Split-nut precision fasteners

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.

I claim:  
     
         1 . A flanged ball-and-socket nut assembly comprising: 
 a nut having a convex hemispherical surface 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 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    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.    
     
     
         2 . The nut assembly of    claim 1   , wherein 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.  
     
     
         3 . The nut assembly of    claim 2   , wherein the tool engaging means comprises a recess.  
     
     
         4 . The nut assembly of any one of claims  1 ,  2  or  3 , wherein the nut assembly comprises a material suitable for use in orthopedic surgery.  
     
     
         5 . A split-nut assembly comprising: 
 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.    
     
     
         6 . The split-nut assembly of    claim 5   , wherein the first groove is disposed adjacent a first end of the nut.  
     
     
         7 . The split-nut assembly of    claim 6   , wherein the second groove is disposed between the first groove and a second end of the nut.  
     
     
         8 . The split-nut assembly of    claim 5   , wherein the band is an o-ring or a snap ring.  
     
     
         9 . The split-nut assembly of    claim 8   , wherein a portion of the surface of the band mates with corresponding portions of the peripheral surface of the nut.  
     
     
         10 . The split-nut assembly of    claim 5   , wherein the nut further comprises a shoulder interposed the first and second grooves.  
     
     
         11 . The split-nut assembly of    claim 10   , wherein each groove further comprises a flange to keep the retainer in its respective groove.  
     
     
         12 . The split-nut assembly of    claim 5    comprising: 
 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.  
 
     
     
         13 . A pivot wing bolt tissue-tensioning assembly comprising: 
 a threaded shaft having a head comprising a swing stop and a wing mount;    a single wing having an aperture engaged with the wing mount such that the wing is rotatably mounted on the wing mount; wherein:    the linear axis of the wing is alignable with the linear axis of the threaded shaft; and    the swing stop limits the rotation of the wing about the wing mount to less than one revolution.    
     
     
         14 . The assembly of    claim 13   , wherein the aperture in the wing is recessed.  
     
     
         15 . The assembly of    claim 13   , wherein the swing stop limits the rotation of the wing about the mount to about 90 degrees of revolution or less.  
     
     
         16 . The assembly of    claim 13   , wherein the threaded shaft has a longitudinal bore there through.  
     
     
         17 . The assembly of    claim 16   , wherein the longitudinal bore has two or more openings.  
     
     
         18 . The assembly of    claim 17   , wherein at least one of the openings are disposed at or adjacent the head of the threaded shaft.  
     
     
         19 . The assembly of    claim 13   , wherein the wing mount comprises a hub and an axle.  
     
     
         20 . The assembly of    claim 13   , wherein the wing is flat and its width approximates or is less than the width of the head of the threaded shaft.  
     
     
         21 . The assembly of    claim 13    further comprising: 
 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.  
 
     
     
         22 . The assembly of    claim 21   , wherein the tool has a first end that mates with at least one end of the wing.  
     
     
         23 . The assembly of    claim 21   , wherein the threaded shaft passes through the tool.  
     
     
         24 . The assembly of    claim 21   , wherein the tool is a sleeve having a first end that mates with at least one end of the wing.  
     
     
         25 . The assembly of    claim 21   , wherein the 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.  
     
     
         26 . The assembly of    claim 13    further comprising a nut assembly engaged with the threaded shaft.  
     
     
         27 . The assembly of    claim 26   , wherein the nut assembly is selected from the group consisting of a conventional nut, a split-nut assembly, and a ball-and-socket nut assembly.  
     
     
         28 . The assembly of    claim 27   , wherein 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.    
     
     
         29 . The assembly of    claim 27   , wherein the ball-and-socket nut assembly 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.    
     
     
         30 . The assembly of    claim 13   , wherein at least the wing comprises a material that deteriorates in an environment of use.  
     
     
         31 . The assembly of    claim 30   , wherein the wing comprises one or more dissolvable polymers.  
     
     
         32 . The assembly of    claim 30   , wherein the wing, the threaded shaft and the nut assembly are comprised of a material that deteriorates in an environment of use.  
     
     
         33 . The assembly of    claim 13   , wherein the threaded shaft comprises buttress threads.  
     
     
         34 . The assembly of    claim 26   , wherein each of the threaded shaft and the nut assembly comprises buttress threads  
     
     
         35 . The assembly of    claim 34   , wherein 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.  
     
     
         36 . A tissue-tensioning bolt assembly comprising: 
 a first threaded shaft having a tissue retainer at a first end; and    a first flanged ball-and-socket nut assembly according to any one of claims  1 - 4 .    
     
     
         37 . The tissue-tensioning bolt assembly of    claim 36    further comprising: 
 a second threaded shaft having a second tissue retainer at a second end; and  
 a second flanged ball-and-socket nut assembly.  
 
     
     
         38 . The tissue-tensioning bolt assembly of    claim 37    further comprising a tissue graft attached to each of the first and second tissue retainers.  
     
     
         39 . The tissue-tensioning bolt assembly of    claim 36   , wherein the tissue retainer is an eyelet or hole.  
     
     
         40 . A transverse impaction screw comprising: 
 a tool engagement means;    a threaded portion adjacent the tool engagement means; and    a non-threaded extended member attached to the threaded portion and comprising a flat surface.    
     
     
         41 . The screw of    claim 40   , wherein the plane defining the flat surface is not parallel to the linear axis of the screw.  
     
     
         42 . A suture nut comprising: 
 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    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    the suture nut is capable of securing a suture when the band is disposed in the second groove.    
     
     
         43 . The suture nut of    claim 42    further comprising a second non-threaded bore having a friction surface such that the suture nut can retain at least two suture portions.  
     
     
         44 . The suture nut of    claim 42   , wherein the bore is non-circular and the suture nut will retain at least two suture portions in the same bore.  
     
     
         45 . 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 claims  42 - 44 .    
     
     
         46 . 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    claim 36   .  
     
     
         47 . 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    claim 37   .  
     
     
         48 . 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    claim 3     8 .  
     
     
         49 . A method of tensioning a biological tissue comprising the step of retaining and tensioning a biological tissue with a pivot wing bolt tissue-tensioning assembly according to any one of claims  13 - 35 .  
     
     
         50 . A flanged ball-and-socket nut assembly comprising: 
 a longitudinally split-nut having a convex hemispherical surface having an internal threaded bore for receiving a threaded shaft;    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    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    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.    
     
     
         51 . The flanged ball-and-socket nut assembly of    claim 50   , wherein the sections of the split-nut are longitudinally slidably engaged with each other.  
     
     
         52 . The flanged ball-and-socket nut assembly of    claim 50   , wherein the split-nut comprises tool engaging means.  
     
     
         53 . The flanged ball-and-socket nut assembly of    claim 50    further comprising a sleeve interposed the socket and the split-nut.  
     
     
         54 . The flanged ball-and-socket nut assembly of    claim 53   , wherein an outer portion of the sleeve engages the interior of the socket and the split-nut is disposed within a bore in the sleeve.  
     
     
         55 . The flanged ball-and-socket nut assembly of    claim 50   , wherein the socket is a compression tower.  
     
     
         56 . A pivot wing bolt tissue-tensioning assembly comprising: 
 a threaded shaft having a head comprising a wing mount;    a single wing having an aperture engaged with the wing mount such that the wing is rotatably mounted on the wing mount; and    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:    the linear axis of the wing is alignable with the linear axis of the threaded shaft; and    the swing stop limits the rotation of the wing about the wing mount to less than one revolution.    
     
     
         57 . The pivot wing bolt tissue-tensioning assembly of    claim 56   , wherein the swing stop is integral with the wing.  
     
     
         58 . The pivot wing bolt tissue-tensioning assembly of    claim 56   , wherein the swing stop is integral with the head of the threaded shaft.  
     
     
         59 . A split-nut assembly comprising: 
 two or more nut sections which form a nut when assembled, the nut having a threaded bore; and    section retaining means selected from the group consisting of a band, a socket, and a combination thereof,    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 wherein the sections of the split-nut are detached from one another or attached to each other by way of a living hinge.    
     
     
         60 . The split-nut assembly of    claim 59   , wherein 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.  
     
     
         61 . The split-nut assembly of    claim 60   , wherein 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.  
     
     
         62 . The split-nut assembly of    claim 59   , wherein the section retaining means is a socket having a first larger diameter inner portion, and a second smaller diameter inner portion.  
     
     
         63 . The split-nut assembly of    claim 59   , wherein 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.