 2A . 
         FIG. 11  is a perspective view of yet another embodiment of an external fixation system having a plurality of pins engaged to housings with the pins having independent pin trajectories. 
         FIG. 12  is a partial view showing an end of telescoping rod shown in  FIG. 2A  having a built-in thread such that the telescoping rod may be coupled to other external fixation constructs. 
         FIG. 13A  is an embodiment of a bolt adapter that can be coupled to a telescoping rod of the present invention. 
         FIG. 13B  is an embodiment of a rod clamp that can be coupled to a telescoping rod of the present invention. 
         FIG. 13C  is an embodiment of a hinge coupling that can be coupled to a telescoping rod of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-6 , there is shown an embodiment of an external fixation system  100  having a telescoping rod  120 , a first housing  220 , a second housing  240 , a plurality of pin clamping members  260  and a plurality of locking post members  280 . 
       FIG. 2A  is a perspective view of an assembled telescoping rod  120  having an actuation member  140 , a first elongate tube member  160 , and a second elongate tube member  180 . 
     As shown in  FIGS. 2B and 2C , actuation member  140  includes an actuation portion  142 , a base portion  144 , an engagement portion  146  and a shaft portion  148 . Actuation portion  142  projecting outwardly in a distal direction from a distal end surface  150  of base portion  144 . Engagement portion  146  projects outwardly in a proximal direction from a proximal end surface  152  of base portion  144 . Shaft portion  148  projects outwardly in a proximal direction from engagement portion  146 . Actuation portion  142  is preferably configured to be engaged and manipulated by hand or with a tool. In the embodiment shown, actuation portion  142  has four angled flat surfaces  154  in a square configuration with four rounded edges  156  between adjacent surfaces  154 . Engagement portion  146  preferably includes first and second recesses  155 ,  157 . Shaft portion  148  is preferably substantially threaded  159 . 
     First elongate tube member  160  includes a distal end surface  162  and a proximal end surface  164 . First elongate tube member has a bore  168  extending through the proximal and distal end surfaces  162 ,  164  thereof and a protrusion  170  projecting outwardly from an inner surface  172  thereof. 
     Second elongate tube member  180  includes a distal end surface  182 , a proximal end portion  184 , a tube portion  186  and a shaft portion  188 . Tube portion  186  includes an inner threaded surface  190  and an outer surface  192  having a longitudinal recess  194 . Proximal end portion  184  is preferably threaded in order to couple second elongate tube member to other external fixation constructs, if desired. 
     In assembling telescoping rod  120 , distal end surface  162  of first elongate tube member  160  preferably mates with proximal end surface  152  of base portion  144  of actuation member with shaft portion  148  of actuation member  140  being housed within bore  168  of first elongate member. When actuation member  140  is operatively coupled to first elongate tube member  160 , engagement portion  146  of actuation member  140  engages inner surface  172  of first elongate tube member  160 . Recesses  155 ,  157  of engagement portion  146  may act as relief portions for coupling purposes or may house a ring member in order to maintain the coupling of actuation member  140  and first elongate tube member  160 . 
     Once actuation member  140  and first elongate tube member  160  are coupled, protrusion  170  of first elongate tube member  160  is coupled to longitudinal recess  194  of tube portion  186  at distal end surface  182  of tube portion  186  and slid along longitudinal recess  194  until threaded portion  159  of shaft portion  148  of actuation member  140  comes in contact with inner threaded surface  190  of tube portion  186  of second elongate tube member  180 . Actuation portion  142  is then rotated in a clockwise direction in order to threaded shaft portion  148  onto threaded surface  190 . As actuation portion  142  continues to be rotated in a clockwise direction, protrusion  170  continues to ride along longitudinal recess  194  of tube portion  186  in a first direction until proximal end surface  164  lies adjacent a distal end surface  196  of shaft portion  188 . Because protrusion  170  rides along longitudinal recess  194 , first elongate tube member  160  does not rotate with respect to second elongate tube member  180 . Instead, first elongate tube member  160  only translates with respect to second elongate tube  180  along longitudinal axis L 1 . 
     If actuation portion  142  is rotated in a counterclockwise direction, protrusion  170  will continue to ride along longitudinal recess  194  of tube portion  186 , but in a second direction along longitudinal axis L 1  such that proximal end surface  164  will be separated from distal end surface  196  of shaft portion  188  a larger linear distance from one another. As long as actuation member  140 , first elongate tube member  160 , and second elongate tube member  180  are coupled to one another, rotation of actuation member  140  in either a clockwise or counterclockwise direction will cause proximal end surface  164  and distal end surface  196  to move closer and further away from one another in a linear direction along longitudinal axis L 1  of external fixation system  100 . 
     In another embodiment, tube portion  186  of second elongate tube member  180  has an outer surface  192  that is square shaped and has no longitudinal recess  192  in the outer surface thereof. Also, first elongate tube member  160  has a bore  168  having an inner surface  172  that is square shaped and no protrusion  170  projecting outwardly from the inner surface thereof. In this embodiment, once actuation member  140  and first elongate tube member  160  are coupled, square shaped inner surface  172  of first elongate tube member  160  is coupled to square shaped outer surface  192  of tube portion  186  of the second elongate tube member  180  at distal end surface  182  of tube portion  186  and is slid along the outer surface  192  until threaded portion  159  of shaft portion  148  of actuation member  140  comes in contact with inner threaded surface  190  of tube portion  186  of second elongate tube member  180 . Actuation portion  142  is then rotated in a clockwise direction in order to threaded shaft portion  148  onto threaded surface  190 . 
       FIG. 3  is a perspective view of a first embodiment of a housing  300  of the external fixation system  100 . Housing  300  includes side surfaces  302 ,  304  having a bore  306  therethrough. Bore  306  defines a longitudinal axis L 2  of housing  300 . Housing  300  includes a front face  312  and a back face  314  and a plurality of apertures  322  therethrough. Each of the plurality of apertures  322  has a longitudinal axis that is perpendicular and offset to longitudinal axis L 2  of housing  300 . An internal circumference of each of the plurality of apertures  322  perpendicular to the longitudinal axes of each of the plurality of apertures  322  and is open to bore  306  such that a portion of each of plurality of apertures  322  intersects bore  306 . Housing  300  further includes bores  332  extending into housing  300  from bottom and top surfaces  334 ,  336  thereof. Bores  332  are also open to bore  306  such that a portion of bores  332  intersect bore  306 . In the embodiment shown, housing  300  includes four apertures  322 . Two of the four apertures are located above longitudinal axis L 2  and two of the four apertures are located below longitudinal axis L 2 . 
       FIG. 4A  is a perspective view of a second embodiment of a housing  400  of the external fixation system  100 . Housing  400  includes side surfaces  402 ,  404  having a bore  406  therethrough. Bore  406  defines a longitudinal axis L 3  of housing  400 . Housing  400  includes a front face  412  and a back face  414  and a plurality of apertures  422  therethrough. Each of the plurality of apertures  422  has a longitudinal axis that is perpendicular and offset to longitudinal axis L 3  of housing  400 . An internal circumference of each of the plurality of apertures  422  perpendicular to the longitudinal axes of each of the plurality of apertures  422  and is open to bore  406  such that a portion of each of plurality of apertures  422  intersects bore  406 . Housing  400  further includes bore  432  extending into housing  400  from a top surface  436  thereof. Bore  432  is also open to bore  406  such that a portion of bore  432  intersects bore  406 . In the embodiment shown, housing  400  includes two apertures  422 . 
       FIGS. 5-6  are views of one embodiment of a pin clamp  500  that can be used with housings  300 ,  400  of external fixation system  100 . Pin clamp  500  includes side surfaces  502 ,  504  and an outer circumference surface  506  intermediate side surfaces  502 ,  504 . Side surfaces  502 ,  504  have an inner surface  508 . Pin clamp  500  has a slot  512  that extends through side surface  502 ,  504  and outer circumference surface  506 . Slot  512  provides a resiliency to pin clamp  500  such that if a force is applied to outer circumference surface  506 , pin clamp  500  may flex. In flexing, a width of slot  512  is either decreased or increased depending on how the force is applied to outer circumference surface  506 . Preferably, slot  512  has a neutral width when pin clamp  500  is in a relaxed state and a lesser width when a force is applied to outer circumference surface  506 . 
     Pin clamp  500  includes a bore  520  extending through side surfaces  502 ,  504 , the bore  520  having a longitudinal axis L 3 . Bore  520  has a diameter D 1  at side surface  502 ,  504  when pin clamp  500  is in a relaxed state. Upon a force being applied to outer circumference surface  506 , bore  520  preferably has a diameter D 2  at side surfaces  502 ,  504 . Diameter D 2  is preferably less than D 1 . 
       FIG. 4B  is a cross-section view of housing  400  taken along line  4 B- 4 B of  FIG. 4A . In this figure, a clamping mechanism of housing  440  is shown. Clamping mechanism includes an actuation member  600 , a wedge member  620 , and first and second pin clamps  500  each engaged to housing  400 . AS shown in  FIG. 4B , pin clamps  500  are housed with apertures  422  of housing  400  and actuation member  600  and wedge member  620  are housed within bore  432  of housing  400 . 
     Actuation member  600  may be referred to as a locking post member having an actuation portion  602 , a threaded portion  604  and a protrusion  606 . Wedge member  620  includes first and second contact surfaces  622 ,  624  and a recess portion  626 . Protrusion  606  of actuation member  600  is configured to be received in recess portion  626  of wedge member  620  and contact on outer surface  628  of wedge member  620 . In other embodiments, actuation member  600  and wedge member  620  are integral such that the clamping mechanism does not include protrusion  606  of actuation member  600  and recess portion  626  and outer surface  628  of wedge member  620 . 
     In another embodiment, protrusion  606  does not projecting outwardly from threaded portion  604 . Instead, the base of threaded  604  is rounded. Also, wedge member  620  does not include recess portion  626 . In this embodiment, rounded surface of threaded portion  604  interacts with a flat surface of wedge member  620 . 
     In use, pin clamps  500  are received in apertures  422  of housing  400  such that outer circumference surface  506  is located substantially between front and back surfaces  412 ,  414 . Apertures  422  are preferably bounded by inner walls  423  of housing  400 . When clamping mechanism of housing  400  is in a neutral state, pin clamps  500  may rotate in polyaxial directions with at least a portion of outer circumference surface  506  contacting inner walls  423 . The polyaxial rotation of pin clamps  500  is bounded by the outer circumference surface  506  thereof and the structure surrounding of housing  400 . 
     In order to restrict the polyaxial movement of pin clamps  500  with respect to housing  400 , clamping mechanism of housing  400  may be activated. In activating clamping mechanism, actuation member  600  is rotated in a clockwise direction causing the protrusion thereof to move proximally and contact outer surface  628  of wedge member  600 . The result of this contact is wedge member  600  also moving in a proximal direction such that first and second contact surfaces  622 ,  624  thereof contact outer circumference surface  506  of pin clamps  500  and causes the diameter of bore  520  at side surfaces  502 ,  504  of pin clamps  500  to decrease. Pin clamps  500  also move in a proximal fashion when actuation member  600  is rotated in a clockwise direction. In order to bring clamping mechanism back to a neutral state, actuation member  500  is rotated in a counterclockwise direction. 
     As shown in  FIG. 1 , housing  400  is coupled to shaft portion  188  of second elongate tube member  180 . When clamping mechanism is in a neutral state, housing  400  may rotate with respect to second elongate tube member  180  such that longitudinal axis L 3  of housing  400  may rotate with respect to longitudinal axis L 1  of external fixation system  100  even though longitudinal axis L 1  and L 3  are preferably coaxial. When clamping mechanism is activated, wedge member  620  compresses pin clamps  500  between contact surfaces  622 ,  624  thereof and shaft portion  188  of second elongate tube member  180 . Another result of activation of the clamping mechanism is that housing  400  preferably can no longer rotate with respect to second elongate tube member  180 . 
     The same clamping mechanism of housing  400  that is shown in  FIG. 4B  is also included in housing  300  except that housing  300  preferably includes two separate clamping mechanisms on each side of longitudinal axis L 2  thereof. As shown in  FIG. 1 , housing  300  is coupled to an outer surface of first elongate tube member  160 . When the clamping mechanisms thereof are in a neutral state, housing  300  may rotate with respect to first elongate tube member  160  such that longitudinal axis L 2  of housing  300  may rotate with respect to longitudinal axis L 1  of external fixation system  100  even though longitudinal axis L 1  and L 2  are preferably coaxial. When either clamping mechanism of housing  300  is activated, a wedge member thereof preferably compresses pin clamps  500  between contact surfaces of the wedge member and outer surface of first elongate tube member  160 . Another result of activation of either clamping mechanism  300  is that housing  300  preferably can no longer rotate with respect to first elongate tube member  160 . 
     The present invention provides a dynamic mini-rail that allows for many degrees of freedom between components parts thereof. First and second elongate tube members  160 ,  180  may translate with respect to one another. Housings  300  and  400  may rotate with respect to first and second elongate tube members  160 ,  180  and housings  300  and  400  may rotate about first and second elongate tube members  160 ,  180  with respect to one another. Pin clamps  500  may rotate at independent trajectories while housed within housings  300 . 
       FIG. 7  is a perspective view of a third embodiment of a housing  700  of the present invention. Housing  700  includes a base member  720 , first and second plate members  740 ,  760 , a plurality of pin clamps  500 , and first and second fixation post members  780 . Base member  720  is coupled to a clamping mechanism that includes bottom and top plate members  740 ,  760 , the plurality of pin clamps  500  and first and second fixation post members  780 . Base member  720  has a bore  722  therethrough and a longitudinal axis L 4 . A longitudinal axis of first and second plate members  740 ,  760  is preferably parallel with longitudinal axis L 4  of base member  720 , but may be angled with respect to longitudinal axis L 4  of base member  720 . 
     First and second plate members  740 ,  760  each have a threaded vertical bore  790  extending through outwardly and inwardly facing surfaces  750 ,  770  thereof. First and second plate members  740 ,  760  further have a longitudinal recess  775  in the inwardly facing surfaces  770  thereof. Longitudinal recess  775  is shaped to receive a portion of outer circumference surface  506  of the plurality of pin clamps  500  in order to couple and partially house the plurality of pin clamps  500  with respect to first and second plate members  740 ,  760 . 
     Fixation post members  780  have a head portion  782  and a threaded shaft portion  784 . Threaded shaft portion  784  of fixation post members is received and threaded into vertical bore  790  of first and second plate member  740 ,  760 . Upon threading of fixation post members into vertical bores  790  of first and second plate members  740 ,  760 , a bottom surface  786  of head portion  782  of fixation post members  780  presses against outwardly facing surface  750  of one of the first and second plate members  740 ,  760  and cases the inwardly facing surfaces  770  of the first and second plate members  740 ,  760  to move closer to one another such that the plurality of pin clamps  500  become compressed. 
       FIG. 8  is a perspective view of another embodiment of an external fixation system  900  of the present invention including two of the third housings  700  shown in  FIG. 7  each coupled to the telescoping rod  100  shown in  FIG. 2A . One of the third housings  700  is coupled to a first elongate tube member  160  and the other of the third housings  700  is coupled to a second elongate tube member  180 . 
       FIG. 9  is a perspective view of yet another embodiment of an external fixation system  1000  of the present invention including first housing  300  coupled to second elongate tube member  180  and first housing  300  and second housing  400  coupled to first elongate tube member  160 . 
       FIG. 10  is a perspective view of yet another embodiment of an external fixation system  1100  of the present invention including third housing  700  coupled to second elongate tube member  180  and first housing  300  and second housing  400  coupled to first elongate tube member  160 . 
       FIG. 11  is a perspective view of yet another embodiment of an external fixation system  1200  of the present invention including second housing  400  coupled to second elongate tube member  180  and second housing  400  coupled to first elongate tube member  160 . A plurality of pins  480  are received and housed with pin clamps  500  of housings  400 . The plurality of pins  480  have independent pin trajectories with respect to one another. In activating clamping mechanism of housings  400 , actuation member  600  is rotated in a clockwise direction causing it to move proximally and compress outer circumference surface  506  of pin clamps  500  and causes the diameter of bore  520  at side surfaces  502 ,  504  of pin clamps  500  to decrease. The result of activating the clamping mechanism of housings  400  is the pin clamps  500  cannot rotate and angulate independently of housing  400 . In order to bring clamping mechanism back to a neutral state, actuation member  500  is rotated in a counterclockwise direction, which will also pin clamps  500  housing pins  480  to rotate and angulate with respect to housings  400  once again. 
       FIG. 12  is a partial view showing an end of second elongate tube member  180  of a telescoping rod having a built-in thread  184  such that the telescoping rod may be coupled to other external fixation constructs. Such constructs, for example, are shown in  FIGS. 13A-13C , which are a bolt adapter  1220 , a rod clamp  1240 , and a hinge coupling  1260 , respectively. These coupling mechanism are all known in the art of external fixation systems and all the external fixation systems of the present invention to be compatible with such constructs. 
     In a method of correcting a bone deformity of the present invention, an external fixation system having a plurality of housings (may be housing  300 ,  400  or  700 ) are coupled to a telescoping rod  100 . A plurality of pins such as those shown in  FIG. 11  are coupled to the housings. One end of the pins are received in pin clamps housed within the housings and another end of the pins are engaged to bone at or adjacent to the deformity in the bone being corrected. A first end of pins are preferably engaged to bone. A second end of pins are then received through a bore hole in a pin clamp coupled to a housing, the housing coupled to a telescoping rod. Additional pins engaged at one end to bone may all be received through a bore hole in another pin clamp coupled to the housing or a different housing coupled to a telescoping rod. Once the desired number of pins are engaged to bone and the other ends of the pins are coupled to pin clamps, the fixation or set screws of the housing may then be tightened to set the angle of the pins with respect to the housings each are coupled to. 
     Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.