The present application is directed to device and methods for moving vertebral members, and more specifically, to devices and methods for spacing vertebral members over multiple levels.
The spine is divided into regions that include the cervical, thoracic, and lumbar regions. The cervical region includes the top seven vertebral members identified as C1-C7. The thoracic region includes the next twelve vertebral members identified as T1-T12. The lumbar region includes five vertebral members L1-L5. The vertebral members are spaced apart forming an intervertebral space between each adjacent vertebral member. Intervertebral discs are located within this space and permit slight flexion, extension, lateral flexion, and rotation.
Various procedures include spacing apart the vertebral members that extend along a section of the spine. These procedures may be required due to damage to one or more of the vertebral members and/or intervertebral discs. The damage may be caused by a specific event such as trauma, a degenerative condition, a tumor, or infection. Currently, decompression of vertebral members along a spinal section is completed independently at each spinal level. These techniques have the potential for applying too much force at one or more levels that could affect the single or multilevel kinematics of the adjacent spinal levels.
The present application is directed to devices and methods to space apart vertebral members over two or more spinal levels. One embodiment may include a power source, a supply line, and two or more expandable members. Each of the members may be placed at different locations along the spine. The supply line may operatively connect the members with the power supply. Activation of the power supply may cause each of the expandable members to increase in height and space apart the vertebral members within the spinal levels at issue.
The present application is directed to devices and methods to space apart vertebral members over two or more spinal levels. The devices and methods may include placing expandable members within two or more levels of vertebral members. The expandable members may be connected by a supply line to a power source. Activation of the power source may feed power throughout the supply line and to two or more of the expandable members causing the members to increase in height and apply a common force to the vertebral members.
In one embodiment, power source 20 provides power to the members 40 to move from the closed orientation towards the open orientation. In one embodiment, the system uses a fluid to adjust the orientation of the members 40. In one specific embodiment, the system uses a hydraulic fluid. In one embodiment, a reservoir 21 may be operatively connected with the power source 20 for holding the fluid when it is not within the supply line 30 or members 40. Reservoir 21 may be an integral with or remotely located from the power source 20. In one embodiment, power source 20 includes a pump for moving the fluid through the supply line 30 and into each of the members 40. Power source 20 in one embodiment is adjustable to move fluid into the supply line 30 at various speeds and at various pressures as necessary for the necessary vertebral spacing. In one embodiment, power source 20 may further operate in a reverse direction to pull the fluid from the members 40. The reverse movement of the fluid from the members 40 towards the power source 20 may cause the members 40 to move from the open orientation towards the closed orientation.
Another embodiment includes a power source 20 that moves gas including air. In one embodiment, power source 20 is a compressor that moves the gas into the supply line 30 and members 40. Another embodiment features an electrical power source 20. In one embodiment, expandable members 40 are electrically actuated and movable between the open and closed orientations. Each member 40 may include a torque limiter to control the extent of force applied to the vertebral members 100.
In one embodiment, members 40 are movable between open and closed orientations. In the embodiment, the members 40 are sized to fit within the intervertebral disc space formed between the vertebral members 100 when in a closed orientation.
In one embodiment, contact surfaces 49 may be contoured and/or shaped to correspond to the geometry of the vertebral members 100. Further, contact surfaces 49 in one embodiment may be removably connected to the first and second sections 41, 42 and are replaceable as necessary to match the geometry of the vertebral members 100. Members 40 and the contact surfaces 49 may be shaped to simulate lordotic implants or include implant shaped endplates so the surgeon can template the final implant size in height, width, and depth.
In one embodiment, one or both sections 41, 42 include a connection for attachment of the supply line 30. Introduction of fluid, gas, or electricity (hereinafter called power) in one embodiment into the member 40 causes the sections 41, 42 to expand thereby increasing the height measured between the contact surfaces 49. In one embodiment, removal of the power from the member 40 causes the sections 41, 42 to move together thus decreasing the height. In one embodiment, member 40 includes a piston that actuates upon receipt of power through the supply line 30.
In one embodiment, different types of members 40 may be used at different spinal levels to space apart the vertebral members 100. In one embodiment as illustrated in
In one embodiment, members 40 include a locking mechanism to lock the member 40 at a specific height. Locking members in one embodiment may maintain the height even after the power is removed from the member 40. In one method, member 40 is expanded to a height and a locking mechanism is activated to prevent further size changes. After activation, power source 20 can be deactivated without affecting the height of the locked member 40. In one embodiment, the locking mechanism is a valve for maintaining fluid pressure within the member 40. In another embodiment, locking mechanism is a hermetic seal for maintaining gas pressure within the member 40. In another embodiment, locking mechanism is an electronic circuit for maintaining a current or voltage to the member 40.
Supply line 30 moves fluid between the power source 20 and the members 40. The supply line 30 may include the same size between the power source 20 and the members 40, or may include different sizes. In one embodiment, more than one supply line 30 extends between the power source 20 and one or more of the members 40. In one embodiment as illustrated in
In one embodiment, connectors, generally referred to as 35, connect together the various lines of the supply line 30. One connector type 35a, 35b, includes a three-way connection having a first and second connections 36, 38 along a first section of the supply line 30, and a third connection 37 that connects with the feed line 34 that leads to and from the member 40. A second connector type 35c includes first and third connections 36, 37 as described above. In another embodiment (not illustrated), the farthest secondary line 32 from the power source 20 connects directly with one of the members 40.
In one embodiment, one or more valves 60 may be positioned along the supply line 30 to control the power leading into the members 40. In one embodiment, each of the valves 60 independently control the power introduced into each one or more members 40. In one embodiment, valves 60 may be selectively positionable between open and closed orientations. In one embodiment of the open orientation, the amount of power fed out of the valve 60 is the same that is fed further downstream along the supply line without any affect. In one embodiment of the closed orientation, the amount of power fed from the valve 60 is less than the power fed into the valve 60. In one embodiment, valve 60 can control the amount of power feed from about 100% (i.e., in an open orientation) to about 0% (in a closed orientation).
Valves 60 may be positioned at a variety of locations along the supply line 30. In one embodiment as illustrated in
In one embodiment, an indicator 50 may be operatively connected to the supply line 30 to detect the amount of power within the supply line 30. In one embodiment, indicator 50 includes a gauge 51 for visual observation of the power. In one embodiment as illustrated in
In one embodiment, a feedback system 70 may be operatively connected with the device 10 to provide immediate, real-time, and/or requested information to the surgeon regarding one or more of the device characteristics. Feedback system 70 may be independent or associated with the indicator 50. In one embodiment, feedback system 70 provides an indication when a desired or predetermined separation characteristic of the members 40 is obtained, and/or when certain threshold separation characteristics are obtained and/or approached. By way of example, system 70 can provide the force being exerted by each of the members 40 to the vertebral members 100, and the resulting spacing of the vertebral members 100.
Once each member 40 is inserted, in one embodiment the power source 20 is activated to supply power into the supply line 30 (step 402). The fluid moves through the supply line and into each member 40 thereby causing the member height to increase. In one embodiment, a substantially equal amount of power is introduced into each member 40 thus causing each member to apply the same force to the vertebral members 100. In one embodiment, the applied force is substantially the same, regardless of the starting size of the intervertebral disc space or final distraction magnitude. By way of example using
In one embodiment, at some point in the process, the spacing between the vertebral members 100 is measured (step 404). In one embodiment, physical measurements of the vertebral member spacing are taken periodically during the process. If additional spacing is required, the power source 20 is adjusted accordingly (step 408). If the spacing is adequate, the expansion process is complete (step 406).
In one embodiment, once spacing is adequate replacement spacers are inserted and take the place of the members 40. In one embodiment, removal of the members 40 includes operating the power source 20 in a second direction and drawing power from each member 40 causing the height to decrease to an amount that the members can be removed. In one embodiment, the heights of each of the members 40 decreases at the same amount as power is equally drawn from each member 40. In one embodiment, each member 40 is independently moved towards the closed orientation.
In one embodiment, valves 60 act as the locking mechanisms to control the size of the members 40. Turning the valve 60 from an open to a closed position while in the open orientation prevents a reduction in the member size.
One embodiment includes accessing the spine from an anterior approach to the cervical spine. Other applications contemplate other approaches, including posterior, postero-lateral, antero-lateral and lateral approaches to the spine, and accessing other regions of the spine, including the cervical, thoracic, lumbar and/or sacral portions of the spine.
The embodiments described above feature the members 40 positioned within the intervertebral space formed between adjacent vertebral members. The members 40 may also be used for spacing other sections of the spine, including pedicles, lamina, and processes.
In one embodiment, a single member 40 is positioned between the vertebral members 100. In one embodiment, multiple members 40 are positioned between the same vertebral members 100 to work in combination to achieve the proper spacing.
In one embodiment, the device is modular in the sense that additional members 40 may be added and deleted from the supply line 30. By way of example, the device illustrated in
Spatially relative terms such as “under”, “below”, “lower”, “over”, “upper”, and the like, are used for ease of description to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the device in addition to different orientations than those depicted in the figures. Further, terms such as “first”, “second”, and the like, are also used to describe various elements, regions, sections, etc and are also not intended to be limiting.
The present invention may be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. More than one power source 20 may be attached to the supply line 30. In one embodiment, members 40 remain within the patient in an open orientation during additional surgical procedures. In one embodiment, drawing the power from the member 40 comprises deactivating the power source 20. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.