摘要:
An acetabular cup having an outer surface with a first set of steps formed in a first direction and a second set of steps formed in a different, second direction is effective to provide positional stability and enhanced load transfer after implantation in the acetabulum. The stepped outer surface of the acetabular cup provides a significant increase in effective surface area. The multi-directional first and second steps convert shear loads to compressive loads in their respective directions, resulting in enhanced fixation of the cup.
摘要:
In a human hip replacement process, the steps include providing a selected size generally longitudinally extending stem and laterally angled neck, the stem received endwise into a recess in an elongated femur, there being a ball on the neck, the neck and stem having a non-circular tongue and groove interfit connection to resist relative rotary displacement therebetween, the connection defining a generally longitudinal axis, fitting the ball in a socket on a hip bone, to pivot in the socket, the selection of stem and neck, and tongue and groove connection between the size selected stem and neck, enabling accurate pivoting of the ball. A set of different size balls and neck units are enabled for selective choice, as during surgery.
摘要:
A tulip-shaped rod-receiving member in a spinal rod system is provided with a transverse slot accessible from the top of the tulip member for placing the rod therein until the rod seats. A locking assembly includes a cap having inclined surfaces that cooperate with inclined surfaces on the rod-receiving member to lock and bias inwardly the rod-receiving member relative to the cap. A novel seating ring is provided for the bone screw to be supported in the tulip in a manner that maximizes support and optimizes axial alignment of forces.
摘要:
A tamp system includes a plurality of tamps, each of which includes an elongated body having a stepped outer surface. The body has a diameter and a longitudinal axis, wherein the diameter decreases from a proximal end to a distal end thereof. The stepped outer surface includes a plurality of steps each having a distal-facing surface and a side-facing surface. Each tamp is adapted for compacting morsellized bone matter in a canal in a bone. The compacted bone matter can be used to resize the canal for a new prosthesis in a prosthesis revision surgery.
摘要:
A system for reaming a cavity in bone for implantation of a prosthetic component, such as an oblong acetabular cup having an outer surface formed by adjacent hemispheres. In one embodiment, the reaming system is useful to form a second cavity in relation to an already formed first cavity. The reaming system includes an instrument with an elongate handle and a drive member coupled to a bearing plate with a locator member removably and replaceably mountable to the bearing plate. The drive member has a distal reamer mating end and a proximal end for coupling with a drill mechanism. The distal reamer mating end is axially movable toward and away from the bearing plate to ream the cavity corresponding to the secondary hemisphere of the acetabular cup to be implanted. In another embodiment, the reaming system includes a plurality of reamers each having different outer dimensions and being matable to the drive member. In a further embodiment, the system includes a plurality of locator members for positioning a respective one of the reamers to form the second cavity at a desired location.
摘要:
A system of reconstruction for a spinal joint is directed to a modular implant assembly that includes an upper part and a lower part. The upper and lower parts each comprise a unitary body having an approximately ninety degree bend defining vertical and horizontal components. Each vertical component has a fastener hole for attaching it to a bone segment using a bone fastener. The horizontal sections each have a complementary contact surfaces in order to transmit compressive load therebetween and to accommodate sliding and pivoting relative movement therebetween. The vertical sections of each of the upper and lower part are offset with respect to a vertical centerline so that successive assemblies bridging more than one adjacent vertebral space can have an upper part and a lower part according to the present invention coexist on a single vertebra in a space-efficient manner wherein the vertical sections nest spatially.
摘要:
A system of reconstruction for a spinal joint allows adjacent vertebrae to move relative to each other in a generally pivotal manner and in a limited sliding manner in either or both of the anterior-posterior direction and the medial-lateral direction. The system includes base components and a middle component. The base components are for attachment to adjacent vertebrae and support a pivoting cooperative engagement of a concave or cup-shaped component with a convex or dome-shaped component.
摘要:
A vertebral plate system and associated method minimizes the number of required multiple configurations and sizes of hardware on hand during surgery for repair, stabilization or fusion of bone segments. A novel aspect of the invention is a resilient split ring that cooperates with angled contact surfaces in a plate for allowing convenient and fast dynamic locking between the plate and a bone screw. In another aspect of the present invention, a screw or similarly elongated fastener having a generally spherical or part-spherical head with a section of helical threads is configured in a generally horizontal band and positioned around a maximum-diameter section of the head. The screw is loosely retained to a first structure by a snap-ring formed from a ring of elastic material having a slot cut so that the ring is a “C” ring. The ring is seated on an annular shoulder formed in a through-hole in the first structure. The section of the through-hole above the shoulder tapers inwardly in an upward direction to a minimum diameter that is smaller than the outside diameter of the ring when the ring is in an unstressed state. The inner diameter of the ring has an edge that is adapted to cooperate with and ride in the threads on the screw head.
摘要:
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.
摘要:
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.