Johnson & Johnson Professional, Inc.

Depuy Orthopaedics, Inc.

Jorge A Ochoa

Dennis P Colleran

Robert E Sommerich

Farid Bruce Khalili

Laurel Rogers

Frank W Chan

Michael J O'Neil

Thomas S Thornhill

Stefan M Gabriel

Erik S Larson

Frank D Matthews

William H Kennefick

C M Jayashankar

A prosthetic component is configured to have intentional interruptions in an articulating face thereof. The intentional interruptions are configured to yield an optimum contact area or bearing surface, particularly with regard to low wear and greater lubricity through the application of lubrication and contact mechanics theory for the particular prosthetic component. Such optimization is applied to a wide range of prosthetic component sizes of the particular prosthetic component. The optimum range of percentage area of relief or interruptions, defined as a percentage of a baseline uninterrupted bearing surface area to be removed by the features of the interrupted bearing surface configuration is from 0.3% to 73.7% for hard-on-hard bearing components and from 5.7% to 83.2% for polyethylene-on-hard bearing components. The range for both hard-on-hard and polyethylene-on-hard implants translates to a relieved area ranging from 0.3% to 31.9% of the area of the entire articulating surface, depending on the size of the implant. For both hard-on-hard and polyethylene-on-hard bearing combinations, optimally decreasing the contact area or bearing surface by interruptions in the articulating surfaces will allow for the benefits of larger diameter prosthetic components with an increased range of motion and decreased potential for dislocation, and the low frictional torques and lower wear of smaller diameter components.

Prosthetic joints having reduced area bearing surfaces and application thereof to a range of sizes of prosthetic joints

An articulating prosthesis includes a cup having a shell and a liner and at least one resilient locking element. The shell has a spherical outer surface that may be adapted to articulate with an acetabulum and the liner has a spherical inner surface that forms an articulation surface for the spherical head of a stem member. The resilient locking member extends inward toward a longitudinal axis of the cup and at least partially in a superior direction. The resilient locking element defines a nominal first diameter expandable to a larger second diameter in response to a force and is returnable to the first diameter in the absence of the force for securing the head of a stem prosthesis member.

Bipolar hip prosthesis with locking head

A sleeve component for engagement with a prosthetic component, such as a revision femoral component, compensates for bone loss and/or anatomical anomalies. In one embodiment, the sleeve includes a compensating region which provides an eccentric outer surface for offsetting proximal, posterior bone loss in the patient's femur. The sleeve has a bore through which the stem of a femoral component is insertable. The inner walls of the bore taper so as to complement a proximal outer surface of the stem when the sleeve abuts a shoulder portion of the femoral component. In one embodiment, the compensating region is defined by a radius which is offset from the longitudinal axis of the sleeve. In another embodiment, the compensating region is defined by a radius extending from the longitudinal axis and having an increased length.

Proximal femoral sleeve for a revision hip prosthesis

A bone allograft applicator device and system is effective to apply a bone graft slurry to an artificial joint without having to remove a previously implanted prosthetic component. In one embodiment, the device includes a hollow member coupled to an actuation mechanism for discharging the bone slurry from the device via a nozzle coupled to a distal end of the hollow member. The device can be used to discharge bone graft slurry from the nozzle and through a screw hole in an acetabular component implanted in the acetabulum of a patient. A bone allograft system can include various components for loading the device with the slurry and/or a plurality of nozzles each having a geometry suited for a particular application.

Morsellized bone allograft applicator device

A joint prosthesis comprising a metallic body having a plurality of negative surface features such as through-slots, deep grooves, tunnels or pits, or valleys defined between projecting fingers or flutes. The metallic body constitutes the structural component of the prosthesis, such as a shell, plate or stem. A second part attaches to and extends the body to provide both a fit and a change in the initial stiffness. The second part provides a time-evolving structural coupling, such that the prosthesis initially fits the patient's remnant bone to provide rigid fixation, while the mechanical properties shift with time in vivo to change its contact or loading characteristics. In one embodiment a femoral stem joint prosthesis is modular and the first, or structural component, accommodates bio-absorbable second components of varying geometries and dimensions which fit a range of bore sizes, and achieve different stiffnesses or strengths affecting load or strain distribution.

Prosthesis with variable fit and strain distribution

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.

Femoral component condyle design for knee prosthesis

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.

Femoral stem with reduced coefficient of friction with respect to bone

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. Features with directional asymmetry or angled suspension allow the textured surface to slide or deflect when the fixation device moves in one direction, while presenting a high resistance to torque or linear motion when moved in the other direction. Manufacturing is achieved with ion beams or directional treatment with energetic radiation, and regular arrays of the microfeatures may be produced as stationary surface growth phenomena without the use of pattern masks or mechanical contact. One manufacturing apparatus rotates the fixation device about a longitudinal axis while it is irradiated along an oblique axis. A bone pin may have centrally-directed spurs that allow a multi-segment fracture to be securely pinned without threading. An elastic fastener body such as a screw or pin can be pre-tensioned to place the bone under a torsional or compressive load, or introduce strain at the healing site.

Directional bone fixation device

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 both in perfect alignment and in malalignment conditions. Moreover, contact stresses placed upon the articulation surfaces in perfect alignment and in malalignment are reduced. High contact area and low contact stress on the articulation surfaces can be maintained even while matching knee prosthesis components of different sizes.

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Norton, MA, United States of America

Jorge A Ochoa