Patent Publication Number: US-2016220274-A1

Title: Quick-release systems for extraskeletal fixation

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This patent application is a Continuation-in-Part that claims priority to patent application Ser. No. 14/454,703 filed Aug. 7, 2014 that in turn claims priority to Provisional Patent Application No. 61/863,425 filed Aug. 7, 2013, both entitled “QUICK-RELEASE FASTENERS FOR EXTRASKELETAL FIXATION.” 
    
    
     INCORPORATION BY REFERENCE 
     All publications, including patents and patent applications, mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication was specifically and individually cited to be incorporated by reference. 
     FIELD OF THE INVENTION 
     Described herein are systems and methods for orthopedic external fixation to support bones in appropriate relative positions to promote healing. 
     BACKGROUND OF THE INVENTION 
     External fixation varies widely comprising many different types of apparatus. Typically bone pins are inserted through the soft tissue into the bone fragments; devices are then affixed to the pins and serve to connect the bone fragments in such a way as to maintain correct anatomic position during the healing process. As is often the case, placement of the bone pins must be carefully selected to avoid damaging structures such as blood vessels, nerves, tendons, etc. Additionally consideration must be given to the structural integrity of the bone stock in combination with geometric stability considerations of the final construct. 
     When external fixation devices are used, it is very important that the connecting rods and bone pins are securely held in place by the clamps or attachment blocks. Nonunion of the bone or other structural damage can occur if a connecting rod or bone pin were to become detached or loose while the external fixation device is in use, which could require revision surgery. Many of the prior art external fixation clamps or attachment blocks are secured to the connecting rod or bone pin with a nut and bolt system extending through the collar and center of the clamp. When the screw is tightened, it engages with the connecting rod or bone pin locking them in place. While these clamps are generally effective, the screw must be very tight to adequately secure the connecting rods and bone pins. This frequently makes the clamp with a nut and bolt system very difficult in small spaces and awkward patient positioning. The surgeon may also miss or not completely tighten all bolts. The nut and bolt system is also very difficult to remove or adjust during and after surgical procedures. Often times the surgeon is required to frequently adjust the external fixation device many times during a procedure in order to achieve the optimal bone alignment. 
     Current connecting rods have smooth surfaces and round shapes. Thus unless the clamps or attachment blocks are fastened tightly they can rotate and lose the desired positioning. Benefits would be achieved if there were receptacles for the fasteners so once positioned the clamp or attachment block could not rotate or move longitudinally. Alternative rod shapes can be helpful as well to aid in the fixation so the clamp or attachment block will not rotate around the connecting rod. Dye (Donald W. Dye, “Orthopedic Instrument with Quarter-Turn Disconnect Mechanism,” U.S. Pat. No. 5,496,323, Mar. 5, 1996) teaches a mechanism providing for a female socket on a cutting instrument and a male plug on the cutting apparatus. While this is an orthopedic application it is not related to external fixation or similar application. 
     Because of the difficulties associated with using conventional bolts, it would be of benefit to have a quick-release fastener that can be easily engaged or disengaged. 
     SUMMARY OF THE INVENTION 
     The present invention relates to spring-loaded fasteners for connecting a first component to a second component requiring only one quarter turn to switch between a fastening/locking position and a release position. 
     The present invention, aims to provide greater speed, security, visualization and placement flexibility in a more compact construct than is presently available. It comprises the placement of fixation elements on either side of a fracture. These fixation elements are commonly referred to as pins, whereby one or more pins are screwed into a bone. One or more pins are located on either side of a fracture and connected to a bar via a clamp and/or a clamping system. The present invention relates to connecting rods and bone pins with one or more bars in order to fixate a fracture. Such bars may also be connected to other bars or structures, if needed. In connecting pins to rods, it is advantageous to have mobility in a clamping system to allow for ease of placement and/or post placement manipulation. The present invention also requires no tools to utilize, although use of a tool to engage or release the fastener is not precluded. Embodiments of the device include the capability of the objects clamped to pivot and rotate to many different angles. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a diagram of quarter-turn fastener. 
         FIG. 2  illustrates an extraskeletal fixation device using quarter-turn fasteners. 
         FIG. 3  shows quarter-turn fasteners including a spring mechanism using a wave washer with  FIG. 3A  showing the position with the fastener engaged and  FIG. 3B  the position with the fastener unengaged. 
         FIG. 4  demonstrates an alternative twist means for a quarter-turn fastener with  FIGS. 4A-C  showing alternative handle configurations. 
         FIG. 5  illustrates a frame rod with blind holes for receiving the rod end of a quarter-turn fastener. 
         FIGS. 6A-6F  show alternative cross sections of circular and non-circular connecting rods. 
         FIG. 7  shows a perspective view of a dimpled connecting rod or bone pin. 
         FIG. 8  demonstrates a cam-clamp fastener. 
         FIGS. 9A  and B show a dual-sphere locking device with quarter-turn clamps with  FIG. 9A  showing the internal view and  FIG. 9B  showing the external view. 
         FIGS. 10A  and B show a dual-sphere device with a rigid lock with  FIG. 10A  showing the external view and  FIG. 10B  showing the internal view. 
         FIG. 11  illustrates a quarter-turn locking mechanism. 
         FIG. 12  shows a ten-point connecting rod. 
         FIGS. 13A  and B show a parallel clamp with  FIG. 13A  showing the external view and  FIG. 13B  the internal view. 
         FIGS. 14A  and B illustrate alternative parallel clamps mechanism,  FIG. 14A  with octagonal and oval clamping openings and  FIG. 14B  with two types of stellate clamping openings. 
         FIG. 15  illustrates a pinch-clamp assembly. 
         FIG. 16  shows a side, external view of the pinch-clamp assembly of  FIG. 15 . 
         FIG. 17  illustrates clamp using twist-release programmable magnets. 
         FIG. 18A  shows the programmed maxel pattern for a twist-release configuration and  FIG. 18B  illustrates a sample maxel dot pattern. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention incorporates a quarter-turn quick-release fastener-based clamp and release mechanism into extraskeletal orthopedic frame assemblies. The quarter-turn mechanism is applicable whether the frame is assembled prior to surgery (the usual practice) or during surgery. As opposed to the quarter-turn fastener, prior art implementations use a conventional screw inserted into a threaded hole. Thus a tool, usually a wrench, is employed to tighten the end of the screw against the connecting rod or the bone pin. This is both inconvenient and requires the operator to determine him or herself how much to tighten the fastener. A quick-release fastener is one that may be engaged or disengaged without the use of a tool. 
     An articulation clamp consists of a plurality of adjustable jaws for the purpose of fixating the relative position of connecting rods and/or bone pins of an external bone fixator. Projecting elements of the attachment blocks are the bone pins going into the bone and the connecting rods going between the attachment blocks. The clamps or attachment blocks can be square, rectangular, spherical, or combination shapes. Passages are eccentrically arranged through the attachment blocks to accept the bone pin or connecting rod. In one embodiment, Mullaney (Michael W. Mullaney, “Method and Clamping Apparatus for External Fixation and Stabilization,” U.S. Pat. No. 8,241,285, Sep. 14, 2012), commercialized in the ExtraOrtho XO series, each of the adjustable jaws consists of a pair of hemispherical jaw elements contained within a spherical housing. A passage is eccentrically arranged through the jaw elements to accept the bone pin or connecting rod. Another ExtraOrtho embodiment, involving clamps and links, is Miller (Stephen T. Miller, “Clamping Assembly with Links,” US 2012/0289959, filed Nov. 4, 2011). Neither of these embodiments uses quarter-turn release mechanisms. Hibner and Avimukta (Hibner, J. A. and Avimukta, K., “Biopsy Cannula Adjustable Depth Stop, US 2009/0163830, filed as Ser. No. 12/368,317 on Feb. 10, 2009) describe a rotating guide in the biopsy device with quarter-turn locking, but this application is not related to extraskeletal or other bone fixation. 
     Alleyne and Nonaka (Alleyne, N and M Nonaka, “Bone Fixation Apparatus,” US 2008/0058811, filed at Ser. No. 11/935,990 on Nov. 6, 2007) describe a bone fixation device for spinal stabilization in which a cap is positioned on a receiver with securing them by rotating the cap around one quarter turn. This apparatus is for purpose of containing a threaded bone screw and not either for construction of a frame for extraskeletal fixation or including a quarter-turn fastener where a pin in the turned shaft engages a track in a clamp. Metz-Stavenhagen (U.S. Pat. No. 7,235,075) does specify a quarter-turn fastener and the quarter-turn fastener gripping a rod but does not disclose clamps, cam clamp or connection blocks. The mechanisms only deal with pulling a shaft into a holder, not pushing, do not have a shaft, and require a tool to use. Metz-Stavenhagen is limited to spinal applications and connection blocks required to construct frames for extraskeletal fixation are not specified by Metz-Stavenhagen and neither are bone pins or non-circular connection rods or connecting rods with holes in them to received quarter-turn fastener shafts or where the connection rods have dimples or out-dents. Chin et al. (US 2010/0063552) describe a system for extraskeletal fixation to assemble clamped objects using quarter-turn fasteners with a feature riding in a curved track. The device is used for spinal fixation rather than for assembly of extraskeletal frames. In one primary embodiment, the rotating cap is specifically set up to receive a hexagonal tool and in another primary embodiment, a specific insertion tool is described. 
     Kuslich (U.S. Pat. No. 5,591,235) describes a clamped object that has a surface that is not necessarily smooth and where the cross section is not round. It is used in implantable systems and not applicable to systems for extraskeletal fixation. 
     Beside the frame elements, clamps in extraskeletal fixation systems clamp onto connecting rods or bone pins. These are referred to here as clamped objects so they can be referred to as a group. This group can also include other useful elements such as a support that is only clamped at one end. 
       FIG. 1  shows the quarter-turn, quick release fastener. The shaft  100  of the fastener is turned by applying rotational force to fastener head  110  with leverage applied via elongated handle  120  attached to head  110 . The quarter-turn mechanism engagement catch  130  grabs a feature such as a pin in the attachment block, not shown, with the fastening into the final fixed position accomplished by twisting handle  110  one quarter turn. Pressure against the rod or pin to be held by the attachment block is through fastener end  140 . The handle can be elongated as shown in element  120  or can be shorter or have exposed handles on both sides of fastener head  110 . At least one spiral cam slot is on the stud body and a corresponding cam surfaces on the receptacle whereby relative rotation between the stud body and receptacle will cause the cam surface to follow the cam slot or track between the locked and unlocked positions. The fastener may not require a tool to engage or release the fastener. The fastener need not be exactly 90 degrees; embodiments can include rotations in the range of 30 to 150 degrees, but not limited to those end points. 
       FIG. 2  illustrates a complete assembly associated with fixation of bone segments within body part  200 . In this case, two attachment blocks  210  are linked by connecting rod  220  with fastening provided by quarter-turn fasteners  240  turned by elongated handles  250 . Bone pins  230  are fastened into the attachment block by quarter-turn fasteners  260  turned by elongated handles  270 . More than one such assembly can be used in a given procedure (for example one assembly on each side of a limb being repaired) and there can be cross connecting rods between two assemblies, in which case a cross-connecting rod as well as the connecting rod and a bone pin can be incorporated in a single attachment block or a cross-connecting rod and a connecting rod included in a separate attachment block. The quarter turn system contains a quick release mechanism on the clamp which allows the connecting rods and bone pins to be removed quickly and easily without the use of any tools. In one embodiment, the jaws are attached in a back-to-back fashion through the use of a quarter (¼) turn bolt that acts as a turnbuckle pulling the jaws together when tightened. The quarter turn system will secure connecting rods and bone pins at the optimal compression to prevent loosening and over tightening. Using the quarter turn fastening system plus a flip tab for tightening/locking and loosening requires no tools, thus speeding up the procedure both applying the external fixation system and removing the system. 
     Competitors with the nut and bolt risk interference from soft tissue, and competitors with two nuts require both to be tightened. Competitive systems therefore unnecessarily prolong surgery, especially when nuts have to be retightened. These efficiencies result in saved operating room time, costs, and surgeon/surgical team effort. Our described invention takes up less space and thus provides for better visualization for patient safety. 
       FIG. 3  shows the quarter-turn fastener with a wave washer providing tension that allows smooth transition in clamping. The preload of the wave washer or wave spring takes up the slack in the quarter-turn fastener in the disengaged state. In  FIG. 3A , quarter-turn fastener  305  fastens attachment block  300  with engagement mechanism  320  engaging-pin feature  315  in attachment block  300 . Quarter-turn fastener  300  has a head  310  turned by elongated handle  330  and applies pressure to either a connector rod or a bone pin via rod  325  with a flattened wave washer spring  335  providing tension during turning of the quarter-turn fastener. In  FIG. 3B , quarter-turn fastener  305  going through attachment block  300  is shown in its unengaged position with head  310  and handle  330  distanced from the upper surface of attachment block  300  and wave washer  335  in a relaxed state. When quarter-turn fastener  305  is turned it advances into attachment block  300  against tension generated when wave washer  335  is compressed. This offers the operator a smoother transition and can be more ergonomic. In another embodiment, wave washer  335  would be replaced by a coil or other spring with or without a containing a hole concentric with quarter-turn fastener  305  bored partially through attachment block  300 . A spring is positioned to be biased as the cam surface follows the spiral cam slots thereby assisting in drawing the two members into tight and locked position. Finally, a retainer is provided for maintaining proper orientation of the fastener when the members are subjected to a shear load so that the primary load on the fastener is a shear load thereby increasing the load therein capacity of the fastener. Embodiments can include cases where the engagement pin is in the receptacle as shown in  FIG. 3  or, the engagement pint can be on the shaft of the quarter-turn fastener. The latter case would require an entrance track in the receptacle allowing insertion of said pin down to a portion of the track that is curved to allow fastening engagement by rotating a quarter turn plus a one-way mechanism such as a sprung flap or block that would prevent the pin from being withdrawn back into the entrance track. 
       FIG. 4  shows alternative handles for the quarter-turn fastener.  FIG. 4  shows a plan view of a quarter-turn fastener with head  400  and elongated handle  410 . Another embodiment is shown in  FIG. 4B  in which quarter-turn fastener head  400  has alternative handle assembly in which twist device  420  is attached to support  430  such that  420  can rotate so it can be flattened and lie parallel to head  400 .  FIG. 4C  illustrates pin  440  contained within support  430  by which pin  400  can rotate around pin  440  and come to a position parallel with quarter-turn head fastener  400  for easy storage or having handle  420  not be sticking out before or after the quarter-turn fastener is engaged. The quarter turn clamp mechanism will have a flip tab that is used to tighten/lock and loosen the clamping device. This tab will turn a quarter turn in one direction for tightening and locking into a color-coded position indicating to the surgeon and staff the clamp is in the locked position, taking the guess work out of knowing if the apparatus is completely locked and secured. The tab will then turn in the opposite direction loosing the clamp, the color-coding will indicate to staff and surgeons that the clamp is in the unlocked position. This quarter turn color-coded tab at the top of the clamp will speed up procedure time and insure proper tightness throughout the procedure. 
       FIG. 5  demonstrates an alternative connecting rod in which the surface is not smooth but has holes partially bored through to receive the pin projecting from the end of the quarter-turn fastener. In  FIG. 5 , connecting rod  500  has holes  510  on the top and holes  520  on the side. Such holes can also be located at any position around the connecting rod (such as six or eight or other positions as opposed to four positions). The more such positions, the more angles can be accommodated so finer adjustments can be made, particularly if bone pins are already positioned in bone. In addition to preventing rotation, use of the holes would prevent longitudinal movement as well. The holes themselves can be non-threaded or threaded and can be of different shapes such as round, square, rectangular, oval, octagon, hexagonal, octagonal, and arbitrary. A hole may also include a pin mechanism to receive the engaging catch of a quarter-turn fastener or another style of fastener such as a cam-clamp fastener. Employing such surfaces on connecting rods or bone pins can facilitate use of external-fixation assemblies whether quarter-turn clamps are used or not. 
     As shown in  FIG. 6 , Connecting rod  500  in  FIG. 5  can be of different cross sections.  FIG. 6A  illustrates a round cross section  600 .  FIG. 6B  shows a square cross section  610 .  FIG. 6C  demonstrates a rounded-corned cross section  620 .  FIG. 6D  shows a pentagonal cross section.  FIG. 6E  illustrates a hexagonal cross section  640  and  FIG. 6F  demonstrates an octagonal cross section  650 . Arbitrary cross sections are also part of this invention. An attachment block fastened to a round connecting rod can rotate around the rod unless the fastener is clamped down tightly. If the rod is not round then the clamp cannot rotate because the clamp can move back and forth along the rod, but not around it. The more sides that the shape has, the more resolution there will be in positioning the assembly block around the rod. Thus an octagon can be positioned in twice as many locations as a square. The various embodiments described herein have the advantage of preventing pop-outs of the clamped objects. 
       FIG. 7  shows a dimpled surface  710  connecting rod or bone pin  700 . The surface would match the complementary surface of the associated clamp. A major advantage to the dimpled rod or pin is that the held component is restricted both longitudinally and rotationally. Alternatively the dimple (indent) features on the connecting rods or bone pins could be out-dents. In any case, the features of the connecting rods or bone pins will be opposite and complementary to the features on the surface of an associated clamp. Therefore indent features on the connecting rod or bone pin will engage with out-dent features on the associated clamp. As noted in connection with  FIG. 5 , Employing such surfaces on connecting rods or bone pins can facilitate use of external fixation assemblies whether quarter-turn clamps are used or not. 
       FIG. 8  shows an alternative clamping mechanism, the cam-clamp fastener. The fastener plunger  800  has head  810  and spring  820 . Base plate  840  is either attached to the attachment block or incorporated in that attachment block. Base  840  has clamp support  850  with clamp pin  860  providing a pivot point for the cam clamp what consists of small-radius segment  870 , large-radius segment  880 , and clamp lever  890 . 
     The same approach can be used with a bone pin that equivalently may contained holes bored part of the way through to receive the pin projecting from the end of the quarter-turn fastener. 
       FIG. 9A  shows dual-sphere locking device with quarter-turn clamps: a lockable ball  940  and socket interconnection  960  comprising a ball member  940  and a socket member  950 , the socket member defining an entry for the ball member  940 , the ball member having two spherical end surfaces, each having a radius of curvature greater than the radius of curvature of the entry  965  in socket member  950 , the socket member being adjustable and adapted to receive the ball member such that the ball member is capable of both pivotal and rotational movement within the socket member  950 ; and lock the ball and socket interconnection such that the ball member and the socket member may be fixed in relative position to each other, the lockable ball and socket interconnection characterized in that an intermediate section is located between the two spherical end surfaces and has a radius of curvature less than the radius of curvature of the entry, and whereby the intermediate section renders the ball member releasable in the socket member. The surface of ball  940  and the matching ball  945  may have dimples as well the openings of socket member  950  and its equivalent  955  in the lower section to engage the balls more securely. This connection is locked by tightening a screw mechanism  970  that can be screwed over an external thread formed on the lower portion of the connecting mechanism. Tightening screw mechanism  970 , forces the two ball and sockets against the spherical housing members  950  and  955 , locking the balls in a fixed location and angle. As shown in  FIG. 9B , clamping to connection rods or bone pins (not shown) is accomplished by rod/pin receptacles  980  and  990  with their respective quarter-turn Fasteners  985  and  995 . 
     The device in  FIG. 10A  is a dual-sphere rigid-lock device consisting of lower socket member  1000  and upper lower socket member  1005  with serrated separation interface  1050 . Each of the socket members contains movable balls,  1010  and  1015  respectively. The internal structure of the interface that holds the upper and lower members together is shown on the right. As shown in  FIG. 10B , a vertical rod with the lower portion of the rod  1065  and upper portion of the rod  1060  with cap  1070  and its equivalent below pierce the serrated interface location  1055  with upper spring  1085  and lower spring  1075  allowing separation of the upper and lower halves by pulling them apart so that the upper and lower halves with their included balls  1015  and  1010  can be rotated relative to each other. When the upper and lower halves are released, they come together and are rotatably fixed. Illustrated in  FIG. 10A , quarter-turn or non-quarter turn rod and handle assembly  1020  locks ball  1010  in its position. Quarter turn or non-quarter turn rod and handle assembly  1025  locks Ball  1015  in its position. Connecting rod or bone-pin clamp  1030  affixed to ball  1010  clamps the rod or pin using quarter turn or non-quarter turn rod and assembly  1040 . In like manner, connecting rod or bone-pin clamp  1035  affixed to ball  1015  clamps the rod or pin using quarter turn or non-quarter turn rod rod and assembly  1045 .  FIGS. 9 and 10  are examples of embodiments allowing pivoting and rotating of clamped objects to many different angles. 
     As shown in  FIG. 11 , a quarter-turn locking mechanism with head  1110  pulling upper housing  1100  and lower housing  1140  together is depicted with the receiving receptacle  1130  that has a protruding pin  1120  that slides within a slot  1125  in the pin shaft  1135  to guide the shaft into locked engagement with the socket. The shaft also has a cantilever body which wedges into a tapered region in the socket to frictionally bind the shaft and socket together. The fixed body is basically composed of the cylinder of the lock, which is connected to a sliding arm, and the arm in turn is connected to a shaft or movable body. When the shaft of the lock is activated, the sliding arm is moved, thus moving the rod&#39;s articulator. This small rotational movement of the rod&#39;s articulator is sufficient to alter the course of the protruding pin that is associated to the locking elements, locking or unlocking the clamping mechanism. In this embodiment, engaging the quarter-turn fastener draws engaged elements towards head  1110  of the fastener as opposed to the embodiments of  FIGS. 1 and 3  in which the shaft is advanced, for example, to be moved into the holes of the rod in  FIG. 5 . 
       FIG. 12  shows a 10-point connecting rod  1200 . As shown, 10-point connecting rod  1200  has 10 triangular features  1210 . When the matching clamp, not shown, is simultaneously slipped over the ten triangular features  1210  the matching clamp will not be able to rotate and therefore the relationship between 10-Point Connecting rod  1200  and the matching clamp will be rotationally fixed. General to the field of external fixation, and more specifically, to connection rods having 10 rigid points that allow for both rapid and gradual adjustments and overall strength of the connection of clamps rods. The same principle applies to bone pins. The 10-point connecting rod  1200  is lightweight and simple for fixating bones that is strong enough to hold the bones in their intended positions. The 10 points also allow for more accurate clamping and prevents the connecting rod from “popping out” of the clamp. The number of points not necessarily 10; other number are suitable. The greater the number of points, the more resolution there is to allow finer control of the angular relationship of one pin to another pin. 
       FIG. 13  shows a parallel clamp for external bone fixation. The clamp may include one or more of the following features. For example, the clamping assemblies may be arranged back-to-back with respect to one another. The first-shaped clamping surfaces may be generally parallel, flat faces. The second-shaped clamping surfaces may include non-parallel clamping surfaces, such that two connecting rods or a combination of connecting rods and bone pins may be clamped between the non-parallel clamping surfaces are fixed at a non-parallel angle with respect to each other. A pair of clamps holding a connecting rod, a connecting rod and a bone pin, or two bone pins can be rotated relative to each other around the axis defined by the quarter-turn clamping fixture, the locking mechanism. Types of connections are shown in TABLE 1. Another case is where one of the clamped elements incorporated in the frame system is a support that is only clamped at one end. 
     
       
         
           
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                 CONNECTIONS 
               
            
           
           
               
               
               
               
            
               
                 TYPE 
                 CONNECTION 1 
                 CONNECTION 2 
                 CONNECTION 3 
               
               
                   
               
               
                 Frame 
                 Connecting Rod 
                 Connecting Rod 
                 — 
               
               
                 Frame 
                 Connecting Rod 
                 Connecting Rod 
                 Connecting Rod 
               
               
                 Bone Pin 
                 Connecting Rod 
                 Bone Pin 
                 — 
               
               
                 Bone Pin 
                 Connecting Rod 
                 Bone Pin 
               
               
                   
               
            
           
         
       
     
     As shown in  FIG. 13A , the parallel clamping jaws may include one clamping jaw set with a star-shape  1350  contained within jaws  1340  and  1345  and another clamping jaw with differently shaped channels  1335  contained within jaws  1325  and  1330 . The various styles of channels  1350  and  1335  create a strong and stable base while preventing rotation of the connecting rods and bone pins. This is essential to the foundation of the clamping mechanism. Clamp set pair  1325  and  1130  and clamp set pair  1340  and  1345  may rotate in any angle in respect to each other, where as to meet the optimal bone fixation angle. As shown in  FIG. 13B , the clamp assembly is further comprised of a quarter-turn locking mechanism  1305  for locking the parallel clamp sets in a fixed position. The locking occurs with the rotation of shaft  1330  within compartment  1320  with slot  1355  employed to rotate the shaft axis. The quarter-turn locking mechanism works because pin  1315  protruding from compartment  1320  engages in curved slot  1310  in shaft  1300  and as slot  1355  is rotated pulls most distal clamp jaw  1325  thus pulling the remaining clamps and associated connecting rods and bone pins together and locking them all into place. The small rotational movement of the quarter-turn articulator  1305  is sufficient to engage or disengage pin  1315 , locking or unlocking the clamping mechanism. 
       FIG. 14  illustrates parallel clamping devices comprised of jaws  1400  and  1405  in  FIG. 14A  and jaws  1440  and  1445  in FIG.  FIG. 14B . The clamp set made of jaws  1400  and  1405  has eight-sided opening  1410  and  12 -sided opening  1415  for holding connecting rods or bone pins has associated pivot hinge  1420 . In like manner, the clamp set made of jaws  1440  and  1445  has star-shaped openings  1450  and  1455  for holding connecting rods or bone pins has associated pivot hinge  1460 . The non-circular outlines of opening  1410 ,  1415 ,  1450 , and  1455  demonstrate alternative connecting rod or bone-pin containing shapes that will restrict the clamped elements preventing them from rotating. The respective quarter-turn quick-release latching mechanisms are  1425  in  FIG. 14A and 1465  in  FIG. 14B . 
       FIG. 15  shows the cross section of a pinch-clamp assembly for engaging connecting rods and bone pins with a locking means in which collapsible sphere with left component  1500  and right component  1505  are rotatably fixed with within bracket  1575  being pushed away from each other by spring  1545 . If attached handles  1510  and  1515  are squeezed towards each other, left component  1500  and right component  1505  rotate around hinge pivot  1570  and disengage from bracket  1575  and can rotate right to left, front to back, or a combination of those directions. The outsides of left and right components are covered with dimples and the inside of bracket  1575  is covered with matching divots (or vice versa). When the handles  1510  and  1515  are relaxed, the dimples and divots are engaged and the left and right spherical components locked into place. The hinge pivot  1570  is attached to connecting rod/bone pin clamp  1530 . The connecting rod or bone pin are placed within opening  1535  and locked into place with quarter-turn or non-quarter turn locking mechanism  1540 . In like manner bracket  1575  has opening  1550  (vertical in  FIG. 15  so not visible) with the connecting rod or bone pin able to be locked into place with quarter-turn or non-quarter turn locking mechanism  1525 . 
       FIG. 16  shows the external view of the pinch-clamp assembly illustrated in  FIG. 15 . In this view the outside of bracket  1615  that surrounds the collapsible sphere with left component  1600  and right  1605 . The articulation of the two components is at hinge pivot point  1610  to which connecting rod/bone pin clamp  1630  with its opening  1635  and locking mechanism  1640 . The other connecting rod/bone pin is held in clamp  1650  (vertical in  FIG. 16  so not visible) with the connecting rod or bone pin able to be locked into place with quarter-turn or non-quarter turn locking mechanism  1625 . 
       FIG. 17  shows a Quick-Turn, external-fixation clamp with the use of programmable magnets: the figure illustrates an embodiment using programmable magnets showing two clamps, upper clamp  1700  and lower clamp  1705  mechanically interfaced by rod  1790 . The details for each of clamps  1700  and  1795  are the same so they are illustrated in upper clamp  1700 . This figure shows the Quick Turn clamp utilizing the programmable magnets  1720  and  1725 . Programmable magnet  1725  is in a fixed position while programmable magnet  1720  rotates and moves in a vertical position. These magnets can be programmed for greater locking strength and programmed to repel one another at certain rotational orientations so that tools, although they can be used, are not needed. Upper clamp  1700  itself is comprised/composed of upper section  1710  and lower section  1715 . Upper section  1710  is kept rotatably fixed relative to lower section  1715  with two slidable elements, the first composed/comprised of compartment  1740  and sliding pin  1745  and the element composed of compartment  1750  and, sliding pin  1755 . Programmable magnet  1720  is rotated on shaft  1730  with rotation accomplished by rotating knob  1735 . In an alternative embodiment, there can be a shaft protruding from one of the programmable magnet halves  1710  or  1715  and a receiving hole in its opposite half. A spring  1795  surrounding shaft  1790  is used to keep upper and lower clamps in their relative position to each other. At each end of shaft  1790  are ball-and-socket joints located in upper clamp  1700  as ball  1760  contained within compartment  1765 . The ball and socket locking mechanism is offset for greater degrees of variance if desired by the user. The ball-and-socket mechanism uses the quick-turn locking mechanism consisting of shaft  1770  enclosed in a hole including boss  1780  that pressed against ball  1760  using quarter-turn catch feature  1785  to secure the clamps in the desired position by turning knob  1775 . The twist-release clamp can be used in a variety of extraskeletal-assembly configurations, such as the one shown in  FIG. 2 . 
       FIG. 18A  shows the gross pattern of maxels for a Polymagnet with twist-release behavior. Overall pattern  1800  has two broad fields of maxels  1810  and  1820  with opposite polarities so when the two halves of the Polymagnet (opposite half not shown in figure) are rotated, they will repel as the magnetic regions of the same polarity are exposed to each other and thus the clamp will be released. When one half of the Polymagnet pair is further rotated the magnetic regions will again be of opposite polarity and the clamping will return. The pair of programmable magnets has a strong attractive force when the regions of opposite polarity are facing each other but repel and thus release when the magnet is rotated and regions of opposite polarity are facing each other. During the assembly of the extraskeletal frame, re-clamping would only be applied when a given component of the frame being clamped was in the desired position in three-dimensional space. Twist-release programmable magnets do not have to be set to turn in 90-degree increments; other twist-release angle patterns work as well, such as 45 degrees and 22.5 degrees. The two halves of the magnet must be axially constrained to allow the desired behavior to be exhibited; otherwise the two magnet halves will separate radially. The regions  1810  and  1820  in  FIG. 18A  are made up of individual maxels.  FIG. 18A  illustrates a programmable-magnet twist-release pattern of 90 degrees since each of the four sectors has a 90-degree angle.  FIG. 18B  illustrates a more highly magnified field of maxels  1850 . The more darkly shaded maxels represented by maxel  1830  is of opposite polarity of the lightly shaded maxels represented by maxel  1840 . Both the rotational torque of the Polymagnets and the attachment force of the Polymagnets are programmed to meet the requirements of the clamping. For extraskeletal fixation, torque will be typically be on the order of 2 to 5 inch-pounds for 90-degree twist-release clamping, although not limited to this range. For example, the rotational-torque ranges in inch-pounds could be in the ranges 0.5 to 3, 3 to 7, 7 to 12, and 12 to 20. 
     Attachment forces when the clamping is active with the faces of the halves of the programmable magnets is contact can vary from a few pound-forces (lbf) to in excess of 50 lbf according to what is required for the given extraskeletal-fixation frame, for example in the attachment forces in pound-forces are in the ranges of 1 to 10, 10 to 25, 25 to 50, 50 to 100, and 100 to 200. 
     The programmable magnets, designated as Polymagnets®, are produced on magnetic printers (MagPrinters) from Correlated Magnetics Research (CMR) (U.S. Pat. Nos. 8,648,681, 8,773,268, 9,105,384, and 9,269,482) with the magnets themselves by magnet vendors/service bureaus such as Amazing Magnets, LLC of Anaheim, Calif. and Industrial Magnetics, Inc. of Boyne City, Mich. These vendors also supply translucent magnetic viewing film so the magnetic regions can be displayed. CMR MagPrinters create highly focused, high-intensity magnetic fields that penetrate magnetizable material producing the maxel (magnetic element, like a pixel is a picture element). Each maxel has a specified consistent size, shape, polarity, amplitude, and orientation. The technology is capable of producing high-resolution maxel patterns including overlapping ones. The programmable technology allows production of various behaviors. This patent application employs the “twist-release” behavior. Examples of other behaviors are spring, latch-repel, and rotational alignment. 
     The various embodiments described above are provided by way of illustration only and should not be construed to limit the invention. Based on the above discussion and illustrations, those skilled in the art will readily recognize that various modifications and changes may be made to the present invention without strictly following the exemplary embodiments and applications illustrated and described herein. Such modifications and changes do not depart from the true spirit and scope of the present invention.