Various methods and tools have been developed for the treatment of the spinal column, including those for the removal and replacement of the intervertebral disc between adjacent vertebrae of the spine. The necessity for this type of surgical treatment can arise due to disease, degeneration and/or injury that can significantly impair the routine functioning of a patient's spinal column and can generate debilitating pain. Existing techniques can involve bone grafting techniques and discectomy. Options for replacement of the disc include artificial disc implantation or the introduction of a cage into the intervertebral space. However, the insertion of a cage is highly invasive and the cage structure has provided limited mobility.
Existing techniques utilize a large open surgical incision to access the annular region. Some have proposed the use of a balloon that is inserted into the vertebral body for inflation in an attempt to stabilize the spinal column, reduce pain and enhance post-operative mobility. Thus far such methods have failed to gain acceptance. Improvements are needed to provide a safe and effective treatment that better emulates normal functioning of the spine.
The present invention relates generally to systems and methods for treatment of the spine. A preferred embodiment includes a system providing endoscopic access to the intervertebral space, tools for the removal of tissue from the intervertebral space, a system for the endoscopic delivery of a plurality of inflatable or expandable members into the intervertebral space and a fluid delivery system to control inflation of the inflatable members using a plurality of fluids.
A preferred embodiment employs a tool kit having a plurality of tools for removing inner portions of the annulus fibrosus and the nucleus pulposus from between a pair of vertebral bodies to provide a cavity of sufficient size. It is preferred to remove a region of cartilaginous endplate material to punctuate bleeding. It is necessary to remove at least 60%, and preferably over 80% of the disc material while leaving the outer annulus intact, so that the implanted material can stabilize the spacing between vertebrae and reduce the risk of further injury.
Endoscopic access is generally accomplished using a cannula providing a portal that is less than 8 mm in diameter. Thus, the elements of the system being introduced into the intervertebral space must be inserted through the cannula or an endoscope working channel. Additionally, a second endoscopic access region can also be used to provide visualization of the intervertebral space as well as a second port to introduce tools or prosthetic devices. Due to the small diameter of the access port(s) and the relatively large volume of tissue to be removed, an important aspect of preferred embodiments of the invention involves the use of an articulating end for the tools being introduced into the space. Due to the varying characteristics of the material being removed, different tool elements must be inserted through the narrow channel and yet be moved over an arcuate path within the intervertebral space to access the material to be removed. In certain cases, a sufficient mechanical force must be imparted using the tool to dislodge fragments of tissue. A combination of rongeurs, curettes, rakes and ring curettes with distal ends having an angular adjustment range can be used for tissue removal. An adjustable angle shaver can also be used to shave or condition the vertebral endplates around the corners. The shaver can be a mechanical shaver with a rotating or oscillating blade or cutting edge, or alternatively, can comprise an RF electrode assembly. Light from a laser coupled into the annular cavity can also be delivered using a fiber optic probe to assist in the removal of tissue or conditioning of the cavity. The combination of mechanical, electro-mechanical and optical instruments provide for complete discectomy through at least one cannula. The system for tissue removal can also include the delivery and removal of fluid to assist in the removal of tissue debris that has been detached from the internal surfaces of the cavity.
Following removal of tools from the cavity, the device for implantation of the prosthesis can then be inserted into the cannula. A preferred embodiment utilizes a probe having a first balloon and a second balloon mounted at the distal end. The first balloon is preferably shaped to conform to the patients' intervertebral cavity when expanded into position. As it is desirable to verify proper spacing of the vertebrae, a measurement of the precise spacing, such as between adjacent lumbar vertebrae, can be performed using one balloon that has been inflated with removable fluid. The first balloon is mounted onto the distal end of the probe which has one or more internal lumens to provide for fluid delivery and removal. The second balloon can also be mounted on the probe shaft proximal to the connector that releasably connects the first balloon to the probe. Thus, both balloons are inserted using a single probe. The second balloon is used to provide proper spacing between the endplates of adjacent vertebral bodies while the first balloon is positioned and filled with cement. The second balloon is subsequently removed after the first balloon is filled with an implant material such as bone cement and has hardened into a fixed geometry. A fluid control system can be used to control delivery of fluids such as saline and bone cement. After the probe is detached from the first balloon, additional bone cement or bone graft is inserted to fill to cavity and seal the annulus. The balloons used for a particular patient can have a size and shape selected to conform to the particular intervertebral space which can be determined using medical imaging procedures, such as computed tomography x-ray scanning systems. Fluoroscopy can be used during and after balloon insertion to verify proper positioning of the implant. The balloon or inserted fluid can serve as a fluoroscopic marker.
The present invention provides systems and methods for treatment of the spine. A preferred embodiment of a system in accordance with the invention is illustrated in connection with
The intervertebral disc space 10 can be accessed from both sides using two 6.9 mm cannulas 12, 14, for example, which are inserted using standard dilation procedures. Note that other size cannulas can also be used, however, preferred embodiments of the invention utilize one or more cannulas under 80 mm in diameter to minimize trauma to the patient. A tool system 20 is used to insert a plurality of tool instruments into the disc space 10 to remove tissue. Tool system 20 can be connected to computer 65 and can include an imaging device and suction elements. The tool system has a plurality of tools 26 long enough to extend through cannulas into the disc space 10. The user grasps the handle 24 of each tool used to operate switches or manually actuates 22 which operate the directional movement of the articulating tip 21 and/or the tool element 25. The tool can include a cable and/or tubing 28 that can include electrical connection wiring, a suction tube, or fluid delivery and removal tubing to the system 20 which can also house a pump. Following removal of the disc, a balloon delivery system 40 is used to insert inflatable membranes or balloons into the cavity and a fluid management system 50 is used to deliver and remove fluids to inflate the balloons in a selected sequence. The balloon delivery system 40 can be inserted into one of the cannulas 12, 14 using handle 42 with actuators 45 to control fluid flow through tube 44 from system 50. A visualization system 60 can include an insertable probe that is inserted through the second port and/or an endoscope viewing channel which can be inserted through the same port with the tool and/or balloon delivery systems. Thus, a preferred embodiment provides visualization with the articulating tip 21 in combination with tissue removal. The system 60 can include a computer and/or controller 65 and a display 66. The computer 65 can be attached to an endoscope handle 64 and an endoscope tube 62 that is inserted into cannula 12 and/or 14, as needed to visualize the intervertebral space 10. Note that tissue removal can also be conducted through one or both cannulas 12, 14, either separately or in conjunction with tool delivery.
A procedure for performing surgery 100 in accordance with preferred embodiments of the invention is illustrated in
A sequence of tools can be used to remove tissue 106. This can involve use of a drill to remove tissue and thereby open a channel to enable the insertion of the end of the cannula into an operative space. The nucleus pulposus is then removed using articulating tools to remove tissue including material from the inner annulus wall surface. The tool system can include suction to remove disc material during the procedure. Alternatively, a fluid delivery and removal system can be included in which a fluid is pumped into and removed from the intervertebral space. This can also improve visualization of the internal space during tissue removal. The resulting annular cavity can have a volume approximately 40 mm×30 mm×12 mm, for example. The precise volume will vary depending on which disc is removed (for example, L1-L2 or L4-L5), whether the individual is male or female, age, etc. Generally the volume is in a range of 10,000 mm3 to 15,000 mm3. Consequently, in adult patients undergoing repair of lumbar discs, it is necessary to remove at least 10,000 mm3 of tissue from the intervertebral space to accommodate the amount of material required for insertion and stabilization of the spine.
An abrading tool, such as a shaver, is used to condition 108 each vertebral endplate such as removal of cartilaginous endplate material to achieve punctate bleeding. Subsequently an implantable device is inserted 110 through the cannula into the annular cavity and a fluid is inserted 112 into the implantable device through the cannula so that the implant conforms to the vertebral space. A preferred embodiment utilizes a probe having a first balloon and a second balloon. The second or inner balloon is temporarily inflated to provide proper spacing between the vertebral bodies. The second balloon is then filled with a second fluid material for permanent placement. The inner balloon is then either filled with cement or collapsed and removed 114. Additional graft or bone cement material can be inserted 116 to complete the implant and seal the annulus.
Illustrated in
Illustrated in
A preferred embodiment utilizes a release and locking mechanism 422 actuated by the user from the proximal end of the tube 402. When the release mechanism 422 is pulled 428 toward the proximal end of the tube 402, this allows first member 418 to rotate 426 (
A grasping tool 410, such as a rangeur, can be mounted on the distal end with a connector 420, so that different tool elements 25 can be mounted on the distal end. In this example, a control wire 406 extending through the tube 402 is used to actuate the grasping element, such as forceps, or other device mounted at the distal end. A control tube or rod 405 can be used to rotate the tool 410. The tube 405 can incorporate a channel for suction 440. Spacer 442 can position the tube 405 and the central wires
As shown in
Shown in
More generally, the maximum tip angle 452 can be in a range of 30-40 degrees depending upon the location in the cavity. The bending or rotating length 455, that is the length of the distal end of the tool that rotates relative to the tool axis, must be adjustable to reach the desired amount of intervertabral material to be removed. Thus, both the bending length and the bending angle of the distal end of the tool must have a plurality of selectable values to access the different portions of the cavity. Thus, the tip angle can range from zero to at least 25 degrees, and preferably up to a maximum angle in the range of 30-40 degrees.
Shown in
In the embodiment of
Schematically shown in
In a preferred sequence, first and second balloons are filled with a fluid such as saline to separate first vertebra 640 from second vertebra 642 as shown in the side view of
The shape of the balloon is selected to conform to the volume defined by the endplates and the surrounding radius. As shown in
A perspective view of a two balloon system 700 in accordance with the invention is shown in
The inner, or second balloon, 702 is attached to the probe extending through coupling 708 to the connector 706. Due to the varying distance between the endplate of the adjoining vertebra, a first side 712 can be higher than the second side 710. The second balloon 702 can also have a first sidewall 714 that is higher than the second, or opposite, sidewall 716. The pressure at which each of the respective balloons is inflated can be adjusted separately to maintain proper spacing of the vertebrae. Thus, while the first balloon is deflated the pressure in the second balloon can be increased to maintain proper spacing. When the first balloon is filled with cement, the pressure in the second balloon can be lowered to maintain proper spacing.
A preferred embodiment of the connector assembly 800 is shown in the perspective view of
The fluid management system 50 of
Another preferred embodiment of the fluid management system illustrated in
While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention or equivalents thereof as defined by the appended claims.
This application is a continuation of U.S. application Ser. No. 14/355,503, filed on Apr. 30, 2014, which is a 35 U.S.C. § 371 national stage filing of International Application No. PCT/US2012/067399, filed on Nov. 30, 2012, which claims priority to U.S. Provisional Application 61/565,153 filed on Nov. 30, 2011, the entire contents of all of the above applications being incorporated herein by reference.
This invention was made with Government support under Contract No. W81XWH-07-2-0011 awarded by the U.S. Army Medical Research and Material Command. The Government has certain rights in the invention.
Number | Date | Country | |
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61565153 | Nov 2011 | US |
Number | Date | Country | |
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Parent | 14355503 | Apr 2014 | US |
Child | 16023588 | US |