Abstract:
The present invention provides orthopedic devices useful in applying tension or compression to biological tissues, and facilitating surgical procedures. Various aspects of the invention include a split-nut fastener, a tension bolt, a suture nut, a pivot wing bolt and a transverse impaction screw. Each of these devices reduces surgery time, improves the reliability of the tissue position and simplifies surgical procedures as compared to known devices. The split-nut is used in combination with many implantable fasteners used in orthopedic devices. The split-nut, which has two halves, slides down a threaded rod until a ring surrounding the two halves forces them together. The split-nut is then readily threaded tightly onto the threaded rod. The pivot wing bolt assembly is used to secure one end of a threaded rod into the hollow or marrow of a fractured bone. Together with the split-nut or any other nut, the pivot wing bolt is used to fixate the fractured bone. The suture nut is used to minimize surgery time by avoiding the need to make hand-made knots in a suture being used during the surgery. Together with a suture, the suture nut is particularly useful for closing incisions in tissues. The suture nut grasps the suture where desired, thereby avoiding slippage of the suture after closure of the incision and avoiding the need to make a knot in the suture. The transverse impaction screw is used to increase the contact area between a ligament graft and the surrounding bone when fixating the ligament to a bone. Once the ligament is draped over the screw, the screw is turned in a first direction to impact the ligament onto a surface of a bone to which the ligament will attach during healing.

Description:
CROSS-REFERENCE TO EARLIER FILED APPLICATIONS  
       [0001]    The present application claims the priority of earlier filed International patent application serial no. PCT/IB00/00364 filed Mar. 28, 2000; U.S. provisional application for patent Ser. No. 60/193,000 filed Mar. 28, 2000; U.S. provisional application for patent Ser. No. 60/174,386 filed Jan. 3, 2000; U.S. patent application serial no. [to be added] filed Dec. 18, 2000, which is a divisional application of U.S. patent application Ser. No. 08/601,177, filed Feb. 14, 1996, now U.S. Pat. No. 6,162,234, issued Dec. 19, 2000, which is a continuation-in-part application of co-pending U.S. patent application Ser. No. 08/184,121, filed on Jan. 21, 1994, which is a continuation-in-part application of U.S. patent application Ser. No. 08/034,269 filed Mar. 23, 1993, the entire disclosures of which are hereby incorporated by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to orthopedic devices for fastening biological tissues under a controlled degree of tension and in particular to systems comprising a split-nut, winged bolt and/or transverse compaction screw.  
         BACKGROUND OF THE INVENTION  
         [0003]    Orthopedics is often rightfully called “bone carpentry”, as its object is to screw, staple or bolt pieces of bone together as closely and as precisely as possible so that the bone can heal together. Fasteners that hold the bones together are known. In surgery, repair must take place within the time space of the few hours of the surgery. The human tissue cannot simply be cut and moved out of the way in order to facilitate the repair of the bones, as the resultant healed muscles and ligaments that were cut will not function properly after healing. Further, orthopedic devices must remain in the body at least until the tissue heals and usually much longer.  
           [0004]    The anterior cruciate ligament (ACL) spans the knee joint and attaches to the upper bone, the femur and the lower bone, the tibia, to maintain smooth movement between their adjacent bone surfaces during knee movement. It rips in sporting accidents, requiring replacement with a graft that is fastened at one end to the femur, and at its opposite end to the Tibia. The ligament graft is typically secured with screws to these two bones. Such fasteners cannot easily adjust the tension on the ligament graft once installed. Hence, if, during surgery, the replacement ligament in perceived to be loose, allowing excessive play between the femur, and the tibia, it is often left this way, leading to discomfort and arthritis in the knee postoperatively.  
           [0005]    In surgical repair of a fractured mid-thigh bone, an intramedullary rod is inserted through the long canal that runs the length of the thighbone and one end is attached to the bone near the hip joint while the other end is secured to bone near the knee joint. Winged intramedullary rods are known. The Brooker-Will™ rod, for instance, has two thin fins that slid out of a long hollow rod and anchor in the soft bone near the knee. The fins tend to migrate in the soft bone so the bones misalign and the fins often fail to retract though thin slots in the long hollow rod, preventing removal of the rod at a later date.  
           [0006]    U.S. Pat. No. 436,101 to Freedland discloses a multi-winged anchor for fractures of the femoral neck. U.S. Pat. No. 4,721,103 to Freedland discloses an intramedullary rod, which has two wings that expand outwardly. U.S. Pat. No. 4,862,883 to Freedland discloses an intramedullary rod placed within the central longitudinal cavity in the femur. U.S. Pat. No. 5,098,433 to Freedland discloses a toggle, bolt with wings that collapse so that the wings along with the body of the toggle bolt can be removed from the bore in the bone. These Winged Intramedullary rods have multiple moving parts that, and if they are left in the body for a long period, they tend to corrode, leading to problems in retracting the wings and removing the rod.  
           [0007]    A threaded shaft with a threaded nut for fastening body tissue is known. Fasteners that slide and rotate on a rigid shaft are known. U.S. Pat. No. 5,098,433 to Freedland discloses a slide-on nut arrangement where the nut is secured by a cross pin to the shaft and an outer ring on the nut rotates to vary the force on the adjacent tissues.  
           [0008]    Closing tissue during surgery with suture knots during surgery is slow and cumbersome. Many different devices, which attempt to facilitate the tying of knots, have been disclosed. To date, however, very few surgical devices, which can be used in place of a knot in a suture, have been developed. Banded clamps made of rigid material that join two ends of a suture are known. The Y-Knot by Innovasive, Inc. fastens two ends of a suture loop simultaneously. The Y-Knot™ includes a compression ring, or band, and a single disk having a single annular groove and a single centrally located bore. A suture is retained between the band and the annular groove of the disk.  
           [0009]    Banded fasteners, wherein a soft cylindrical jacket is compressed against a cable by a band that surrounds it, are known. U.S. Pat. No. 5,626,590 discloses a cylindrical jacket made of a deformable material around which a rigid band is placed. U.S. Pat. No. 590,294 discloses a device having a long cylindrical jacket with an internally and externally threaded, split-nut and collet. All of these banded fasteners utilize long cylindrical jackets wherein only a portion of the jacket exerts pressure on the cable or shaft via the pressure of the band that surrounds it making them inefficient fasteners in size and in strength.  
           [0010]    Screws that traverse a bore in a bone such as the Bone Mulch™ screw by Arthrotec Endoscopy are utilized for anchoring or fastening large ligaments to a knee bone. This fastener does not cause the graft to become compacted against the adjacent bone.  
           [0011]    The above-mentioned references disclose a variety of orthopedic devices, which attempt to meet the needs in the field. However, many needs in the field of orthopedic surgery go unmet. The present invention provides a variety of tensioning devices capable of being implanted  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention overcomes the disadvantages of known related orthopedic fasteners and thus is generally directed to orthopedic devices that can be used to control the amount of tension and compression or distance between biological tissues.  
           [0013]    The present invention includes a toggle bolt with a single cross piece that rotates into position, rather than tradition toggle-like wings. Since it is a single wing, the size of this wing, and the shaft, can be maximized. This invention contemplates a metal shaft for the fastener so that it can withstand the tremendous stress along the longitudinal axis. At the opposite end, while this cross piece can be rotated back to the pre-insertion position by using a tool, it is designed to take advantage of the dissolvability of many materials on the orthopedic market today. In such case, the single toggle is made from a dissolvable material so that the problems of removal can be circumvented.  
           [0014]    The present invention, in the Suture Nut design, has a relatively non-deforming cylindrical jacket that is cut in sections for their entire length and surrounded by a relatively rigid band. This allows the Suture Lock to be compact and the sections of the split-nut to apply great pressure to the suture.  
           [0015]    The dissolving material of the invention would ideally have great strength for a period of two or three menthes while the bone heals and then would rapidly dissolve so that the rod could be removed from the bone when the surgeon wishes. In a preferred embodiment, the cross piece can be made of a very durable dissolving plastic, one that is known to last in the body an inordinate amount of time, but that has tremendous strength. Once the healing takes place, a catalyst can be introduced into its proximity to facilitate its dissolution. The present invention contemplates a means of introducing such a catalyst even though the crosspiece is embedded deep in the knees and the entry to the thighbone is located far away at the hip.  
           [0016]    The technique for reconstructing a fractured hip would be to make a bore in the bone from the top of the thigh bone, down into the knees, insert the fastener with its cross piece initially parallel to the shaft. The crosspiece would be rotated perpendicular to the shaft once it is past the mid-thigh fracture and in the knee. The surgeon would then pull up on the shaft so that the crosspiece would impact on the bone around it and bring the lower bone fragment into the upper bone fragment, impacting them together.  
           [0017]    At the other end, a nut would be placed on the threaded shaft and rotated until it pressed against the upper edge of the hip bone and the excess shaft would be cut off. In such a procedure, the amount of excess shaft that would protrude out of the bore in the hip, would be dependent up the placement of the cross piece, the length of the thigh bone, and the amount of impaction that is achieved between the bone fragments.  
           [0018]    Having a one-size-fits-all is preferable from an economic standpoint to requiring the hospital to carry many different lengths of the same rod. Yet, to allow for the many different lengths of hips that must be fastened, means that a typical compression rod must be, perhaps, ten centimeters longer than its final state after being cut to size. This necessitates turning the nut many revolutions before it comes to rest against the bone and apply proper compression. The split-nut is designed to speed this process for the surgeon so that rather than rotating the nut all the way down the shaft, it can slide along the shaft until into position and then rotate in order to apply precision compression to the bone pieces. The present invention relates to fastening and applying tension to materials in vivo with a threaded nut on a threaded rod in a rapid fashion. The speed nut is a split-nut whose sections expand to allow it to slide until encompassed by a compression ring at the surface of a bone. It is rotated while compressed against the bone surface, it causes a threaded rod to move in or out of a bore in the bone, and thereby apply compression to the bone pieces.  
           [0019]    In another embodiment of the split-nut, a portion of the shaft is replaced by a soft tissue link, such as an eye, so that the soft tissue becomes incorporated as the structures heal. In this case, the split-nut is rotated to pull the rod out of the bore in the bone, increasing tension on a ligament or muscle that is attached to the eye at the opposite end of the shaft.  
           [0020]    This embodiment is particularly useful in fastening a large ligament such as the ligaments of the knee, with precise tension. The speed nut is a threaded nut fastener that compresses against the hard surface of the Tibia, rather then fastening within the softer internal bone as do screws and staples, and over a large surface area, giving it much greater fixation strength. It rotates against the bone surface against which it is compressed to bring a threaded rod attached to a graft, out of the bore, thereby putting adjustable tension on the graft. To save time in rotating the fastener up to the surface of the tibia, it is split so that its sections temporarily distend and it slides rather than rotates to reach the surface of the Tibia. Once at the bone surface, its pieces slide against each other so their bore size decreases and the fastener threads mesh with the threaded rod. With the speed nut compressed against the bone surface, it causes the rod to moves through rotation only. The tension of the graft can be measured and readjusted with joint motion in between measurements to help settle the graft in place, without affecting the strength of the fastener, a technique presently not available in state-of-the-art fasteners.  
           [0021]    In summary, the speed nut, is stronger than typical knee ligament fasteners, and adjusts the ligament tension where adjustment typically cannot be made. It is designed to install rapidly without time wasted on rotating the nut up to the bone surface.  
           [0022]    The present invention includes a donut-shaped fastener, cut and banded in pie-like sections which easily and quickly reaches a desired position on a shaft or cable. At the opposite end is a tissue receptacle that when working in conjunction with the SPLIT-NUT, precisely adjusts tissue position.  
           [0023]    The various embodiments of the pivot wing in the PRECISION COMPRESSION RODS can be made of dissolvable materials. A novel method is shown in the patent whereby such dissolvable materials, even when buried deep in the bone, can be made to dissolve more rapidly when in contact with a catalytic agent.  
           [0024]    In one aspect the present invention provides a ball-and-socket nut assembly. The nut generally has a convex-shaped surface and mates with a flanged concave-shaped socket. The flanged socket has a slit to allow passage of the convex-shaped nut on a threaded rod as it is seated in the socket. The convex-shaped nut swivels in the socket, allowing the threaded rod to conform to a variety of bore angles. The flanged socket in which the nut rests compresses against the hard surface of the Tibia, rather then fastening within the softer internal bone as do screws and staples, and covers a large surface area, giving it much greater fixation strength than state-of-the-art bone screws. When the nut assembly is implanted into a bone, the flange is disposed on the surface of the bone and the socket is disposed within a bore in the bone. The nut is rotated while seated in the socket, and the flange compresses against the bone surface and causes the threaded rod to move in or out of a bore in the bone, and thereby adjusts the distance or forces between reconstructed body tissues.  
           [0025]    In one embodiment of the threaded shaft or bolt, a portion of the shaft is replaced by a retainer, such as an eye, for soft tissue. A soft tissue graft is attached to the eye and the split-nut is rotated to pull the rod out of the bore in the bone, thereby increasing tension on the soft tissue graft that is attached to the eye at the opposite end of the shaft. The tension of the graft can be measured and readjusted with joint motion in between measurements to help settle the graft in place, without affecting the strength of the fastener, a technique presently not available in state-of-the-art fasteners. This embodiment is particularly useful in fastening large ligaments such as the ligaments of the knee, with precise tension while the ligament graft fibers incorporate into the surrounding bone, providing a knee that functions properly.  
           [0026]    In another aspect, the present invention provides a split-nut, or speed-nut, fastener that can be used in conjunction with many known implantable orthopedic fasteners. The snap ring nut is a split-nut whose sections expand to allow it to slide until encompassed by a compression ring. It is rotated while compressed against the bone surface and causes a threaded rod to move in or out of a bore in the bone, and thereby change the distance between the body tissues. The split-nut is designed to speed the threading process for the surgeon by circumventing the need to thread the nut down the entire length of the screw. Instead, the split-nut is slid approximately all the way down the shaft until it is in proper position, the split-nut sections are compressed toward each other and grasp the threaded shaft so that it will rotate on the threaded shaft so as to change the distance between biological tissues. The split-nut is particularly useful when used in combination with long, or one-size-fits-all, threaded shafts or screws. The one-size-fits all screw is preferable from an economic standpoint since it minimizes the need for a hospital to carry many different lengths of the same rod or screw. In one embodiment, the speed nut is used in place of the solid nut of the ball-and-socket fastener noted above.  
           [0027]    In another aspect, the present invention provides a pivot wing bolt with a single crosspiece that rotates into position. Since it is a single wing, the size of the wing, and the shaft, can be maximized. In a specific embodiment, the invention provides a metal shaft for the fastener so that it can withstand the tremendous stress along the longitudinal axis. At an opposite end, the crosspiece can be rotated to a deployed position and back to the pre-insertion position by using a tool. In another preferred embodiment, the crosspiece is made of a material that dissolves or degrades in a physiological environment. The dissolving material will preferably maintain its integrity for a period of about two or three months during which time the bone in which it is implanted heals. Near the end of such a period, the material will generally dissolve or degrade so that the rod could be removed from the bone as desired. In a specific embodiment, the crosspiece can be made of a very durable dissolvable plastic, one that is known to last in the body an extended period of time and that has sufficient strength to provide acceptable performance. Once the bone in which the toggle bolt has been implanted has healed, a catalyst, such as an enzyme, can be introduced into its proximity to facilitate its dissolution. Accordingly, the present invention also provides a means of introducing such a catalyst into the bone in proximity of the crosspiece even though the crosspiece is embedded deep in the knees and the entry to the thighbone is located far away at the hip.  
           [0028]    In another aspect, the present invention provides a suture nut. The suture nut generally comprises a relatively non-deforming cylindrical jacket that is cut into two or more sections throughout its entire length and is surrounded by a relatively rigid band. The suture nut is compact, and the sections of the suture nut apply a significant amount of pressure to a suture engaged with the suture nut.  
           [0029]    Another aspect of the invention provides a transverse impaction screw that is implantable in bone and is used to increase the forces between biological tissues such as a ligament, tendon, fascia or muscle and a bone. The transverse impaction screw is threaded into a bone preferably approximately normal to a bore through the bone. The transverse impaction screw has a smooth, flat, narrow central region. It is installed perpendicular to the linear axis of a bore in a bone, such as the femur, and initially, the flat section spans the bore such that the short axis defining the width of the flat section is placed parallel to the axis of the bore. The biological tissue is draped over. The flat section of the screw and the screw is turned such that the short axis that defines the width of the flat section is perpendicular to the axis of the bore thereby occupying a large portion of the transverse diameter of the bore. By so doing, the screw pushes the ligament graft radially outward and brings it into contact with the surrounding bone matrix. The ligament is thus compressed into the matrix thereby increasing the bond and resultant strength of attachment between the two.  
           [0030]    Another aspect of the invention provides a flanged ball-and-socket assembly comprising:  
           [0031]    a nut having a convex hemispherical surface having an internal threaded bore for receiving a threaded shaft;  
           [0032]    an approximately hemispherical concave socket adapted to receive, mate with and retain the nut, the socket having a hole and slot through a portion thereof for receiving a portion of a threaded shaft engaged with the nut, wherein the slot and hole is smaller in size than the nut; and  
           [0033]    a flange attached to a portion of the periphery of the socket, the flange having a notch through a portion thereof, wherein the notch is sufficiently large in size to permit passage of the nut into the socket.  
           [0034]    Specific embodiments of the flanged ball-and-socket assembly include those wherein: 1) the nut further comprises tool engaging means adapted to receive a tool that can be used to drive or rotate the nut when engaged with a threaded shaft; 2) the tool engaging means comprises a recess; and/or 3) the nut assembly comprises a material suitable for use in orthopedic surgery.  
           [0035]    Still another aspect of the invention provides a split-nut assembly comprising:  
           [0036]    two or more nut sections which form a nut when assembled, the nut having a threaded bore, a first annular groove having a first diameter, and a second annular groove having a second diameter,  
           [0037]    wherein the second diameter is larger than the first diameter and smaller than the widest diameter of the nut; and  
           [0038]    a band disposed in either of the first and second grooves to keep the two or more nut sections in assembly;  
           [0039]    wherein the nut sections are spaced from one another a first distance when the band is in the first groove and in closer proximity or in contact with one another when the band is in the second groove.  
           [0040]    Specific embodiments of the split-nut assembly include those wherein: 1) the first groove is disposed adjacent a first end of the nut; 2) the second groove is disposed between the first groove and a second end of the nut; 3) the band is an o-ring or a snap ring; 4) a portion of the surface of the band mates with corresponding portions of the peripheral surface of the nut; 5) the nut further comprises a shoulder interposed the first and second grooves; 6) each groove further comprises a flange to keep the retainer in its respective groove; and/or 7) the split-nut comprises two nut sections which form a nut when assembled, the nut having a threaded bore, a first annular groove having a first diameter, a second annular groove having a second diameter, a shoulder interposed the first and second grooves, wherein the second diameter is larger than the first diameter and smaller than the widest diameter of the nut; a snap ring disposed in either of the first and second grooves to keep the two or more nut sections in assembly; wherein, the nut sections are spaced from one another a first distance when the band is in the first groove and in closer proximity or in contact with one another when the band is in the second groove; and a portion of the surface of the snap ring mates with corresponding portions of the peripheral surface of the nut.  
           [0041]    Yet another aspect of the invention provides a pivot wing bolt tissue-tensioning assembly comprising:  
           [0042]    a threaded shaft having a head comprising a swing stop and a wing mount; and  
           [0043]    a single wing having an aperture engaged with the wing mount such that the wing is rotatably mounted on the wing mount; wherein:  
           [0044]    the linear axis of the wing is alignable with the linear axis of the threaded shaft; and  
           [0045]    the swing stop limits the rotation of the wing about the wing mount to less than one revolution.  
           [0046]    Specific embodiments of the pivot wing bolt tissue-tensioning assembly include those wherein: 1) the aperture in the wing is recessed; 2) the swing stop limits the rotation of the wing about the mount to about 90 degrees of revolution or less as measured from the linear axis of the shaft; 3) the threaded shaft has a longitudinal bore there through; 4) the longitudinal bore has two or more openings; 5) at least one of the openings of the longitudinal bore are disposed at or adjacent the head of the threaded shaft; 6) the wing mount comprises a hub and an axle; 7) the wing is flat and its width approximates or is less than the width of the head of the threaded shaft; 8) the pivot wing bolt tissue-tensioning assembly further comprises an installation tool that controls deployment of the wing from a first position parallel to the linear axis of the threaded shaft to a second position not parallel to the linear axis of the threaded shaft; 9) the installation tool has a first end that mates with at least one end of the wing; 10) the threaded shaft passes through the installation tool; 11) the installation tool is a sleeve having a first end that mates with at least one end of the wing; 12) the installation tool is rotated about and pushed along the linear axis of the threaded shaft to deploy the wing from a first position to a second position; 13) the pivot wing bolt tissue-tensioning assembly further comprises a nut assembly engaged with the threaded shaft; 14) the nut assembly is selected from the group consisting of a conventional nut, a split-nut assembly, and a ball-and-socket nut assembly; 15) the split-nut assembly comprises two or more nut sections which form a nut when assembled, the nut having a threaded bore, a first annular groove having a first diameter, and a second annular groove having a second diameter, wherein the second diameter is larger than the first diameter and smaller than the widest diameter of the nut; and a band disposed in either of the first and second grooves to keep the two or more nut sections in assembly; wherein the nut sections are spaced from one another a first distance when the band is in the first groove and in closer proximity or in contact with one another when the band is in the second groove; and optionally wherein the sections of the split-nut are detached from one another or attached to each other by way of a living hinge; 16) the ball-and-socket nut assembly engaged with the threaded shaft comprises an approximately hemispherical convex nut having an internal threaded bore for receiving a threaded shaft; an approximately hemispherical concave socket adapted to receive, mate with and retain the nut, the socket having a slot and hole through a portion thereof for receiving a portion of a threaded shaft engaged with the nut, wherein the slot and hole is smaller in size than the nut; and a flange attached to a portion of the periphery of the socket, the flange having a notch through a portion thereof, wherein the notch is sufficiently large in size to permit passage of the nut into the socket; 17) at least the wing comprises a material that deteriorates in an environment of use; 18) the wing comprises one or more dissolvable or biodegradable polymers; 19) the threaded shaft and the nut assembly are comprised of a material that deteriorates or degrades in an environment of use; 20) the threaded shaft, and optionally the nut, comprise buttress threads; 21) the buttress threads have a long slope on one surface and a short slope on another surface such that the nut sections expand in and out as the nut is moved linearly forward on the threaded shaft; 22) the pivot wing bolt tissue-tensioning bolt is used in conjunction with another tensioning assembly comprising a second threaded shaft having a second tissue retainer at a second end; and a second flanged ball-and-socket nut assembly; 23) the tissue-tensioning bolt assembly further comprises a tissue graft attached to each of the first and second tissue retainers; and/or 24) the tissue retainer is an eyelet or hole.  
           [0047]    According to another aspect, the invention provides a transverse impaction screw comprising:  
           [0048]    a tool engagement means;  
           [0049]    a threaded portion adjacent the tool engagement means; and  
           [0050]    a non-threaded extended member attached to the threaded portion and comprising a flat surface.  
           [0051]    Specific embodiments of the transverse impaction screw include those wherein: 1) the plane defining the flat surface is not parallel to the linear axis of the screw.  
           [0052]    Yet other aspects of the invention provide a suture nut comprising:  
           [0053]    two or more nut sections which form a nut when assembled, the nut comprising a non-threaded bore with a friction surface, a first annular groove having a first diameter, and a second annular groove having a second diameter, wherein the second diameter is larger than the first diameter and smaller than the widest diameter of the nut; and  
           [0054]    a band disposed in either of the first and second grooves to keep the two or more nut sections in assembly;  
           [0055]    wherein the nut sections are spaced from one another a first distance when the band is in the first groove and in closer proximity or in contact with one another when the band is in the second groove; and  
           [0056]    the suture nut is capable of securing a suture when the band is disposed in the second groove.  
           [0057]    Specific embodiments of the suture-nut include those wherein: 1) the suture nut further comprises a second non-threaded bore having a friction surface such that the suture nut can retain at least two suture portions; and/or 2) the bore is non-circular and the suture nut will retain at least two suture portions in the same bore.  
           [0058]    The suture nut is used in a method of suturing an incision comprising the step of clamping one or more portions of a suture with a suture nut according to any one of the one described herein.  
           [0059]    The tissue-tensioning bolt assembly can be used in a method of tensioning a biological tissue comprising the step of retaining and tensioning a biological tissue with a tissue-tensioning bolt assembly according to any of the ones described herein.  
           [0060]    Another flanged ball-and-socket nut assembly comprises:  
           [0061]    a longitudinally split-nut having a convex hemispherical surface having an internal threaded bore for receiving a threaded shaft;  
           [0062]    an approximately hemispherical elongated concave socket adapted to receive, mate with and retain the nut, the socket having a hole and slot through a portion thereof for receiving a portion of a threaded shaft engaged with the nut, wherein the slot and hole is smaller in size than the nut, and wherein the socket has a first larger inner diameter section and a second smaller diameter inner section; and  
           [0063]    a flange attached to the first larger diameter portion at the periphery of the socket, the flange having a notch through a portion thereof, wherein the notch is sufficiently large in size to permit passage of the nut into the socket; wherein  
           [0064]    the socket is adapted to compress the split-nut when the split-nut is engaged with the second smaller diameter inner section of the socket.  
           [0065]    Specific embodiments of the flanged ball-and-socket assembly include those wherein: 1) the sections of the split-nut are longitudinally slidably engaged with each other; 2) the split-nut comprises tool engaging means; 3) the flanged ball-and-socket nut assembly further comprises a sleeve interposed the socket and the split-nut; 4) an outer portion of the sleeve engages the interior of the socket and the split-nut is disposed within a bore in the sleeve; and/or 5) the socket is a compression tower.  
           [0066]    Another embodiment of the pivot wing bolt tissue-tensioning assembly comprises:  
           [0067]    a threaded shaft having a head comprising a wing mount;  
           [0068]    a single wing having an aperture engaged with the wing mount such that the wing is rotatably mounted on the wing mount; and  
           [0069]    a swing stop that limits the rotation of the wing from a first position approximating parallel to the linear axis of the threaded shaft to a second position approximating normal to the linear axis of the threaded shaft; wherein:  
           [0070]    the linear axis of the wing is alignable with the linear axis of the threaded shaft; and  
           [0071]    the swing stop limits the rotation of the wing about the wing mount to less than one revolution.  
           [0072]    Other specific embodiments of the pivot wing bolt tissue-tensioning assembly include those wherein: 1) the swing stop is integral with the wing; and/or 2) the swing stop is integral with the head of the threaded shaft.  
           [0073]    Another embodiment of the split-nut assembly comprises:  
           [0074]    two or more nut sections which form a nut when assembled, the nut having a threaded bore; and  
           [0075]    section retaining means selected from the group consisting of a band, a socket, and a combination thereof;  
           [0076]    wherein the nut sections are spaced from one another a first distance when the section retaining means is engaged with a first portion of the split-nut and in closer proximity or in contact with one another when the section retaining means is engaged with a second portion of the split-nut; and  
           [0077]    wherein the sections of the split-nut are detached from one another or attached to each other by way of a living hinge.  
           [0078]    Other specific embodiments of the split-nut assembly include those wherein: 1) the nut comprises a first annular groove having a first diameter, and a second annular groove having a second diameter, wherein the second diameter is larger than the first diameter and smaller than the widest diameter of the nut, and the section retaining means is engageable with the annular grooves of the nut; 2) the section engaging means is a band disposed in either of the first and second grooves to keep the two or more nut sections in assembly; 3) the section retaining means is a socket having a first larger diameter inner portion, and a second smaller diameter inner portion; and/or 4) the nut comprises a first annular portion having a longitudinally graded diameter and a longitudinally adjacent second annular portion having a longitudinally graded diameter, wherein the larger diameter portion of the second annular portion abuts the smaller diameter portion of the first annular portion, and wherein the section retaining means is a band that is engageable with the first and second annular portions of the nut.  
           [0079]    Other features, advantages and embodiments of the invention will be apparent to those skilled in the art by the following description, accompanying examples and appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0080]    The following drawings are part of the present specification and are included to further demonstrate certain aspects of the invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of the specific embodiments presented herein.  
         [0081]    A. INTERLOCKING NUT—where the sections of the split-nut interlock.  
         [0082]    [0082]FIG. 1 depicts a front elevation view of a shaft sitting in the cup.  
         [0083]    [0083]FIG. 2 depicts a sectional side view of the cup with a side elevation of the shaft.  
         [0084]    [0084]FIG. 2 a  is an inset depicting the threads in circle mm of FIG. 2.  
         [0085]    [0085]FIG. 3 depicts top plan view of the interlocking nut along lines B-B of FIG. 4.  
         [0086]    [0086]FIG. 4 depicts a side elevation view of the interlocking nut of FIG. 3 with the two sections distended or spaced-apart.  
         [0087]    [0087]FIG. 5 depicts a sectional side view of the interlocking nut along lines C-C of FIG. 3.  
         [0088]    [0088]FIG. 6 depicts a top plan view of a rotation (driving, tightening or installation) tool, along lines D-D of FIG. 7.  
         [0089]    [0089]FIG. 7 depicts a side elevation view of the rotation tool of FIG. 6.  
         [0090]    [0090]FIG. 8 depicts a partial top plan view of the interlocking nut and socket and a sectional view of the threaded shaft along lines E-E of FIG. 9.  
         [0091]    [0091]FIG. 9 depicts a partial sectional side view of the interlocking nut and a sectional side view of the cup in a cross section of bone.  
         [0092]    [0092]FIG. 10 depicts a partial top plan view of the interlocking nut and socket and a sectional view of the threaded shaft along lines F-F of FIG. 11.  
         [0093]    [0093]FIG. 11 depicts a partial sectional side view of the interlocking nut and a sectional side view of the cup in a cross section of bone and a side elevation view of the installation tool.  
         [0094]    [0094]FIG. 12 depicts a side elevation view of the interlocking nut and tool and a sectional side view of the cup in a bone, wherein the assembly in shown at two different orientations (incident angles) with respect to the bone.  
         [0095]    [0095]FIG. 13 depicts a sectional bottom plan view of the cutting tool along lines G-G of FIG. 16.  
         [0096]    [0096]FIG. 14 depicts a sectional top plan view of the interlocking nut and socket along lines H-H of FIG. 15 after the sections of the nut have been compressed together by the socket.  
         [0097]    [0097]FIG. 15 depicts a side elevation view of the interlocking nut, tool and tension gauge and a sectional side view of the cup installed in a bone.  
         [0098]    [0098]FIG. 16 depicts a side elevation view of the interlocking nut and cutting tool and a sectional side view of the socket in a bone.  
         [0099]    [0099]FIG. 17 depicts a front elevation view of the interlocking nut installed in the knee of a mammal.  
         [0100]    [0100]FIG. 18 depicts a side elevation view of the interlocking nut and a sectional side view of the cup installed in the knee joint. This figure also depicts a section of threaded shaft and an engaged cutting tool after the shaft has been severed by way of the cutting tool.  
         [0101]    B. BANDED NUT—where the sections of the split-nut are encircled by an elastomeric, resilient or elastic band.  
         [0102]    [0102]FIG. 19 depicts a top plan view of the banded nut along lines K-K of FIG. 20.  
         [0103]    [0103]FIG. 20 depicts a side elevation view of the banded nut of FIG. 19.  
         [0104]    [0104]FIG. 21 depicts a side elevation view of one section of the banded nut and a sectional side view of the band along lines L-L of FIG. 19.  
         [0105]    [0105]FIG. 22 depicts a sectional side view of view of the banded nut along lines J-J of FIG. 19.  
         [0106]    [0106]FIG. 23 depicts a partial sectional side view the banded nut and a sectional side view of a cup installed in a bone.  
         [0107]    [0107]FIG. 24 depicts a partial top plan view of the banded nut along lines M-M of FIG. 23.  
         [0108]    [0108]FIG. 25 depicts a side elevation view the banded nut and rotational tool and a sectional side view of a cup installed in a bone.  
         [0109]    [0109]FIG. 26 depicts the assembly of FIG. 25 except that the threaded shaft and nut shown at two different incident angles with respect to the cup and bone.  
         [0110]    [0110]FIG. 27 is not included herein.  
         [0111]    [0111]FIG. 28 depicts the assembly of FIG. 25 except that the nut has been collapsed and threaded about the shaft to tension the graft engaged with the tissue retainer. The gauge is used to indirectly measure the tension placed on the graft tissue.  
         [0112]    [0112]FIG. 29 depicts a side elevation view of the banded nut and rod and a sectional side view of the cup installed in the knee.  
         [0113]    C. ENCASED NUT—where the cup acts as an encasement for the SPLIT-NUT sections and not necessarily a flanged socket.  
         [0114]    [0114]FIG. 30 depicts a front elevation view of one of the sections of the encased nut along lines P-P of FIG. 32.  
         [0115]    [0115]FIG. 31 depicts a side elevation view of the encased nut sections along lines N-N of FIG. 32.  
         [0116]    [0116]FIG. 32 depicts a top plan view of the encased nut sections.  
         [0117]    [0117]FIG. 33 depicts a sectional side view of the encased nut sections along lines O-O of FIG. 32.  
         [0118]    [0118]FIG. 34 depicts a front elevation view of a shaft and cup assembly place on the surface and within a bone.  
         [0119]    [0119]FIG. 35 depicts a sectional front view of the encasement along lines S-S of FIG. 37.  
         [0120]    [0120]FIG. 36 depicts a sectional side view of the encasement along lines R-R of FIG. 37.  
         [0121]    [0121]FIG. 37 depicts a top plan view of an encasement within which a split-nut of the invention can be placed.  
         [0122]    [0122]FIG. 38 depicts a side elevation view of the threaded rod and a sectional side view of a cup along lines Q-Q of FIG. 34 installed in a bone.  
         [0123]    [0123]FIG. 39 depicts a partial cross section of the encased nut, a sectional side view of the encasement and a sectional side view of the cup installed in the bone.  
         [0124]    [0124]FIG. 40 depicts a partial top plan view of the encased nut along lines T-T of FIG. 39.  
         [0125]    [0125]FIG. 41 depicts a side elevation view of the encased nut and driving tool and a sectional side view of the encasement, cup and bone.  
         [0126]    [0126]FIG. 42 depicts a partial top plan view of the encased nut along lines U-U of FIG. 41.  
         [0127]    [0127]FIG. 43 is not included herein.  
         [0128]    [0128]FIG. 44 depicts a top plan view of the encased nut along lines V-V of FIG. 45. However, the nut is shown in two different laterally displaced positions with respect to the encasement.  
         [0129]    [0129]FIG. 45 depicts a side elevation view of the split-nut, shaft and driving tool and a sectional side view of the encasement, cup and bone.  
         [0130]    [0130]FIG. 46 depicts the assembly of FIG. 45 except that the nut has been collapsed with the encasement and threaded about the shaft to tension the engaged biological tissue.  
         [0131]    [0131]FIG. 47 is not included herein.  
         [0132]    [0132]FIG. 48 depicts the assembly of FIG. 45 after installation into the joint of a mammal.  
         [0133]    D. SIDE PIVOT WING BOLT—where the rod has a single pin on one side to which the wing is secured.  
         [0134]    [0134]FIG. 49 depicts a side elevation view of the side pivot wing bolt assembly.  
         [0135]    [0135]FIG. 50 depicts a sectional side view of the assembly along lines Y-Y of FIG. 49.  
         [0136]    [0136]FIG. 51 depicts a sectional side view of the assembly along lines W-W of FIG. 49.  
         [0137]    [0137]FIG. 52 depicts a side elevation view of the assembly of FIG. 49.  
         [0138]    [0138]FIG. 53 depicts a top plan view of the assembly along lines Z-Z of FIG. 56.  
         [0139]    [0139]FIG. 54 depicts a side elevation view of the wing of FIG. 56.  
         [0140]    [0140]FIG. 55 depicts a side elevation view of the assembly of FIG. 56 except that the wing is being deployed by the deployment tool depicted in a side elevation view as well.  
         [0141]    [0141]FIG. 56 depicts a side elevation view of the assembly of FIG. 55 except that the wing has been completely deployed by the tool.  
         [0142]    E. COMPRESSION TOWER ASSEMBLY—a specific embodiment of the cup (socket) that allows removal of the hardware without additional surgery.  
         [0143]    [0143]FIG. 57 depicts a top plan view of a compression tower and banded-nut and a sectional top plan view of an engaged threaded shaft along lines rr-rr of FIG. 58.  
         [0144]    [0144]FIG. 58 depicts a side elevation view of a banded nut and side pivot wing bolt assembly and a sectional side elevation view of a compression tower after the entire assembly has been installed.  
         [0145]    [0145]FIG. 59 depicts a side elevation view of the compression tower of FIG. 58.  
         [0146]    [0146]FIG. 60 depicts a sectional side elevation view of the compression tower of FIG. 58.  
         [0147]    [0147]FIG. 61 depicts a sectional side elevation view of a bone compression assembly being installed in a fractured elbow.  
         [0148]    [0148]FIG. 62 depicts a side elevation view of prior art devices used to reduce a fractured elbow.  
         [0149]    F. HOLLOW ROD—where the rod has a channel for the delivery of a substance.  
         [0150]    [0150]FIG. 63 depicts a sectional side elevation view of the bone compression assembly of FIG. 58 after is has been installed in a fractured elbow. The threaded shaft has a bore throughout it length to permit delivery of a degrading material to the site where the wing of the assembly is installed.  
         [0151]    [0151]FIG. 64 depicts a sectional side elevation view of the assembly of FIG. 63 except that it is being removed from the bone once the bone has healed and the wings have degraded sufficiently that they are no longer strongly attached to the threaded shaft.  
         [0152]    [0152]FIG. 65 is not included herein.  
         [0153]    G. SWING PIVOT WING BOLT—where the wing can rotate at least or approximately 180 degrees in a transverse direction with respect to the linear axis of the threaded shaft.  
         [0154]    [0154]FIG. 66 depicts a rear elevation view of the swing pivot wing bolt of FIG. 67 wherein the wing is shown in sectional view along lines c-c.  
         [0155]    [0155]FIG. 67 depicts a side elevation view of the swing pivot wing bolt wherein the wing has been deployed transversely to about normal with respect to the linear axis of the shaft.  
         [0156]    [0156]FIG. 68 depicts a side elevation view of an installation/deployment tool.  
         [0157]    [0157]FIG. 69 depicts a top plan view of the tool along lines a-a of FIG. 68.  
         [0158]    [0158]FIG. 70 depicts a sectional rear view the swing pivot wing bolt along line b-b of FIG. 67.  
         [0159]    [0159]FIG. 71 depicts a side elevation view of the swing pivot wing bolt assembly and deployment tool and a sectional view of a fractured femur in which the assembly in being installed.  
         [0160]    [0160]FIG. 72 depicts a sectional side elevation view of the assembly of FIG. 71 except that the deployment tool has been rotated to begin deployment of the wing in the bone.  
         [0161]    [0161]FIG. 73 depicts a sectional side elevation view of the assembly of FIG. 72 except that the deployment tool is deploying the wing.  
         [0162]    [0162]FIG. 74 depicts a sectional side elevation view of the assembly of FIG. 73 except that the wing is even further deployed.  
         [0163]    [0163]FIG. 75 depicts a sectional side elevation view of the assembly of FIG. 74 except that the tool has been rotated back to its original position.  
         [0164]    [0164]FIG. 76 depicts a sectional side elevation view of the assembly of FIG. 75 except that the wing is fully deployed in the femur.  
         [0165]    [0165]FIG. 77 depicts a sectional side elevation view of the assembly of FIG. 76 except that the assembly has been pulled in a direction opposite its installation direction such that the wings engage the inner surface of the femur.  
         [0166]    H. ENCASED SPLIT-NUT METHOD FOR REDUCING A FRACTURED FEMUR.  
         [0167]    This embodiment can be used with all of the various pivot wing bolt embodiments described herein.  
         [0168]    [0168]FIG. 78 depicts a sectional side elevation view of an encased nut assembly comprising a split-nut and an associated flanged cup or encasement installed in one end of the femur, which is also depicted in sectional view.  
         [0169]    [0169]FIGS. 78 b - 78   d  depict a sectional side elevation view of the encasement and a side elevation view of the split-nut of FIG. 78 except that the split-nut is shown in various different stages of installation into the encasement.  
         [0170]    [0170]FIG. 79 depicts the assembly of FIG. 78 installed in a countersunk bore at one end of the femur before the sections of the split-nut have been collapsed.  
         [0171]    [0171]FIG. 80 depicts the assembly of FIG. 79 except that the split-nut has been collapsed.  
         [0172]    [0172]FIG. 81 depicts the assembly of FIG. 80 except that a gauge is used to measure the amount of compression being applied by the assembly to the fractured femur.  
         [0173]    [0173]FIG. 82 depicts the assembly of FIG. 81 in combination with a cutting tool that severs the excess length of threaded shaft after the proper amount of compression is being applied onto the femur by the assembly.  
         [0174]    [0174]FIG. 83 depicts the assembly of FIG. 82 after completion of its installation into the femur.  
         [0175]    [0175]FIG. 83 b  depicts a partial sectional side elevation view an alternate embodiment of the encasement nut assembly comprising an encasement band (shown in section), rather than an encasement cup, and a split-nut. The assembly is shown with the sections of the split-nut spaced apart.  
         [0176]    [0176]FIG. 83 c  depicts the assembly of FIG. 83 b  except that the sections of the split-nut are being compressed by the encasement band and a portion of the split-nut is disposed within a countersunk bore in a bone.  
         [0177]    I. HINGED SPLIT-NUT—where the Split-nut sections are partially joined by a living hing, resilient or pliable material, hinge or other such engagement.  
         [0178]    [0178]FIG. 84 depicts a top plan view of the hinged split-nut along lines M-M of FIG. 85.  
         [0179]    [0179]FIG. 85 depicts a side elevation view of the hinged split-nut of FIG. 84.  
         [0180]    [0180]FIG. 86 depicts a sectional front view of the hinged split-nut along lines N-N of FIG. 84.  
         [0181]    [0181]FIG. 87 depicts a partial sectional view of a hinged split-nut installed in a flanged cup (depicted in section) and a bone. The cup has an inner bore having two different sections: one section with a larger diameter and the other section with a smaller diameter.  
         [0182]    [0182]FIG. 88 depicts the assembly of FIG. 87 except that the hinged split-nut has been engaged with and collapsed by the socket. The driving tool is being used to thread the nut about the threaded shaft.  
         [0183]    [0183]FIG. 89 depicts the assembly of FIG. 88 except that the threaded shaft, hinged split-nut, gauge and driving tool are shown at two different incident angles with respect to the bone.  
         [0184]    [0184]FIG. 90 depicts the assembly of FIG. 89 except that the excess length of shaft has been cut off.  
         [0185]    J. STOP PIVOT WING—where the pivot wing is held at an oblique angle with respect to the rod by a vertical ledge in the pivot wing.  
         [0186]    [0186]FIG. 91 depicts a partial sectional side view of a stop pivot wing bolt, wherein the wing is shown in section and at an angle approximately normal to the linear axis of the shaft.  
         [0187]    [0187]FIG. 92 depicts the pivot wing bolt of FIG. 91 except that the wing is at an angle approximately parallel to the linear axis of the shaft.  
         [0188]    [0188]FIG. 93 depicts a rear sectional elevation view of the pivot wing bolt of FIG. 91.  
         [0189]    [0189]FIG. 94 depicts a side elevation view of the pivot wing bolt of FIG. 91.  
         [0190]    [0190]FIG. 95 depicts a top plan view of the pivot wing along lines g-g of FIG. 94.  
         [0191]    [0191]FIG. 96 depicts a sectional side elevation view of the pivot wing along lines h-h of FIG. 95.  
         [0192]    [0192]FIG. 97 depicts a side elevation view of a stop pivot wing bolt assembly and installation/deployment tool installed within a bone shown in section.  
         [0193]    [0193]FIG. 98 depicts the assembly of FIG. 97 except that the tool has been rotated to effect initial deployment of the pivot wing.  
         [0194]    [0194]FIG. 99 depicts the assembly of FIG. 98 except that the shaft has been pulled partial out of the bore in the bone thereby causing both ends of the pivot wing to engage the surface of the bore.  
         [0195]    [0195]FIG. 100 depicts the assembly of FIG. 99 except that the shaft has been pulled out of the bore a sufficient amount to effect complete deployment of the wing, e.g., until the wing is about normal to the axis of the shaft.  
         [0196]    [0196]FIG. 101 depicts the assembly of FIG. 100 except that a flanged curved socket is being installed at one end of the shaft.  
         [0197]    [0197]FIG. 102 depicts the assembly of FIG. 101 except that a rounded or curved nut is engaged with the shaft.  
         [0198]    [0198]FIG. 103 depicts the assembly of FIG. 102 except that the nut has been engaged with the socket and threaded about the shaft a sufficient amount to provide the desired amount of compression to the fractured bone. This assembly also includes a cutting tools that cuts the excess length of shaft.  
         [0199]    [0199]FIG. 104 depicts the assembly of FIG. 103 during cutting of the shaft with the cutting tool.  
         [0200]    K. STOP ROD PIVOT WING BOLT—where the pin hinge of the shaft is located off-center to the longitudinal axis of the bolt such that head of the bolt engages the pivot wing and maintains the pivot wing at an oblique angle with respect to the longitudinal axis of the bolt.  
         [0201]    [0201]FIG. 105 depicts a partial sectional side elevation view of the stop rod pivot wing bolt assembly comprising a pivot wing and a bolt that are engaged to one another by a hinge located transversely off the linear axis of the bolt.  
         [0202]    [0202]FIG. 106 depicts a rear elevation view of the assembly along lines s-s of FIG. 105.  
         [0203]    [0203]FIG. 107 depicts a front sectional elevation view of the assembly of FIG. 106.  
         [0204]    [0204]FIG. 108 depicts the assembly of FIG. 105 except that the wing is disposed about parallel to the linear axis of the bolt.  
         [0205]    L. AXLE ROD—where the rod has two posts with a transverse beam, serving as the hinge, in between.  
         [0206]    [0206]FIG. 109 depicts a front elevation view of the assembly of FIG. 108 except that a different hinge is being used.  
         [0207]    [0207]FIG. 110 depicts a sectional side view of the assembly of FIG. 109.  
         [0208]    [0208]FIG. 111 depicts an opposite sectional side elevation view of the assembly of FIG. 110.  
         [0209]    [0209]FIG. 112 depicts a side elevation view of the assembly of FIG. 110 except that an installation/deployment tool is engaged with pivot wing and shaft.  
         [0210]    [0210]FIG. 113 depicts a partial sectional front elevation view along lines u-u of FIG. 110.  
         [0211]    [0211]FIG. 114 depicts a front view of the assembly of FIG. 110 along lines t-t.  
         [0212]    [0212]FIG. 115 depicts a rear view of the assembly of FIG. 110 along lines v-v.  
         [0213]    M. AXLE ROD WITH AXLE RECEPTACLE where the assembly comprises a pivot wing and a rod, wherein the rod comprises two connected posts (extended members) and connected by at least two transverse beam such at least one post is disposed at each (opposite) end of the extended member and one of the transverse beams serves as a pivot hinge at one end and the other transverse beams serves as a ligament fastener bar at the other end of the extended members.  
         [0214]    [0214]FIG. 116 depicts a side elevation view of an axle rod assembly and an engaged ligament installed in a bone shown in section.  
         [0215]    [0215]FIG. 117 depicts a front elevation view of the assembly of FIG. 116.  
         [0216]    N. SUTURE NUT—a banded split-nut having an internal friction surface instead of threads and a relatively non-elastomeric band that engages the surface of the sections of the split-nut.  
         [0217]    [0217]FIG. 118 depicts a top plan view of the ring of the suture nut.  
         [0218]    [0218]FIG. 119 depicts a top plan view of the suture nut comprising two nut sections and the ring of FIG. 118.  
         [0219]    [0219]FIG. 120 depicts a side elevation view of the suture nut of FIG. 119 except that the ring, which has a graded inner and optionally outer diameter, is disposed on a lower of two longitudinal sections of the split-nut. The longitudinal sections have a graded outer diameter such that the larger diameter portion of the lower section abuts the smaller diameter portion of the upper section. Overall, the upper section has a larger diameter than the lower section.  
         [0220]    [0220]FIG. 121 depicts the assembly of FIG. 120 except that the ring is shown in section along line w-w of FIG. 119 and the two halves of the split-nut are spaced from one another as they loosely a suture.  
         [0221]    [0221]FIG. 122 depicts a sectional front elevation view along line y-y of the assembly of FIG. 119.  
         [0222]    [0222]FIG. 123 depicts another sectional view of the suture nut.  
         [0223]    [0223]FIG. 124 depicts the assembly of FIG. 120 wherein the ring is being moved longitudinally from the lower longitudinal portion of split-nut toward its upper longitudinal portion.  
         [0224]    [0224]FIG. 125 depicts the assembly of FIG. 124 except that the ring has been moved even further up.  
         [0225]    [0225]FIG. 126 depicts a partial sectional view of the assembly of FIG. 125.  
         [0226]    [0226]FIG. 127 depicts the assembly of FIG. 126 except that the ring has been moved even further up.  
         [0227]    [0227]FIG. 128 depicts a side elevation view of the assembly of FIG. 127.  
         [0228]    [0228]FIG. 129 depicts the assembly of FIG. 128 except that the ring is now fully engaged with the upper longitudinal larger diameter section of the split-nut such that the halves of the split-nut are in contact with one another and the split-nut engages the suture tightly.  
         [0229]    [0229]FIG. 130 depicts a partial sectional side view of the assembly of FIG. 129.  
         [0230]    [0230]FIG. 131 depicts a top plan view of the assembly of FIG. 129.  
         [0231]    O. TRANSVERSE IMPACTION SCREW—wherein the screw comprises a flat surface on a rod such that when the rod is rotated about its linear axis a change in the position of a tissue engaged with the rod is affected.  
         [0232]    [0232]FIG. 132 depicts a top plan view of the transverse impaction screw along lines H-H of FIG. 133.  
         [0233]    [0233]FIG. 133 depicts a side elevation view of a transverse impaction screw having a flat rod portion, a tool-engaging means at one end and a threaded shaft portion interposed the flat rod portion and the tool-engaging means.  
         [0234]    [0234]FIG. 134 depicts a partial front elevation view of the screw of FIG. 133 along lines J-J.  
         [0235]    [0235]FIG. 135 depicts a rear elevation view of the screw along lines G-G of FIG. 133.  
         [0236]    [0236]FIG. 136 depicts a partial sectional front view of the transverse impaction screw as installed in a bone such that the flat rod portion of the screw is disposed within a bore in the bone (shown in section) and engaged with a biological tissue, such as a ligament or tendon.  
         [0237]    [0237]FIG. 137 depicts a side elevation view of the screw, bone and ligament of FIG. 136 wherein the bone is shown in section.  
         [0238]    [0238]FIG. 138 depicts the screw, bone and ligament of FIG. 136 except that the flat surface of the flat rod is disposed transverse rather than parallel to the linear axis bore in the bone.  
         [0239]    [0239]FIG. 139 depicts the screw, bone and ligament of FIG. 137 except that the short (horizontal) axis of the flat surface of the flat rod portion is disposed transverse or about normal to the linear axis of the bore in the bone.  
         [0240]    [0240]FIG. 140 depicts a perspective view of ligament graft engaged with two tissue-retainers according to the invention. The ligament graft forms a double loop.  
         [0241]    [0241]FIG. 141 depicts the ligament graft of FIG. 140 except that the two ends of the graft are sutured together.  
         [0242]    [0242]FIG. 142 depicts the ligament graft of FIG. 141 except that a portion of the adjacent longitudinal edges of the loops of the ligament graft are sutured to each other.  
         [0243]    [0243]FIG. 143 depicts the ligament graft of FIG. 142 except that the loops of the ligament graft have been sutured to each other approximately along their entire length. The loop portions disposed within the tissue retainers may or may not be sutured to each other.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0244]    Although specific embodiments of the invention will now be described with reference to the drawings, it should be understood that such embodiments are by way of example only and are merely illustrative of but a small number of the many possible specific embodiments to which the principles of the invention may be applied. Various changes and modifications obvious to one skilled in the art to which the invention pertains are deemed to be within the spirit, scope and contemplation of the invention as further defined in the claims.  
         [0245]    The Interlocking Split-nut—FIGS.  1 - 18   
         [0246]    [0246]FIG. 1 depicts the open end of the cup  93 , the threaded shaft  12  engaged with the cup and with the ligament graft  27  through the eye  15  of the threaded shaft. FIG. 2 depicts the threaded shaft  12  with threads  8  and eye section  15  attached to ligament graft  27  disposed within the cup  93  (in section) along line A-A. The cup includes a circumferential flange  91  and an inner surface  92  defining a bore in the cup. The bore has two differently-sized sections. The first section proximal to the flange has a larger diameter, and the second section distal from the flange has a smaller diameter. A shoulder region between the first and second sections can have a graded diameter.  
         [0247]    [0247]FIG. 2 a  depicts an inset m-m of the encircled portion from FIG. 2. The inset depicts the buttress threads  8  of the threaded shaft  12 . These threads  8  have a slope  89  that is short and perpendicular, or about perpendicular, to the linear axis of the shaft  12 . The slope  88  is long and disposed at an obtuse angle relative to the shaft  12 . While these threads  8 , referred to as buttress threads, can be regular threads, the preferred embodiment for the threads, when used with a split-nut such  36 , are as depicted in FIG. 2 a.    
         [0248]    [0248]FIG. 3 depicts a top plan view of the interlocking split-nut  36 . It has two sections  1 ,  3  that form a generally donut-shaped nut  36 . The tabs  20  and  21  located on section  3  mate with and engage the depressions  21   a  and  20   a  in section  1 , thereby maintaining the two sections of the split-nut together but in slidable relation to each other. The internal threads  61  are located within the bore  60  of the split-nut. The threads may or may not cover the entire surface defining the bore  60 . The split-nut also includes driving tool-engaging means  22  and  23  that may be female or male engaging means. As depicted, the tool-engaging means are receptacles or recesses that can engage a screwdriver or driving tool  63 , depicted in FIG. 7. The two sections  1  and  3  are distended, or spaced apart, from each other so that if the shaft  12  of FIG. 1 were disposed within the bore  60 , the split-nut would be able to slide longitudinally along the shaft length without having to be turned.  
         [0249]    [0249]FIG. 4 depicts that split-nut  36  with an optionally arcuate outer circumferential surface.  
         [0250]    In FIG. 5, the threads  61  on section  3  preferably do not span the entire 180 degrees surface of the inside diameter of the section. This permits the sliding of the spaced-apart split-nut along the length of the shaft. If the threads were to extend the full 180 degrees, the threads on the sides would not ratchet away from the shaft  12 , preventing the buttress thread from sliding forward.  
         [0251]    The screwdriver  63  depicted in FIGS. 6 and 7 is a round and hollow cylinder that fits over the shaft,  12 . The two prongs (male nut-engaging means)  64  and  65  enter the two slots  22  and  23  in the split-nut and serve to push the nut linearly forward on the threaded shaft  12 . When the sections,  1  and  3  are in the collapsed position, due to an external force such as the force of cup wall  92 , the threads  60  and  61  are in direct contact with the threads  8  of the shaft  12 . As described later, the screwdriver  63  can also be used to turn the nut so that it rotates about the shaft  12 .  
         [0252]    [0252]FIG. 8 depicts the split-nut  36  superposing the socket  93  and engaged with the threaded shaft  12  (shown in section). The threaded shaft  12  is shown in cross section and the threads,  60 ,  61 , are loose against the thread  8  of the shaft  12 .  
         [0253]    [0253]FIG. 9 depicts the assembly of FIG. 8, wherein the threaded shaft  12  passes through the cup  93  and into a bore  53  in a cross section of bone  51 . The bore  53  has been drilled through the bone  51 . The eye (or tissue retainer)  15  of the threaded shaft  12  is disposed within the bore  53  and engaged with the ligament graft  27 . The split-nut is shown in partial cross section with half of section  1  cut away so that the threads,  61  of section  1  is depicted as well as the slot  23  for a prong  64  of the screwdriver  63 .  
         [0254]    The threads  61  of section  1  have short slope  89   a  and long slope  88   a  that are complementary to long slope  89  and short slope  88  of the threads  8  of the shaft  12 . As the long slope  89   a  of section  1  passes the long slope  89  of shaft  12 , section  1 , is pushed radially outward from the longitudinal axis of shaft  12 . As the slope  89   a  of section  1  passes the long slope  89  of shaft  12 , short slope  88   a  of section  1  comes in contact with short slope  88  of shaft  12  and section  1  moves radially inward to the longitudinal axis of shaft  12 .  
         [0255]    Each time the split-nut  36  passes the long slope  89  of the shaft  12 , it moves slowly outward. As the split-nut passes each short slope thread  88  of the shaft  12 , it moves rapidly inward thereby affecting a ratchet-type of motion. Until the section  1  and  3  of the split-nut are pushed by an outside force toward the shaft  12 , the split-nut  36  can move toward the eye  15  of the shaft  12  in this ratcheting motion.  
         [0256]    Because there is no force that keeps the sections  1  and  3  distended, they do not tend to stay distended so that they are prohibited, by the action of the short slope  89  of the buttress threads, from sliding away from the eye  15 . This sliding motion can continue as long as the two sections  1  and  3  of the nut  36  are allowed to distend in the wider diameter section of the cup  93 , prior to coming in contact with the smaller diameter section of the cup  93 .  
         [0257]    [0257]FIG. 10 depicts the assembly of FIGS. 8 and 9, except that the sections  1  and  3  of the split-nut are no longer spaced apart any significant distance. Therefore the threads of the shaft are fully engaged with the threads of the split-nut. At this point, the screwdriver  63  must be utilized to rotate the split-nut and drive it forward, as it will only move forward by rotation about the shaft.  
         [0258]    [0258]FIG. 11 depicts the sections  1  and  3  as they come into contact with the smaller diameter section of the bore  92  of the cup. The sections are compressed toward each other so that the threads  61  and  60  compress against the threads  8  of the shaft  12 . The prongs  64  and  65  of the screwdriver are shown engaged with the mating slots  22  and  23 . The split-nut  36  is rotated until it contacts the most distal end of the socket, i.e., the end nearest the tissue retainer of the shaft, so that the sections  1  and  3  are fully compressed against the shaft  12  and the nut  36  cannot move by ratcheting within the cup  93 .  
         [0259]    The cup  93  is stabilized against the outer surface of the bone by way of the flange. The cup actually sits within the countersink of the countersunk bore  53 . As note in FIG. 12, the shaft and split-nut assembly generally have a ball-and-socket configuration. This swivel action of the nut  36  in the cup  93  is important because the bore  53  may be drilled at a less than optimal angle. In the diagram, this is shown by bores  53   b  and  53   a  within the bone  51 . This swivel is a result of curved surface  92   a  of the nut  36  that abuts against curved surface of the cup  93  at its most distal end. If there were not this ability to swivel, the eye  15  can be pulled laterally away from the longitudinal axis of the threaded shaft  12 , when the bore  53   b  is drilled at this non-optimal angle, causing undue stress on the shaft  12 . The shaft  12  would tend to bend at the eye  15 , since the cup  93  would hold the hinged split-nut  36  stationary while the shaft  12  would be pulled from a different direction. Also note that the screwdriver  63  has a smaller distance between the two prongs  64  and  65 , than is the distance between the receptacles of the nut  36 , so that the screwdriver it will not block the nut  36  from swiveling in the curved  92   a  section of the cup  93 .  
         [0260]    [0260]FIG. 14 depicts the sections  1  and  3  compressed against each other and against the threaded shaft  12 . The prongs,  64  and  65  are shown in cross section inside the grooves  22 ,  23  of the split-nut  36 . The cup,  93 , is shown in cross section at narrow section  92  demonstrating that there is almost no space between the walls  92  of the cup and the nut  36  sections,  1  and  3 .  
         [0261]    [0261]FIGS. 14 and 15 depict the split-nut assembly almost completely installed. The sections of the split-nut are in close contact with one another as they are being forced against each other by the inner surface of the bore in the socket. The proximal end of the ligament graft  27  is attached to one end to the eye  15 , while the distal end (not shown) of the ligament graft extends toward the other end of the bore  53 . Further rotation of the nut  36  causes the eye  15  of the threaded rod  12  to move toward the cup  93  and pull on (apply tension to) the ligament graft  27 . Further clockwise rotation of the nut  36  causes further tensioning of the ligament  27 . Counterclockwise rotation of the nut  36  causes the ligament  27  to loosen. A gauge  82  attached to the threaded shaft  12  measures the tension in the ligament graft  27 .  
         [0262]    By pulling the gauge  82  away from the cup  93 , the gauge can register the tension force that is placed on the ligament graft  27 . After pulling on the gauge, the nut  36  is pulled slightly out of the cup section  92 . The nut  36  is then tightened while the gauge registers the tension force, until the nut  36  sits in the cup  93 . The bone is then put through range of motion, by rotating it against the nearest bone at the nearest joint, and the ligament graft  27  is allowed to stretch and acclimate to its new environment through the movement. The gauge  82  is then pulled away from the cup to the proper tension level and the nut  36  is then tightened until it makes contact with the cup  92 . When the tension appears to be stable, the nut  36  can be loosened one time and the gauge  82  is pulled at the proper tension and the nut  36  is tightened one final time as it sets within the cup  92 . In this fashion, precision tension is applied to the ligament  27 .  
         [0263]    Alternatively, the tension placed upon the ligament could be measured by measuring the compressive force between the outer surface of the nut and the inner surface of the socket. A compressive-force measuring cell would be placed between the nut  36  and the cup walls  92 . The nut would then be tightened until it the proper compression force registers on the measuring device.  
         [0264]    FIGS.  16  depicts the split-nut  36  installed within the cup  93  wherein the gauge  82  has been removed after the ligament graft  27  has depicted that it is stable at the proper tension level. FIGS. 13 and 16 depict the scoring (cutting) tool  73  placed about and rotated around the shaft  12  while the lever  73   a  is pulled in direction p so that the cutting tooth  71  is held against the shaft  12  with pressure and cuts into the shaft  12  with score  80  around the shaft  12 . Once the shaft  12 , is fully scored  80 , the shaft beyond the score  80  is broken off by pulling lever  73   a  sharply, away from the shaft  12 , in direction p. The result of this action is depicted in FIG. 18, with the excess shaft, along with the scoring tool,  73 , being taken away from the cup  93 . An alternative cutting means, instead of a scoring tool  73  that is rotated around the shaft, would be large wire cutter that is used to cut the shaft  12 , beyond the nut  36 . Still another cutting means would be a shearing tool that shears the shaft  12  beyond the nut  36 .  
         [0265]    A close up of the cutting tool  73  and the cut length of shaft  12  at score  80  along lines G-G is shown in FIG. 23. The cutting tooth is shown cutting into the shaft  12 , shown in cross section so that the shaft  12 , is scored  80 .  
         [0266]    A view of the knee, made up of the tibia  51 , femur  52  and an outline of the patella  70 , is shown in FIG. 17. The nut  36  is sitting inside the cup  93 . The patella has been removed and is shown in outline  70 . The ligament graft  27  is also shown in ghost lines inside the bore  51  and  52 , also shown in ghost lines. The graft  27  passes from the tibia  51  to the femur  52  where, also shown in ghost lines is a fastener  52   c  that serves to hold the end of the graft  27  opposite the eye  15 , in the femur  52 .  
         [0267]    [0267]FIG. 18 further depicts the tibia  51  in full cross section and femur  52  in partial cross section with the ligament graft  27  traversing the bore  53  in the tibia and going into a bore into the femur  52 . The ligament graft  27 , as pictured, is constructed to duplicate the Anterior Cruciate Ligament that has been ripped and must be replaced. The kneecap,  70 , is shown in cross section. The cup  93  is shown in cross section with the nut  36  fully seated in the cup  93  and the shaft  12 , cut nearly flush to the nut  36 . The ligament graft,  27 , by virtue of the rotation of the nut  36  on the threaded shaft  12 , has tightened the ligament graft  27  to the optimal level. The ligament  27  keeps the bones  51  and  52  stable against each other with proper pressure so that the patient has a stable knee.  
         [0268]    The Banded Split-nut—FIGS.  19 - 28 .  
         [0269]    The banded split-nut  46  depicted in FIGS.  19 - 22 . The split-nut has two sections  2  and  4  distended (spaced apart) from each other. The band  5  is elastomeric (resilient or elastic) in nature and is shown in the stretched position due to the distension of the section  2  and  4 . The threads  61  of section  4  partially cover the 180 degrees of the inside diameter. Slots  22  and  23  are adapted to receive the screwdriver prongs  54  and  65  of screwdriver  63 .  
         [0270]    [0270]FIG. 20 depicts a side view of the split-nut  46 . The banded split-nut  46 , in the distended position, is depicted in FIG. 22 with sections  2  and  4  in cross section, along lines J-J of FIG. 19. The band  5  is also shown in cross section.  
         [0271]    A view of section  4  with the slot  23  is depicted in FIG. 21, with the band  5  cut along lines L-L of FIG. 19. The threads  61  of the banded split-nut  46  do not extend the full  180 -degree curvature of the inside diameter of the nut  46 . This is to allow the two sections,  2  and  4 , to expand and contract along a threaded shaft as they move linearly forward on the shaft toward the eye  15 .  
         [0272]    In FIG. 23, the banded Split-nut  46  is shown sliding longitudinally forward on the threaded shaft  12 . Since the band  5  is elastic, the threads of sections  2  and  4  continually hug the threads  8  of the shaft  12 . The threads  61  of section  4  have short slope  89   a  and long slope  88   a  that are reciprocal to long slope  89  and short slope  88  of the threads  8  of the shaft  12 . As long slope  89   a  of section  4  passes the long slope  89  of shaft  12 , section  4 , is pushed radially outward from the longitudinal axis of shaft  12 . As slope  89   a  of section  4  has passed long slope  89  of shaft  12 , short slope  88   a  of section  4  comes in contact with short slope  88  of shaft  12  and section  4  moves radially inward to the longitudinal axis of shaft  12 . As the split-nut  46  passes the long slope  89  of the shaft  12 , it moves slowly outward. As the split-nut passes each short slope thread  88  of the shaft  12 , it moves rapidly inward. Until the section  4  and  3  of the split-nut are pushed by an outside force toward the shaft,  12 , the split-nut  46  can move toward the eye  15  of the shaft  12  in this ratcheting motion.  
         [0273]    Because band  5  is elastomeric, sections  2  and  4  do not stay distended after slope  89   a  passes slope  89 . Section  4  is prohibited, by the action of the short slope  89  of the buttress threads, from sliding in an opposite direction, away from the eye  15 . The ratchet sliding motion toward eye  15  can continue as long as the two sections  2  and  4  of the nut  46  are in the wider diameter section of the cup  93 , prior to coming in contact with the smaller diameter section of the bore  92  of the cup  93 . FIG. 24 depicts a top plan view of the banded split-nut of FIG. 23.  
         [0274]    At this point, the operation of the banded split-nut is similar to that of the split-nut depicted in FIGS.  8 - 18 . Accordingly, operation of the banded split-nut is depicted in FIGS.  25 - 29 . In FIG. 25, the banded split-nut is in the smaller diameter section of the bore  92  of the cup  93  so that the sections  2  and  4  are compressed by the walls of the cup  93 . At this stage, there is no room for the sections  2  and  4  to expand outward, so they remain collapsed against the threaded shaft  12 . A screwdriver  63  is required to turn the nut  46  so that it moves in a rotational fashion forward into the cup  93 . When the nut  46  is seated in the bottom section  92  of the cup, it can swivel in the cup  93  so that if the bore  53   b  is too high or too low,  53   a , the shaft  12  can swivel inside the cup  93 , along with the screwdriver.  
         [0275]    Due to the rounded and curved surface construction of the banded split-nut, the nut and socket form a ball-and-socket type of joint. Although preferred, it is not necessary for the curved outer surface of split-nut to be complementary to the curved inner surface of the bore. Accordingly, FIG. 26 depicts the split-nut and shaft assembly disposed at various incident angles with respect to the surface of the bone, while maintaining the relative incident angle of the socket approximately constant.  
         [0276]    Operation of the ball-and-socket assembly of FIG. 28 with a tension-measuring gauge is similar to operation of the ball-and-socket assembly of FIG. 15. After achieving the precise tension on the ligament graft, the excess length of shaft is cut with a cutting tool (as depicted in FIG. 16). Completed installation of the assembly is depicted in FIG. 29.  
         [0277]    The Encased Split-nut—FIGS.  30 - 48 .  
         [0278]    FIGS.  30 - 33  depict various different views of an encased split-nut. In FIG. 32, the two sections  6  and  7  of the split-nut  48  include threads  40  that, however, do not cover the full 360 degrees of the inner surface of the bore of the nut. This incomplete thread coverage permits movement of the section from the collapsed to the distended position. The split-nut comprises external paired radially rounded portions  18   a  and  19   a  and paired flat portions  13  and  14 . In this embodiment, the individual members of the pairs are opposing.  
         [0279]    [0279]FIG. 30 depicts a front elevation of section  7  along lines P-P with flat sections  13  and  14  and threads  40  that cover only a portion of inside diameter area  40 .  
         [0280]    [0280]FIG. 31 depicts a side elevation of the two sections  6  and  7  along lines N-N, with flat surface  14  of section  7  and flat surface  14   a  of section  6 . Note that the encased split-nut has a longitudinally curved outer surface as well. Therefore, the assembled split-nut forms a ball-shaped or about hemispherical nut having two opposing surfaces flattened.  
         [0281]    [0281]FIG. 33 depicts the two sections  6  and  7  of the split-nut  48  in cross section along lines O-O. The threads  40  are depicted with their buttress configuration with long slope  88   a  and short slope  89   a . These buttress threads,  40  are reciprocal to those of the threads  8  of the shaft  12 , as depicted in FIG. 34. Also depicted in FIG. 33 is the side profile of curve  18   a  of section  6  and curve  19   a  of section  7 . These curves,  18   a  and  19   a , allow the Split-nut  48  to swivel when sitting in a curved encasement  95  with curves  18   b  and  19   b  as depicted in cross section R-R of FIG. 36.  
         [0282]    [0282]FIG. 34 depicts the threaded shaft  12  with its eyelet  15  engaging a ligament graft  27 . The shaft passes through the cup  55  and by way of the hole  74 . This cup  55  holds the encasement  95 , depicted in FIGS. 36 and 37. The encasement comprises inner flat sections  83  and  84  that are complementary to and compress the flat sections  13 ,  13   a ,  14  and  14   a  of the split-nut. These flats cause sections,  6  and  7  rotate around shaft  12  clockwise as the encasement  95  rotates clockwise, and counterclockwise when the encasement  95  is rotated counterclockwise. The rounded sections  18   a  and  19   a  of the split-nut fit against rounded casement edge  96  and  97 , respectively, depicted in FIG. 37 when the split-nut  48  is in the upper section of encasement  95 . As noted, when the split-nut  48  edges  18   a  and  19   a  are against edges  18   b  and  19   b  of FIG. 36, the split-nut  48  can swivel in the encasement  95 . Flat wall edge  83  is about parallel to flat wall edge  84 . These two flat walls,  84  and  83  cause the split-nut  48  to rotate in the same direction that the encasement  95  rotates. Curves wall edge  97  is opposite curved wall edge  96 . These two curved walls allow the split-nut sections  48  to swivel back and forth while sitting in the cup  95 .  
         [0283]    [0283]FIG. 36 depicts a cross-section of the encasement  95  along lines R-R of FIG. 37. FIG. 35 depicts a cross-section of the encasement  95  along lines S-S of FIG. 37. In this cross section, flat edge  84  is adjacent flat edges  14  and  14   a  of the sections  6  and  7  respectively. Flat edge  85  is adjacent flat edges  13  and  13   a  of sections  6  and  7  respectively. As the encasement  95  is rotated clockwise, flat edges  84  and  85  push against the flat edges  14 ,  14   a ,  13  and  13   a  of sections  6  and  7 , causing the sections to rotated clockwise. As the encasement  95  is rotated counter clockwise, flat edges  84  and  85  push against the flat edges  14 ,  14   a ,  13  and  13   a  of sections  6  and  7 , causing the sections to rotated counterclockwise.  
         [0284]    [0284]FIG. 38 depicts the threaded shaft  12  placed in a cup  55  that is designed to hold encasement  95  and allow the encasement to rotate either clockwise or counter clockwise. The purpose of cup  55  is to keep the encasement  95  at a specific angle N relative to the bone surface  55   a . The threaded shaft  12  and ligament graft  27  are located within a countersunk bore  53  that has been drilled in the bone  51 . Cup  55  is particularly important when bone  51  has a soft inner consistency but a hard surface along surface  55   a . In this case, cup  55  not only holds the encasement  95  at the proper angle N relative to the bone surface  55   a , but also prevents the encasement  95  from working its way into the soft bone. Ballast against sinking in the bone  51  is provided by the greater surface area across the bone surface  55   a  by the flanged edges  55   b  and  55   c.    
         [0285]    The split-nut  48  and the encasement  95  are together referred to as the encased split-nut  201 . Operation of the encased split-nut (depicted in FIGS.  39 - 48 ) is different than operation of the previously described embodiments. FIG. 39 depicts the encased split-nut  201  placed on shaft  12  with sections  6  and  7  held loosely in register against the threads  8  of the shaft  12 . As is noted, the thread  8  of the shaft  12 , are buttress in nature, and the thread  40  of the section  7 , is a reciprocally threaded buttress thread. At this stage, the encasement  95  is placed on the shaft  12  and pushed into the cup  55 . Sections  6  and  7  move forward as they pass each thread of the buttress thread of the shaft in the ratcheting motion previously described. The encased split-nut  201  is pushed up the shaft  12  until it rests inside the cup  55 .  
         [0286]    A top plan view of the cup  55  along lines T-T of FIG. 39 is depicted in FIG. 40. Note that the sections  6  and  7  can move outward or inward against the shaft as there is room within the encasement  95  for this movement when they are near edges  96  and  97 . The top of the split-nut also has optional driving-tool engaging means.  
         [0287]    In FIGS. 41 and 42, the torque (driving) tool  136  is a hollow tube with an outside square or rectangular shape. This tool  136  can be placed within the encasement  95  so that its flat sides,  84   a  and  85   a  lie against the flat edges  84  and  85  respectively of the encasement  95 . As the torque tool,  136  is rotated clockwise, the encasement,  95  rotates clockwise around the threaded shaft  12 . As the encasement  95  rotates clockwise around the shaft  12 , the threads  40  of the section  6  and those of section  7  rotate around the threads  8  of the threaded shaft  12 . As these two sections,  6  and  7  rotate with the encasement  95 , the two sections  6  and  7  move linearly in an upward direction, away from edges  96  and  97  with respect to the encasement  95 . With rotation of encasement  95 , while in cup  55 , the sections  6  and  7  linearly traverse the distance from edges  97  and  96  until they sit in aperture  66 . With this type of construction, the driving tool need not directly engage the split-nut; however, FIG. 41 depicts optional nut-engaging means at one end of the driving tool. When present, the nut-engaging means could engage the driving tool-engaging means on the upper end of the split-nut.  
         [0288]    [0288]FIGS. 44 and 45 depict the encased split-nut after the encasement  95  has fully engaged the cup and more particularly after a peripheral outwardly extending flange on the encasement has engaged an inwardly extending shoulder or seat in the bore of the cup, thereby stopping any further penetration of the encasement into the cup. However, the split-nut can continue to be threaded on the shaft along the length of the shaft. The two sections  6  and  7  are seated at the front  66  aperture of the encasement  95  so that the two sections  6  and  7  are collapsed against the threaded shaft  12  by the narrow walls,  18   b  and  19   b  of the encasement  95 . The shaft and split-nut maintain their ball-and-socket relationship and swivel action within the encasement  95  as the shaft  12  moves toward and away from the longitudinal axis of the cup  55 .  
         [0289]    [0289]FIG. 46 depicts operation of the encasement split-nut with a tension gauge. The sections  6  and  7  are located in the front area  66  of the encasement  95  and a tension gauge  82  is attached to the shaft  12 . By pulling on the gauge,  82  in a direction away from the graft  27 , the encasement nut  201  is pulled out of the cup  55 . The proper tension is placed on the ligament graft  27  and the rotation tool  136  is rotated so that the encasement nut  201  is tightened until it sits in the cup  55 . The bone  51  is then put through range of motion with respect to the adjacent bone by moving the intervening joint. The ligament graft  27  is allowed to stretch and acclimate itself through this movement. The gauge  82  is then again pulled away from the cup to the proper tension level so that the encased split-nut  201  pulls slightly out of the cup  55 . The rotation tool  136  is again rotated until the Encased Split-nut  201  seats in the cup  55 . When the tension appears to be stable and at the precise required level, the Encased Split-nut  201  can be loosened one last time and the gauge  82  is pulled at the proper tension. The Encased Split-nut  201  is then tightened one final time so that it sets within the encasement  95 .  
         [0290]    An alternative tension measuring means would be to place a load-measuring cell  623  attached to a measuring gauge  624  between the encased split-nut  201  and the cup  55 . The pressure of the encased split-nut  201  against the load-measuring cell would give an ongoing reading of the pressure between the encased split-nut  201  and the cup  55 , indicating the exact tension in the ligament graft  27 . With such a load cell, loosening of the encased split-nut one final time would not be necessary as the gauge  624  would already indicate the tension within the ligament graft  27 .  
         [0291]    With the tension in the ligament graft  27  stable and at the correct level, a cutting tool, such as the one depicted in FIG. 16 would be used to cut the excess length of shaft. FIG. 48 depicts the ligament graft  27  in a tibia  51  and passing through the bore  53  across the joint and into the femur  52  that is shown in partial cross section. The ligament graft  27  is attached to the eye  15  of the threaded shaft  12  that is surrounded by sections  6  and  7  of the nut  201  that is sitting in the encasement  95  that is in turn sitting in the cup  55 .  
         [0292]    Compression Rod with Side Pin Wing—FIGS.  49 - 64 .  
         [0293]    A compression rod with side pin wing  182  is depicted in FIGS.  49 - 58 . The threaded shaft  12  has buttress threads  8 , a wing  193  attached to the flat section  35  of the shaft  12  at the pin hinge  105 . The cross section of the pin hinge  105  along lines Y-Y of FIG. 49 is depicted in FIG. 50 with the pin hinge  105  integral with flat section  35  and the wing  193  is not shown. Note that flat surface  11   9   a  of the pin hinge  105  rests against flat edge  119  of the wing  193  to keep the wing  193  flush against the flat surface  119   c  of the flat area  35  of the shaft  12 . The flat section  35  has a stop  31  that protrudes from the flat section  35  of the shaft  12 . This stop  31  is depicted in FIG. 51, which is a cross section along line W-W of FIG. 49. The opposite side of the compression rod as shown in FIG. 49 is depicted in FIG. 52. Here the flat section  35 , is shown fully, and it is integral and an extension of the shaft  12 . Added to the diagram is the pushing (installation) tool  108  that serves to push the wing  193  into position.  
         [0294]    The wing  193  is depicted in FIG. 54 with the pin hinge  105  removed. The hole  64  for the pin hinge  105  is exposed and the shoulder  119  for the pin hinge is depicted. FIG. 53 depicts a top plan view of the compression rod of FIG. 56. FIG. 55 depicts the compression rod  182  with the wing  193  being pushed toward the perpendicular position by the action of the pushing tool  108 . The upper edge  191  of tool  108  cams against the curved edge  192  of the wing  193  and then along straight edge  192   a , pushing the wing  193  toward the perpendicular position in respect to the shaft  12 . The stop  31  serves to keep the wing  193  from rotating past the perpendicular by its action against the adjacent lower edge of the wing,  31   a , which is along edge  192   a.    
         [0295]    The compression rod  182  depicted in FIG. 58 shows the wing  193  deployed into perpendicular to the shaft  12 . The surface  3  la is located on the edge  192   a  and pressed against stop  31  that is located on the flat  35  portion of the shaft  12 . Threads  8  on shaft  12  stop at curved surface  12   a  where the curved edge  192  of the wing  193  was situated when the wing  193  was parallel to the shaft  12 .  
         [0296]    An additional feature included with the compression rod is a compression tower  119  with prongs  115 ,  116 ,  117  and  118  as depicted in FIGS. 59 and 60. The compression tower depicted in FIG. 60 with the cup  119  being rounded so that the banded split-nut  5  of FIG. 58, can fit into the cup  119  and can swivel within the cup  119 .  
         [0297]    If the compression tower&#39;s longitudinal axis is not exactly aligned with the longitudinal axis of the shaft  12 , the eye  15  can be pulled laterally away from the longitudinal axis of the threaded shaft  12  causing undue stress on the shaft  12 , if the compression tower is not present. The shaft  12  would tend to bend as it exits the nut  136 , as the cup  93  would hold the split-nut  46  stationary while the shaft  12  would be pulled from a different direction.  
         [0298]    The purpose of the compression tower is to keep the fastener,  5 , external to the skin so that the entire compression rod assembly can be removed from the bone without making a large incision in the skin for the nut  136  to be removed. This will be depicted in the upcoming diagrams.  
         [0299]    [0299]FIG. 62 depicts an elbow fracture  184  that spans the narrow region of the ulna bone just below the joint, where the ulna joins the humerus  175 . A conventional method of fixating (reducing) this fracture is depicted FIG. 62. Two thick wires, referred to as Kirschner wires,  198  and  197 , are placed through the ulna bone, across the fracture  184 . These serve to align the bone portions. A thin stainless steel wire is looped through holes drilled in the bone and tightened to bring the fracture  184  together. The length of the incision  101  is often between five and seven inches and results in a long period of physical therapy to keep the post-surgical scar from inhibiting joint motion.  
         [0300]    In FIG. 63, the compression rod assembly  182  is fully installed within the ulna. The wing  193  is perpendicular to the shaft  12  and abuts against the hard bone surface  336  within the bone of the elbow joint. The wing  193  is kept from rotating past the perpendicular by the action of the stop  31 . The compression tower  119  is placed so that the pins  117  and  115  pierce the skin  196  and rest against the bone surface  368  of the below bone  176 . In this way, the banded split-nut  136  is held above the level of the skin and can be removed from the shaft  12  without having to make a large skin incision. After the compression rod assembly  182  is fully installed, the fracture  184  is fully compacted and the nut  136  in the compression tower is fully tightened, the shaft,  12 , is cut to size. This feature allows a one-size-fits all fastener bolt thereby providing a savings to a hospital by reducing inventory and storage space and eliminating the need for multiple sizes of fixation rods.  
         [0301]    In FIG. 63, the shaft  12  has a channel  189  through it. This channel is used for introducing a catalyst that will help to dissolve the wing  193  when it is manufactured from dissolvable materials. In this fashion, a relatively strong dissolvable material, that tends not to easily dissolve, can be used for the wing  193 . After the fracture  184  has healed, the catalyst is introduced through the channel  189  so that it engulfs the wing  193  and causes it to dissolve more rapidly. Additionally, if the shaft  12  is manufactured from dissolvable material, the catalyst will cause the rod to dissolve. According to another embodiment, the wing is made of a biodegradable material that is metabolized or degraded over a period of time during which the bone heals.  
         [0302]    [0302]FIG. 64 depicts the compression rod assembly  182  being removed from the bone. After the wing  193  has sufficiently dissolved, the shaft  12  is pulled from the bore  189  so that the wing  193  breaks and is left in the bone  176  to further dissolve. The banded split-nut  136  and the compression tower  119  are removed along with the shaft  12  without making a large incision  186  for removal.  
         [0303]    Balanced Pivot Wing Assembly of FIGS.  66 - 77   
         [0304]    In FIG. 67, the balanced pivot wing assembly  146  includes a pivot wing  145  that pivots and is held against the shaft  12  by the pin hinge  166  that is shown in the longitudinal center of the pivot wing  145 . The pivot wing has a bore  147  that together with the pin  166  defines a hinge. The ends of the wing include irregular V-shaped profiles such that one leg of the V is longer than the other.  
         [0305]    [0305]FIG. 66 is a cross section of FIG. 67 along line b-b. FIG. 66 shows that the pivot wing  145  is boat-shaped or U-shaped. FIG. 70 demonstrates that the pivot wing  145  rotates around the shaft  12  via pin hinges  166  and  167  that protrude through the walls of the wing.  
         [0306]    [0306]FIG. 68 depicts the tool  138  having a beveled end  144 . The tool  143 , as depicted in FIG. 69, is a tube that fits around the shaft  12  of the balanced pivot wing assembly.  
         [0307]    FIGS.  71 - 77  depict the procedure for installation of the balanced pivot wing assembly  146 . In FIG. 71, the beveled end of the tool is shown engaged with V-shaped end  312  of the pivot wing  145 . The tool is used to keep the pivot wing parallel to the shaft  12  during installation until the wing is ready to be deployed into a position that is substantial perpendicular to the shaft  12  as depicted in  67 . Note that the apex of the end  312  of the pivot wing  145  does not line up with the center of the pin hinge  166  that holds the pivot wing to the shaft. This design permits the beveled end  144  to maintain the pivot wing  145  parallel to the shaft  12  during insertion in the bore  153  in the bone  151  and subsequently drive the pivot wing into a deployed position.  
         [0308]    [0308]FIG. 71 depicts the pivot wing  145  being held parallel to the shaft  12  by a tool  138  while it is inserted into a bore  153  that has been drilled into the femur  151 , thereby preventing the pivot wing  145  from moving in a clockwise rotation around the pin  166 . The Pivot wing,  145 , is prevented from rotating in the counterclockwise fashion by the action of its boat shape, as depicted in FIG. 66, as the bottom of the boat  313 , comes against the shaft,  12 .  
         [0309]    In FIG. 72, the tool has been removed from close contact with the pivot wing  145  and has been rotated 180 degrees around the axis of the shaft  12 . In FIG. 73, the beveled edge  144  of the tool, in its turned around position, is driven against the pivot wing  145  causing it to rotate in a clockwise fashion and deploy into an angle that is oblique with respect to the linear axis of the shaft.  
         [0310]    The pivot wing  145 , as depicted in FIG. 74, rotates until its long edge  314  is flush against the end  144  of the tool  138 , and the pivot wing  145  is at an oblique angle with respect to the shaft  12 . In FIG. 75, the tool has been rotated about 180 degrees again. The end  144  is used to further coax the pivot wing  145  to the perpendicular position as depicted in FIG. 76.  
         [0311]    When the pivot wing  145  is fully rotated so that the pivot wing  145  is approximately perpendicular to the shaft, the shaft  12  is pulled upward from the bone to impact the pivot wing  145  into the hard bone  124  and  125  on either side of the condyles of the femur  151  (FIG. 77). This serves to reduce the fracture  111  of the femur  151  so that the adjacent bones portions contact against each other at the fracture line  111  thereby closing this gap.  
         [0312]    With the pivot wing  145  fully impacted into the bone walls,  124  and  125 , attention is directed to the opposite end of the shaft  12 .  
         [0313]    Alternate Encased Split-nut Fastener.  
         [0314]    FIGS.  78 - 82  describe the use of an alternate embodiment of the encased split-nut fastener with the balanced pivot wing assembly. The encased split-nut  201  can be utilized in a harder bone, such as the femur  151 . In this embodiment, the encasement  95  includes shoulders  153   c  and  153   d  and the cup  55  (FIGS.  39 - 45 ) is not required, since the outer surface of the bone provides sufficient ballast to keep the encasement  95  from sinking into the bone during installation of the device. The surfaces  153   c  and  153   d  are generally perpendicular to the long axis of the bone  151 , so there is no need to use a cup  55  to hold the encasement  95  at a specific angle. The countersink  153   a  of the countersunk bore  153  is sufficiently large to receive the encasement  95  without the aid of a cup  55 ; however, the counter sink will generally be smaller in diameter than the circumferential flange comprising the shoulders  153   c  and  153   d.    
         [0315]    As depicted in FIG. 78, the bone  151  has a countersunk longitudinal bore  153  which has a cup-shaped countersink  153   a  at the entrance to the bore. This cup shape  153   a  is designed to receive the encased split-nut fastener  201  with its two sections  6  and  7  that were depicted in FIG. 32. This Encased split-nut is a securing means that is introduced onto the shaft  12  at the end opposite the pivot wing  145 . Note that the encasement  95  inserts directly into the bone  153 , rather than into a frame  55  as in FIG. 39. The encasement  95  is first slid along the shaft  12  until it sits in the prepared bore in the bone  51  as depicted in FIG. 79. The encasement  95  is rotated so that the sections  6  and  7  of the split-nut rotate with the encasement and move deep into the encasement as depicted in FIG. 80.  
         [0316]    In FIG. 81, a force gauge  82  has been placed between the encasement  95  and the bone  151  to measure the amount of compressive force that is exerted on the bone by the combined action of the encased split-nut and the pivot wing assembly. This gauge can also be inserted between the encasement  95  and the sections  6 , 7  of the split-nut, to register the compressive forces. Based upon the reading of the gauge  82 , the fastener  201  can be loosened or tightened until the exact pressure is reached and remains stable.  
         [0317]    [0317]FIG. 83 depicts the pivot wing  145  fully seated against the hard bone  124 ,  125  and the encased split-nut  201  in the femur  151 . Rotating the encasement  95 , causes further movement of the shaft so that the pivot wing,  145 , exerts pressure on the bone walls,  124 ,  125 , as depicted in FIG. 83, where the fracture  111  gap has decreased in size. With the bone  51  fully fastened, the shaft  12  can be cut to size. In FIG. 82, the tool  73  creates a score  80  in the shaft,  12 . And as shown previously as in FIGS. 18 and 29, the excess shaft,  12 , is snapped off so that the shaft  12 , is at the correct length so that it doesn&#39;t protrude while it holds the bone  151  together until it heals. Instead of a cutting tool that is rotated around the shaft, a large wire cutter or shearing tool can be utilized.  
         [0318]    As in FIG. 83, further rotation of the encasement,  95 , causes the shaft to move upward, causing the pivot wing,  145  to impact into the bone walls,  124 ,  125 . This in turn causes the fracture  111  to reduce in size, and align the bone  151  along the shaft. To prevent friction from developing between the encasement  95  and the bone  151 , as the encasement  95  is rotated in the bone, a washer  95  can be provided as an interface between the cup  95  and the bone  151 .  
         [0319]    The Pivot wing, firmly embedded in the bone  124 ,  125 , helps prevent the bone from twisting at the fracture  111 , meaning that the upper half and lower half of the bone will not twist about their linear axes with respect to one another.  
         [0320]    The Pivot wing  145 , if made of metal, is removed using the tool  138 , to rotate the pivot wing  145  it counter clockwise and hold it during removal so that the pivot wing,  145  is parallel to the shaft,  12 . Alternatively, if the pivot wing  145  is made of dissolvable material, it will dissolve over time. The shaft  12  can be made with a hollow channel such as channel  226  of FIG. 63 whereby a catalyst is introduced to cause the pivot wing  145  to dissolve. With the pivot wing,  145 , dissolved, the shaft,  12  and the split-nut,  201 , can be pulled together out of the bore,  153  in the bone,  151 , after healing of the fracture,  111 , has occurred. Still another embodiment would have the shaft  11  and pivot wing  145  made of dissolvable materials that would dissolve over time with or without the aid of a catalyst.  
         [0321]    The arrangement, where the shaft  12  is metal and the pivot wing  145  is dissolvable, allows the shaft,  12 , to withstand the greatest forces along the length of the bone,  151 , particularly at the fracture  111  edges. The pivot wing,  145 , made from weaker dissolvable material, is not subjected to the forces of those of the shaft,  12 , during weight bearing on the limb. Its purpose is merely to provide the proper level of compression between across the fracture  111  line. Hence it can be made of weaker dissolvable polymers.  
         [0322]    An alternate embodiment of the encased split-nut assembly is depicted in FIGS. 83 b  and  83   c . In this embodiment, the encasement is a washer  955 . The bone is countersunk with the bore  153  such that the countersink  153   e  is rounded. The washer is placed over the shaft  12  and then the split-nut is placed over the shaft. The split-nut is then pushed down the length of the shaft and engaged with the washer and the countersink. The encased split-nut assembly so formed could be tightened by rotating the washer, if the washer has driving tool engaging means, or by rotating the split-nut, if the split-nut has driving tool engaging means.  
         [0323]    While the balanced pivot wing assembly  145  is used in reducing and fixating the fracture  111  of the femur, other compression rods described herein, having a single wing of almost any design, would work well.  
         [0324]    Hinged Split-nut—FIGS.  84 - 90 .  
         [0325]    FIGS.  84 - 86  depict a hinged split-nut  46  comprising two sections  2 ,  4 , held together by a living hinge  147 . The top plan view, along lines M-M, is shown in FIG. 84. The hinge comprises a pliable or resilient material. Although a living hinge is depicted, an articulating hinge, where sections  4  and  5  are separate and abut each other or are joined by a rotational hinge connection, could be used as well. The hinged split-nut has ridges  122 ,  123  that receive a rotation tool. The threads  350  and  350   a  generally do not extend fully around the inside bore of the nut  147 . This allows the sections  4  and  5 , when separated, as in FIG. 85, to slide along the shaft  12  while the threads,  350  and  350   a , do not contact the threads  8  of the shaft.  
         [0326]    The hinged split-nut is depicted in cross section in FIG. 86, along lines N-N of FIG. 84. The raised ridge  123  engages with a driving tool that turns the hinged split-nut  137 . The area where section  4  joins to section five is shown in cross section by hatch areas  147  and  147   a.    
         [0327]    Operation and installation of the hinged split-nut is very similar to that of the banded split-nut and the split-nut described above. FIG. 87 depicts a cross section of bone  51  having a countersunk bore  53 . The assembly includes the cup  93  in which is seated the nut  46  and the shaft  12 . The shaft has an eye-type of tissue retainer  15  to which the ligament graft  27  is attached. The hinged split-nut  46  slides linearly along the threaded shaft  12  into the cup  93 . The nut section  4 , is shown in partial cross section so that the threads  350  are visible. The threads  350  of this section do not touch the threads  8  of the shaft  12 , so that it moves linearly forward or backward. Alternatively, the angle between the sections  4  and  5  can be reduced so that the nut  46  moves along the shaft  12 , toward the eye, with the ratcheting motion described previously.  
         [0328]    In FIG. 88, the hinged split-nut  46  has moved into area  92  of cup  93  where the walls are thicker. The area  92  has a smaller diameter than the area adjacent the flanges of the cup and cause the sections  4 ,  5  of the hinged split-nut to be compressed together. As in other embodiments described herein, once the sections  4 , 5 , are compressed, the nut can only rotate about the shaft in order to move along the length of the shaft. Sections  4 , 5  of the hinged split-nut  46  have ridges  122 ,  123  that engage receptacles in the driving tool  63  depicted. The driving tool  63  is used to rotate the nut  46  clockwise so that it moves linearly toward the eye  15  of the shaft  12  and into the narrow portion  92  of the cup  93 .  
         [0329]    The hinged split-nut  46  is rotated with the rotation tool  63  about the shaft until, as in FIG. 89, it seats in the narrow portion  92 , of the cup  93 . Here, the sections,  4  and  5  are fully compressed against the threads  8  of the shaft  12 . Further rotation of the Hinged Split-nut  46  causes the eye  15  of the shaft  12 , to move toward the cup  93  creating more tension on the ligament graft  27  that sits in bore  53 , in a cross section of bone  51 . The spherical nature of the Hinged Split-nut  46  allows it to swivel within the curved section  92  of the cup  93 , so that if the bore  53 , is drilled at a skewed angle such as  53   a  or  53   b , the shaft  12  and eye  15 , can swivel to accommodate the angle. The rotational tool  63  that has captured ridge  123  and ridge  122  does not impede the swivel action. As the nut  46  swivels, the tool  63  generally does not contact the walls of the cup  93 . Were the rotational tool to hinder the swivel action of the nut  46 , the shaft  12  would bend at the nut as it assumes a different angel than that of the nut  46 .  
         [0330]    The tension on the ligament  27  is measured with a gauge  84 . The ligament graft  27  tends to stretch out after a few minutes of sitting in the bore  53  or through movement of the adjacent joint through range of motion. The rotation tool  63  is rotated clockwise so the Hinged Split-nut  46  rotates and tightens the ligament graft  27 . The operation of the gauge is conducted similar to as described above.  
         [0331]    Once the tension on the ligament  27  is stable, the shaft is cut as above. FIG. 90 shows a hinged split-nut assembly after completion of installation.  
         [0332]    Alternate Stop Pivot Wing Compression Rod—FIGS.  91 - 104   
         [0333]    FIGS.  91 - 96  depict an alternate embodiment of the stop pivot wing compression rod assembly  352 . The assembly also employs a boat-shaped or U-shaped pivot wing  146 , except that unlike the balance pivot wing  146  that can rotate almost 180 degrees and is held in place by the action of the bone, this assembly has a stop  82  that prevents the pivot wing  146  from rotating past 90 degrees. The pivot wing  146  is depicted in cross-section in FIG. 91 with the shaft  12 , which has threads  8  (not shown). The vertical stop  82  is integral with the pivot wing and rests against the shaft  12 , thereby holding the pivot wing at the oblique angle when pressure is placed on tip  56  of the wing.  
         [0334]    The pivot wing  146  is depicted in FIG. 92 in a position that is approximately parallel to the linear axis of the shaft. This is the position used to insert the assembly into a bore.  
         [0335]    In FIG. 93, the shaft  12  is depicted in cross-section to shown the dual pin hinges  166  and  167  that articulate with the pivot wing  146 . The pivot wing  146  rotates from the vertical position in FIG. 92 to the horizontal position in FIG. 91 and is prevented from rotating any further by the stops  83  and  82 . It should be noted that stops  83  and  82  can be manufactured at a variety of different angles so that the pivot wing  146  can be limited in rotation by these stops  82  and  83  to more or less than 90 degrees. This features allows the pivot wing compression rod  352  to be adapted to a variety of environments in the body where the pivot wing must hold the bone with a compressive force at an angle that is oblique to, or different than, 90 degrees.  
         [0336]    [0336]FIG. 94 depicts a side elevation view of the entire pivot wing compression rod  352  with pin hinge  166  shown in the pivot wing. This demonstrates how the rod  352  appears when it is in the deployed position, with the wing  146  configured at 90 degrees with respect to the shaft  12 .  
         [0337]    [0337]FIG. 95 depicts a top plan view of the pivot wing  146  without the shaft  12 . The pivot wing end  56  is split due to the position of the pivot wing  146  when in the vertical position. The end  56  has two sides  186  and  187  with a space  188  in between. This width of this space  188  approximates but is larger than the diameter of the shaft  12 . The stop,  82  that prevents the pivot wing  146  from rotating past the oblique angle, is located behind the pin hinge opposite the end  56 .  
         [0338]    The cross-section of the pivot wing  146 , without the shaft  12 , is depicted in FIG. 96. The wing has a pin hinge hole  166   a  through with a pin is passed.  
         [0339]    FIGS.  97 - 104  demonstrate the operation and installation of the stop pivot wing compression rod assembly. The assembly depicted in FIG. 97 is inserted into a bore  129  through the bone sections,  114 ,  215  so that its shaft,  12 , spans the fracture  111 . The installation tool  511  is used to hold the pivot wing  146  parallel to the shaft  12 . Its tip  556  keeps the pivot wing  146  from rotating out of the position in which it is parallel to the shaft  12 .  
         [0340]    In FIG. 98, the tool  511  has been rotated 180 degrees around the shaft  12  so that its tip  556  is touching the area of the pivot wing  146  that is near tip  56 . The tool is being used to push the tip  56  into the bone  215 . At the same time that the tip  56  is pushed, the shaft is pulled outwardly so that the pivot wing  146  rotates into the bone in an upward direction to help the impaction of tip  56  into the bone  215 .  
         [0341]    The pivot wing continues to rotate toward a perpendicular position as the shaft  12  is pulled upward, as depicted in FIG. 99. The tip  56  serves as the stable point around which the pivot wing  146  rotates as the shaft  12  is pulled upward in a direction opposite its insertion direction.  
         [0342]    [0342]FIG. 100 depicts the tool  511  being used to stabilize the pivot wing  146  while shaft  12  is pulled upward. The pivot wing has assumed the horizontal position on pin hinge  166  with point  56  embedded in the bone  215  and the end  56   a  of the pivot wing that is opposite the first end  56  is also embedded in the bone. Whether or not point  56   a  embeds in the bone, is dependent upon the length of the pivot wing  146 , the diameter of the bore  129  and the angle that the pivot wing  146  assumes in relation to the shaft  12 . In FIG. 100, the pivot wing  146  is held perpendicular to the bone by the action of the stop,  82  as shown previously in FIG. 91. This allows it to anchor in the bone  215 . The assembly is useful in bones where the inside of the bore  129  does not demonstrate architecture. In FIG. 100, the stop  82  keeps the pivot wing  146  from rotating past 90 degrees.  
         [0343]    Solid Spherical Compression Nut—FIGS.  101 - 104   
         [0344]    [0344]FIG. 101 depicts the just-described stop pivot wing compression rod assembly being used in combination with a ball-and-socket joint. A spherical cup  252  is place over the shaft at the surface of the bone such that the pivot wing  146  and the spherical cup  252  are at opposite sides of the fracture  111 , which separates the two bone portions  215  and  114 . The shaft  12  passes through the aperture  353  of the cup  252 , while the pivot wing  146  remains in the position that it attained previously.  
         [0345]    In FIG. 102, a solid nut  246 , which is another embodiment of the Compression fastener, is threaded onto the shaft. The solid threaded nut  246  has the same spherical shape as the split-nut  36  of FIG. 9 so that it can swivel in the cup  252  and allow for differences in the angle of the bore  129 . However, it does not have the capacity to be applied to the proper position quickly by sliding linearly. Instead, it must be turned on its threads until it reaches the proper position on the threads  8  of the shaft  12 . This nut  246  is useful in areas where a shaft  12  of a specific length is used, so that the shaft  12  is made with little excess threaded  8  area. Hence, there is no need to spend a great amount of time turning the nut  246  into place. The nut  246  is rotated on the threads  8  of the shaft  12  until it engages the cup  252  that is now resting against the bone  114 .  
         [0346]    In FIG. 103, the nut  246  is shown fully seated in the cup  252 . There is compressive force between the nut  246  the pivot wing  146  so that the fracture  111  gap has been closed. As in the embodiment of FIG. 81, a load cell can be inserted between nut  246  and the cup  146  to measure the compressive force. When the compressive force is stable and at the proper level the shaft  12  is scored with the scoring tool,  316  and then the shaft, in FIG. 104 is broken at the score  80 . The shape of the cup  252  can be deeper to permit placement of the score  80  deeper in the cup  252  so that the score doesn&#39;t rub against tissue above it. Although the pivot wing of FIGS.  101 - 104  are shown at an angle different than that of FIG. 100, it is not necessary that the wing assume this other angle.  
         [0347]    Off-Center Pin Stop Compression Rod—FIGS.  105 - 108 .  
         [0348]    In the prior embodiments of the compression rod assembly, the hinge has been located approximately through the transverse center of the shaft, i.e., through the center of the width of the shaft. However, FIGS.  105 - 108  depict the off-center pin stop compression rod that includes a pin  342  that is off-center to the longitudinal axis of the shaft  12 . The pivot wing  429  is in the deployed position. The stop  420 , which is integral with the wing, rests against the end of the shaft  12  along edge  452  so that the pivot wing  429  must stop at a specific oblique angle with respect to the shaft  12 .  
         [0349]    [0349]FIG. 106 depicts the pivot wing  429  and the shaft. The pin hinges  346 ,  345  are seen between the sides (stands) of the boat-shaped (U-shaped) pivot wing and extend from the shaft  12  through the sides of the pivot wing. Note that the shaft is wider than the shaft when viewed from the front. To permit the nut to secure the shaft  12 , the threads  8  (not shown) are located on a narrower section of the shaft, which has approximately the same diameter as the shaft  12  of FIG. 12.  
         [0350]    [0350]FIG. 107 depicts a rear partial sectional view pivot wing and shaft. The pin hinges  346  and  345  are engaged with holes located on the sides of the pivot wing  429 .  
         [0351]    In FIG. 108, the pivot wing is in the pre-deployed position with the edge of the stop  420   a  against the rod  12 , so that the pivot wing remains parallel to the shaft  12  during insertion into a bore in a bone. During installation in a bone, the pivot wing  420  is manipulated by way of an installation tool similar to the tool  511  and according to a technique similar to that of FIGS.  97 - 100 .  
         [0352]    Axle Rod Compression rod of FIGS.  109 - 117   
         [0353]    The Axle Rod is another embodiment of a shaft  13  with a single wing  512  that rotates oblique to the shaft  13 . However, the pivot wing  512  has a single blade that is not boat-shaped, as opposed to the boat shape of pivot wing  146  in FIG. 106. The Axle Rod includes two posts  503 ,  505  and a transverse beam or axle,  168 , serving as the hinge axis. The rod  13  is flat and wide, as depicted in FIG. 109, and narrow, as depicted in FIG. 110. The threaded  8   a  area of the upper portion  13   a  is a narrower portion where a solid nut  146  or split-nut,  46  can be used for securing this end. The pivot wing  512  has a stop  182 , as depicted in FIG. 110.  
         [0354]    The pivot wing and rod are shown in cross section in FIG. 111, with the shaft  13  corresponding to the post  403 . The axle  168  is also shown in cross section as is the pivot wing  512 .  
         [0355]    [0355]FIG. 112 depicts the axle rod with the pivot wing  512  in the vertical position. Note that the stop  183  keeps the pivot wing  512  from rotating clockwise past the shaft  13 .  
         [0356]    [0356]FIG. 113 depicts a partial sectional front view of the pivot wing  512  along line u-u of FIG. 110. The stop  183  is shown along the lower portion of the pivot wing  512 , and the axle  168  is shown in elevation.  
         [0357]    [0357]FIG. 114 depicts a front elevation view of the axle rod.  
         [0358]    [0358]FIG. 115 depicts a rear elevation view of the axle rod. The rear of the pivot wing  512  is shown with the stop  18  against the shaft  12 , so that the stop  182  keeps the pivot wing  512  in the oblique angle.  
         [0359]    Axle Rod with Axle Receptacle—FIGS.  116 - 117 .  
         [0360]    An alternate embodiment of the axle rod is depicted in FIGS.  116 - 117 . The axle rod  168  comprises the shaft  13  and the pivot wing  512  that is resting on bone  321 . The shaft  13  is located within the bore  540  in the bone  321 . A ligament  408  is suspended from the tissue retainer of the shaft  13 .  
         [0361]    In FIG. 117, the shaft  13  comprises two extended posts  441 , 442  and a crossbeam  443  over which the ligament  408  is suspended. At the opposite end of the shaft from the ligament is a pivot wing  512 . The extended member are secured to each other by a first transverse member, which is the pin of the pin hinge, a second transverse member, which is the tissue retainer, or crossbeam,  443  and optionally a third transverse member between the first two transverse members. This configuration can be used when the bone  321  is the femur and the ligament  408  is a graft of the Anterior Cruciate Ligament of the knee.  
         [0362]    Split Suture Nut—FIGS.  118 - 131 .  
         [0363]    The split-nut of the invention can be used as a suture nut. In this embodiment, the split-nut is used for a non-threaded shaft, a suture, particularly in securing the suture S depicted in FIG. 120. The suture nut includes a band B and two split-nut sections c 1  and c 2 . The band encircles and retains the sections C 1  and C 2 . FIG. 118 depicts the band B that is used to compress the section C 1  and C 2  of the split suture nut SSN. FIG. 119 depicts the suture nut SSN with the band B surrounding the sections C 1  and C 2 , and the suture s in the center. The sections C 1  and C 2  define a bore H around the suture S that serves to clamp the suture S when the sections C 1  and C 2  compressed together.  
         [0364]    [0364]FIG. 120 depicts the split suture nut SSN engaged with the lower longitudinal portion of the split suture n. The upper and lower longitudinal portions of the split nut include graded diameters, ramped surfaces. The upper ramped surface R 1  of the split suture nut SSN engages the band B when the suture nut is compressed and the lower ramped surface R 2  (shown in FIG. 121) engages the band B when the sections of the suture nut are spaced apart.  
         [0365]    In FIG. 121, the split suture nut SSN is depicted in partial section. The lower ramped surface R 2  has an overall narrower diameter than the upper ramped surface R 1 , so that when the band B is around the Split Suture Nut SSN at the lower Ramp R 2 , the sections C 1  and C 2  are not compressed against the suture S. In the orientation of FIG. 121, the split suture nut SSN is able to slide along the suture S forward and backward.  
         [0366]    In FIG. 122, the band B in cross section and sections C 1  and C 2  in cross section, taken along lines Y-Y of FIG. 119. This figures shows that each section C 1  and C 2  is of unitary construction even though each section C 1  and C 2  has its own respective ramped surfaces. The ramped surfaces R 1  and R 2  are separated by the ledge L where the Band B reside when it is around the upper ramped surface R 1 .  
         [0367]    Once the Suture Split-nut SSN is in place, the band is moved from the surface R 1  to the surface R 1  to cause the sections C 1 , C 2 , to clamp the suture S. In FIG. 123, the band B is shown approaching the ramped surface R 1 . This brings the sections C 1  and C 2  toward each other so that the hole H is narrower and almost clamping the suture S. This same position of the band is depicted in FIG. 124.  
         [0368]    In FIGS. 125 and 126, the band B has been moved even further along the lower ramped surface R 2  upwardly toward the upper ramped surface R 1 . In FIGS. 127 and 128, the bottom of the band is almost to the top of the ramped surface R 2  and in proximity of the ledge L. In FIGS. 129, 130 and  131 , the band is fully engaged with the upper ramped surface R 1  and held inplace, generally irreversibly, by the ledge L. The band B holds the sections C 1  and C 2  together so that the friction surface H comes to bear on the suture S and hold the split suture nut SSN securely on the suture.  
         [0369]    Although not shown, the sections C 1  and C 2  of the split nut can comprises even more ramped surfaces and ledges forming an overall stepped or ratcheting outer surface. Likewise, the band can comprise inner ramped surfaces that mate with the ramped surfaces of the split-nut.  
         [0370]    The suture nut provides a very efficient method for applying fixation force to suture as its sections are fully cut longitudinally so they apply pressure their entire length. This device installs in small areas as it can be installed with a tube-within-a-tube instrument with one tube stabilizing the two sections, C 1  and C 2  while the other tube is used to pull the band, B, along the Ramp R 2  until in place in Ramp RI. This double tube tool reaches the Split Suture Nut SSN along the suture, S, so that it can insert through a tiny incision that the Suture, S enters.  
         [0371]    Crimping tools that are used in clamping a conventional fastener (not of the invention) around cable such as around bales of hay, require access to the Crimping tool be manipulated by one&#39;s hand from the side of the cable. Such crimping fasteners cannot install in small areas such as those allowed in surgery. The Suture Nut can install in small areas, where tools only of small diameter can be applied to manipulate the band, B, to move on the sections, C 1  and C 2 , to clamp the suture, S.  
         [0372]    The Transverse Flat Rod  227 —FIGS.  132 - 139   
         [0373]    As depicted in FIG. 132, the transverse flat rod (or transverse impaction screw)  237  includes a tapered flat area  238  for receiving a ligament graft  227  (not shown). This area  238  is a non-threaded area. The rod  237  has threads  242  in a middle portion, for anchoring the rod in a bore of a bone, and a receptacle  241  for engaging a driving tool used to install and change the orientation of the rod.  
         [0374]    [0374]FIG. 133 depicts a side elevation view of the device including the flat portion  238 . The flat portion  238  is skewed upwardly with respect to the linear axis of the rod. FIG. 135 depicts a partial sectional front elevation view of the rod, and FIG. 134 depicts a rear elevation view of the rod and its receptacle  241 .  
         [0375]    [0375]FIG. 136 depicts the transverse flat rod  237  installed in a bone  251  having a bore  253  there through. The rod is installed such that its linear axis is about normal to the linear axis of the bore. The rod is depicted with the non-threaded portion  237  in cross-section, and showing the flat section  238  with its short planar axis approximately parallel to the linear axis of the ligament  227  that is draped over it and to the bore  253 . As depicted in FIG. 137, the rod  237  spans the width of the bore  253 . The ligament  227  has been draped over the flat surface  138 .  
         [0376]    In FIGS. 138 and 139, the rod  237  is depicted with the flat surface  238  approximately perpendicular to the linear axis of the ligament  227  and to the linear axis of the bore s 53 . When the rod  237  is in this position, the ligament  227  is pressed between the surface of the bore in the bone  251  and the edges  243  and  244  of the flat region. This compression of the ligament  227  into the walls of the bore  253  serves to create greater contact between the ligament  227  and the bone  251  and to promote healing.  
         [0377]    Suturing the Ligament Graft—FIGS.  140 - 143   
         [0378]    Ligament is the fibrous tissue that holds two bones in register as they move. A tendon is the fibrous material that holds a muscle to a bone. To reconstruct a ligament a muscle is removed from the body, the fibers are taken from the muscle and this long strand of tendon is fashioned into a ligament.  
         [0379]    FIGS.  140 - 143  depict a new method for constructing a ligament graft  27 . According to this method, a ligament, such as from the Semi-Tendinosis Muscle, is harvested from the hamstring muscle group. The red muscle tissue is stripped to form a strip of tendon approximately 26 centimeters in length.  
         [0380]    As depicted in FIG. 140, the ligament is made into a dual loop by passing the ends  27   a  and  27   b  of the ligament  27  twice through the eyes (tissue retainers)  15  and  15   a . The ends of the ligament are then joined by suture so that the ends are on the side of the loop. The entire ligament loop is a dual strand that passes through the two securing means. The ends of the ligament are stitched together with suture  621  and the adjacent strands (loops  642  and  643 ) are then stitched to each with suture  622  other approximately along their entire length. This method provides an exceptionally strong ligament graft because the sutured ends are held to the side of the graft and not solely at the junction of the graft and the eye  15 , as is conventionally done in this procedure. This method can be adopted for four strands, rather than two strands, of ligament.