The present invention discloses a bionic artificial interphalangeal joint. The bionic artificial interphalangeal joint includes three sets of proximal prostheses and distal prostheses matched with the proximal prostheses and respectively corresponding to the three joints from the metacarpal bone to the distal phalanx. According to the specific position of the joint to be replaced, the corresponding artificial interphalangeal joint can be selected for replacement. Among them, the bionic artificial interphalangeal joint that can be installed between the metacarpal bone and the proximal phalanx has multiple degrees of freedom, which allows the proximal phalanx to bent in any direction like a real finger, and the bending angle of the proximal phalanx can be up to about 90 degrees when the proximal phalanx is bent toward the inner side of the finger.

An interspinous spacer that includes a body having a distal portion and a proximal portion; an actuator at least partially disposed in the body; and a first arm and a second arm, where the first and second arms are rotatably coupled to a distal portion of the body and coupled to the actuator, where the actuator, first arm, and second arm are configured, upon rotation of the actuator in a first direction, to move the first and second arms from an implantation position, in which the first and second arms extend from the distal portion of the body back toward the proximal portion of the body, to a deployed position, in which the first and second arms extend away from the body.

Hip arthroplasty trial systems and associated medical devices, methods, and kits are described that can be utilized in situ to complete a femoral head trial. An example embodiment of a hip arthroplasty trial system includes a medical device and a femoral stem. The medical device has a head member, a spacer, a shaft, and a locking member. The spacer is disposed within the head member and is moveable from a first position to a second position. The shaft is disposed within the head member and contacts the femoral stem. The shaft is moveable from a first position to a second position. Movement of the shaft from the first position to the second position moves the spacer from its first position to its second position. The locking member is disposed within the head member and releasably attaches the shaft to the head member.

Provided is an expandable lumbar cage including an upper member, a lower member, a sagittal adjustment unit to adjust sagittal balance of a spine, and a coronal adjustment unit to adjust coronal balance of the spine. According to the foregoing description, it is possible to simultaneously adjust the sagittal balance of the spine as well as the coronal balance, thereby achieving effective treatment of the spine having compound deformity.

Intradiscal implants, systems, and methods thereof. The intradiscal system may include an expandable implant and one or more intradiscal implants. The intradiscal implants may be supplemental to or integrated with the expandable implant. The intradiscal implant may include one or more flexible anchors with a straight configuration and a curved configuration. The anchor may be bendable, for example, using a shape-memory material.

A device includes a core having proximal and distal ends and defining a first female thread. A drive screw includes first and second ends. The first end includes a first male thread. The second end including a second male thread that engages the first female thread. A first body includes a second female thread that engages the first male thread. A second body is coupled to the drive screw. A first plate is coupled to the core and the first body. The first plate includes a first vertebral engaging surface. A second plate is coupled to the core and includes a second vertebral engaging surface. The drive screw is configured to rotate relative to the core to simultaneously pivot the first plate relative to the core and alter a distance between the first vertebral engaging surface and the second vertebral engaging surface.

A device includes a core defining first and second female threads. A first member includes a first body and a first drive screw coupled to the first body, the first drive screw being configured to engage the first female thread. A second member includes a second body and a second drive screw coupled to the second body, the second drive screw being configured to engage the second female thread. A first plate is coupled to the core and the first body. The first plate includes a first vertebral engaging surface. A second plate is coupled to the core and the second body. The second plate includes a second vertebral engaging surface. The drive screws are configured to independently rotate relative to the core to pivot the first plate relative to the core and to alter a distance between the first vertebral engaging surface and the second vertebral engaging surface.

A spinal fixation system includes an expandable disc replacement body and an adjustment mechanism. The expandable disc replacement body includes a first wall, a second wall, a hinge connecting the first wall and the second wall, and a first bone-screw receiving section at a proximal end of the first wall. The adjustment mechanism is positioned between the first wall and the second wall, and an angle between the first wall and the second wall can be varied by movement of the adjustment mechanism.

A variety of expandable cage improvements are provided. The cages can have a width expansion assembly that operates independently of a height expansion assembly and the wedges and ramps do not need to make contact with each other. Wedges, or movable spacers with pivotal link connections, can be used, and any portion of the cage can be expanded in width or in height in an amount that differs from other portions of the cage to provide any of a multitude of desired cage shapes. Interdigitating fingers, slidable and/or pivoting, are provided to distribute stresses over a vertebral endplate as desired.

An acetabular hip implant includes a plurality of rings secured to an acetabular shell component. A method of fabricating a customized, patient-specific version of such an implant is also disclosed.