WO2001049189A1

WO2001049189A1 - Precision tension bolt

Info

Publication number: WO2001049189A1
Application number: PCT/IB2000/000364
Authority: WO
Inventors: Yosef Freedland
Original assignee: Justec, Inc.
Priority date: 2000-01-03
Filing date: 2000-03-28
Publication date: 2001-07-12
Also published as: AU2745401A; WO2001049207A8; EP1411857A2; WO2001049207A3; WO2001049207A2; AU3316300A

Abstract

The present invention provides orthopedic devices useful in applying tensionor compression to biological tissues, and facilitating surgical procedures. Various aspects of the invention include a split nut fastener (45), a tension bolt (8), a suture nut (58), a pivot wing bolt (25) 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.

Description

Precision Tension Bolt

FIELD OF THE INVENTION

The present invention concerns orthopedic medical devices, in particular, implantable orthopedic devices used to apply tension or compression to biological tissues. The devices of the present invention include a ball-and-socket nut assembly, a snap ring, or split nut, fastener, a pivot wing Bolt assembly, a compression screw and a suture nut.

BACKGROUND OF THE INVENTION

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.

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.

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 fin^ 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.

U.S. Patent 436,101 to Freedland discloses a multi- winged anchor for fractures of the femoral neck. U.S. Patent 4,721,103 to Freedland discloses an intramedullary rod, which has two wings that expand outwardly. U.S. Patent 4,862,883 to Freedland discloses an intramedullary rod placed within the central longitudinal cavity in the femur. U.S. Patent 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.

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. Patent 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.

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.

Banded fasteners, wherein a soft cylindrical jacket is compressed against a cable by a band that surrounds it, are known. U.S. Patent 5,626,590 discloses a cylindrical jacket made of a deformable material around which a rigid band is placed. US Patent 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.

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.

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

The present invention overcomes the disadvantages of known related orthopaedic 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.

hi one aspect the present invention provides a ball-and-socket nut assembly. A nut 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. With 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.

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. 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.

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 preferred 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 preferably dissolve or degrade so that the rod could be removed from the bone as desired. In a preferred 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.

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.

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 a bore in a bone, such as the femur and initially, the flat section spans the bore with the plane defining 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 plane that defines 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.

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

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.

FIG. 1 is a cross-sectional side view of an internally threaded concave-shaped nut, which is adapted to thread onto the threaded shaft of the tension bolt in FIG. 3.

FIG. 2 is a front perspective side view of a flanged concave cup, which is adapted to receive the concave shaped nut of FIG. 1.

FIG. 3 is a partial cross-sectional side view of a precision tension bolt in use.

FIG. 4 is a partial cross-sectional side view of the precision tension bolt of FIG. 3, wherein a driver tool is used to thread the nut on the threaded shaft. The incident angle of the precision tension bolt relative to the flanged concave cup can be changed as indicated by the bolt drawn in phantom lines. FIG. 5 is a partial cross-sectional side view of the precision tension bolt of FIGS. 3 and 4, wherein a gauge is used to measure the amount of tension that the bolt is applying to a biological tissue.

FIG. 6a is a sectional side view of two opposing tension bolts implanted in a bone, wherein the bolts are attached to a ligament that has been tensioned by the opposing bolts.

FIG. 6b is a tool used to cut the threaded shaft of a tension bolt.

FIG. 7 is a elevation view of a pivot wing bolt threaded shaft used to compress a biological tissue.

FIG. 8 is a top plan view of the single wing, or crosspiece, used in the pivot wing bolt of FIG. 7.

FIG. 9 is a sectional side view of the single wing of FIG. 8.

FIG. 10 is a sectional side view of the threaded shaft of the pivot wing bolt of FIG. 7.

FIG. 11 is a partial sectional view of the pivot wing bolt of FIG. 7 having the single wing of FIG. 8 attached and being implanted into a fractured radius with a tool.

FIG. 12 is a partial section view of the pivot wing bolt of FIG.11 having the wing being deployed into position by a tool.

FIG. 13 is a partial sectional view of the pivot wing bolt of FIG. 11 having the tool removed.

FIG. 14 is a partial sectional view of the pivot wing bolt of FIG. 11 having the wing completely deployed.

FIG. 15 is a bottom plan view of the split nut, wherein the snap ring is not forcing the halves of the split nut together. FIG. 16 is a bottom plan view of the split nut, wherein the snap ring is forcing the halves of the split nut together.

FIG. 17 is a sectional side view of the split nut of FIG. 15.

FIG. 18 is a sectional side view of the split nut of FIG. 16.

FIG. 19 is a side view of a threaded shaft, which can be used with the split nut of

FIGS. 15-18.

FIG.20 is an inset view of the buttress threads on the threaded shaft of FIG. 19.

FIG. 21 is a perspective and sectional side view of a snap ring, which is adapted to engage the split nut of FIGS. 15-18

FIG. 22 is a partial sectional side view of the split nut of FIG. 17 and the snap ring of FIG. 21 engaged with the pivot wing bolt of FIG. 11.

FIG. 23 is a perspective view of a ring tower, or pedestal, which is used in combination with the split nut of FIG. 17.

FIG. 24 is a side view of the assembly of FIG. 22, wherein the split nut and snap ring are shown adjacent the ring tower after the split nut and snap ring have been slid down the threaded shaft.

FIG. 25 is a sectional side view of the split nut, snap ring and ring tower of FIG. 24 once the snap ring has been used to force together the halves of the split nut.

FIG. 26 is a side view of the assembly of FIG. 22, wherein the split nut and the snap ring have been threaded and tightened onto the threaded shaft of the pivot wing bolt.

FIG. 27 is a side view of the assembly of FIG. 26, wherein a tool is used to tighten the split nut onto the threaded shaft thereby closing the fracture in the radius. FIG. 28 is a side view of the assembly of FIG. 27, wherein the extra length of the threaded shaft of the pivot wing bolt has been removed and the entire tensioning device is completely installed.

FIG. 29 is a side view of the assembly of FIG. 28, wherein the assembly is being removed once the fractured radius has healed and the crosspiece has deteriorated in the bone.

FIG. 30 is side view of a modified split nut and snap ring assembly being used as a suture nut. The halves of the split nut are separated.

FIG. 31 is a side view of the suture nut of FIG. 30, wherein the snap ring is engaged more tightly with the split nut thereby forcing its halves together.

FIG. 32 is a bottom plan view of the assembly of FIG. 30.

FIG. 33 is a bottom plan view of the assembly o FIG. 31.

FIG. 34 is a cross-sectional perspective view of the snap ring of FIGS. 30-33.

FIGS. 35-37 are perspective views of a suture nut in operation.

FIG. 38 is a side elevation view of a transverse impaction screw according to the invention.

FIG. 39 is a sectional end view of the transverse impaction screw of FIG. 38 implanted in a bore in a bone and engaged with a Ligament Graft

FIG. 40 is a side elevation partial sectional view of the transverse impaction screw of FIG. 39.

FIG. 41 is a top plan view of a transverse impaction screw according to the invention. FIG. 42 is a sectional end view of the transverse impaction screw of FIG. 41 implanted in a bore in a bone and engaged with a Ligament graft. FIG. 43 is a side elevation partial sectional view of the transverse impaction screw of FIG. 42.

DETAILED DESCRIPTION OF THE INVENTION

Tension bolt assembly.

FIG. 1 depicts a flanged cup assembly (1) comprising a flange (3) and concave- shaped socket (2). The cup assembly (1) is adapted to receive the internally threaded nut (4) depicted in FIG. 2. FIG. 3 depicts a precision tension bolt assembly (8) implanted within a bore (7b, 7c) in a bone (7). The bolt assembly comprises the nut (4), the flanged cup (1), and a threaded shaft (9). The nut (4) is disposed within the flanged cup (1). As depicted in FIG. 3, the socket (2) and the flange (3) each have a slot through which the threaded shaft (9) (4) passes as the socket (2) and flange (3) are placed around the threaded shaft (9) between the nut (4) and the bone surface (7a). The nut (4) has been rotated down the shaft until it is in proximity of the cavity (5) within the socket (2). At least a portion of the flange (3) is disposed on the surface (7a) of the bone. The end of the threaded shaft (9) that is disposed within the bore includes a soft-tissue retainer, such as an eyelet or hole (10) to which ligament (11) is attached.

The tension bolt assembly (8) is typically used as depicted in FIGS. 4-6. FIG. 4 demonstrates that the threaded shaft (9) of the tension bolt assembly (8) can be disposed at different incident angles with respect to the surface of the bone and to the flanged cup (1). The actual incident angle of implantation will depend upon the incident angle at which the bore through the bone is made. This diverse use is due to the swiveling of the nut (4) within the socket (2) This construction allows the threaded shaft to rotate and swivel in a variety of angles within the flanged cup to fit a variety of brothels or bores in the bone. The driver or tool (12) is used to rotate the nut (4) in the cup and to drive the nut up and down the shaft (9). FIG. 5 depicts the nut (4) mating with the socket (2). A tool (12) is used to thread the nut about the threaded shaft (9) and thereby pull the shaft partially out of the bone in the direction of the arrow (A). In so doing, the ligament (11), which is engaged with the eye (10) is tensioned to a precise level. This control of tension averts the problem of arthritic loose knees that result from loose ligament replacements that allow the joint surfaces to slide and rub out.

FIG. 6A depicts the tension bolt assemblies (16, 23) installed in a knee. For each assembly, the nut (18, 21, respectively) is disposed within the flanged cup (17, 20, respectively). The flange of each flanged cup rests on the bone surface. The shaft (19, 22) of each assembly has been cut to the size to minimize protrusion of the threaded shaft beyond the surface of the bone. The opposing tension bolt assemblies (16, 23) are attached to opposite ends of a length of tensionable biological tissue, such as a ligament graft. The assemblies (16, 23) are disposed within the femur and the tibia. The tool (13) depicted in FIG. 6B is used to cut the threaded shafts.

The technique for implantation of the assemblies into a knee generally proceeds as follows. A drill is used to make a single bore through each the tibia (14) and the femur (15) over a guide wire that preferably passes through the point of attachment of the original ligament that has been torn. The ligament replacement (11) is passed through the eyes of two threaded shafts, one at each end, and the ligament is sutured onto itself to form a continuous loop. The ligament, with a threaded shaft at either, end, is passed into each bore so that each threaded shaft protrudes from its respective bore, one from the bore in the tibia (14) and one from the bore in the femur (15). The flanged cup (17, 20) is then put around its respective threaded shaft (19, 22) between its respective nut (18, 21) and its respective bone surface (14, 15). The femoral nut (18) is rotated until it is disposed within its respective flanged cup, and the tibial nut (21) is rotated until it is disposed within its respective flanged cup. The assemblies (16, 23) tension the ligament (11) in the direction of the arrows (B, C, respectively). The tension on the ligament is measured and adjusted, and the threaded shafts are cut to size. Accordingly, the present invention provides a method of tensioning a biological tissue by using one or more of the tension bolt assemblies according to the invention.

The tension bolt assembly according to the invention can be configured to receive a variety of body tissues such as a tendon at the end of a muscle that is being transferred to replace a muscle which is non-functional due to a debilitating or paralytic disease. Use of the tension bolt assembly allows for the proper tensioning of the transferred muscle thereby allowing the muscle to acclimate to its new environment and heal more efficiently. An eye (10) is shown being used to attach a ligament graft of to a knee. Alternatively, the tension bolt assembly could comprise a perforated plate for attaching multiple tissue strands or a hook that will allow the surgeon to hook the rod into a loop of tissue in the body during surgery.

Pivot wing bolt assembly.

The pivot wing bolt provides a means of applying compression to a body tissue. FIGS. 7-10 depict a pivot wing bolt (25) comprising a threaded shaft (26), a head portion (27), a mount (29) in the head portion, a pivot wing stop (28), and two or more ports (37, 38). The wing (30) is rotatably mounted on the mount (29), which allows the wing to rotate about the axle (33) as it is retained by the hub (34). The pivot wing stop (28) prevents the wing from rotating more than 90 degrees about the axle (33). The wing (30) includes a recessed hole 31) comprising a shoulder (32). The threaded shaft (26) and head portion (27) preferably have a longitudinal passageway (36) there through. The passageway can be used as a guide through which a guide wire passes. It can be used to introduce materials that will speed the dissolution of the wing as detailed below.

FIG. 11 depicts the pivot wing bolt (25) during its initial stages of installation into a fractured (43) radius (42) of an elbow. The fracture (53) is located at the narrow area of the radius bone, just below the humerus bone (41). The depicted end of the humerus is often called the "funny bone", as this spot is rather sensitive to contract. The radius (42) has a bore (44) which has been drilled into the fractured end of the radius. The wing (30) is depicted aligned with the axis of the threaded shaft (26) and the bore (44). The installation tool (40) is used to hold the wing in a pre-deployed position. The tool (40) is notched (40a) at the end that mates with the tip (30a) of the wing (30) so that the wing will not rotate during insertion.

FIG. 12 depicts the pivot wing bolt (25) after it has come to the proper position straddling the fracture (43). The tool (40) is rotated 180 degrees in the direction of the arrow (E) and pushed against the wing (30) in the direction of the arrow (D) to effect deployment of the wing. As the wing is deployed, it rotates on the axle (not shown) in the direction of the arrow (F) thereby causing the wing to rotate outwardly from the longitudinal axis of the threaded shaft.

FIG. 13 depicts the pivot wing bolt after the tool (40, not shown) has been removed.

The threaded shaft (26) is then pulled partially out of the bore (44) in the direction of the arrow (G) thereby causing the wing to contact the bone wall (X) in the area of the elbow. As the threaded shaft is pulled even more, the wing deploys even further until it is about normal to the axis of the threaded shaft (26). In FIG. 14, the wing is depicted in a fully normal position and held in place by the opposing effects of the wing stop (28) and the bone wall (X) at two points on either side of the axle along the flat edge of the wing: At this point, the fracture has not yet been reduced to a significant degree. The technique for removal of the pivot wing bolt is detailed below.

The technique for reconstructing a fractured hip using a pivot wing bolt according to the invention would generally include the steps of: 1) making a bore in the bone from the top of the thigh bone down into the knees; 2) inserting the pivot wing bolt assembly and tool into the bore to maintain the wing, or crosspiece, approximately parallel to the shaft; 3) rotating the tool to deploy the wing once the wing is past the mid-thigh fracture and preferably in proximity of the knee; 4) removing the tool and pulling the shaft to cause the wing to contact the inner surface of the surrounding bone wall thereby bringing the lower bone fragment into contact with the upper bone fragment; 5) placing a nut at the end of the shaft opposite the head; 6) threading the nut on the shaft until it pressed against the upper edge of the hip bone and reduces the fractured bone; and 7) cutting of the excess length of threaded shaft which extends beyond the nut. In such a procedure, the amount of excess _ __

-14- shaft that protrudes out of the bore in the hip, would be dependent up the placement of the crosspiece, the length of the thigh bone, and the amount of impaction that is achieved between the bone fragments.

Snap ring split nut.

FIGS. 15-18 depicts a snap ring split nut assembly (45) in an expanded state. The split nut comprises two or more portions (46, 47) which are held in relation to each other by the snap ring, or ring or band, (48). The split nut has at least two grooves: upper groove (49) and lower groove (48), which is narrower in diameter than the upper groove. In order to maintain the portions (46, 47) proximal but spaced, the snap ring (48) is initially located at a lower groove (50). The lower groove (50) has a smaller overall diameter, in the assembled split nut, than does the upper groove (49). In the expanded state, the split nut assembly can be slid down a threaded shaft (26) of the proper diameter thereby avoiding having to be threaded down the shaft.

By moving the ring to the upper groove (49), the portions (46, 47) are forced together to the closed position to form a nut having a threaded bore (51) which can be threaded about the shaft (26) but which cannot be slid up the shaft.

In order to facilitate threading the closed split nut on the threaded shaft, a driving tool (not shown) can be used. For this reason, the split nut assembly (45) will generally comprise an engagement means (55) that is adapted to engage the driving tool.

The threaded shaft depicted in FIG. 19 preferably has buttress threads as depicted in

FIG. 20. Buttress threads generally have a long slope on one side and a short slope on the other. When the split nut (45) is in the expanded position, the buttress threads on the inside of the nut contact those of the threaded shaft. As the split nut is slid down the length of the shaft, the sections (46, 47) are pushed outwardly. The short slope of the thread prevents the split nut from moving backward up the length of the shaft.

When the split nut is in the closed position, it can move up or down the length of the shaft only by rotation about the shaft and not by sliding on the shaft. This construction allows the split nut to rapidly slide to a general position on a rod and then, have its snap ring moved into the compression groove, causing the nut sections to compress the rod. FIG. 21 depicts a perspective cross-section of the ring (48). It slanted or sloped inner surface is adapted to mate with the surface of the grooves (49, 50). In addition, the grooves (49, 50) are separated by a circumferential shoulder that aids in keeping the band (48) in either the upper or lower groove. Each groove also preferably has an outer flanged portion, which also aids in keeping the band seated in a desired groove without sliding off of the split nut.

Although the split nut assembly (45) can be used on the pivot wing bolt assembly (25) as is, it is preferred that a pedestal (52), as depicted in FIG. 23 be used to space the split nut assembly from the surface of the bone to which it is being mounted. The pedestal will generally comprise a platform (54) and spacing means, such as the legs (53). The pedestal allows the nut to put force against the bone, while keeping the split nut outside the body for easy removal. FIG. 22 depicts the pivot wing bolt assembly (25) engaged with the pedestal (52). Following placement of the pedestal, the split nut assembly (45) is mounted onto the threaded shaft (26). An incision in the skin and tissues overlying the elbow allows the pedestal to be seated against the bone surface around the bore (42). The split nut assembly is slid onto the threaded shaft in the direction of the arrow (K) such that the snap ring (48) is closest to the pedestal.

FIG. 24 depicts the split nut assembly being slid down the length of the threaded shaft and approaching the platform (54) of the pedestal (52). At this point, the facture (43) may be reduced, but there is no compression along the fracture (43)

FIGS. 25-26 depict the split nut assembly in contact with the pedestal. Upon pressing the split nut assembly against the pedestal, the snap ring moves from the lower groove (50) to the upper groove (49), thereby closing the nut about the threaded shaft. When closed, the split nut assembly will not slide up and down the threaded shaft, and any further motion of the split nut assembly is accomplished by rotating it with a driver. FIG. 27 depicts a driver tool (56) being used to rotate the split nut assembly in a clockwise direction about the threaded shaft. This threading creates opposing compressive forces from the wing (30) and the split nut assembly, thereby causing the bone sections to move toward each other in the direction of the arrows L with a precision force to further reduce the fracture (43). A gauge (not shown) can be used to measure the compressive forces exerted by the pivot wing bolt assembly and split nut assembly.

Once compressed to the desired degree, the excess length of threaded shaft (26) is cut to size, as depicted in FIG. 28. Over a period of time of four to eight weeks, preferably four, , the bone will heal. During or after the period of time that the bone heals, the wing (30) will begin to deteriorate in the bone. Optionally, the head (27) and the threaded shaft of the swing bolt assembly (25) can also be made of dissolvable material and begin to dissolve. By deteriorate is meant to dissolve, degrade or dissipate, through hydrolysis or enzymatic action intrinsic to the body tissue so that each section in question loses at least part and preferably at least a majority of its physical integrity.

There are several known dissolvable materials used in orthopedic implants on the market today. The materials include for examplePGA-TMC — poly(glycolide-co- trimethylene carbonate), which is used in the Suretac™ soft tissue to bone tack by Acufex Medical Mansfield, Mass; PGA-DLPLA — poly(l-lactide-co-glycolide), which is used in the Biologically Quiet Interference™ screw for the knee by Instrument Makar, Norwood, Conn.; and LPLA (dl-lactide-co-glycolide), which is used in an Interference screw for the knee by Arthrex of Naples, Florida. Each polymer combination can be varied to give the resultant implant specific properties, such as a desired strength and speed of deterioration.

The hard and strong materials generally resist breakdown in the body and remain in the body tissue for up to several years after implantation. Polymer combinations that dissolve rapidly tend to be very soft and weak. As a means of affording a useful hard material without the disadvantage of slow deterioration, FIG. 28 depicts the use of a deterioration catalyst (57), such as an enzyme among other things, that has been injected into the passageway (36) of the threaded shaft (26) after the bone has healed. The deterioration catalyst can be of any of several materials that induce the polymer to dissolve more rapidly and include, for example, hyaluronic acid. Whether the wing (30) is composed of a material that undergoes enhanced deterioration in the presence of a deterioration catalyst, or whether the material is designed to undergo relatively rapid deterioration after installation, the threaded shaft can be removed from the bone (42) simply by pulling in the direction of the arrow (M). Before or during the removal step, the deteriorated wing (30) breaks and is left behind in the bone during removal as depicted in FIG. 29.

The Suture Nut.

The suture nut provides a very efficient method for applying compressive and fixating force by its button shape on the suture. The suture nut presses against the surrounding tissue surface. Since the suture nut's sections are fully cut longitudinally, they transmit the pressure of the encircling band relatively evenly along their entire length with their interface along the suture. As it is are preferably made from relatively non-deforming bioabsorbable materials, the suture nut's sections transmit the full force of the encircling band to the suture, making the Suture Nut a strong fastener. The Suture Nut can be installed through small laparoscopic incisions and placed in small areas of the body using fine instrumentation. It saves operating room time as the Suture Nut installs much faster on the sutures than it takes to tie a knot in suture. Further, the Suture Nut's position against the tissue it is securing can be gauged much more precisely than with suture knots.

FIG. 30 depicts a suture nut assembly (58), which is a particular embodiment of a snap ring split nut assembly. The suture nut assembly comprises two partial nut sections (58a, 58b) and a snap ring (60). Unlike the split nut assembly, which includes a threaded bore, the suture nut includes a bore (58c) that is generally not threaded. Moreover, the surfaces that define the bore (58c) at the inside of the suture nut are friction surfaces that are designed to grasp suture material. In most other aspects, the suture nut (58) has approximately the same construction as the above-described split nut.

The suture nut is generally used as follows. The band (60) is engaged with the lower groove (59a) such that the sections (58a, 58b) are adjacent yet spaced from one another. A suture (61) is placed within the bore (58c) and the Suture Nut is slid along the suture until it sits against the tissue that is to be secured against. The snap ring is slid from the lower groove (59a) to the upper groove (59b), thereby causing the sections (58a, 58b) to clamp the suture (61).

The suture nut (58) can be installed with a tube-within-a-tube instrument, wherein a first tube stabilizes the two sections (58a, 58b), and the second tube is used to move the band (60) from the first groove (59a) to the second groove (59b). This double tube tool can place the suture nut along the suture (61) disposed in a body through an incision that is distant to the tissue being secured with suture since the tool can be inserted through even a small incision through which the suture enters the body.

FIGS. 35-37 depict a suture nut as it is generally used to facilitate closure of an incision in a body tissue. A suture nut (58) is clamped onto a first end of the suture (61), which has a needle (63) at its second end. The needle and suture are threaded through the tissue adjacent an incision (62) in any manner used by a surgeon. The suture is pulled so that the suture nut abuts the tissue surface. The surgeon then continues to stitch the tissue to close the incision. Once the final stitch is made, the suture is tightened to close the incision and the second suture nut (64) is clamped onto the portion of the suture that is just exterior to the skin and is part of the last stitch. The suture is then cut to size, and the excess suture and attached needle are removed.

In an alternate embodiment, the suture nut includes a single enlarged bore, or a pair of small bores, which is adapted to receive two suture ends. In this embodiment, a single suture nut can be used to grasp two different portions of a suture simultaneously. The paired holes can be separated as desired. Alternatively, the single enlarged hole can be oval or otherwise shaped to simultaneously accommodate two suture portions within it. In this case, the suture would pass from one side of the wound to the other, and the single suture nut would grasp both ends of the suture that exit the skin.

The Suture Nut is preferably constructed from one or more of the combinations of polymers used in dissolvable implants, some of which were noted above. Transverse impaction screw.

The transverse impaction screw (65) depicted in FIGS. 38-43 is used to compress a ligament graft to a bone matrix. Use of this device in reconstructive knee surgery results in a knee having improved ligament adhesion to the bone. The screw comprises a tool engaging means (67), a threaded portion (68) and an extended member (66) having a flat surface (71). The tool engaging means provides a means by which a tool can engage the screw to drive the screw into a bone matrix. The threaded portion (68) provides a means by which the screw is secured to the bone. The extended member (66) and flat surface (71) together provide means by which a ligament can be draped over and retained by the screw. During use, a bore (72) is drilled into a bone (69). The screw (65) is screwed into the bore in a direction that is approximately normal to the linear axis of the bore and rotated so the flat surface (72) is parallel to the long axis of the bore as in figure 39. Once the extended member (66) has passed from one side of the bore to the other, a ligament (70) is draped over the extended member. The ends (not shown) of the ligament are then secured as desired to another surface or device. The ligament (70) is then compressed or impacted against the inner surface of the bone matrix by rotating the screw such that the plane defining the flat surface (71) is perpendicular to the linear axis of the bore. By so doing, the edges (73) of the flat surface (71) contact the ligament and impact it against the bone matrix that defines the bore. By rotating the screw to squeeze the fibers into the surrounding bone matrix, the surface contact between the ligament and the bone matrix is maximized, thereby providing a basis for the formation of a strong ligament-bone joint.

The above is a detailed description of particular embodiments of the invention. It is recognized that departures from the disclosed embodiments may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art. Those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed herein and still obtain a like or similar result without departing from the spirit and scope of the invention. All of the embodiments disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure.

Claims

CLAIMSI 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:

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

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 38.

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.