Abstract: A bone fixation element comprises a shaft extending substantially along a longitudinal axis of the fixation element in combination with a head including a plurality of fixation element openings distributed about a perimeter thereof. Each of the fixation element openings extends through the head from a proximal surface thereof to a distal surface of the head. Each of the fixation element openings extends through the head along an opening axis.

Abstract: Provided are acetabular cup implant assemblies that can be used in hip replacement surgery. Example assemblies comprise a shell and a liner. The liner can be positioned within a shell. Optionally, the liner can be rotated relative to the shell until the liner is seated in the shell in a position where the liner and shell can be secured to one another. Waveform-shaped features of the shell and liner can guide the relative rotation of the liner and shell. Also provided are methods of seating a liner in shell of an acetabular cup implant assembly.

Abstract: A bone fixation system includes a bone plate and a bone screw having a threaded head. The inner surface of the bone plate is adapted for facing a bone surface on which the plate is mounted. The outer surface of the bone plate faces away from the bone surface. A through opening extends from the inner surface to the outer surface of the plate wherein the through opening comprises a guiding portion and a blocking portion. The guiding portion of the opening is provided with a guiding thread for guiding a thread of a shaft of the bone screw. The blocking portion is provided with a blocking thread for blocking a thread of the head of the bone screw. The blocking thread has a larger diameter than the guiding thread and the guiding portion is located closer to the inner bone plate surface than the blocking portion.

Abstract: An anchor for securing an implant within bone. In one embodiment, the anchor is used to aid in securing an acetabular cup within an acetabulum. The anchor may be implanted within an ischial defect of the pelvis, and is attached to an outer surface of the acetabular cup shell. The anchor is made at least in part of, and may be made entirely of, a porous metal material to facilitate the ingrowth of surrounding bone into the anchor for osseointegrating the anchor into the surrounding bone. The anchor may be secured to the acetabular shell by a screw fastener or by cement, for example. The anchor may be secured to the acetabular shell before the anchor and the acetabular shell are together implanted into the acetabulum, or the anchor may be implanted into the ischial defect, followed by seating the acetabular shell in the acetabulum and then securing the acetabular shell to the anchor.

Abstract: An acetabular cup assembly implantable at an acetabular socket can include an acetabular cup defining a partially spherical bone engaging surface and having a uniform thickness. A spacer can include a body portion formed of porous metal and define a radial support surface. The porous metal can be adapted to receive bone ingrowth through interstitial space at pores defined therein. The spacer can further comprise a piercing portion adapted to be advanced into the acetabular socket. The spacer can bridge a gap defined between the acetabular socket and the acetabular cup. Filler can be disposed between the acetabular cup and the acetabular socket in areas adjacent to the spacer such that the spacer and the filler collectively define a continuous support surface adapted to support the acetabular cup at the bone engaging surface.

Abstract: An acetabular cup has a shell having a recess therein, the recess is open to an outer surface of the shell. The recess has an enlarged portion spaced from the shell outer surface with a diameter greater than the diameter of the opening at the surface. An insert is provided for insertion into the recess in the shell outer surface. The insert has a height greater than a depth of the recess and has a solid portion and a bifurcated portion having at least two side openings forming two to four sectors. A base of the sectors formed by bifurcated portion has an outwardly extending flange for insertion into the enlarged portion of the recess.

Abstract: A pelvic implant assembly and associated methods. The implant assembly includes an acetabular component, and a compliant fixator coupling the acetabular component to the pelvis.