Abstract: A bone fracture stabilization apparatus includes a cable positioning insert for a bone plate of the type having a series of apertures therein for receiving bone screws for attaching the bone plate to the bone. The cable positioning insert has a body shaped for at least partial insertion into at least one of the apertures of the bone plate. The insert further includes a flange extending from the body for engaging either the outer or inward surface of the bone plate. A boss extends from the body in a direction away from the bone when the bone plate is mounted thereon. The boss has at least one opening and preferably two openings therein for accommodating a cerclage cable and positioning it relative to the apertures in the bone. The boss may be made of a malleable material that deforms under pressure to flatten the openings therein and capture the cable.

Abstract: A beam adapted for implantation within a bone is able to support bending and torsional loading forces applied thereto. The beam has a stiffness defined by a modulus elasticity, which stiffness varies along the length of the beam to match the corresponding stiffness of the cortical bone adjacent the beam after implantation within the bone. The beam is made from an elongated core formed of continuous filament carbon fibers embedded in a thermoplastic polymer matrix with the carbon filaments extending in a direction substantially parallel to the longitudinal axis of the beam. Encasing the core is a filler molded to the core, which filler is made up of the same thermoplastic polymer as the core but contains no reinforcing carbon fibers. The filler provides the prosthesis with a shape generally conforming to the desired shape of the final prosthetic implant. A sheath formed of carbon reinforced filament fibers embedded in the thermoplastic polymer is wound in spiral formation around the filler and molded thereto.

Abstract: An acetabular cup for use in a total hip prosthesis includes an implant/cement interface portion for location in a cement mantle. The cup has an enclosure element for allowing the cup to slide lengthwise to re-engage itself in the cement mantle to accommodate creep or movement thereof. Thus, should there be a tendency for the cup to become loose, the construction according to the invention is intended to relock the cup within the cement mantle. Thus, if the bone remodels, then the cement mantle will creep to re-adapt itself to the bone and the implant will re-engage in the cement mantle accommodating to the movement of the cement. If the bone cement is too highly stressed in places, it will creep in order to relieve this stress and the implant will re-settle.

Abstract: An acetabular cup for use as a prosthetic implant has an insert with a body including a central bore for receiving a positioning rod therein. A key element is formed on the bore and is adapted to align the positioning rod. The insert has a locating element formed on an outer surface of the body and also includes spring elements extending radially outwardly from the body. The acetabular cup has a generally hemispherical shell member coupled to the outer surface of the insert. The shell has an outer surface for engaging the acetabulum and an inner surface having a circumferential groove for receiving the spring elements. The spring elements may be deflected radially inwardly out of engagement with the groove for releasing the insert from the shell. The shell has a plurality of apertures extending from its inner to its outer surface, which apertures are located in an asymmetrical pattern about the shell.

Abstract: A method and apparatus for use in reducing the volatilization of the monomer component of bone cement is used after a prosthesis is implanted and throughout the polymerization of bone cement. The apparatus includes a generally annular inflatable sealing member having a centrally located opening therein for fitting over the exposed end of the prosthesis. The sealing member has an outer diameter covering the exposed surface of the bone cement. The sealing member has a deformable surface disposed in a substantially co-planar relationship with the exposed surface of the bone cement. The sealing member is resiliently expandable by inflation and extends beyond the edges of the bone defining the cavity, to seal the bone cavity upon the deformation of the deformable surface thereon. A pump is provided for inflating the sealing member and causing the deformable surface to apply pressure to the exposed surface of the bone cement.

Abstract: A prosthetic cup member, in particular for use in the hip joint, has a hollow outer shell which is adapted to be affixed to the bone. The cup has an inner shell having a recess for accommodating a bearing element. The inner shell and the outer shell are spaced radially from each other at a predetermined distance to define an intermediate space therebetween. The outer surface of the outer shell has coaxial threads interrupted by grooves extending transversely to the thread. The threads are self-tapping threads and are formed to permit the threaded outer shell to be screwed into the bone. The outer shell has a plurality of elongated openings or slots connected to the intermediate space to permit loose spongious material such as cancellous bone, to be introduced into and held in the intermediate space during surgical emplacement of the cup member. This enhances the growth of new bone tissue into the intermediate space. The elongated openings extend over almost the entire axial length of the outer shell.

Abstract: A hip joint femoral prosthesis has a rod, the proximal end of which has a cross-section of oval shape and a surface area increasing towards the proximal end. At least one wall of the proximal end includes alveoli therein hollowed out so as to present a maximum depth on their side towards the proximal end. The alveoli are of a circular or semi-circular shape and intersect, thereby providing a surface which improves the stability and anchoring of the prosthesis into the femur.

Abstract: The cutting head for a surgical reamer has a leading end for insertion into a bone canal and a trailing end for attachment to a drive shaft. The cutting head has a cutting surface formed about an axis of rotation of the cutting head. The cutting surface is formed by the rotation of the cutting edges on a plurality of flutes spaced around the axis of rotation. Each cutting edge has a first portion spaced a predetermined radial distance from the axis of rotation at the tip portion and terminates at a terminating point which is at a greater radial distance from the axis of rotation than the starting point. The cutting edge on each flute has a second portion having a starting point at the trailing end of the cutting head which is at a second predetermined radial distance from the axis of rotation. The second portion extends axially towards the tip portion and terminates at a point at a greater radial distance from the axis of rotation than the starting point thereof.

Abstract: A modulator apparatus for use in the preparation of bone surfaces and the implantation of a modular total knee prosthesis in a patient, which apparatus comprises cutting guides, templates, alignment devices, a distractor and clamping instruments which provide modularity and facilitate bone resection and prosthesis implantation.

Abstract: A prosthetic acetabular cup 100 includes a fixation element 102 for introduction into the acetabulum. The fixation element 102 has a concave inner surface with a generally circular base formed in a plane generally perpendicular to the central longitudinal axis. A bearing component 7 is formed from a deformable material and has a concave opening therein for receiving a spherical head of a prosthetic femoral component. The bearing component 7 has an outer surface that nests within the concave inner surface of the fixation element 102. A snap lock mechanism is used to lock the bearing component 7 within the fixation element 102 in the axial direction. Both the fixation element 102 and the bearing component 7 include a plurality of circumferentially spaced recesses 3, 12 located around a common pitch circle adjacent the generally circular base of the fixation element 102.

Abstract: A prosthetic part for use as an orthopedic implant has a base member defining an outer surface for implantation adjacent a prepared bone surface. The outer surface includes a recessed area having a predetermined shape and depth. A first rigid plate having this predetermined shape and having a plurality of elongated slots formed therein is fixedly attached within the recesssed area of the base member. A second rigid plate also having the same predetermined shape as the recess and also having a plurality of elongated slots formed therein is attached to the first rigid plate. The elongated slots of the second plate are angularly offset with respect to the elongated slots in the first plate to produce a controlled porosity. The thicknesses of the first and second plates are predetermined so that the outer surface of the second plate is continuous with the non-recessed outer surface of the base member.

Abstract: A bone cement is disclosed wherein the liquid component contains a therapeutic or diagnostic substance in combination with an emulsifying agent for said substance.

Abstract: A multi-piece trial femoral component kit is used for preparing and sizing a femoral cavity prior to implantation of a prosthetic femoral component. The trial component kit has at least three trial stem portions of differing size and at least three trial body portions of different size. The stem and body portions include mating male and female elements which allow the stem portions to be securely coupled to the body portions. In order to ensure that the so-coupled stem and body portions form a trial femoral component having a size equal to an available orthopedic femoral implant, the male and female elements include a key and keyway which are sized so that only trial stem and body portions resulting in an available femoral implant can be combined and used as a trial femoral component.

Abstract: An acetabular cup for use as a prosthetic implant has an insert with a body including a central bore for receiving a positioning rod therein. A key element is formed on the bore and is adapted to align the positioning rod. The insert has a locating element formed on an outer surface of the body and also includes spring elements extending radially outwardly from the body. The acetabular cup has a generally hemispherical shell member coupled to the outer surface of the insert. The shell has an outer surface for engaging the acetabulum and an inner surface having a circumferential groove for receiving the spring elements. The spring elements may be deflected radially inwardly out of engagement with the groove for releasing the insert from the shell. The shell has a plurality of apertures extending from its inner to its outer surface, which apertures are located in an asymmetrical pattern about the shell.

Abstract: A centralizer for the stem of a prosthetic orthopedic implant adapted for implantation into a medullary canal has a hollow annular body portion. The annular body portion has an interior for receiving the stem of the implant. The body portion also includes at least three spring elements extending outwardly from the exterior surface of the body portion. Each spring element has a portion thereof extending generally tangentially with respect to the axial extent of the tapered stem and deformable circumferentially and inwardly towards the stem upon insertion into the medullary canal.

Abstract: A method for preventing adhesion between vital tissues includes the step of placing between the tissues a material made up of biodegradable derivatives of chitin which are soluble in aqueous solutions containing dilute acids such as acetic acid. This material has the advantage of requiring no reoperation for its removal since it would be degraded and absorbed after completing its function in vivo. These materials may be in the form of a visco-elastic fluid, a gel, a film or a membrane.

Abstract: A tibial component for a replacement knee prosthesis comprising a tibial tray for connection to a suitably prepared tibia has a tray carrying fixed lateral and medial condylar bearing components. Only the medial component has a shock absorber located beneath it.

Abstract: An apparatus for mixing and dispensing a surgical adhesive having at least two components has a barrel with a central longitudinal axis extending from a first to a second end thereof. The second end includes a nozzle with a discharge port. A rotatable screw conveyor shaft extends through the barrel position along the longitudinal axis. A dispensing element is mounted within the barrel and has a threaded bore for operative engagement with the screw shaft. The dispensing element has a keyway and may freely rotate at the first end of the barrel. A snap element is included to move the dispensing element into engagement with a key on the inner surface of the barrel which prevents the rotation of the dispensing element and causes the dispensing element to move from the first end of the barrel to the second end dispensing the adhesive.

Abstract: A prosthetic nucleus for a vertebral disc is made of a hydrogel material. The hydrogel prosthetic nucleus has a shape generally conforming to the natural nucleus pulposus. The hydrogel has a water content of at least 30% and has a compressive strength of 4MNm.sup.-2 or greater. When the hydrogel material is dehydrated, it has a dimension of less than half of that of the hydrated hydrogel nucleus. The prosthetic nucleus may be formed of two or more pieces of hydrogel material which pieces, when combined, have a shape generally conforming to the natural nucleus.

Abstract: A tibial component of a replacement knee prosthesis includes a tibial tray for connection to a suitably prepared tibia. The upper surface of the tray carries one or more bearing components provided with means for altering the position of the tibia relative to its co-operating femur by alternatively altering one or more of the following variables: medio-lateral offset, antero-posterior offset, antero-posterior tilt, tibial rotation and tibial condyle depression profile. The tray carries either one bearing component which cooperates with both femoral condyles, or two distinct bearing components, each of which cooperates with a single femoral condyle.