Abstract: An apparatus and method for determining offset-inset distances in the course of a total hip arthroplasty procedure. The apparatus includes a first attachment attachable to the superior eminence of the acetabulum, a second attachment point capable of being fixed to the femur at approximately the position of the greater trochanter, and preferably, a measuring device for measuring and noting the distance between the reference point and either the third or fourth fixed points.

Abstract: The present invention provides an insertion tool and an associated acetabular cup implant. The tool includes a housing and an inner expansion pin for expanding the curved ends of resilient expandable arms of a collet on the distal end of the housing. The expandable arms engage corresponding curved surfaces in a groove in the concave surface of an acetabular cup. The tool also includes an actuation assembly which translates a slight rotation of a sleeve member on the housing to longitudinal movement of the expansion pin to radial expansion or contraction of the arms of the collet to engage or disengage the acetabular cup. A positioning assembly is also provided.

Abstract: An instrument for holding an acetabular cup. An elongate hollow tubular member has a proximal end and a distal end and a generally transverse end face at the distal end. A pair of pins extend axially outwardly from the transverse end face. An elongate rod is mounted within the elongate hollow tubular member for axial movement relative thereto. A ball is attached to one end of the elongate rod proximate the transverse end face and is moveable together with the elongate rod. The ball has a spherical surface for engaging a portion of the inner bearing surface of an acetabular cup that extends radially inwardly relative to the polar axis of the acetabular cup. Retraction of the ball toward the end face of the tubular member draws the cup toward the end face. Corresponding holes in the rim of the cup receive the pins to prevent lateral movement of the cup on the end face of the instrument.

Abstract: An acetabular bone graft impactor comprising a contact surface at least part of which is located on a head connected to a shaft provided with and anvil to be hit with a hammer. A flange extends from the head so that the contact surface shape can be selectively altered.

Abstract: Embodiments of an acetabular cup inserter include an elongated stem to which a handle is assembled in such a way that its orientation with respect to the stem may be adjusted 360.degree., that is, completely about the periphery of the stem. A buttress device is provided to engage the metal cup resiliently by use of an O-ring which prevents metal-to-metal contact avoiding fretting of the cup surface. The various embodiments disclosed include one embodiment wherein the buttress is axially aligned with the majority of the stem length as well as an embodiment wherein the axis of the buttress is parallel to and offset from the axis of the majority of the stem.

Abstract: An instrument for implanting an acetabular cup prosthesis includes a head adapted for supporting a selected one of a plurality of prostheses of various sizes carried on one end of the instrument. The instrument is effective for orienting, inserting and impacting the selected prosthesis for implantation, after which the instrument is removed from the implanted prosthesis.

Abstract: An acetabular cup prosthetic device comprised of an outer shell component and a inner bearing insert and the method of implanting the acetabular cup prosthetic within a patient. The outer surface of the shell component for the present invention acetabular cup has a plurality of regions which conform to the curvature of at least one ellipsoid. To implant the shell component, the acetabulum of a patient is spherically reamed to a size slightly smaller than that of the outer surface of the shell component. As the shell component is inserted into the spherically shaped acetabulum, the interior surface of the acetabular cavity deforms to assume a substantially ellipsoidal curvature, producing an interference fit between the rim region of the shell component and the upper peripheral rim region of the acetabulum.

Abstract: A prosthetic socket implant installation apparatus and method combines holding, impacting, and aligning functions in a modular device. The apparatus comprises an installation tool that firmly engages a feature around the inner rim of a prosthetic socket implant so that the shell does not disengage during the installation process. An implant engaging arrangement on the installation tool is capable of extending to properly engage and hold implants in a broad range of sizes. The tool provides both axial and angular alignment references to facilitate the correct alignment of a prosthetic socket implant during installation. A mechanically isolated impacting rod slideably attaches within an opening along the longitudinal axis of the tool thus facilitating impact at the proper location and angle and allowing the alignment and impacting to be performed by one person.

Abstract: A method of implanting an acetabular cup includes preparing an acetabular socket to receive said cup, placing cement in said socket before or after locating a loading tube in line with the socket and inserting the acetabular cup through the tube into said socket. This is done by pushing it down the tube with an inserter to a predetermined position therein defined by a stop element acting on the inserter or an attachment thereto.

Abstract: An acetabular cup having an outer shell of a hard material defining a cavity circumscribed by an annular surface, and a bearing insert of a material which is softer than the material of the outer shell, the bearing insert being disposed within the cavity of the shell, and coupling tracks disposed on the annular surface for coupling a tool to the outer shell, the tool being used for installing the cup in a patient's acetabulum, the coupling tracks operating to prevent the tool from damaging the bearing insert during the installation of the cup.

Abstract: The insertion instrument of this invention includes a generally cylindrical handle portion and a cup engaging portion held in a spaced relationship by an arcuate intermediate portion. Handle portion includes a longitudinal throughbore and an impaction head. The cup engaging portion includes a rotatable threaded stud for threaded accommodation within a threaded hole of an prosthetic acetabular cup. The stud includes a head having a recess formed therein for accommodating a driving device. The longitudinal bore of the handle portion and the head of the threaded stud are placed in alignment such that the shaft of a screwdriver extending through the threaded bore is aligned with the head of the screw. Therefore, a surgeon using the instrument of this invention does not need to have a clear view of the threaded stud to attach a screw driver. This is especially useful after the surgeon has impacted the acetabular cup within a prepared acetabulum and needs to remove the insertion instrument.

Abstract: An instrument 2 used to install both the outer shell 40 and bearing liner 50 of a conventional acetabular cup assembly 4. Instrument 2 includes an impactor 30 and a reversible cup or head component 10, which is adapted for driving shell 40 into the acetabulum and for seating bearing liner 50 into the shell. Head component 10 has a rounded semi-spherical surface 12 on one end and a substantially flat surface 14 on the opposite end. Impactor 30 includes a longitudinal extension 36 which can be inserted into a bore 20 in head component 10 from either direction to secure the head component to the impactor. When instrument 2 is used to seat shell 40 into the acetabulum, head component 10 is fitted to impactor 30 with semi-spherical surface 12 facing outward for abutment against inner surface 44 of shell 40. Shell 40 is connected to the distal end 39 of extension 36, which protrudes from semi-spherical surface 12 of head component 10.

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 spring elements can be deflected by pushing a sleeve down the rod to make contact with and deflect the spring element.

Abstract: An acetabular cup having optionally removable portions to permit a choice between methods of affixation is provided. The cup has recesses in the surface of the wall of the cup. A post extends from the base of the recess inwardly toward the interior of the cup, but does not extend past the inner surface of the wall into the interior of the cup. A very thin annular section of the wall remains at the base of the recess. To open a hole, a tool is used to grasp and pull the post. The pulling force applied to the post causes the wall at the annular section to break or tear. The base and post is removed and a hole remains through which a fastener can be inserted. The hole or recess is configured to receive a standard bone screw, but may be configured to complement the shape of the head of any desired bone fastener.

Abstract: The acetabular cup positioner of this invention provides a resilient collar to be carried on its distal end for contacting the interior surface of the acetabular cup. The resilient collar prevents damage to the interior of the cup during impaction. Since the resilient collar will compress a small amount during the impaction, the threaded connector of the positioner and the threads for the acetabular cup will be under a sizable load. Therefore, to protect the positioner and the cup, the threaded connector is shiftably connected to the positioner body. The connector is biased toward the distal end by a helical spring.

Abstract: An implantation instrument and methods for reliably implanting a prosthetic acetabular cup in the acetabular area of the pelvic bone during a total prosthetic hip implant operation are disclosed. Such implantation device and methods also provide means for determining the adequacy or strength of the implant.The implantation device includes means for receiving an implantation force from, for example a mallet, and imparting this force to press fit the prosthetic acetabular cup into a recess formed in the acetabular area of the pelvic bone. The apparatus also includes means for testing the strength or adequacy of the acetabular cup implant by receiving and imparting a torquing moment. Finally, the apparatus includes an alignment arm which is laterally displaced from the longitudinal axis of the apparatus, and selectively fixed or rotatably connected, in order to implant the prosthetic acetabular cup in the desired orientation.

Abstract: An acetabular cup inserting instrument includes a first handle and a second handle rotatable about and extending from the first handle. The second handle is ratchetable about the first handle and selectively lockable in a desired position with respect to the first handle. The ratchet mechanism of the second handle includes a biased pawl that engages radially spaced notches on the first handle.

Abstract: The acetabular cup positioner of this invention provides for a sighting guide which is removable connected to the shaft of the cup positioner by a tapered locking configuration. The taper lock provides for a secure connection of the sighting guide to the shaft of the cup positioner which enhances the accuracy of the device. The taper lock provides such a strong lock that in order to provide for its removal, the cup positioner of the invention includes a slaphammer carrier on the shaft of the guide which may be employed by the surgeon to remove the guide from the positioner without undue effort.

Abstract: A tool driver which has a body having a bore. The bore has a longitudinal axis. A plunger is disposed in the bore. The body and the plunger have a lock. An actuator is disposed on the body. The actuator and the plunger are loosely coupled. The actuator is axially movable relative to the body and the plunger between a locked position and a retracted position. The actuator, in the locked position, substantially immobilizes the plunger relative to the body. The actuator and the plunger are axially movable together, relative to the body, between the retracted position and an extended position.

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: An assembly (10) for positioning a prosthetic acetabular cup assembly (110) in a patient's hip is provided. The assembly (10) includes a bearing component (114) having an inner bearing surface (134) for receiving a femoral ball and an outer surface (132) attachable to a shell component (112) The shell component (112) is attached to an acetabulum to replace a natural hip socket. The shell component (112) includes an inner surface (120) defining a cavity (126) for receiving the outer surface (132) of the bearing component (114) therein. The assembly (10) includes a handle (12) attached to a split head (30). The split head (30) is divided into first and second gripping elements (36, 38) that jointly form a gripping surface to engage the inner bearing surface (134) of the bearing component (114). The assembly (10) holds the bearing component (114) at a selected orientation with relation to the shell component (112), and is used to drive the bearing component/shell component (114/112) into the acetabulum.

Abstract: An apparatus for aligning an acetabular cup for proper placement in a socket in hip joint replacement includes a frame having feet which are placed against and fastened to the anterior superior iliac spines and the pubic tubercles respectively of the pelvis. A light beam is directed from a source through an aperture to a mirror mounted on an implant inserter. The light beam is reflected back from the mirror to a target region. When the incident and reflected beams are coincident, the cup is aligned for correct placement. The target region is rotatably and pivotably mounted for precise adjustment of the angles of abduction and anteversion respectively.

Abstract: An installation tool has a head for engaging an acetabular cup, and an elongated member mounting the head adjacent an end that projects from the head and is insertable into an opening through the cup. The member end is expandable for engaging the cup at the opening to prevent movement of the cup relative to the member end and hold the cup in engagement with the head in order to move the cup with movement of the member end to place the cup for implanting at a desired position. The member end also is contractable for releasing the cup after implanting at the desired position. The elongated member is composed of a tubular shaft having a passage therethrough and a rod slidably disposed through the shaft passage. The member end is composed of a split collet with expandable and contractable jaws on one end of the shaft and an outwardly flared cam element formed on one end of the rod and extending between the collet jaws.

Abstract: A hand-held surgical rotary impact tool and instrument extension for removing artificial hip, or acetabular, cups of a hip joint by rotating the cup a predetermined number of degrees. This rotational limitation is provided by a pin and arcuate groove connection between a fixed housing and rotatable shaft. While instrument extensions are sized to allow for different acetabular, or hip, cups, the cup engaging end can have radially adjustable pins for permitting a variable diameter for connection to a cup.

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 system for implanting an acetabular cup prosthesis includes an instrument and a disposable adapter. The disposable adapter engages the prosthesis and is supported on the instrument. The instrument is effective for orienting, inserting and impacting the prosthesis for implantation, after which the adapter is removed from the instrument for disposal. The adapter and the disposable prosthesis may be arranged as a pre-implantation assembly, thereby reducing the overall implantation time as is desirable.

Abstract: An instrument for implanting an acetabular cup prosthesis in a patient's acetabulum. The cup is gripped on the base of the instrument and is aligned and inserted in accordance with a plane normal to the plane in which a patient is positioned and normal to a line between the right and left anterior/superior iliac spines. With the acetabular cup so aligned, the cup is impacted to be retained in a prepared acetabulum. The instrument is actuated for gripping the cup and is locked to maintain the cup gripped for the aforenoted alignment, insertion and impaction, and is thereafter unlocked and actuated for releasing the cup so that the instrument can be removed from the cup without disturbing the position thereof. The alignment of the cup is adjustable to accommodatae various implantation situations as may occur.

Abstract: A prosthesis holding system is provided for holding and positioning a prosthetic cup during surgery. The rim of the cup includes opposed inwardly and outwardly facing recesses. A holder includes an elongated rod having a shoe at one end. The shoe includes a tab for engaging the inwardly facing recess in the rim of the cup. The shoe further includes a threaded aperture alignable with the outwardly facing recess in the rim of the cup. A clamping screw is engageable with the threaded aperture and is further engageable with the outwardly facing recess in the rim of the cup. Tightening of the clamping screw securely holds the cup without interfering with either the interior concave surface of the cup or the exterior convex surface of the cup, to enable efficient implantation of the cup in a patient during surgery.

Abstract: An instrument for implanting an acetabular cup prosthesis in a patient's acetabulum. The cup is gripped on the base of the instrument and is aligned and inserted in accordance with a plane normal to the plane in which a patient is positioned and normal to a line between the right and left anterior/superior iliac spines. With the acetabular cup so aligned, the cup is impacted to be retained in a prepared acetabulum. The instrument is actuated for gripping the cup for the aforenoted alignment, insertion and impaction and is thereafter actuated for releasing the cup so that the instrument can be removed from the cup without disturbing the position thereof.

Abstract: A mechanically fixable acetabular unit for hip prostheses, having a conical acetabular basket made of a tissue-compatible metal alloy, the acetabular basket (1) is provided with cutouts (3) running in the direction of the generatrix and L-shaped anchors (4) are inserted into the cutouts (3) so, as to be tilted around the geometric axis running parallel with the tangent of the mantle of the acetabular basket and in such a manner that the shorter shank of the anchors (4) is arranged at the end with a smaller diameter of the acetabular basket and on the outer end it is formed as a pointed sharp claw (7), while the thickness of the longer shank (6) corresponds substantially to the wall-thickness of the acetabular basket (1), while the length corresponds to the length of the cutout (3).