FENESTRATED PEDICLE NAIL
Embodiments are directed to spinal treatments and, more particularly, to a fenestrated pedicle nail, wherein the pedicle nail performs as an anchored system for pedicle instrument constructs that prevents fracturing from over-compressing of bone of poor quality. Embodiments include a pedicle nail comprising a shank and a nail head. The shank may comprise a proximal end and a distal bone engagement end. The nail head may be disposable on the proximal end of the shank, wherein the nail head may threadably engage the proximal end thereof. The nail head may have external bone threads.
This application is a continuation of U.S. Pat. Application No. 16/452,645, filed on Jun. 26, 2019 (published as U.S. Pat. Pub. No. 2020-0405362), which is incorporated herein by reference in its entirety for all purposes.
BACKGROUNDMany types of spinal irregularities can cause pain, limit range of motion, or injure the nervous system within the spinal column. These irregularities can result from, without limitation, trauma, tumor, disc degeneration, and disease. Often, these irregularities may be treated by immobilizing a portion of the spine. This treatment typically may involve affixing a plurality of screws and/or hooks to one or more vertebrae and connecting the screws or hooks to an elongated rod that generally extends in the direction of the spine.
Treatment for these spinal irregularities often involves using a system of pedicle screws and rods to attain stability between spinal segments. Instability in the spine can create stress and strain on neurological elements, such as the spinal cord and nerve roots. In order to correct this, implants of certain stiffness can be implanted to restore the correct alignment and portion of the vertebral bodies. In many cases, an anchoring member such as a pedicle screw along with a vertical solid member may help restore spinal elements to a pain free situation, or at least may help reduce pain or prevent further injury to the spine.
A pedicle screw system is sometimes used as an adjunct to spinal fusion surgery, thereby providing a means of gripping a spinal segment. A conventional pedicle screw system may comprise a pedicle screw and a receiving device. The pedicle screw may include an externally threaded stem and a head portion. The rod-receiving device may couple to the head portion of the pedicle screw and can receive a rod, commonly referred to as a distraction rod. Two such systems may be inserted into respective vertebrae and adjusted to distract and/or stabilize a spinal column, for instance during an operation to correct a herniated disk. The pedicle screw does not, by itself, fixate the spinal segment, but instead may operate as an anchor point to receive the rod-receiving device, which in turn receives the rod. One goal of such a system may be to substantially reduce and/or prevent relative motion between the spinal segments that are being fused.
Although the pedicle screw minimizes relative motion between the spinal segments, the pedicle screw is still subject to windshield-wiper loosening, which can potentially result in pull out of the pedicle screw. Accordingly, there exists a need to further decrease axial motion.
SUMMARYA first exemplary embodiment provides a pedicle nail that may comprise a shank and a nail head. The shank may comprise a proximal end and a distal bone engagement end. The nail head may be disposable on the proximal end of the shank, wherein the nail head may threadably engage the proximal end, and wherein the nail head can have external bone threads.
A second exemplary embodiment provides a pedicle nail system that may comprise a pedicle nail and a tulip. The pedicle nail may comprise a shank, wherein the shank may comprise a proximal end and a distal bone engagement end, wherein the proximal end may comprise mounting threads attached thereto. The tulip may comprise a proximal end and a distal end
A third exemplary embodiment provides a pedicle nail system that may comprise a pedicle nail, a tulip, and a driver. The pedicle nail may comprise a shank, wherein the shank may comprise a proximal end and a distal bone engagement end, wherein the proximal end may comprise mounting threads attached thereto. The tulip may comprise a proximal end and a distal end, wherein the tulip may be configured to be mounted on the pedicle nail. The driver may comprise a proximal end and a distal end; wherein the distal end of the driver is removably connected to the proximal end of the insertion tool assembly.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and the specific examples, while indicating the preferred or exemplary embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
These drawings illustrate certain aspects of some examples of the present disclosure, and should not be used to limit or define the disclosure, wherein:
Embodiments are directed to spinal treatments and, more particularly, to a pedicle nail, wherein the pedicle nail performs as an anchored system for pedicle instrument constructs that prevents fracturing from over-compressing of bone of poor quality. Embodiments of the pedicle nail may be used in a wide variety of spinal treatments for treatment of spinal irregularities, where the pedicle nail can increase stability of the bone/nail interface in the cancellous region of the vertebral body; reduce pull-out of the nail from the windshield-wiper effect; minimize the diameter of the nail or other pedicle instrument needed in a revision procedure; and reduce the risk of fracturing from over-compression.
Embodiments of the pedicle nail can be implanted inside a cancellous region of the vertebral body, attached to a nail head implanted into the cortical bone. The pedicle nail can be curved with a curvature angle θ. Hence, although a bone screw may be subject to windshield-wiper loosening, the geometry of the curved pedicle nail can change the insertion vector, thereby reducing the axial motion. In some embodiments, the difference between the pitch of the mounting thread of the pedicle nail and the bone screw thread of the nail head can decrease the chance of over-compression because the nail can be pulled toward the nail head, traveling through a cavity that was previously created using a curved awl.
In some embodiments, a medical professional (e.g., a surgeon) may first prepare for the area to be treated by creating an incision in a patient’s back and adjusting the lower back muscles to access the desired area. Some embodiments may use the curved awl to create a pathway for insertion of the pedicle nail. Embodiments may then include tamping down the pedicle nail, for example, with a tamping or hammering tool, until the nail head contacts the cortical bone. In at least one embodiment, the nail head, having external bone threads thereupon, may be threaded into the cortical bone, then a polyaxial tulip may be assembled by threadable connection to the proximal end of the nail head. Alternatively, the nail head may be removed after tamping for threadable attachment of a monoaxial tulip to the proximal end of the pedicle nail. More specifically, for example, a threaded shaft locking assembly, having an outer shaft and an inner shaft, may be retracted to allow the outer shaft to be threaded into a monoaxial tulip and seated therein. The monoaxial tulip can then be threaded into the cortical bone.
In the illustrated embodiment, the pedicle nail 100 has fenestrated perforations 112 positioned about the longitudinal axis of the shank 102. Accordingly, embodiments of the pedicle nail 100 may be referred as “fenestrated.” However, it should be understood that the fenestrated perforations 112 are optional and embodiments of the pedicle nail 100 may not include the fenestrated perforations 112. The shank 102 may also include at least two protrusions configured along the longitudinal axis, wherein the protrusions 113 form channels 115 along the longitudinal axis of the shaft 102. The protrusions 113 may have an exposed vertical edge, wherein the vertical edge may have at least two notches 114 therein, wherein the notches 114 may be in vertical alignment with one another.
As illustrated, the shank 102 can be a curved shank, having a curvature angle θ. The shank 102 can have any suitable curvature angle θ. Those with ordinary skill in the art will appreciate the curved shank 102, in that the curvature angle θ may allow for rotational movement or angular adjustment of the pedicle nail 100 in connection with bone structures. Moreover, the curved shank 102 may have several additional features, including, but not limited to, thread pitch, shank diameter to thread diameter, overall shank shape, and the like, depending, for example, on the particular application.
Specifically referring to
In one embodiment (not shown), the pedicle nail 100 can be cannulated, which means a channel can extend axially through the entire length of the pedicle nail 100. For example, depending upon the specific procedure, the channel can allow the pedicle nail 100 to be maneuvered over and receive a Kirschner wire, commonly referred to as a K-wire. The K-wire can typically be pre-positioned using imaging techniques, for example, fluoroscopic imaging.
Specifically referring to
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
Claims
1. A pedicle nail system comprising:
- a pedicle nail having a shank including a proximal end and a distal bone engagement end, the pedicle nail further including a nail head disposable on the proximal end of the shank, wherein the nail head threadably engages the proximal end, the nail head having external bone threads; and
- a tulip, wherein the tulip comprises a proximal end and a distal end.
2. The pedicle nail of claim 1, wherein the shank is a curved shank, having a curvature angle θ.
3. The pedicle nail of claim 2, wherein the shank comprises fenestrated perforations about the longitudinal axis thereof, wherein the number of fenestrated perforations can range from about 2 to about 100.
4. The pedicle nail of claim 3, wherein the shank comprises at least two protrusions configured along the longitudinal axis thereof, wherein the protrusions form channels along the longitudinal axis, wherein the protrusions have an exposed vertical edge, wherein the vertical edge has at least two notches, wherein the notches are in vertical alignment with one another.
5. The pedicle nail of claim 1, wherein the proximal end comprises mounting threads, wherein the mounting threads have a pitch, wherein the bone threads have a pitch, and wherein the pitch of the mounting threads and the pitch of the bone threads are unequal.
6. The pedicle nail of claim 5, wherein the pitch of the bone threads is greater than the pitch of the mounting threads.
7. The pedicle nail of claim 1, wherein the nail head comprises external bone threads thereabout, wherein the nail head has a proximal end and a distal end, wherein the distal end of the nail head threadably engages with the proximal end of the shank, and wherein the proximal end of the nail head comprises an insertion assembly tool interface therein.
8. The pedicle nail system of claim 1, wherein the tulip is a monoaxial tulip, wherein the monoaxial tulip comprises external bone threads disposed on or about the distal end thereof, wherein the monoaxial tulip is configured to be disposed on the proximal end of the shank by threadably receiving the mounting threads attached thereto.
9. The pedicle nail system of claim 8, further comprising a nail head having a proximal end and a distal end; wherein the nail head comprises external bone threads; and wherein the distal end of the nail head is configured to be disposed on the proximal end of the shank by threadably receiving the mounting threads attached thereto.
10. The pedicle nail system of claim 9, wherein the proximal end of the nail head comprises an insertion assembly tool interface therein.
11. A pedicle nail system comprising:
- a pedicle nail, wherein the pedicle nail comprises a shank, wherein the shank comprises a proximal end and a distal bone engagement end, wherein the proximal end comprises mounting threads attached thereto; and
- a tulip wherein the tulip comprises a proximal end and a distal end, wherein the distal end of the tulip is configured to be mounted on the pedicle nail; and
- a driver, wherein the driver comprises a proximal end and a distal end; wherein the distal end of the driver is removably connected to the proximal end of the insertion tool assembly.
12. The pedicle nail of claim 1, wherein the shank is a curved shank, having a curvature angle θ.
13. The pedicle nail of claim 12, wherein the shank comprises fenestrated perforations about the longitudinal axis thereof, wherein the number of fenestrated perforations can range from about 2 to about 100.
14. The pedicle nail of claim 13, wherein the shank comprises at least two protrusions configured along the longitudinal axis thereof, wherein the protrusions form channels along the longitudinal axis, wherein the protrusions have an exposed vertical edge, wherein the vertical edge has at least two notches, wherein the notches are in vertical alignment with one another.
15. The pedicle nail of claim 11, wherein the proximal end comprises mounting threads, wherein the mounting threads have a pitch, wherein the bone threads have a pitch, and wherein the pitch of the mounting threads and the pitch of the bone threads are unequal.
16. The pedicle nail of claim 15, wherein the pitch of the bone threads is greater than the pitch of the mounting threads.
17. The pedicle nail of claim 11, wherein the nail head comprises external bone threads thereabout, wherein the nail head has a proximal end and a distal end, wherein the distal end of the nail head threadably engages with the proximal end of the shank, and wherein the proximal end of the nail head comprises an insertion assembly tool interface therein.
18. The pedicle nail system of claim 11, wherein the tulip is a monoaxial tulip, wherein the monoaxial tulip comprises external bone threads disposed on or about the distal end thereof, wherein the monoaxial tulip is configured to be disposed on the proximal end of the shank by threadably receiving the mounting threads attached thereto.
19. The pedicle nail system of claim 18, further comprising a nail head having a proximal end and a distal end; wherein the nail head comprises external bone threads; and wherein the distal end of the nail head is configured to be disposed on the proximal end of the shank by threadably receiving the mounting threads attached thereto.
20. The pedicle nail system of claim 19, wherein the proximal end of the nail head comprises an insertion assembly tool interface therein.
Type: Application
Filed: Feb 27, 2023
Publication Date: Jul 6, 2023
Inventor: Kurt Faulhaber (Cape Coral, FL)
Application Number: 18/175,042