An access device for accessing an intervertebral disc having an outer shield comprising an access shield with a larger diameter (˜16-30 mm) that reaches from the skin down to the facet line, with an inner shield having a second smaller diameter (˜5-12 mm) extending past the access shield and reaches down to the disc level. This combines the benefits of the direct visual microsurgical/mini open approaches and the percutaneous, “ultra-MIS” techniques.

The present invention is directed at minimally invasive systems in which the proximal end portion of the working channel has either zero or a limited range of movement in the lateral direction. A first embodiment has a slidable collar attached to a pair of flanges, wherein movement of the collar is bounded by an annular frame. A second embodiment has a substantially spherical element attached to the tube. A third embodiment has a plurality of caps. A fourth embodiment is adapted for a larger working channel.

A multi-portal method for treating a subject's spine includes distracting adjacent vertebrae using a distraction instrument positioned at a first entrance along the subject to enlarge an intervertebral space between the adjacent vertebrae. An interbody fusion implant can be delivered into the enlarged intervertebral space. The interbody fusion implant can be positioned directly between vertebral bodies of the adjacent vertebrae while endoscopically viewing the interbody fusion implant using an endoscopic instrument. The patient's spine can be visualized using endoscopic techniques to view, for example, the spine, tissue, instruments, and implants before, during, and after implantation, or the like. The visualization can help a physician throughout the surgical procedure to improve patient outcome.

A retractor system with a closed loop control includes a retractor having one or more sensors, which measure parameters associated with a retracted tissue. The system further includes a positioning mechanism connected to the retractor and a controller which receives feedback signals from the sensors. Based on the feedback signals from the sensors, the retractor is actuated by the positioning mechanism so that the tissue can be retracted while maintaining the parameters associated with the retracted tissue above a threshold level or within a desired range. Another retractor system includes a retractor with a force sensor and at least one additional sensor, which can be used without a closed loop control arrangement.

An access device for accessing an intervertebral disc having an outer shield comprising an access shield with a larger diameter (˜16-30 mm) that reaches from the skin down to the facet line, with an inner shield having a second smaller diameter (˜5-12 mm) extending past the access shield and reaches down to the disc level. This combines the benefits of the direct visual microsurgical/mini open approaches and the percutaneous, “ultra-MIS” techniques.

A neuromonitoring system utilizes transcutaneous, trans-abdominal nerve root stimulation to monitor the health and status of the motor neural pathways of the lower extremities during the portions of a surgical procedure in which a tissue retraction assembly is used to maintain an operative corridor. A method of monitoring the status of nerve during a spinal surgical procedure delivers a transcutaneous, trans-abdominal stimulation signal to the spine. A determination is made of a stimulation threshold required to elicit a neuromuscular response from the stimulation signal.

The present invention includes a novel procedure and corresponding medical devices for a Percutaneous Posterior Lumbar Interbody Fusion (PePLIF). In PePLIF, the surgeon performs the entire operation percutaneously without the use of a microscope, endoscope, or magnifying loupes. An adjustable retractor system is disclosed that enables the surgeon to percutaneously perform the surgery through accessing the facet joint (and later disc space) that was created by said retractor system. This retractor system provides the surgeon a safe area to work and operate without fear of damaging nerves, blood vessels, or other tissue. An expanding trial may be inserted into and removed from the disc space through the interior of the retractor system to determine the proper size for the expandable cage. The retractor system also enables the expandable cage to be inserted into the disc space.

A surgical access system including a tissue distraction assembly and a tissue retraction assembly, both of which may be equipped with one or more electrodes for use in detecting the existence of (and optionally the distance and/or direction to) neural structures before, during, and after the establishment of an operative corridor to a surgical target site.

A surgical access system comprising a tissue dilation assembly and a tissue retraction assembly, both of which may be equipped with one or more electrodes for use in detecting the existence of (and optionally the distance and/or direction to) neural structures and one or more pressure sensors for determining and monitoring pressure on neural structures near the tissue dilation assembly or the tissue retraction assembly.

A tissue retraction system comprising a drive gear coupled to a shaft. The tissue retraction system includes a first plurality of linking members located along a second axis and configured to rotate along the second axis based on contact with the drive gear as the drive gear is rotated. The tissue retraction system includes a linking member selector configured to rotate along the first axis, wherein the linking member selector comprises a cylindrical body integrally formed with a handle. The tissue retraction system includes a right arm assembly, a left arm assembly, and a center arm that are each configured to move along trajectories. The tissue retraction system includes a first retractor blade, a second rector blade, and a third retractor blade. The tissue retraction system includes an array with tracking markers.