Abstract: A surgical site chemical dispensing system for dispensing a liquid chemical agent, such as an antibiotic, anesthetic, growth factor, hormone, anti-neoplastic agent, or the like, directly onto a site of a surgical procedure. The system includes at least one bladder formed from a pair of thin sections of a flexible material to have an internal cavity that connects to an open tube wherethrough the liquid chemical agent is passed, under pressure, into the bladder. The liquid chemical agent passes, as a low volume flow, through at least one hole formed through a bladder section of material and onto the surgical procedure site. The invention includes a fixation device that includes at least one hollow pin for passing a volume of the liquid chemical agent therethrough directly into or onto a bone proximate to a fracture therein.

Abstract: Disclosed is a bone fixation device of the type useful for connecting two or more bone segments during the healing process. The device comprises an elongate pin having a distal anchor thereon. A proximal anchor is axially movably disposed with respect to the pin, to accommodate different bone dimensions and permit appropriate tensioning of the fixation device. The bone fixation device may comprise bioabsorbable or permanent materials such as poly-p-dioxanone, poly L-lactide (PLLA), nylon or stainless steel.

Abstract: The bone-fixing devices which are designed to allow for a freer assembly of the parts which are mounted to maintain plurality of bones in a specified position relationship, and also call for only one or two parts to be tightened to assemble all parts into the whole system. A pedicle 10 to be implanted into a bone is connected by using a connector 20 with a shaft 30 that serves as a reference to position the bones. In order to ensure that the pedicle 10 is connected with the fixture 20, a shaft 12 is supported in a fork 21 formed at the end of the fixture 20, said short shaft 12 is fitted into a concave 11 formed at the head of the pedicle 10, and said short shaft 12 is fixed at the head of the pedicle with a retaining screw 13 so that the fixture 20 is mounted rotatably about the short shaft with reference to the pedicle 10.

Abstract: A bone fastener is adapted to deliver biologically active substances to a bone site. An applicator is saturated with the substance and is disposed within an inner cavity of the fastener, near the bone site. Channels through the body of the fastener permit the substance to flow to the bone site. The substance can include therapeutic drugs, such as antibiotics, analgesics, bone morphogenic proteins, DNA, chemotherapy drugs and angiogenesis factors.

Abstract: An internal fixation device used in surgical procedures to the internal fixation of femoral hip fractures, especially prevalent in elderly persons suffering from osteoporosis. This device includes a femoral shaft side plate, an internally threaded sleeve pivotally mounted on said side plate, an elongated screw member insertable in the sleeve to fasten the sleeve in the femoral head, and wedge-shaped washer means for fixing the pivot angle between the sleeve and the femoral side plate at the natural angle between the axis of the femoral neck the femoral shaft of the hip being treated.

Abstract: A modular intramedullary nail which, selectively, includes two or three connectable sections that are connectable end to end. In the two section nail the second section is an elongated curved nail component having an elongated, open-ended longitudinal bore, and terminating in a distal end. The three section nail includes an upper proximal nail component having an open-ended bore. The second section is a central nail section that is an elongated curved nail component having an open ended longitudinal bore. The third section is a lower distal nail component having an elongated open ended longitudinal bore. The nail components are connected at the end using corresponding conical socket and conical projecting end portions of adjoining end nail components that can be fitted together and secured upon impact. Upon assembly, the connections are self orienting, providing corresponding tooled "flat" portions adjacent the respective conical socket and conical projecting end portions of the nail components.

Abstract: Presented is a metallic cannulated rivet adapted for implantation in a bone mass through use of arthroscopic or open surgery for attachment of soft tissue thereto. The rivet in a first configuration is implanted, following which, a portion of the implanted rivet projecting from the bone site and penetrating the soft tissue is reformed in situ to clamp the soft tissue to the bone site. In a second aspect, the invention comprises the method and instrumentalities for effecting implantation of the rivet and reformation thereof in situ to mechanically clamp the soft tissue to the bone site. The method includes forming a small portal or incision to expose and prepare the bone site, torn or severed soft tissue is mobilized to intimately contact the bone site, the soft tissue is retained in proper position and a K-wire is advanced through the portal to penetrate the soft tissue and the bone mass to a predetermined depth and mark the point of implantation of the cannulated rivet.

Abstract: The present invention relates to a guide instrument which is adapted for use at operations for fixation of bone fragments at bone fractures, preferably femoral neck fractures, whereby the bone fragments are intended to be fixed relative to each other by means of at least two bone screws, whereby the guide instrument (1) is adapted for guiding a first and a second drill steel which are adapted for drilling passages in the bone fragments for the bone screws. The guide instrument (1) is designed to permit guiding of the drill steels, driving through of threaded front portions of the bone screws and guiding of uptapped or unthreaded rear portions of said bone screws.

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: A hip joint prosthesis to be permanently anchored in a patient's hip is disclosed. The prosthesis comprises an attachment part for a ball unit designed to be anchored in the neck of a human femur. The attachment part comprises a primary fixture which may be an elongate anchoring element which is intended to be inserted into a channel extending through the femoral collum. The prosthesis also includes a secondary fixture for carrying a ball intended to be attached to the collum after removal of the head of the collum. The primary fixture and the secondary fixture are connected to each other. The prosthesis is preferably designed so that the length of the primary fixture terminates close to the head of the collum. The secondary fixture preferably comprises a plug-like part which is intended to be inserted in a cylindrical countersunk recess that is cut into the cancellous bone of the collum and which extends to the cortical bone in at least three locations.

Abstract: A new cutting tip and a very simple method for making the tip are given. The tip has no flutes but has a built-in chip clearance. It is self-drilling, self-tapping, and self-locating and can be positioned on a threaded or unthreaded member. When it is the tip on a suture anchor, it maximizes holding strength of the anchor.

Abstract: An anchoring screw (1) is disclosed for implantation in bone, consisting of a tissue compatible material for supporting prostheses, artificial joint components, or the like. The anchoring screw (1) has at least one slot (5, 5a) extending from its threaded outer surface at a distance from the insertion end (3). The slot (5, 5a) is arranged to receive a blanking element (6, 6a) which shields the slot (5, 5a) during the application of the anchoring screw (1) and its integration in a recess prepared beforehand in the bone during a healing stage. The blanking element (6, 6a) is replaced, after integration of the anchoring screw (1) with the bone, by a holder for a prosthesis, the holder including a web portion insertable into said slot. There is also disclosed an anchoring arrangement comprising at least one such anchoring screw and such a holder or coupling, and a method for application of such an anchoring arrangement in osseous tissue.

Abstract: Hip joints are reinforced preventively by a device composed of a tubular element fashioned from biocompatible material, accommodated by a socket drilled in the femoral bone parallel and adjacent to an axis connecting the ball and the diaphysis, and two independent locking assemblies operating unidirectionally and in mutual opposition, likewise of biocompatible material, by which the tubular element can be deformed and manipulated in such a manner as to lodge stably in the surrounding bone tissue of the socket, establishing a load-bearing axis that functions as a bridge between the weaker axis and the main axis of the femur.

Abstract: A prosthesis for interfacing with an internal region of a bone of a given structure and function such as a femoral head and/or neck, wherein the internal region of the bone can be an avascular necrotic region. The prosthesis comprises porous filling member for filling a cored channel provided in the internal region of the bone to provide mechanical stability which preserves the function and the structure of the bone and accommodate an ingrowth of healthy vascularized bone tissue into the internal region of the bone. Also, a method for mechanically stabilizing a bone using the prosthesis.

Abstract: A fixator for internally fixating bone fractures includes an elongate plate portion, a head portion and a barrel extending from the head portion. The elongate plate portion defines at least one plate aperture extending through the plate for receiving bone screws to fasten the fixator to a shaft of a bone. The barrel extends from the head portion and has a generally cylindrical inner surface configured for slidably receiving an end of both keyed and non-keyed lag screws. The cylindrical inner surface further defines at least one keyway along a length of the tube for receiving a key of a keyed lag screw to prevent rotation of the keyed lag screw and for also allowing rotation of a non-keyed lag screw.

Abstract: A longitudinal revascularization conduit is formed in the body of an implant. It is blind at the distal end of the body to be implanted in one bone fragment, such as the trochanter, and open via transverse orifices and at the proximal end of the body to be implanted in another bone fragment, such as the femoral head. At least one self-tapping section situated at the distal end of the body immobilizes the body in the bone, or an anchor end-piece is slidably mounted on the body and contains a damping device adapted to push the end-piece in the proximal direction and the body in the distal direction in order to maintain the fracture in compression. The distal end of the body may be mounted in a cylindrical portion of a plate secured on the diaphysis of the femur.

Abstract: The present invention relates to an implant for fixing femoral fractures and the like. The implant consists of three main parts, namely a first part consisting of an angle element, a second part which forms a holder and a third part in the form of a screw. The angle element includes a sleeve for receiving the screw. Both the sleeve and the screw are intended to be passed into a channel provided through the neck and head of the femur of a patient. The angle element moreover includes a slide which is slidingly accommodated by the holder. The holder is, in its turn, secured by means of anchorage screws in the shaft of the femur. By cooperation between the slide and the holder the possibility is afforded that the angle element may move in relation to the shaft of the femur. The sleeve of the angle element is disposed at an angle in relation to the slide.

Abstract: An anchoring member is provided which comprises a shaft 2 to be fastened to a bone and a head 3 for connection with a rod 10, the head having a substantially U-shaped cross-section and being connected with the shaft 2 at the base 5 thereof, the head further comprising two free legs 6, 7 defining a channel 4 for receiving the rod 10. The free legs 6, 7 are provided with an internal thread 8 extending in direction of the legs. A fastening member 11 and a member 12 embracing the legs at the outside thereof are provided. In order to allow not only straight rods, but also curved rods to be received and thus to allow an individual adaptation to the conditions of the spinal column to be treated the free legs have an external thread 9 and the member 12 has an internal thread cooperating therewith. The fastening member 11 comprises a thread cooperating with the internal thread 8 to allow the fastening member to be screwed in.

Abstract: The invention contemplates a compression wire for fixated retention of a fractured small bone fragment in an osteosynthesis procedure. The wire comprises a smooth-walled shank portion and an adjoining threaded portion, of lesser diameter than the diameter of the shank portion, there being a step-down shoulder between the shank portion and the threaded portion. The shank portion is adapted for chucked engagement to a portable rotary drill, and the distal end of the threaded portion is configured for self-tapping entry into and threaded implantation in bone. The implantation is complete when the shoulder engages cortex tissue of the fragment, holding the same in compression against remainder structure of the fractured bone. Once implanted, the shank may be nipped by a cutter tool at relatively close offset from the shoulder.

Abstract: A prosthesis is provided having at least a smooth non-articulating load bearing surface disposed adjacent a bone. The prosthesis includes a substrate formed from a metallic alloy. At least the regions of the substrate defining the load bearing surface are coated with a biologically inert abrasion resistant material harder than the substrate for preventing leaching of ions from the substrate into adjacent body tissue and for preventing wear. The coating may be titanium nitride or zirconium or other such material exhibiting biological inertness and acceptable hardness. The coating preferably defines a thickness of 8-10 microns.

Abstract: Method and apparatus for reduction of spondylolisthesis involving the insertion of an elongate implant which is split longitudinally into two side-by-side members, one of which is movable relative to the other, into the disk space between two misaligned vertebrae. Each of the members is provided with teeth for engaging the adjacent vertebrae and positioned on the members so as to be located on opposite sides of the implant. The implant formed by the two side-by-side members is generally rectangularly-shaped in cross section, the height of the rectangularly-shaped cross section being less than the width so that the implant can be inserted between the adjacent vertebrae with the lesser, height dimension oriented in the same direction as the axis of the spinal column and the larger width dimension at approximately a right angle to that axis.

Abstract: An odd angle internal fixation device for a transverse fracture located at the junction of the metaphysis and diaphysis of a long bone such as the proximal humerus. The internal fixation device includes an elongated lag screw and a rectangular shaped guide plate. The lag screw is introduced through the diaphyseal segment of the fracture at an angle ranging approximately between 155.degree. to 170.degree., cross fixing the bone fracture line and settling in the depth of the epiphysis. The guide plate serves as a guide for the lag screw and allows the engagement of the head of the screw to the inner wall of its short barrel. The engagement would cause the rectangular guide plate which is attached to the barrel, to be compressed against the diaphyseal cortex as the screw advances deeper into the epiphysis.

Abstract: A modular knee prosthesis includes a femoral component having a pair of laterally spaced apart condylar portions each having a superior, articulation surface and an inferior surface. A boss structure is disposed between and connects the condylar portions. The boss structure has an inferior surface that extends generally horizontally in the transverse plane, and an opposed superior surface. The boss structure has an aperture having a selected configuration formed therein and which extends between the inferior and superior surfaces. The boss structure has formed on the superior surface thereof a positioning structure, e.g., a plurality of grooves, that define one or more positions, in the transverse plane, in which to seat a femoral stem assembly. A washer is mountable upon the superior surface of the boss structure and over a portion of the boss aperture. The washer includes at least one detent that cooperates with the positioning structure to secure the washer in one of the mounting positions.

Abstract: A bone plate is disclosed having a longitudinal shaft section with boreholes to admit attachment screws. Two forklike prongs are attached to the shaft section. The prongs are bent relative to the longitudinal axis of the shaft section at an angle from 60 degrees to 150 degrees. The prongs can be lengthened individually so that the bone plate can be adjusted to different applications, even interoperatively, and without great expense.

Abstract: A low cost and easy to assemble external fixator for the stabilization of a bone fracture is disclosed. The assembly of the external fixator makes use of a clamp to secure a pin to a stabilization bar. The body of the clamp will have an indentation that can be placed over the stabilization bar. Each arm of the indentation will have a hole with the two holes being aligned such that a single pin can be placed through both holes across the mouth of the indentation. Once the stabilization bar is within the indentation a pin can be inserted through the two holes in the arms of the body to restrain the stabilization bar within the clamp. The clamp will have a force applicator such as a screw that will lock both the stabilization bar and pin to prevent relative motion of the stabilization bar and the pin relative to the clamp. The preferred clamp will have a retaining clasp for gripping the stabilization bar to resist the separation of the stabilization bar from the clamp.

Abstract: An anchoring member for connecting a rod with a bone comprises a screw member having a treaded portion and a screw head with a spherical segment-shaped portion, a seat part receiving said screw head of said screw member and said rod, and a pressure member formed to embrace said screw head from its side opposite to said threaded portion. The seat part has a first end, a second end opposite to said first end, an axis of symmetry passing through said first and second end and a bore which is coaxial with said axis of symmetry for passing said threaded portion therethrough and has a first portion adjacent to said first end, said first portion having a substantially U-shaped cross-section with two free legs with an internal screw thread for receiving said rod therebetween.

Abstract: A method for repairing fractures of the olecranon including creating a hole in the proximal end of the ulna, where the hole extends from the proximal end of the ulna to the fracture to define a first region, and from the fracture to the proximal end of the medullary canal to define a second region. A screw is selected having a cancellous section and a medullary section extending from the cancellous section. The cancellous section includes a threaded region adjacent the medullary section and the medullary section is adapted to fit into the medullary canal of the ulna. The medullary section is installed into the hole up to the threaded region and the screw is then rotated to drive the threaded region into the hole until the threaded region engages the cancellous bone surrounding the hole in the second region and the medullary section extends substantially into the medullary canal.

Abstract: A compression hip screw plate for a hip screw system used to compress a proximal femur having a shaft with a lateral aspect and a neck extending from the shaft at an anteverted angle, both of which follow the anatomical contours of the proximal femur. The compression hip screw plate may include a side plate having a face side attachable to the lateral aspect of the shaft of the proximal femur; and a barrel having a first end extendable through the lateral aspect of the shaft of the proximal femur and into the neck of the proximal femur, and having a second end attached to the side plate with the first end extending away from the face side of the barrel at an anteverted angle. The compression hip screw plate may include a side plate with an anterior bow to match the natural femur.

Abstract: Apparatus for reattaching a ligament or implanting a ligament replacement in bone comprising a first ligament attaching element for coupling to a first end of the ligament or ligament replacement, a second ligament attaching element for coupling to a second end of the ligament or ligament replacement, a first engaging element slidably disposed on the first ligament attaching element and having at least one longitudinally extending finger, a second engaging element slidably disposed on the second ligament attaching element and having at least one longitudinal extending finger. The finger of each engaging element is directed toward the other. The first attaching element and first engaging element are adapted to be inserted in a first bore in a first bone member.

Abstract: The invention contemplates a compression wire for fixated retention of a fractured small bone fragment in an osteosynthesis procedure. The wire comprises a smooth-walled shank portion and an adjoining threaded portion, of lesser diameter than the diameter of the shank portion, there being a step-down shoulder between the shank portion and the threaded portion. The shank portion is adapted for chucked engagement to a portable rotary drill, and the distal end of the threaded portion is configured for self-tapping entry into and threaded implantation in bone. The implantation is complete when the shoulder engages cortex tissue of the fragment, holding the same in compression against remainder structure of the fractured bone. Once implanted, the shank may be nipped by a cutter tool at relatively close offset from the shoulder.

Abstract: A device for stabilizing fractures of the upper end of the femur, comprising a plate which includes in its upper part two parallel, cylindrical barrels offset by a first angle with respect to a vertical plane passing through the middle of the plate and a second angle with respect to a horizontal axis passing through the middle of the plate.

Abstract: An expandable bone marrow cavity fixation device comprises a hollow tubular body provided peripherally with a plurality of through holes, in each of which a diameter-adjusting element is movably disposed. An adjustment element is adjustably disposed in the hollow interior of the tubular body such that the inner end of the diameter-adjusting element is urged by the adjustment element. An urging element is rotatably disposed in the hollow interior of the tubular body such that the upper end of the adjustment element is urged by the bottom end of the urging element, and that the adjustment element can be so actuated by a rotational motion of the urging element as to force the diameter-adjusting elements to jut out of the through holes of the tubular body to bring about an increase in outer diameter of the tubular body.

Abstract: A cannulated bone screw for anchoring bidirectional suture threads to bone is provided, comprising a biocompatible body having a proximal end and a distal end, the body including exterior screw threads, preferably self-tapping, for inserting and retaining the body into the bone; a passageway extending through the body, the passageway including a central portion, a proximal portion, and preferably a distal portion, the central portion being sized to receive a suture thread therethrough, the proximal and distal portions each being sized to receive a suture thread knot, the central portion being sized smaller than the proximal and distal portions, the central portion being sufficiently small as to prevent a suture thread knot from being drawn therethrough; and a drive socket, formed into the proximal end of the body, the drive socket being sized to prevent a drive tool from contacting a suture thread knot within the proximal portion of the passageway.

Abstract: A femoral intramedullary rod has a thin or reduced proximal segment so as to provide room for the use of femoral hip screws. Use of the rod for femoral shaft fixation permits subsequent independent treatment of an ipsilateral femoral hip fracture as an isolated injury, regardless of whether initially detected. Different rod embodiments are formed by the omission of different proximal portions of the rod. It is in such portions that the femoral screws may be placed to set hip fractures. The rod is cannulated for installation over a guide wire. Internal rod threads, below the thin proximal segment in some embodiments, are used for initial installation of the rod with a driving member screwed into such threads. Without driving forces on the thin proximal segment, such segment can be made even thinner. Once the rod is seated, hip screws may be installed if there is a detected hip fracture. Subsequent to healing, the femoral screws and interlocking screws (if any) may be removed.

Abstract: The device includes a medullary rod that is locked to a bone of a patient and that has at least one threaded hole with an axis parallel to the femoral neck of the bone, at least one self-drilling, self-tapping screw designed to pass through the hole in the rod and to engage the femoral neck of the bone, at least one sleeve designed to fit around a proximal end of the screw and to be threaded into the hole in the rod, and a shoulder on the sleeve for immobilizing the sleeve relative to the rod. According to the invention, the proximal end of the screw has a circular cross section which is formed to slide within a bore in the sleeve. Each sleeve has a threaded exterior portion which engages the threaded hole, and a proximal end portion shaped to allow the sleeve to be threaded into the hole in the rod. The shoulder on the sleeve bears against the rod to immobilize the sleeve relative to the rod when the sleeve has been fully threaded into the hole.

Abstract: An improved device for repairing fractured bones is provided, the device comprising a specially designed connector, which is especially useful in combination with a plate having a tab cut out, a stop, a flat portion and a bore portion and with a compression screw and a lag screw.

Abstract: A modular implant for use in stabilizing femoral bone disorders resulting from injury, disease or congenital defects. In one embodiment the implant has an upper side plate with a widened head and a angled barrel, and a lower side plate adapted to be engaged with the upper side plate in a tongue and groove configuration. The side plates, once engaged, conform with the cortical wall of the femur.

Abstract: A device for treating fractures of the neck and shaft of bones such as the femur, which includes a sleeve strap and a trochanter stabilization plate, and is designed so that the stabilization plate can be positioned over a previously installed sleeve strap.

Abstract: The invention relates to systems and methods for harvesting bone marrow and biopsy sections of bone. A hollow screw is attached to the bone and then a negative pressure is applied to the screw to withdraw the bone marrow through the hollow portion of the screw. One system and method includes inserting a pin into the bone and then positioning the screw on the pin. A guide cannula may be used to insert the pin. The screw is inserted into the bone and then the pin withdrawn, leaving the screw in the bone to withdraw the bone marrow. Another system and method includes using a screw with a head end and an opposing threaded end, with the threaded end being provided with cutting flutes or partial or full missing threads, or both, and then withdrawing the bone marrow from voids created by the flutes or the missing threads.

Abstract: A bone screw comprises a receiver member (5) and a screw member (1) having a threaded portion (2) and a head (3) having a spherical segment-shaped portion. The receiver member (5) comprises an internal thread (10) for allowing a relative adjustment of receiver member and screw member and the connection of the receiver member with a round rod. A pressure means (12) acts onto the head (3) and the rod (16) is placed on top of the pressure means. The arrangement is locked by means of a rod locking nut (13) and a lock nut (14) is screwed onto an external thread (11).

Abstract: A bone fixation screw employs plural interleaved and axially symmetrical spiral threads. The threads are machined at the screw tip to form symmetrically disposed leading cutting edges. An interference-screw embodiment has a central axial cannula and a female hexagonal drive socket. The plural threads assist in unbiased starting and fast advance of the screw.

Abstract: A device for the holding and compression of the fragments of a fractured bone, the device including a screw whose tip is pyramidal or conical and whose body is provided, at a distal end thereof, with an outside thread, wherein the head of the screw has a plurality of foldable small wings integral with the body and wherein the screw has a device for folding the small wings. The device is useful particularly for fractures of the scaphoid, of the medial malleolus, Garden fractures 1 and 2 of the neck of the femur, pertrochanterian fractures of the femur, and generally, for fractures of small bones, and for putting in place hip or shoulder stops.

Abstract: A surgical connector for cable comprises a body having a pair of opposed ends and a first side extending between the ends. Outwardly extending projections adjacent the first side and ends may be provided to facilitate securance of the connector in a desired position. Cable-receiving bores extend from each of the ends inwardly toward each other, typically at an obtuse angle of less than 180.degree.. The bores have inner ends that communicate with a central aperture which is open to at least the side of the body which is opposed to the first side. Alternatively, the central aperture may extend entirely through the body and be open to both the first side and the opposed side. Also, a novel retention technique for cable is disclosed, for more general use, if desired.

Abstract: The invention relates to a screw for fixing an intramedullary nail in position. An external thread on the screw shank is provided over only a part of the length of the shank. The screw head is provided with an external thread having a direction of helical advance which is opposite the direction of helical advance of the screw-shank thread.

Abstract: A bone screw and its method of manufacturing provides a low modulus osteoinductive bone screw with a high resistance to insertion torquing. The method includes the steps of pre-torquing a plurality of reinforcing fibers, molding a polymer matrix to bond with the pre-torqued fibers, and wherein the screw apparatus is coated with an osteoinductive material such as BMP, growth factors, hydroxyapatite or calcium phosphate.

Abstract: A device for treating fractures of the odontoid apophysis of the second cervical vertebra (axis) by containing the osseous fragments. The device includes a plate shaped to be placed on the caudal fragment of the axis and serves as a support for the head of a screw. The plate additionally contains a barrel for guiding the screw which is threaded into the cranial fragment of the odontoid apophysis of the axis. The plate has a forked part extending on the caudal side of the axis and which part is attached to the anterior surface of the body of the third cervical vertebra. The invention prevents the head of the screw from penetrating into the caudal fragment of the axis and the self-tapping screw from brushing the fragile caudal fragment before forming a positive hold in the cortical cranial fragment.

Abstract: A spinal fixation apparatus and method wherein various elements are mounted to the vertebra and the sacrum of a spine and are selectively interconnected to achieve a predetermined fixation and/or correction of a particular spinal condition. The apparatus includes pedicle screws, bone screws, sacral rods, sublaminar hooks, spinous process hooks, longitudinal rods, lateral rods, universal interlinks, rod clamps, and pedicle screw anchors, all of which can be readily interconnected into a predetermined construct as a spinal fixation apparatus. A burr guide apparatus is provided to prepare the access site for a pedicle screw and a sacral screw guide is used to accurately align the pilot holes for the sacral screws.

Abstract: In a screw device (10; 80) for fixing prostheses to bones, the threaded shank (14) comprises a core (32, 34) of overall frusto-conical shape. The screw has a cylindrical neck (12) of diameter equal to or greater than the maximum diameter of the thread. This latter is of two different types, namely a first thread (26) of large pitch for fixing into the trabecular bone tissue (52) and a second thread (28), which can be of the self-tapping type, for fixing into the cortical bone opposite the point at which the screw is inserted into the bone. The second thread (28) has a number of starts which is a multiple of that of the first thread (26). For orthopedic use the screw (80) can comprise a third thread (128) on a part of the neck (112) for fixing into the relative cortical bone (50). A method for applying the screw device (10; 80) consists of forming a precision hole (40) in the bone, tapping said hole with a tapper (60; 100), and screwing the screw (10; 80) into it.

Abstract: The invention relates to a bone screw (10) which can be anchored in the bone in a firm and vacuum-tight manner, and to the use of the same in arthroplastic surgery and as a drug delivery system. The interior of the bone screw (10) has a continous longitudinal bore (15) through which the medullary canal can be evacuated during the application of bone cement. The use of the bone screw renders it possible to fill the spongiosa honeycombs with bone cement without endangering the life of the patient.

Abstract: A bone screw (1) has a screw head (2), a screw tip (11), and a shaft (5) with a thread (8,14). The threaded segment (6,7) of the shaft (5) has a head-end, essentially cylindrical first shaft section (6) with minor diameter d.sub.1 (16), and a tip-end second shaft segment (7) that is connected with the first shaft segment (6) and which has a smaller minor diameter d.sub.2 (17). The thread (8,14) in the two shaft segments (6,7) has the same pitch (10,12).