BACKGROUND

Back pain is one of the most common diagnoses in medicine today. As the population ages, back pain and other joint related issues create a large burden on our healthcare system. Spinal procedures to address back pain are increasing in both frequency and cost. Surgical interventions aimed at treating back pain have to deal with dysfunctional joints in the spine.

There are two overriding principles when treating degenerative joint disease surgically; replacement or fusion. Spinal fusions have long been the gold standard for treating pain caused by degenerative joint disease in the spine. Disc replacement surgery is a more recent surgical procedure designed to treat back pain while maintaining normal spinal motion. Both procedures are invasive, complicated, and costly.

Recent surgical trends are aimed at minimizing invasion and complications while also reducing procedure cost. Percutaneous pedicle screw placement has become a popular replacement for open pedicle screw placement. Tubular dilators or endoscopic systems are replacing open spine access techniques, providing smaller incisions with less tissue damage.

Intervertebral disc degenerative disease is implicated as a primary cause of back pain. Degenerative joint disease can also lead to neurologic deficits by causing stenosis of spinal spaces designated for neurologic tissue passage. Surgical approaches are designed to decompress and fuse or replicate the motion of the intervertebral disc space. These procedures require openings in the spine identical to or larger than the size of the stabilization device to be implanted. The disk space is made of an annular ring that circumferentially bounds the intervertebral space and contains the intervertebral cushion known as the nucleus pulposus. Surgical openings in the annulus are sized according to the implant that is used to stabilize the intervertebral space. An anterior approach for an interbody fusion is the gold standard because it allows the largest implantable stabilization device and the greatest quantity of fusion graft material to be placed. Fusion graft augmenters such as Infuse® by Medtronic are often utilized with anterior approaches because it can safely be kept away from neurologic structures. The annular opening however is similarly large. This creates instability that must be addressed by the surgical construct.

As an example, in anterior lumbar interbody fusions, the annular opening causes unstable extension of the spine. This must be addressed with instrumentation designed to limit that specific motion. Intervertebral disc replacements also require a large annular opening to be placed. They require endplate replication with metal plates anchored into the bony endplates above and below the disk space as a means of holding the device in the disc space. This causes considerable difficulty if the devices ever need to be removed. It also causes weakness in the bone that can cause endplate fractures if these devices are applied to adjacent segments.

Robotics is an evolving surgical field that aims to significantly minimize the exposure necessary to perform traditional tasks. The application of robotics to spinal surgery has thus far been limited to placement of spinal hardware. Intervertebral disc preparation is trivial through a large enough annular exposure, however, when the annular exposure is small, complete removal of the nucleus pulposus inside of the annulus is nearly impossible with today's tools. For example, the standard posterior discectomy approach makes it nearly impossible to remove the nucleus pulposus from the opposite side of the disk space particularly in the posterior region.

SUMMARY

An aspect of the present disclosure relates to an articulating drill extender and a method for articulating solid torque shafts using bevel gears. This articulating drill extender may be incorporated into standard handheld surgical equipment and additionally or alternatively may be controlled robotically.

The articulating drill extender utilizes a drill bit to morstelize the disc, remove endplate cartilage and prepare a bleeding bony surface if a fusion is the goal of surgery. The drill shaft can be connected to existing drill power sources or to a new drill device controlled by, for example, a surgeon or a surgical robot. The articulating drill extension may be a solid shaft terminating with one or more articulating gears present at the articulation joints of the drill. At each articulation, a new solid drill shaft interfaces with the previous to allow transmission of torque any at articulation angle between 0 and 90 degrees. The articulating torque delivery of the device can find application to other areas outside of medicine as well given its small size, proximal control of distal action and unparalleled ability to deliver high torque remotely to a constrained space.

Another aspect of the present disclosure relates to a hydrostatic disc space expansion device for insertion into a disc space within a patient in a first, compact state and configured to take its predetermined shape within the disc space to separate the discs or otherwise provide a space therein within the patient as the device is configured to take its predetermined shape after placement within the disc space.

Yet another aspect of the present disclosure relates to a formed interbody fixation device for rigid or motion-preserving stabilization within a patient. The fixation device has a predetermined shape selected and tailored for a specific patient's anatomy and assumes its predetermined shape when it is filled with the surgeon's choice the materials.

Another aspect of the present disclosure relates to a stereotactic drill extension access channel.

Another aspect of the present disclosure relates to a stereotactic solution for monitoring movable portions of stereotactic instruments.

Yet another aspect of the present disclosure relates to a planning solution for manufacture of purpose-built spinal implants.

Another aspect of the present disclosure relates to a surgery that is planned ahead of time utilizing additions to spinal planning software. The plan comprises the volume of disc to be resected and plan for sizing a spinal distractor and implant that will meet the patient's needs. The robot or robot-human combination then carries out the surgical plan.

Additionally, or alternatively the plan can be made in real time if the disc space requires mobilization prior to access. The robot utilizes stereotactic navigation to monitor patient anatomy location in the operative space. For example, a combination stereotactic frame/disc space access port may be placed under direct visualization or percutaneously using neurologic monitoring via electromyography and/or endoscopy. The access portal is rigidly fixed inside the patient's disk space or additionally can be held by the robot itself as a reference. It is through this port that the robot arm can complete the morselization of the disc's contents. Once the disk space preparation is complete the space is irrigated through the access portal and the fragments of discs are removed via suction. The annular ligament itself becomes a stabilizing structure in the fusion or disc replacement construct.

Another aspect of the present disclosure relates to a clip for securing a drill extension access channel to retractor system.

Yet another aspect of the present disclosure relates to a robotic arm extension for limiting motion of any instrument to be operated through the working channel of the instrument. Such an extension may be an adapter for an existing robotic arm extension with manual controls to be operated by the surgeon, or a purpose-built robotic arm extension where the robot is able to control the articulating drill extender limitors.

A robot can utilize a very small annular opening for disc space access thereby limiting any destabilization of a disc space. The disc removal is performed with a robotic appendage such as the articulating drill extension and which utilizes a hollow articulating arm with a drill shaft running through the central portion. The drill shaft may be held in a fixed trajectory by the robotic arm and operated by a human operator, or the drill arm can be completely controlled by the surgical robot. This device has applications in various surgical areas. Orthopedic operations, such as knee or hip replacements, are examples of procedures where these devices may be useful.

Another aspect of the present disclosure relates to a system for minimally invasive robotic access to an intervertebral space with placement of a collapsible device designed specifically to meet a patient's a surgeon's needs at the operative level, including spinal fusions and disc replacements. The method is designed to be used as a minimally invasive approach and leverage new robotic surgical technology.

