Tissue retraction and vertebral displacement devices, systems, and methods for posterior spinal fusion
View Patent ↗Devices for retracting tissue during a minimally-invasive, posterior spinal fusion procedure include a blade positionable along a passageway device connected to a connecting element implanted in a vertebra of the spine, such that the blade covers at least a portion of a longitudinal opening of the passageway device. The blade may be coupled to the passageway device by receiving the passageway device with a receiving portion. Systems for displacing the vertebrae of the spine include first and second extenders, the distal ends of each of which are configured to engage the connecting elements. Each extender may include a shaft configured to be securely engaged within a cage of the respective connecting element. The devices and systems of the present invention may be used in connection with an interbody fusion technique performed through an opening extending between the passageway devices, and an intermediate retractor blade may provide additional tissue retraction.
1. A method of displacing tissue within a body, comprising:
connecting a first connecting element to a first vertebra of a spine within the body, the first connecting element having a first passageway device connected thereto and extending proximally therefrom along a first longitudinal axis, the first passageway device defining an at least partially enclosed first tubular space adapted to receive a spinal fusion rod therein, and the first passageway device defining a first longitudinal opening into the first tubular space, the first longitudinal opening extending along at least a portion of the first longitudinal axis;
connecting a second connecting element to a second vertebra of the spine, the second connecting element having a second passageway device connected thereto and extending proximally therefrom along a second longitudinal axis, the second passageway device defining an at least partially enclosed second tubular space adapted to receive the spinal fusion rod therein, and the second passageway device defining a second longitudinal opening into the second tubular space, the second longitudinal opening extending along at least a portion of the second longitudinal axis;
positioning a first retractor blade along at least a portion of the first longitudinal opening such that a solid portion of the first retractor blade covers the portion of the first longitudinal opening; and
positioning a second retractor blade along at least a portion of the second longitudinal opening such that a solid portion of the second retractor blade covers the portion of the second longitudinal opening.
2. The method of claim 1 , wherein the step of positioning the first retractor blade comprises coupling the first retractor blade with the first passageway device, and wherein the step of positioning the second retractor blade comprises coupling the second retractor blade with the second passageway device.
3. The method of claim 2 , wherein coupling the first retractor blade with the first passageway device includes receiving at least a portion of the first passageway device with a first engagement portion connected to the first retractor blade, and wherein coupling the second retractor blade with the second passageway device includes receiving at least a portion of the second passageway device with a second engagement portion connected to the second retractor blade.
4. The method of claim 1 , further comprising forming an opening in skin of the body extending between the first and second passageway devices.
5. The method of claim 4 , further comprising enlarging the opening with an intermediate retractor blade positioned between the first and second passageway devices.
6. The method of claim 4 , further comprising inserting an interbody implant through the opening and into an intervertebral space between the first and second vertebrae.
7. The method of claim 6 , further comprising:
moving at least a portion of the spinal fusion rod within at least one of the first and second passageway devices; and
securing the spinal fusion rod to the first and second connecting elements.
8. The method of claim 1 , further comprising displacing a first extender with respect to a second extender to displace the first and second vertebrae with respect to one another, a distal end of the first extender being engaged with the first connecting element and a distal end of the second extender being engaged with the second connecting element.
9. The method of claim 8 , wherein the first extender includes a first shaft and the second extender includes a second shaft, the method further comprising:
securing at least a portion of the first shaft within a first cage of the first connecting element; and
securing at least a portion of the second shaft within a second cage of the second connecting element.
10. The method of claim 9 , wherein the step of securing at least a portion of the first shaft within the first cage comprises securing a distal portion of the first shaft within the first cage such that the first shaft extends within the first passageway device along the first longitudinal axis, and wherein the step of securing at least a portion of the second shaft within the second cage comprises securing a distal portion of the second shaft within the second cage of the second connecting element such that the second shaft extends within the second passageway device along the second longitudinal axis.
11. The method of claim 9 , wherein the step of securing at least a portion of the first shaft within the first cage comprises securing the first shaft within the first cage with a first set screw such that the first shaft extends transverse to the first longitudinal axis, and wherein the step of securing at least a portion of the second shaft within the second cage of the second connecting element comprises securing the second shaft within the second cage of the second connecting element with a second set screw such that the second shaft extends transverse to the second longitudinal axis.
12. The method of claim 11 , wherein the first extender is integrally formed with the first retractor blade and the second extender is integrally formed with the second retractor blade.
13. A method of displacing vertebral bodies, comprising:
affixing a first connecting element to a first vertebra of a spine using a driver engaged with the first connecting element;
after affixing the first connecting element, disengaging and removing the driver from the first connecting element;
after disengaging and removing the driver, securing a distal end of a first extender within a first cage of the first connecting element affixed to the first vertebra of the spine;
securing a distal end of a second extender within a second cage of a second connecting element affixed to a second vertebra of the spine; and
displacing the first extender with respect to the second extender to displace the first and second vertebrae with respect to one another.
14. The method of claim 13 , wherein the first connecting element includes a first pedicle screw and the second connecting element includes a second pedicle screw.
15. The method of claim 14 , wherein the first cage is polyaxially coupled to the first pedicle screw, and wherein the second cage is polyaxially coupled to the second pedicle screw.
16. The method of claim 15 , wherein the step of securing the distal end of the first extender within the first cage locks polyaxial movement of the first cage with respect to the first pedicle screw, and wherein the step of securing the distal end of the second extender within the second cage locks polyaxial movement of the second cage with respect to the second pedicle screw.
17. The method of claim 13 , wherein the first extender includes a first shaft and the second extender includes a second shaft.
18. The method of claim 17 , wherein the first connecting element has a first passageway device connected thereto and extending proximally therefrom along a first longitudinal axis, wherein the second connecting element has a second passageway device connected thereto and extending proximally therefrom along a second longitudinal axis, wherein securing the distal end of the first extender within the first cage comprises securing a distal portion of the first shaft within the first cage such that the first shaft extends within the first passageway device along the first longitudinal axis, and wherein securing the distal end of the second extender within the second cage comprises securing a distal portion of the second shaft within the second cage such that the second shaft extends within the second passageway device along the second longitudinal axis.
19. The method of claim 17 , wherein securing the distal end of the first extender within the first cage comprises securing the first shaft within the first cage with a first set screw such that the first shaft extends transverse to a longitudinal axis of the first extender, and wherein securing the distal end of the second extender within the second cage comprises securing the second shaft within the second cage with a second set screw such that the second shaft extends transverse to a longitudinal axis of the second extender.
20. The method of claim 19 , wherein the first extender is integrally formed with a first retractor blade and the second extender is integrally formed with a second retractor blade.
21. A method of displacing tissue within a body, comprising:
connecting a first connecting element to a first vertebra of a spine within the body, the first connecting element having a first passageway device connected thereto and extending proximally therefrom along a first longitudinal axis, the first passageway device defining a first longitudinal opening extending along at least a portion of the first longitudinal axis;
connecting a second connecting element to a second vertebra of the spine, the second connecting element having a second passageway device connected thereto and extending proximally therefrom along a second longitudinal axis, the second passageway device defining a second longitudinal opening extending along at least a portion of the second longitudinal axis;
positioning a first retractor blade along at least a portion of the first longitudinal opening;
positioning a second retractor blade along at least a portion of the second longitudinal opening;
engaging a distal end of a first extender with the first connecting element by securing at least a portion of a first shaft of the first extender within a first cage of the first connecting element;
engaging a distal end of a second extender with the second connecting element by securing at least a portion of a second shaft of the second extender within a second cage of the second connecting element; and
displacing the first extender with respect to the second extender to displace the first and second vertebrae with respect to one another.