A mobile surgical tracking system comprises a mobile surgical tracking device comprising an integrated fiducial marker and an imaging device. The imaging device is configured to generate an image of a patient's anatomical structure. The mobile surgical tracking system comprises a tracking system coordinate frame. The integrated fiducial marker has a position which has a known relation to the tracking system coordinate frame for the direct registration of the image to the coordinate system of the mobile surgical tracking device.

A fixation device includes a first anchor portion configured to join to a first bone portion, a second anchor portion configured to join to a second bone portion, and an intermediate component that extends between the first anchor portion and the second anchor portion. The intermediate component is configured to expand, contract, and angulate enabling constrained movement of the second bone portion with respect to the first bone portion. The second anchor portion has a larger configuration relative to the first anchor portion, thereby preventing the second bone portion from depressing below the first bone portion.

A bone fastener assembly instrument that can assemble a two-component bone fastener during surgery is provided. The bone fastener may be of a type that comprises a threaded bolt and nut for securing an implantable device to bone, such as a spinous process. A method for using the bone fastener assembly instrument is also provided.

A pivotal bone anchor assembly includes a receiver defining a cavity with an upper expansion region and a lower locking region, and a shank having a partial spherical head that is up-loadable into the cavity through a bottom opening. The assembly also includes a resiliently expandable retainer that is positionable within the upper expansion region with a discontinuous partial spherical internal surface and an inwardly facing surface above the discontinuous partial spherical internal surface, and a compression insert having a lower outwardly facing surface configured for side-to-side engagement with the inwardly facing surface and a downwardly facing partial spherical surface for frictionally engaging the head of the shank. The compression insert is positionable in overlapping engagement with the retainer within the receiver with the discontinuous partial spherical internal surface extending above and below a hemisphere of the head of the shank to capture the head within the retainer.

A pivotal bone anchor assembly includes a receiver defining a cavity with an upper expansion region and a lower locking region, and a shank having a partial spherical head that is up-loadable into the cavity through a bottom opening. The assembly also includes a resiliently expandable retainer that is positionable within the upper expansion region with a discontinuous partial spherical internal surface and an inwardly facing surface above the discontinuous partial spherical internal surface, and a compression insert having a lower outwardly facing surface configured for side-to-side engagement with the inwardly facing surface and a downwardly facing partial spherical surface for frictionally engaging the head of the shank. The compression insert is positionable in overlapping engagement with the retainer within the receiver with the discontinuous partial spherical internal surface extending above and below a hemisphere of the head of the shank to capture the head within the retainer.

A bone plate for treating acromioclavicular dislocations includes a shaft including a lateral portion sized and shaped to be positioned along a superior aspect of a lateral clavicle, the shaft including a plurality of openings extending therethrough for receiving bone fixation elements therein and a hook member extending from the shaft so that, in an operative position, the hook member is hooked under an acromion and the lateral portion of the shaft is positioned on the superior aspect of the lateral clavicle, the lateral portion of the shaft being substantially rounded so that the hook member is movable in one of an anterior direction and a posterior direction while the shaft maintains contact with the superior aspect of the lateral clavicle without any portion of the lateral portion of the shaft protruding beyond a surface of the lateral clavicle.

A method for treating joint pain in a subject is disclosed. The method can include inserting a bone dowel and a first portion of a bone marrow aspirate into a subchondral region of a bone that is part of a joint being treated and introducing a second portion of the bone marrow aspirate into the intraarticular space of the joint being treated.

A method for treating joint pain in a subject is disclosed. The method can include inserting a bone dowel and a first portion of a bone marrow aspirate into a subchondral region of a bone that is part of a joint being treated and introducing a second portion of the bone marrow aspirate into the intraarticular space of the joint being treated.

Open implant closure structures include a helically wound guide and advancement flange form having splay control surfaces. Multi-start closures and closures with inner set screws have splay control contours for interlocking with cooperating flange forms of bone anchor receivers. Flange form heights, thicknesses and other geometry, such as splay control ramp angle may be varied.

An electronically assisted artificial vertebral disc having an upper disc plate and a lower disc plate is disclosed. An actuator imparts movement to at least one of the upper and lower disc plates. A control device controls the actuator and the amount of movement between the disc plates. The actuator includes a plurality of either linear actuators or rotary actuators that are driven by electric motors in response to the control device. The control device includes at least a first sensor for detecting the position of the actuator and at least a second sensor for detecting the spatial orientation of at least one of the upper and lower disc plates. The control device also preferably includes a microprocessor that calculates the desired positions of the upper and lower disc plates and provides a control signal to the actuator to drive the upper and lower disc plates to their desired positions.