An anchor for an implantable device for arthroplasty can include a hollow anchor body defining an interior cannula space. A slot can extend along a length of the anchor body. The slot can provide an opening from the interior cannula space to an exterior of the anchor body. The slot can have a slot width that is smaller than an internal width dimension in the interior cannula space. The anchor can also include a rounded edge at a transition between the slot and at least one of an interior surface of the anchor body or an exterior surface of the anchor body.

Systems, methods, and devices include a bone repair system with a modular configuration of components. A bone repair device includes a head which tapers from a circular face to a first connector stem. The bone repair device also includes a plurality of interchangeable middle portions. A middle portion includes a first receiving area at a first end and a second connector stem at a second end. The first receiving area is operable to engage the first connector stem of the head portion. The bone repair device further includes a stem portion including a second receiving area at a first end and a tapered implantation stem at a second end. The second receiving area is operable to engage the second connector stem of the middle portion. Furthermore, the stem portion, the middle portion, and the head portion are selectively coupled to form a modular arrangement.

The invention discloses an improved wedging cage within the sacroiliac (SI) joint and fixation screw(s). The wedging cage is adapted to be positioned between the sacrum and the lilac bone (e.g., the sacroiliac joint), and the wedging cage is effective to receive one or more fixation or axial screws to fasten the wedging cage and secure the wedging cage to the adjacent pelvic bones to provide a combination effect of fusion and/or fixation. Accordingly, the improved fixation screw assemblies promote flexibility and adaptability due to the adjustable head being movable to a locked and unlocked position relative to the screw body when implanted onto a substrate.