Medical devices in accordance with various embodiments of the present invention employ one or more coaxial screw gear sleeve mechanisms. In various embodiments, coaxial screw gear sleeve mechanisms include a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing the device to expand.

A dilation introducer for orthopedic surgery is provided for minimally invasive access for insertion of an intervertebral implant. The dilation introducer may be used to provide an access position through Kambin's triangle from a posterolateral approach. A first dilator tube with a first longitudinal axis is provided. A second dilator tube may be introduced over the first, advanced along a second longitudinal axis parallel to but offset from the first. A third dilator tube may be introduced over the second, advanced along a third longitudinal axis parallel to but offset from both the first and the second. An access cannula may be introduced over the third dilator tube. With the first, second, and third dilator tubes removed, surgical instruments may pass through the access cannula to operate on an intervertebral disc and/or insert an intervertebral implant.

Improved hip arthroplasty trial devices and hip arthroplasty trial systems are described. A hip arthroplasty trial device has a head member having a central axis and defining an inner chamber, a head member opening providing access to the inner chamber, and a cavity extending inward from the outer surface of the head member. A rotatable member is disposed in the inner chamber and along an axis between the central axis and one side of the head member. The cavity extends along an axis between the central axis and another, opposite side of the head member. A spacer is disposed within the head member opening and is moveable between a spacer first position and a spacer second position. Rotational movement of the rotatable member moves the spacer from the spacer first position to the spacer second position.

An expandable intervertebral implant is provided for insertion into an intervertebral space defined by adjacent vertebrae. The expandable intervertebral implant includes a pair of outer sleeve portions and an inner core disposed between the outer sleeve portions. Movement of the inner core relative to the outer sleeve portions causes the outers sleeve portions to deflect away from each other, thereby engaging the expandable intervertebral implant with the vertebrae and adjusting the height of the intervertebral space.

An expandable vertebral body device, system, instrument, and methods of assembly and using the device, system, and instrument are disclosed. The vertebral body device includes a body with a first end and a second end, a first rotating member rotatably coupled to the first end, a second rotating member rotatably coupled to the second end, a first extension member moveably coupled to the first end, and a second extension member moveably coupled to the second end. The expandable cage system comprises a vertebral body device and an insertion instrument. Methods for assembling and using the vertebral body device and instrument are also disclosed.

An end cap and a bone screw for use therewith are provided. One or more of the end caps can be used with a spinal implant used to replace portions of a vertebral body after a corpectomy thereof. The end cap can include a first end and a second end opposite from one another, a first side and a second side opposite from one another, and a body portion extending between the first end, the second end, the first side, and the second side. The body portion can include an exterior surface for contacting an endplate of a vertebral body, and an interior cavity formed in the end cap opposite from the exterior surface. The interior cavity can be sized to receive a flange portion of the spinal implant, and can include at least one attachment structure provided in the interior cavity facilitating attachment of the end cap to the flange portion of the spinal implant. One or more of the bone screws can be received through apertures formed in the end cap and into the endplate of the vertebral body. The bone screws can be configured, upon receipt in the apertures in the end caps, to lock in place relative thereto.

A spinal jack adapted for installation between first and second vertebral processes, including a central body supporting first and second inter-expandable jack halves between retracted and expanded positions. Each of the jack halves further includes gripping portions adapted for engaging the vertebral processes. A geared mechanism provides for expanding or retracting the jack halves in order to establish a corrected adjusted orientation between the processes.

An implant assembly including an expandable vertebral body replacement implant. Two outer cores disposed on opposing ends of an inner are configured to move away from each other when the inner core is actuated. The implant assembly may include removable endplate configured to engage vertebral bodies as interbody spacer or through a corpectomy. The implant may include a locking mechanism to prevent collapse or movement the implant assembly after implantation. The locking mechanism may be automatically engage after removal of an inserter instrument from the implant assembly.

An expandable intervertebral total disc replacement implant, including an inferior component, including a first core including a first outer surface and a first inner surface, and a first arm telescopingly engaged with the first core, a superior component, including a second core including a second outer surface and a second inner surface, and a second arm telescopingly engaged with the second core, and an expansion mechanism connected to the first core, the second core, and at least one of the first arm and the second arm.

A bone graft delivery system and method for using same to deliver graft material into a surgical site. The method includes the steps of providing a hollow tube configured to receive the graft material, releasably attaching an implant to a distal end of the hollow tube so as to communicate with at least one opening in the distal end of the hollow tube, the implant being configured to receive the graft material delivered through the hollow tube; placing the implant within the surgical site; advancing the graft material through the hollow tube; conveying graft material through the hollow tube into an interior of the implant, whereby the implant is at least substantially filled with the graft material; and discharging the graft material through at least one opening in the implant into the surgical site, whereby the surgical site is at least substantially filled with the graft material.