Abstract: A novel polymer composition is provided which includes a base material including a biodegradable polymer or copolymer, and a copolymer additive including one or more monomers imparting a tensile strength to the polymer composition at room temperature that is lower than a tensile strength at room temperature for the base material.

Abstract: Bioabsorbable coatings for bioabsorbable implantable medical devices having dragging or engagement surfaces. The coatings on a surface of the devices reduce device drag.

Abstract: A clip to inter-connect primary and secondary bone zones having edges, comprising in combination a first tab to extend over a surface of the secondary bone zone, above a level defined by that surface; a first projection carried by the tab and configured to penetrate the primary bone zone at the edge thereof, and below the first level; and an auxiliary tab associated with the first tab positioned to extend over a top surface of the primary bone zone to guide movement of the clip as the first projection penetrates the primary bone zone.

Abstract: The present invention provides a joint prosthesis system for the joining of two bones. The bioabsorbable joint prosthesis system includes at least one bioabsorbable spacer and at least one connector adapted to be fixedly attached to the two bones, at least a portion of the connector being in contact with the spacer to prevent lateral movement of the spacer. The present invention also includes embodiments drawn to methods of using the joint prosthesis system. In an embodiment of the present invention, the method includes interposing at least one bioabsorbable spacer between the surface of the bones to be joined and connecting the bones with at least one connector such that at least a part of the connector contacts the bioabsorbable spacer.

Abstract: A surgical tissue fixation system is described, including: (1) a bioabsorbable tissue fixation plate having optionally a plurality of through-holes arranged in alternating relation along the plate; (2) bioabsorbable fasteners adapted for insertion into the through-holes to secure the plate to underlying bodily tissue or bone; and (3) an installation instrument which triggers (strikes or shoots) fasteners one after one, in rapid succession, into the through-holes made through the plate and into the underlying bodily tissue or bone, which also optionally includes drillholes.

Abstract: A bone fixing pin comprising a pin body section (2) consisting of poly-L-lactic acid and a metallic perforating section (3) joined to the pin body section (2) and having a drill (4) at a head thereof, wherein at least the pin body section (2) is, preferably both the pin body section (2) and the perforating section (3) are, formed to have a cylindrical shape having the same diameter through the whole of the length direction thereof. Accordingly, the bone fixing pin can be embedded into (buried into) bone fragments to be fixed easily and smoothly. In addition, loose is never caused to occur after the embedding. The embedded pin body section (2) consisting of poly-L-lactic acid is absorbed in an organism to be eliminated after synostosis.

Abstract: A solid powder product with a Ca/P ratio of between 1.40 and 1.90 is prepared from tricalcium phosphate and tetracalcium phosphate. An aqueous solution containing calcium ions and phosphate ions with a Ca/P ratio higher than 0.20 and lower than 0.50 is prepared. The aqueous solution and the solid powder product and optionally water are mixed to obtain a mixture with a liquid/solid weight ratio of between 0.30 and 0.65 and a resulting paste with a Ca/P ratio of between 1.50 and 1.67.

Abstract: A bioabsorbable, cannulated tissue tack having an oblong head is used in sutureless soft tissue fixation to bone, particularly in arthroscopic shoulder surgery. Slotted ribs are formed along the shaft of the tack. Repair of the glenohumeral joint is performed by installing the tack through a hole formed through the soft tissue of the labrum and into the cancellous bone of the glenoid rim. Aligning the oblong head of the tack lengthwise along the glenoid rim provides a low profile that avoids articular impingement on the tack head.

Abstract: A sterile allograft bone screw comprising a screw shank with a uniform diameter threaded portion, an unthreaded portion with a outwardly tapered conical portion and a rectangularly shaped driving head portion with substantially wedge shaped end which can be engagably seated in a seat of a driver member.

Abstract: The present invention relates to a bone screw, a method for producing the threads of the bone screw and a drill for drilling holes therefor. The bone screw is adapted for implants for fixation of bone fragments at fractures and it comprises a threaded or tapped part (16) which is adapted to be screwed into a bone fragment at the fracture. The threaded part (16) extends backwards from a front end portion (17) of the bone screw (6) to an untapped part (18) thereof and has threads (19) with the same outer diameter (YD). The threads (19) have the same pitch of thread (P) and extend from a core (21). At least front parts of the core (21) closest to the front end portion (17) of the bone screw (6) are conical and have their least diameter (MD) situated at the front end portion (17). The threads (19) have truncated crests (23) and the width (b1-b7) of the crests (23) of the threads (19) increases in backwards direction from the front end portion (17).

Abstract: The present invention is directed to a method for the direct, one-step synthesis of crystalline segmented glycolide copolymers having less than 80 percent glycolide-based sequences in the copolyester chain. The copolyester chain can also be formed using a polyether glycol as the initiator for the ring-opening copolymerization of glycolide and other cyclic monomers to form highly hydrophilic materials.

Abstract: This invention relates generally to the production and use of inorganic-conditioning agent complexes for the controlled release of compounds including medicinals. Advantageously, the inorganic used is calcium sulfate and the conditioning agent is calcium stearate.

Abstract: A fixation device, such as a bone screw, includes a bioresorbable proximal shaft portion and a non-bioresorbable distal threaded portion. In one aspect, the shaft portion is provided with a longitudinal throughbore which is aligned with a corresponding longitudinal bore in the proximal region of the threaded portion. A driver mechanism is employed to impart a rotary force so as to enable the device to be inserted into bone tissue. Afterwards, the driver mechanism is withdrawn from the respective bores. In another aspect, the non-bioresorbable distal portion is a substantially elongated solid member and includes a threaded distal region and a shaft-like proximal region. The comparatively smaller bioresorbable proximal region can mate with the distal portion either after or before the distal portion has been inserted into the bone tissue.

Abstract: An apparatus (10) is provided for implantation into an adjacent pair of vertebral bodies (12 and 14) having first and second surfaces (17 and 19) that oppose each other. The apparatus (10), when implanted, is attached to the adjacent pair of vertebral bodies and stabilizes the vertebral bodies (12 and 14) while the vertebral bodies fuse together. The apparatus (10) comprises a platform (24) having a third surface (38) extending transverse to the first and second surfaces (17 and 19). The apparatus (10) further comprises at least one helical spike (50, 52) for embedding into each of the adjacent pair of vertebral bodies (12 and 14) upon rotation of the platform (24) to attach the helical spike to each of the vertebral bodies and thus fasten the vertebral bodies together. The helical spike (50, 52) projects from the platform (24) and extends around a longitudinal axis (22).

Abstract: The present invention contemplates use of a resorbable ceramic or other material inserted into a special container, the outer dimensions of which may be adjusted during insertion to provide firm fixation of a fracture. The special container consists of two spaced plugs connected together with a flexible boot and including actuator means allowing adjustment of the spacing between the plugs. The volume enclosed within the plugs and boot is filled with the resorbable ceramic material. As the actuator means moves the plugs toward one another, the material is squeezed and tends to expand radially outwardly, stretching the boot and increasing the outer diameter of the special container to wedge and fixate the container in the desired position within the location of the fracture. In the preferred embodiments of the present invention, all of the components of the special container are bioresorbable.

Abstract: The present invention relates to orthopedic implants made from a mesh material. The mesh material can be treated in order to promote bone growth, to provide antibiotics, or to provide other beneficial treatment. Specific applications for the implants include, for example, a prosthetic ligament, a tension band, an interbody device, or a fixation device that extends across one or more joints or fractures.

Abstract: The present invention provides an improved orthopedic system in which the part of the device that attaches to the bone is detachable from the parts of the device which provide the bone stabilization, distraction, etc. In a preferred embodiment, the system includes a proximal bone plate and associated proximal fastener, and a distal bone plate and associated distal fastener. The bone plates are affixed to the bone on opposing sides of the bone repair site, which may be an osteotomy. The fasteners serve to mechanically couple the orthopedic device, which may be a distractor, through the bone plates, to the bone. The fasteners are releasably mechanically coupled to the bone plates. This releasability permits the distractor and fasteners to be removed after the orthopedic procedure is complete, leaving only the bone plates in the patient. The bone plates may be made with a low profile, such that they may be left permanently in the patient.

Abstract: The invention provides a composition of an isolated human adipose tissue-derived stromal cell that has been differentiated to exhibit at least one characteristic of a non-adipocyte cell lineage wherein the non-adipocyte cell lineage is osteoblastic. The adipose-derived cell possessing an osteoblastic characteristic can be genetically modified or combined with a matrix. The compositions of the invention can be used in vivo to repair bone and treat bone diseases.

Abstract: An absorbable biocompatible polymeric matrix is described. The matrix has a continuous phase that is preferably amorphous. The matrix also has a disperse phase of low melting biocompatible material that acts as scattering centers for light and melts at a temperature lower than the continuous phase of the matrix. This matrix is especially useful in a variety of medical devices. When this matrix is heated to about the melting temperature of the dispersed phase the matrix undergoes a visual change. This provides a visual cue to a surgeon using the medical devices as to when the device can be safely shaped or manipulated without imparting undue stress to the device. As the medical device cools below the temperature at which it may be safely deformed the matrix resumes its original appearance signalling that it may no longer be safely shaped or manipulated.

Abstract: An absorbable biocompatible polymeric matrix is described. The matrix has a continuous phase that is preferably amorphous. The matrix also has a disperse phase of low melting biocompatible material that acts as scattering centers for light and melts at a temperature lower than the continuous phase of the matrix. This matrix is especially useful in a variety of medical devices. When this matrix is heated to about the melting temperature of the dispersed phase the matrix undergoes a visual change. This provides a visual cue to a surgeon using the medical devices as to when the device can be safely shaped or manipulated without imparting undue stress to the device. As the medical device cools below the temperature at which it may be safely deformed the matrix resumes its original appearance signalling that it may no longer be safely shaped or manipulated.

Abstract: An adhesive composition for surgical use including an &agr;-cyanoacrylate adhesive composition with a polymer characteristic for biodegrading and bioabsorbing the adhesive into the body of a living organism. It is preferred that the polymer is a co-polymer of DL-lactic acid and &egr;-caprolactone or a co-polymer of DL-lactic acid, ethylene glycol and &egr;-caprolactone, or a co-polymer of ethylene glycol and &egr;-caprolactone.

Abstract: A process and product comprising collagen and demineralized bone particles. The product may contain a maximum of 20% by weight inorganic materials. The product may densified by compression. Additional osteogenic factors, mitogens, drugs or antibiotics may be incorporated therein. Inorganic materials may be bound to the organic matrix via precoating with a calcium or hydroxyapatite binding protein, peptide or amino acid. The materials also display long lasting drug release characteristics.

Abstract: Bioresorbable pin systems useful for the reduction of bone fragments and for fixing bioresorbable membranes to a bone are provided, particularly pins having a detachable handle and a pre-fabricated hole in the handle through which a tether may be threaded to facilitate removal of the handle once it has been detached from the pin.

Abstract: A resorbable interbody fusion device for use in spinal fixation is disclosed. The device is composed of 25-100% bioresorbable or resorbable material. The interbody fusion device of the invention can be in any convenient form, such as a wedge, screw or cage. Preferably, the resorbable device of the invention is in the shape of a tapered wedge or cone, which further desirably incorporates structural features such as serrations or threads better to anchor the device in the adjoining vertebrae. The preferred device further comprises a plurality of peripheral voids and more desirably a central void space therein, which may desirably be filled with a grafting material for facilitating bony development and/or spinal fusion, such as an autologous grafting material.

Abstract: Synthetic absorbable medical devices made totally or in part from a random polymer comprising glycolide, lactide, trimethylene carbonate, and caprolactone are provided. The polymer can be fabricated into a monofilament which exhibits physical characteristics equivalent to or superior than gut sutures.

Abstract: Polymer blends of glycolide and/or lactide homopolymer and/or glycolide/lactide copolymer and polycaprolactone and/or polytrimethylene carbonate homopolymer or copolymers thereof and absorbable surgical devices manufactured therefrom having improved mechanical properties, such as improved impact resistance and improved cyclic flex, are disclosed.

Abstract: The present invention relates generally to body tissue fixation systems, including body tissue fixation hardware comprising biocompatible, bioabsorbable (resorbable) thermoplastic plates, and methods of using those systems and hardware.

Abstract: An osteosynthetic implant for a mechanical connection of fractured elements, made of a polymeric biodegradable base material, for use in reconstructive osteosynthesis. An active ingredient assists the regeneration of bone tissue in a fracture area and acts together with the implant to assist growth in the fracture area, so that the mechanical load-bearing capability of the healing fracture increases faster or at least as fast as the load-bearing capability biodegradable implant decreases when decomposing.

Abstract: A bioabsorbable material such as a terpolymer of poly-(L-lactide/D-lactide/glycolide). The material may consist of 85 molar percent L-lactide, 5 molar percent D-lactide, and 10 molar percent glycolide. The material may have a heat of fusion of about 15-25 J/G, tensile strength retention at 26 weeks of incubation of at least about 50%, and tensile strength retention at 52 weeks of incubation of at most about 25%. The material may be used in implantable devices such as bone fixation devices.

Abstract: A tool kit for use in the inducement of the reconstitution and healing of the sternum after an operation on a patient in the chest region in which during the operation the sternum is cut into two hemisterna. The kit serves for the post-operational approximation and fixation of the hemisterna in a position which enables their spontaneous growing together. The kit includes an approximation tool for the application of a selected force to the hemisterna to brig them into reconstituted configuration, and a set of clamping apparatus for firmly locking the hemisterna in the reconstituted configuration. The clamping apparatus is made of a non-immunogenic polymeric material that is readily degraded in the patient's body to yield degradation products readily absorbed by the patient's body.

Abstract: A gauge for measuring bone thickness includes an elongated pin for insertion into a bore through a bone section. The pin has a length sufficient to span the entire bone section with a distal tip protruding therefrom. The pin further has a length measurement indicator disposed along an outer surface, such as a series of colored bands or indicia, the visualization of which communicates bone thickness. In a particular embodiment a protrusion extending away from the pin's outer surface is provided to retain the pin within the bore. A cannula may be provided for facilitating the introduction of the pin into the bone section. Methods are also described for measuring bone thickness and for contouring bone.

Abstract: A substrate is rendered highly lubricious and wettable, by treating the substrate so that it becomes amine-functionalized, and chemically joining an aldonic acid to amine groups on the substrate. In the preferred embodiment, the chemical joining is performed with the aid of a coupling agent, such as a water-soluble carbodiimide, the coupling agent participating in the reaction which joins the aldonic acid to the amine groups, and which forms a residue that can be discarded. The coupling agent makes it possible to perform the process at room temperature. The method can be used to coat articles such as contact lenses, intra-ocular lenses, or other devices which are intended to be temporarily or permanently implanted in the body. The method can also be used in other fields, such as in coating of goggles, windshields, and other objects.

Abstract: A bone fusion apparatus and method for positioning over and attachment to a desired bone area which can provide for radial compression of bones, with particular suitability for wrist fusion by attachment to suitable bones such as, for example, a plurality of carpus area bones, with or without attachment to the radius bone and/or to one or more metacarpal bones. The bone fusion apparatus includes an annular plate having an outer side for at least partially contacting bone and an opposite inner side. The plate has a top outer edge of greatest diameter and a smaller diameter, bottom inner edge which defines an at least substantially central opening through the plate. The plate is substantially conical in shape such that the plate tapers outwardly from the inner edge of the plate to the outer edge of the plate. The plate defines a plurality of preferably countersunk holes therethrough between the inner edge and the outer edge, wherein each of the holes is adapted for receiving a bone fastener.

Abstract: Described are high-strength materials which are degradable and resorbable in the human and animal organisms and shaped articles manufactured therefrom, such as implants, based on cured (meth)acrylic acid esters of polyfunctionally hydroxyl-terminated oligomers of lower hydroxycarboxylic acids {polyfunctional (meth)acrylic acid esters}. The invention is characterized in that said materials and/or shaped articles have been three-dimensionally cross-linked by radiation-curing and/or any other, however boron-free, free radical-initiated polymerization of the polyfunctional (meth)acrylic acid esters and exhibit a tensile strength under standard conditions of at least 10 N/mm.sup.2.

Abstract: An anchor for securing soft tissue within a bone tunnel having an inner wall includes a resilient body member that defines a soft tissue opening and has a first, leading end and a second, trailing end. The anchor also has at least one bone engaging element connected to the body member. The anchor is movable between a first, sliding position wherein the at least one bone engaging element slides along the inner wall of the bone tunnel and the anchor is movable within the bone tunnel, and a second, locking position wherein the at least one bone engaging element engages the inner wall of the bone tunnel to resist movement of the anchor within the bone tunnel. In one embodiment, two opposed bone engaging legs are connected to the body at the second trailing end and extend at an angle away from the longitudinal axis and in a direction from the leading end to the trailing end. A pull tool engaging element provided on the second, trailing end of the body between the two opposed bone engaging legs.

Abstract: The present invention provides an improved orthopedic system in which the part of the device that attaches to the bone is detachable from the parts of the device which provide the bone stabilization, distraction, etc. In a preferred embodiment, the system includes a proximal bone plate and associated proximal fastener, and a distal bone plate and associated distal fastener. The bone plates are affixed to the bone on opposing sides of the bone repair site, which may be an osteotomy. The fasteners serve to mechanically couple the orthopedic device, which may be a distractor, through the bone plates, to the bone. The fasteners are releasably mechanically coupled to the bone plates. This releasability permits the distractor and fasteners to be removed after the orthopedic procedure is complete, leaving only the bone plates in the patient. The bone plates may be made with a low profile, such that they may be left permanently in the patient.

Abstract: A fastener for securing an osteosynthesis plate to a plurality of bone segments is provided. The fastener in the form of a fastener blank includes an elongated shank adapted for insertion through an opening in the plate and into a hole formed in the bone. The upper end of the shank forms a head that serves to secure the plate to the bone. The elongated shank is constructed of a material which when heated will deform to form a tight fit within the hole drilled in the bone. The fastener is preferably made of a resorbable material. The invention also provides a method for securing a plate to a bone using the fasteners of the invention. A fastener blank is positioned into the hole so that a portion of the blank extends into the hole provided in the bone and another portion overlies the plate. The blank is heated to raise the temperature of the blank above the transition temperature of the material from which it is made and deform the blank into a tight fit within the hole.

Abstract: A bone screw comprises a threaded shank having an axis of rotation. A head is integral with the shank, and the head includes a surface disposed generally normal to the axis. A plurality of drive receivers are disposed about the surface wholly remote from the axis. Each of the drive receivers is adapted for engagement with a cooperating driver element of a rotary driver so that the head and thereby the shank may be rotated about the axis.

Abstract: An endoprosthesis in the form of a hip joint has a stem and a joint part. The stem has a first individual stem part and a second individual stem part, wherein the first individual stem part has a first end connected to the joint part and a second end facing the facing end of the second individual stem part. A connection element made of bioresorbable material connects the second end of the first individual stem part and the facing end of the second individual stem part. When the endoprosthesis is implanted, the connection element is gradually resorbed so that the first and second individual stem parts become mechanically decoupled and load is introduced into the bone only via the first individual stem part now ingrown into the bone.

Abstract: An osteosynthetical fixing element, for the fixing of a bone implant, includes an accommodating body which is adapted to be introduced into a bone bore-hole and an expanding body, where, as a result of the driving-in of the expanding body into a longitudinally directed opening having a continuous wall, the accommodating body is radially expandable by a wedge effect. The accommodating body is sub-divided in the longitudinal direction, and includes at least two sub-elements which form a shaft with a cavity and are separate from one another or are connected to one another so as to be moveable in such a manner that as a result of the driving-in of the expanding body into the cavity, the accommodating body is expandable, substantially over its entire length, as a result of the mutual wedge effect of the accommodating body and expanding body.

Abstract: A meniscal tissue repair device includes an elongate body having a pointed distal tip. A plurality of lateral grooves is disposed along the body. Grooves disposed near the distal tip of the device are angled to open proximally and grooves disposed near the proximal end are angled to open distally. A torn meniscus can be repaired using the meniscal repair device by loading the meniscal repair device into an applicator, and inserting the barrel of the applicator through an incision in the knee at a location proximal and perpendicular to the tear in the meniscus. The applicator is actuated to drive the repair device distally into the meniscus across the tear. The distal travel of the repair device is limited by the distally-opening grooves of the repair device.

Abstract: A cannulated screw is employed to fasten an intramedullary nail to a bone of a patient. A guide is disposed within the intramedullary nail and registered with a preformed securing hole in the nail. Preferably, the guide is fabricated from a bio-absorbable material such as polyglycolic acid and fixedly registered to the distal securing holes. A flexible drill shaft is directed to the selected securing hole by the guide. The drill is operated to drill through the bone cortex and soft tissue of the patient to exit the skin of the patient. A cannulated fixation screw is fitted over the exposed drill bit and is then driven into the patient, guided by the drill bit back to the selected securing hole. The drill bit is then extracted and the cannulated screw is driven through the intramedullary nail into the opposite cortex of the bone. After all of the fixation screws have been placed, the intramedullary nail is fastened to the bone.

Abstract: A gauge for measuring bone thickness includes an elongated pin for insertion into a bore through a bone section. The pin has a length sufficient to span the entire bone section with a distal tip protruding therefrom. The pin further has a length measurement indicator disposed along an outer surface, such as a series of colored bands or indicia, the visualization of which communicates bone thickness. The gauge also has a head at a proximal end of the pin, which is dimensioned to prevent its movement into the bone section's bore. In a particular embodiment a protrusion extending away from the pin's outer surface is provided to retain the pin within the bore. Methods are also described for measuring bone thickness and for contouring bone.

Abstract: A method for internal fixation of vertebra of the spine to facilitate graft fusion includes steps for excising the nucleus of an affected disc, preparing a bone graft, instrumenting the vertebrae for fixation, and introducing the bone graft into the resected nuclear space. Disc resection is conducted through two portals through the annulus, with one portal supporting resection instruments and the other supporting a viewing device. The fixation hardware is inserted through small incisions aligned with each pedicle to be instrumented. The hardware includes bone screws, fixation plates, engagement nuts, and linking members. In an important aspect of the method, the fixation plates, engagement nuts and linking members are supported suprafascially but subcutaneously so that the fascia and muscle tissue are not damaged. The bone screw is configured to support the fixation hardware above the fascia.

Abstract: A bone fixation screw system and method of utilization thereof is provided for a bone having first and second sections with a fracture interface there between. A preferred embodiment of the bone fixation screw system includes a side plate having a first part for placement adjacent the bone second section and a second part angled from the first part providing a barrel. The barrel is adapted for insertion into a transsectionally extending bore into the bone in at least the second section of the bone. A lag screw is also provided for positional retention of the first section of the bone with respect to the second section of the bone. The lag screw also has a first part of a resorbable material for threaded connection of the lag screw within the bore of the bone in at least the first section of the bone, the lag screw having a second part connected with the first part made from a stronger nonresorbable material.

Abstract: The present invention provides a bone joining device used for joining, fixing and reinforcing fractured bones. The bone joining device is produced by pressing a molded product of a biodegradable and bioabsorbable resin.

Abstract: A resorbable implant for interposition arthroplasty which is intended to fill a void between two adjacent bone ends, providing a cushion between the bone ends to prevent impingement of the bone ends while providing time for tissue to infiltrate into the space occupied by the implant. It has a protracted resorption time of preferably at least three months to allow time for the proliferation of load-bearing host fibrous tissue in place of the resorbed implant material. The implant preferably is porous with a pore size of greater than about 80 microns in order to enhance infiltration of fibrous tissue. The implant has a modulus in the range of 0.8 to 20 MPa which is soft enough to allow it to conform to surface irregularities of the adjacent bone surfaces while being hard enough to maintain a desired separation between those bones while tissue infiltration replaces the resorbable implant material.

Abstract: A bone fracture is repaired using a flexible, resorbable cannulated, self-tapping (in soft bone) compression and decompression fixation element to retain respective sections of bone in a spatial relationship that facilitates mending with minimal or no compression, that might otherwise lead to collapse and/or misalignment of the bone sections. The fixation element is inserted through a first bone section and intersects a second bone section at an acute angle relative to the fracture. As the fixation element is driven into the second bone section, its elasticity stably secures the mutually facing surfaces of the two bone sections in a mending position. Since the fixation element is flexible, its forward end may be deflected when it encounters the sidewall of the second bone section.

Abstract: Fastening nail which is made of bioresorbable plastic material and is for the fixing of a covering membrane to an endogenous bone surrounding a bone void filled with bone replacement material, has a nail head of a larger diameter, enabling impact with a pressure and/or striking tool, and has, connected thereto, a nail shaft of a smaller diameter, which comprises an essentially cylindrical holder part and, connected thereto, a tip part with a jacket cone surface tapering in the direction towards the nail tip, the plastic material is at least partially non-crystalline (amorphous) and has a glass transition temperature in the region of body temperature, and the plastic material in the region of the nail shaft comprises a preferred molecular orientation that runs essentially parallel to the longitudinal axis of the fastening nail.

Abstract: The present invention discloses a nut to be used in a spinal screw and plate assembly to affix the screw and plate assembly to the spinal bone. The nut has a polymer insert that when contacted with a screw allows a bone plate and screw structure to relax over time.