Abstract: A knee joint prosthesis includes a femoral component, a tibial plateau, and a tibial bearing member. The design and geometry of the articulation surfaces of the condylar elements of the femoral component and tibial bearing member is such that contact area between the articulation surfaces is maximized during flexion of the prosthesis. This is achieved by increasing the coronal radius of the bearing surfaces of the femoral component in the anterior to posterior direction along the bearing surface, i.e., increasing the coronal radius of the bearing surfaces of the femoral component as the femoral component transitions from extension to flexion.

Abstract: A modular acetabular reinforcement system includes a substantially cup-shaped reinforcement body having a peripheral flange portion. One or more fixation wings, of various sizes and shapes, are selectively and separately attachable to the flange portion of the reinforcement body. The system is mountable within the acetabulum of a patient to reinforce the acetabulum and to serve as a platform for other prosthesis components such as an acetabular shell.

Abstract: An orthopedic device is provided having a femoral stem with a proximal end, a distal end, and an intermediate portion extending between the proximal end and the distal end. The intermediate portion tapers from a first cross-sectional geometry near the proximal end to a second cross-sectional geometry near the distal end. A surface region of the femoral stem has a coefficient of friction less than 0.3 with respect to a bone cement. The surface region can include a treated metal region integral with the stem, or a friction reducing coating or sheath that coats or covers a portion of the stem. A collar can be provided near the proximal end of the stem that has a greater diameter than the first diameter of the stem.

Abstract: A bone fixation device such as a screw, pin, staple, cable or anchor has a microtextured contact surface to enhance installation or gripping characteristics, preferably by providing directional or anisotropic engagement. A surface texture comprised of patterned microfeatures imparts a roughness or actual mechanical engagement that prevents loosening. In different embodiments the features resemble an array of microbumps or pyramids, or anisotropic features such as rasp teeth, shingles, or slanted cantilevered fiber/rods. The use of microbumps present a smaller surface area when moving, while providing full area contact after the surfaces have relaxed or decompressed; installation may be effected with low force, while high static or resting friction prevents disengagement.

Abstract: A cushion or pad for orthopedic applications is disclosed. The cushion or pad comprises a bladder filled with a combination of spherical objects in a lubricant and an inflatable air bladder. The inflation of the air bladder is used to properly position an orthesis on a patient.

Abstract: A prosthetic hip joint includes a ceramic hip head having a bore which defines a surface, wherein the bore surface has a layer of malleable material disposed on at least a portion thereof. The surface of the bore includes surface imperfections in the form of peaks and valleys. The prosthetic hip joint can also include a femoral component having a trunnion with a tapered surface adapted for friction fit insertion into the bore of the hip head. The layer of material, such as pure titanium, distributes a load on the joint reducing localized stress points produced by opposing asperity peaks in the load-bearing surfaces of the bore and trunnion.

Abstract: A calcar trial includes a stem having a proximal end and a distal end, and a body. The body is engaged with the stem near the proximal end of the stem and is slidable with respect to the stem. A locking mechanism inhibits movement of the body with respect to the stem when desired. A collar extends radially outward from the stem to surround a portion of the body. The body and stem are configured so that the diameter of the calcar trial at a point between the collar and the distal end of the stem increases as the body is moved toward the distal end of the stem and decreases as the body is moved away from the distal end of the stem. Additionally, the proximal end of the stem can include opposed notches that are egagable by a forked tool.

Abstract: A method of injection molding includes the steps of providing a source of pressurized flowable material, a source of pressurized fluid, and a mold assembly actuatable from an open position to a closed position. The mold assembly includes first and second matable mold portions that define a substantially sealed cavity, an inflatable core member positioned within the substantially sealed cavity and secured to the first mold portion, a pressurized fluid path from the source of pressurized fluid through the first mold portion to the inflatable core member, and a flowable material path from the source of pressurized flowable material into the cavity. The pressurized fluid is introduced into the inflatable core member at a first pressure to provide an inflated core member that defines a core boundary and the pressurized flowable material is injected into a space defined by the cavity and the core boundary at a pressure less than the first pressure.

Abstract: A cement restrictor system is provided for making a cement plug within the medullary canal of a long bone. The system includes an inflatable body, a conduit having first and second ends that defines a fluid passage to and from the inflatable body, and a shield releasably securable to the conduit. In an exemplary method of making a cement plug with the system an obstruction, such as the shield, is placed in a medullary canal of a long bone beyond the isthmus of the long bone. The obstruction is held in place with the flatable body. A predetermined quantity of bone cement is poured into the medullary canal and localized by the obstruction. The bone cement is allowed to harden; and the conduit and inflatable body are removed from the bone.

Abstract: There is disclosed a short leg walker comprising a rigid sole and calf shell and an articulated rigid skin and dorsal shell. The shells are padded at some locations with a non-inflatable padding such as foam or a fiber padding and at other locations with an inflatable bladder and a second bladder between the inflatable bladder and the limb of the patient. The second bladder is responsive to deforming pressure exerted on it and will maintain its support of the limb when the pressure is removed.

Abstract: An orthopedic cast walker boot, that includes a tubular enclosure formed of a semi-flexible material having a first section member for covering the rear of the calf, ankle, heel, and sole of the foot; and a second section member for interfitting with the first section member; the second section member having an upper section for covering the shin area of the leg, and a lower section for covering the top area of the foot. The upper and lower sections being integrally connected by a pliable and flexible intermediate connecting section having multiple joints. Velcro fastening straps are provided for fastening and enclosing the first and second section members to form the tubular enclosure about the leg, the ankle, and the foot of the wearer; and traction treads means are adhesively attached to the bottom surface of the first section member.

Abstract: A medical fastening system for a modular knee prosthesis includes a femoral component having an aperture. A washer having an aperture alignable with at least a portion of the aperture in the femoral component engages the femoral component to inhibit movement of the washer through the aperture in the femoral component. A bolt engages the washer and an elongate shaft portion of the bolt protrudes from the femoral component through the aperture in the washer and the aperture in the femoral component to engage a Morse taper post or femoral stem. The configuration of the washer aperture, its location in the washer, and the orientation of the washer within the femoral component determine the fore and aft positioning of the Morse taper post or femoral stem. The Morse taper post or femoral stem can be provided with a canted base to angle the post or stem with respect to the femoral component.

Abstract: An acetabular cup assembly for use with a femoral implant. The cup assembly includes an outer shell, a bearing liner configured to fit into a cavity in the shell, a generally annular retaining ring and a locking ring configured to hold the retaining ring in the shell adjacent the bearing liner. The locking ring is slidable between locked and free configurations, with at least part of the locking ring being formed as a closed loop to prevent radial contraction of the locking ring inner surface as the locking ring is slid between the free and locked configurations. At least one small circumferential rib is formed on the outer surface of the locking ring to engage a corresponding circumferential groove in the shell when the locking ring is installed therein in the locked configuration.

Abstract: An adaptor is provided to convert a bipolar shell trial to and from a unipolar head trial adaptor. A preferred embodiment provides a spring-loaded, snap-in adaptor and a neck length adjusting mechanism for a trial system.

Abstract: An insertion device for a surgical pin includes a body defining a bore therein and a retainer disposed in the bore for frictionally engaging a portion of the surgical pin. The bore includes an aperture defining an entry into the bore, a surface for limiting the depth of insertion of the surgical pin, a wall surface extending from the insertion limiting surface, and a recess in the wall surface disposed between the aperture and the insertion limiting surface. In an exemplary embodiment, the retainer is an O-ring disposed within the recess. The O-ring defines a resilient aperture having a diameter less than that of the pin.

Abstract: A bone fixation device is provided that includes a retaining member fabricated from a biocompatible material. First and second biocompatible cables are permanently secured at one end to respective first and second sides of the retaining member. A cable crimp is used to bind the free portions of the first and second cables. Cable guides on the retaining member establish an alignment angle for the cables with respect to the longitudinal axis of the retaining member. The retaining member can include gripping members.

Abstract: This invention pertains to a universal hand piece such as a stationary handle or a slap hammer with a universal quick release connector which attaches and detaches to various instruments used in a knee prosthesis implantation surgical procedure. Instrument end pieces to which the hand piece may attach may include, for example, punches, inserters, extractors, impactors, or other instruments in which use of a hand piece is desired.

Abstract: An implantable bone prosthesis, such as an acetabular shell, includes a bone engaging region that is made from a cast metal or metal alloy and an articulation surface that is formed of a ceramic material or a metal that is permanently attached to the metal bone engaging region. The bone engaging region of the prosthesis preferably includes a dampening mechanism to absorb some of the loading forces communicated to the acetabular cavity. The bone prosthesis is formed by a casting process from casting molds that are prepared using a three dimensional printing technique.

Abstract: Methods are provided for producing investment cast articles, such as orthopedic implants, or portions thereof, having at least a partially textured surface that is formed during casting of the article. In an exemplary method, a textured metal casting is produced by creating a heat destructible pattern and spraying the pattern with a texturing material to cause the texturing material to form a textured surface on at least a portion of the pattern. In another embodiment, a textured template is pressed against a heat softenable pattern to provide a textured pattern. With respect to each of these methods, a shell is the created around the textured pattern to form a mold, and the pattern is removed from the shell. Molten metal is introduced into the mold and allowed to harden, after which the mold is removed.

Abstract: A modular knee prosthesis includes a Morse taper post that is matable with a first portion of a femoral sleeve. A second portion of the femoral sleeve is joined with a femoral stem that is introducible within the medullary canal of a distal portion of a femur. In an exemplary embodiment, the modular knee prosthesis includes a femoral component, a bolt, and a Morse taper post. The femoral component has a superior surface, an inferior surface, and an aperture. The bolt includes a head portion engagable with the superior surface of the femoral component to inhibit movement of the bolt through the femoral component, and an elongate shaft portion that extends from the head portion of the bolt. The elongate shaft portion has a length sufficient to protrude through the aperture beyond the inferior surface of the femoral component.