A shape of a neck trial is simplified more than a known one. The neck trial includes a body portion and a fixing portion protruding from a contact surface (P) of the body portion to fix the body portion to a stem broach. The fixing portion includes a plate spring including a protruding portion that engages with a first recessed portion of the stem broach. The fixing portion and the body portion are integrally formed and can be attached to and detached from the stem broach.

An assembly for attachment to a first implant component has a size and shape of a second implant component to be implanted together with the first implant component. The assembly includes a first body defining a protrusion and a second body including a recess into which the protrusion is insertable. When the protrusion is seated within the recess, the first and second bodies are removably connected such that the first and second bodies are prevented from separating. A modular kit includes a plurality of the first bodies each having a different size or shape, and a plurality of the second bodies each having a different size or shape. A method of assembling the assembly includes removably connecting the protrusion of the first body into the recess of the second body, such that the first and second bodies are prevented from separating, and positioning the assembly on the first implant component.

An implantable medical device for implantation in a hip joint of a human patient is provided. The medical device comprises: at least one artificial hip joint surface adapted to replace at least the surface of at least one of the caput femur and acetabulum. At least one artificial hip joint surface comprises: a positioning hole with at least one opening in said at least one artificial hip joint surface. The hole is adapted to be placed and dimensioned such that the medical device is adapted to be fitted using a positioning shaft and at least partly surround the shaft, for positioning the at least one artificial hip joint surface in a desired position in the hip joint. The hole is adapted to be fitted using the positioning shaft, when the shaft is stabilized and placed in at least one of the femoral bone and the pelvic bone for positioning said medical device inside the hip joint.

A hip/shoulder prosthesis includes: a head component; a metaphyseal component; a diaphyseal nail, and a locking device. The head component includes: a front face and rear face; with a bore, and first and second shaped recesses in the rear face. The metaphyseal component includes: a central transverse aperture at an angle to the metaphyseal component's axis; a first end configured for threaded engagement within the bore of the head component; and a longitudinal hole that begins at the second end, transects the transverse aperture and reaches the first end, to receive the locking device. The diaphyseal nail is inserted in the femoral or humeral canal, and includes: fastening apertures that receive corresponding screws for fastening the diaphyseal nail to the femur or humerus; a portion configured to be received within, and engage, the transverse aperture of the metaphyseal component, and a transverse hole configured to receive the locking device.

A prosthesis alignment guide includes a guide body that has an opening that extends at least partially therein and a first alignment hole extending entirely therethrough. The opening is configured to receive a trunnion of a joint prosthesis for mounting the guide body to the joint prosthesis. An alignment member is disposed within the first alignment hole and is axially moveable therein. A locking member is engaged to the guide body and moveable from a first position in which the locking member is disengaged from the alignment member and a second position in which the locking member engages the alignment member and secures it from axial movement within the first alignment hole.

This invention corresponds to a prosthesis for total or hip resurfacing replacement, which comprises a prosthetic femoral head made of highly cross-linked polyethylene, with a diameter ranging from 38 mm to 64 mm, to articulate with a cup or acetabular component made of metal. When the invention applies to total hip replacement, the polyethylene head includes a metal core, which contains inside the female counterpart (14) to mate with the male counterpart (13) of a Morse taper, located at the upper end of the femoral component. The use of this type of head for total hip replacement, articulated with an ultra-polished acetabular cup, reduces the risk of dislocation, transmits less angular and torque forces to the Morse taper than large metal heads, and avoids the problems related to the metal-metal bearing or with the use of large metal heads with thin polyethylene. When the invention relates to hip resurfacing replacement, the highly cross-linked polyethylene femoral head has a lower polyethylene extension or stem with or without internal metal reinforcement (151) or a metal stem integrated into a metal-back (152). Using these types of heads for hip resurfacing replacement heads eliminates the problems associated with metal-on-metal resurfacing replacements.

A system and method for improving assembly of a modular prosthesis, particularly a femoral stem. The system and method may include implementation of assembly systems for modular prosthesis having one or more intermediate components between a pair of “end components” such as a stem and a head. Grip structures are provided on non-aligned assembly axes and holders are used for each phase to engage appropriate grip structures for joinder of components having aligned assembly axes.

A joint replacement implant may include a shaft having a proximal end, a distal end, and a threaded shaft portion, a helical thread disposed about the shaft defining a length of the threaded shaft portion and including a concave undercut surface angled towards one of the proximal end and the distal end of the shaft, and an attachment feature at the proximal end of the joint replacement implant. The attachment feature may be configured to couple an articular member to the joint replacement implant. The articular member may include at least one artificial articular surface that may be shaped to replace at least a portion of a natural articular surface of a joint of a patient.

A femoral trialling kit and method for assessing acetabular cup orientation during a left hip joint surgical procedure and a right hip joint surgical procedure are described. The kit includes a trial femoral head (104, 414, 514, 614, 814) having an inner wall defining a cavity extending along a head axis and a visual alignment guide on an outer surface of the trial femoral head and a trial femoral neck (126, 412, 512, 612, 812) having a taper at a free end, the taper being receivable within the cavity. One of the taper and the inner wall has a first anti-rotation feature (684, 698) and a second anti-rotation feature (686, 700), the first anti-rotation feature and the second anti-rotation feature being inclined, and the other of the taper and the inner wall has a third anti-rotation feature (702). The trial femoral head is attachable to the trial femoral neck in a first angular configuration corresponding to a right hip joint, in which the third anti-rotation feature and the first anti-rotation feature engage, and a second angular configuration corresponding to a left hip joint, wherein the third anti-rotation feature and the second anti-rotation feature engage.

A system and method for improving mechanical assemblies, such as prosthetic implants, intended to be installed in living tissue such as bone. Force-imparting devices are adapted and may include angularity, which may be introduced with specialized additive manufacturing, which may impart congruent cross-sections while providing variable stiffness. In some cases, the variable stiffness may be “stretchy” in a longitudinal direction and “rigid” in a radial directional which may provide an assembly bias. Additive manufacturing may allow the material of a prosthesis to be varied (e.g., density/porosity) to create variable stiffness over a length.