A spacer formed of an intermetallic compound, such as nitinol. The spacer includes at least two segments shaped in opposing arches. The unique properties of the intermetallic compound enable the material to be deformed into a planar, insertable shape when the material is cooled below a transition temperature and returns to the undeformed shape when the material returns to an ambient, operational temperature. An expansion mechanism assembly engages with the spacer to apply an expansion force, extending the spacer longitudinally drawing the spacer into the planar configuration. The expansion mechanism assembly can be used to guide the spacer into the desired position within the patient. The spacer control mechanism assembly is subsequently removed, relieving the expansion force, returning the spacer to the natural un-deformed, arched shape as it returns to body temperature. Retention features can be integrated in the spacer to aid in retaining the spacer in location.

The present invention provides a fused femoral stem system, including a curved short handle, a fixing mechanism and a femoral head prosthesis, one end of the curved short handle is provided with a conical connector, the conical connector is cooperatively connected with a conical connecting hole of the femoral head prosthesis, the other end of the curved short handle is inserted from the osteotomy surface of the femoral neck and stretches to the position of a medullary cavity below a small trochanter, and the curved short handle is connected and fixed with a large trochanter through the fixing mechanism. The present invention has the beneficial effects that, after the growing-in osseointegration with the sclerotin surrounding the proximal bone bed of the host after the surgery of the whole system, the mechanical influence on the retained femoral neck and the sclerotin in the vicinity of the large and small trochanters is substantially similar to the biomechanical state prior to the surgery.

One embodiment of the present invention provides a cage for spinal interbody fusion, which has sufficient durability and allows for bone fusion with a bone implanted to the anterior disk as well as fusion between vertebrae, thereby achieving a more stable bone fusion. The cage for spinal interbody fusion according to the embodiment of the present invention comprises a cage body and a tip which is formed to extend from the cage body and have a predetermined curvature. Further, the cage body has a cavity part which is formed to penetrate from the top surface to the bottom surface of the cage body with a projection part having a plurality of projections formed on the top surface and the bottom surface, and at least one perforation part, which is perforated from the side surface adjacent to the top surface or the bottom surface to the direction of the cavity part, and is located in the anterior direction of the cavity part.

A method for closing a fissure in a region of tissue having an inner surface and an outer surface, the method comprising: providing at least a pair of transverse anchor components, each transverse anchor component being coupled to at least one flexible longitudinal fixation component having a longitudinal axis; placing the transverse anchor components relative to the inner surface of the tissue on both sides of the fissure such that an exposed end of a flexible longitudinal fixation component extends through the tissue and past the outer surface of the tissue on both sides of the fissure; applying axial tension to the exposed ends; and anchoring the exposed ends.

A facet joint replacement system includes an inferior implant with an inferior articular surface, a superior implant with a superior articular surface, and an optional crossbar. The inferior implant and the superior implant are each polyaxially adjustably connected to fixation elements which anchor the implants to adjacent vertebrae. The optional crossbar may be polyaxially adjustably connected to bilateral implants. The system components may be provided in kits which provide components of various sizes and shapes. A set of surgical instruments may facilitate implantation of the facet joint replacement system by providing tools for bone preparation, trialing, implant insertion, implant alignment, and lock-out of modular interconnections.

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.

An intervertebral implant comprising a body formed as an open truss structure, the body having a generally annular shape with a superior surface, an inferior surface, and a perimeter surface extending around an outer periphery of the body. The body may have a central portion and a peripheral portion, the peripheral portion extending inward from the perimeter surface toward the central portion, the peripheral portion including a first set of trusses, and the central portion including a second set of trusses. The implant may further include a strut at least partially defining a boundary between the central portion and the peripheral portion, wherein the strut has an oblong cross-sectional shape oriented to facilitate flow of bone graft material in a substantially radial direction away from the central axis.

An implant may include a body having a first portion and a second portion and a structural member having a central member curve. In addition, the structural member may be exposed on an outer surface of the implant. Further, the central member curve may include a winding segment, and the winding segment of the central member curve may wind around a fixed path extending from the first portion of the body to the second portion of the body. Also, the central member curve may make one or more full turns around the fixed path. And, the structural member may have a member diameter at the winding segment, wherein the winding segment has a winding diameter corresponding with the full turn around the fixed path and the member diameter is greater than the winding diameter.

An expandable intervertebral implant is disclosed for use in between adjacent vertebral bodies in a spine. An expandable intervertebral implant may include an upper plate having a first upper side and a second upper side, a lower plate having a first lower side, a second lower side, and a first lattice that connects the first upper side to the first lower side. The expandable intervertebral implant may further include a second lattice that connects the second upper side of the upper plate to the second lower side of the lower plate and an opening having a longitudinal axis between the upper plate, lower plate, first lattice, and second lattice. The expandable intervertebral implant may further include an expansion mechanism comprising a driver that expands the upper plate and the lower plate away from each other along a cephalad-caudal axis by deforming the first lattice and the second lattice.

Various aspects of methods, systems, and use cases may be used to prevent dislocation of a joint replacement implant by limiting movement of the joint replacement implant to safe zones of movement. In some examples, the joint replacement implant includes a ball, an intermediate shell adapted to receive the ball and engage with a shell mobility structure protruding from the ball, and an outer shell adapted to receive the intermediate shell and provide fixation of the implant within a portion of a joint of a patient. For example, the interaction between the ball, the intermediate shell, and the outer shell prevent dislocation of the ball, and therefore dislocation of the joint replacement implant.