1. Field of the Invention
The present invention generally relates to a device for aligning cage of intervertbral fusion, and more particularly to an insertion apparatus for aligning cage of intervertbral fusion capable of shortening surgery time and enhancing the post-operative effect.
2. Description of the Related Art
Intervertebral disc degeneration of human body is one of common degenerative diseases in middle and elder age group. It always has good therapeutic effect for intervertebral disc degeneration by spinal interbody fusion operation. During the spinal interbody fusion, there is common usage of inserting a cage into the intervertebral disc to hold open vertebral body and maintain disc height, so as to achieve the effects of making the nerve root decompressed, pain relieved and grafting of the intervertebral segments.
There are three different approach routes of the spinal interbody fusion including anterior, posterior and poster-lateral. Each has its own cage types and quantities. The poster-lateral interbody fusion (disclosed as U.S. patent 2004/0106997) can perform minimal invasive surgery and achieve the effects of keeping away from key organs and shortening bed rest time. Therefore, most medical institutes suggest using the poster-lateral interbody fusion.
The above mentioned poster-lateral interbody fusion is performed by placing one single cage. For enhancing the stability, banana-like shaped cage has been paying more attention gradually (disclosed as U.S. Pat. Nos. 6,143,032, 6,648,915, and D533,277).
However, because the operating angle of the above mentioned poster-lateral interbody fusion with banana-like shaped cage is limited, the cage is hard to place between the intervertebral discs by the way of bilateral symmetry in the anterior location. Especially, when the cage will be applied through a percutaneous endoscopic route, A special designed apparatus is required for proper localization of the cages.
It is an objective of the present invention to provide an insertion apparatus capable of adjusting the operating angle when an arc cage is placed in vertebral body and adaptive for the postere-lateral interbody fusion through the percutaneous endoscope.
To achieve the above objectives, the insertion apparatus adaptive for spinal interbody fusion comprises a dilatation set having a first dilatation barrel and a second dilatation barrel sleeved in series, the first dilatation barrel formed with a circular inner cross-section and an elliptic outer cross-section, the second dilatation barrel sleeved outside the first dilatation barrel and formed with an elliptic inner cross-section and a circular outer cross-section; a guiding set having a first guiding tube inserted in the second dilatation barrel and a second guiding tube inserted in the first dilatation barrel, a guiding hole disposed at an outer edge adjacent to one end of the second guiding tube, a smooth curved surface disposed inside the guiding hole communicated with a shaft hole disposed in the second guiding tube; an insert set having a leading rod inserted in the second guiding tube, an outside end of a push rod pivoted at an inside end of the leading rod; and a fusion cage disposed in the second guiding tube and pushed against the push rod moving therein, an arc portion disposed at an outer edge of the fusion cage is passed through the second guiding tube along the smooth curved surface and the guiding hole and adjusted to a predetermined angle. Therefore, when operating the insertion apparatus, it can shorten the surgery time and position the cage exactly.
A best illustrative embodiment of the invention with drawings is described as below.
All the objects, advantages, and novel features of the invention will become more apparent from the following detailed descriptions when taken in conjunction with the accompanying drawings.
Firstly, please refer to
Before operating the present invention, patient's back is cut an opening (the surgical method is disclosed by U.S. patent 2004/0106997) and insert position and direction are detected by a test rod (not shown).
Referring to
The operation process of the dilatation set 20 is extending the first dilatation barrel 22 along the test rod to make the distal end of the first dilatation barrel 22 place between two vertebral bodies, and covering the handle 26 to rotate 90 degree for setting against adjacent up and down vertebral bodies with the corresponding outer edge along long axis of the elliptic cross-section of the first dilatation barrel 22, so as to expand the distance between two vertebral bodies to achieve the effect of shortening surgery time. The distance between two vertebral bodies is further expanded by sleeving the second dilatation barrel 24, and then the first dilatation barrel 22 is removed.
Referring to
The operation process of the guiding set 40 is extending the guiding set 40 along the second dilatation barrel 24 to between the expanded two vertebral bodies, and removing the first guiding tube 42 but keeping the second guiding tube 44 to make the distal end of the guiding hole 440 place in the gap between the two vertebral bodies.
To prevent the sharp edge portion of the guiding hole 440 from injuring body organs, the present invention further comprises an inner guiding rod capable of reciprocating inside the second guiding tube 44, and a support piece 48 disposed at the distal end of the inner guiding rod and formed a curved surface portion thereon to fill inside the guiding hole 440, so as to couple with the inside peripheral wall of the guiding hole 440 to form a smooth surface to prevent from injuring human body. After the second guiding tube 44 is set in position, remove each inner guiding rod 46 and support piece 48.
Referring to
Referring to
The operation process of the fusion cage 80 is fixing the fusion cage 80 at the distal end of the flexible 65, setting against the outer edge of the push rod 62, and then inserting the assembly of each leading rod 61, push rod 62 and fusion sage 80 together into the second guiding tune 44. Next, force the fusion cage 80 to slide out of the second guiding tube 44 through the curved surface of the guiding hole 440 via each leading rod 61 and push rod 62 and into the gap between the expanded two vertebral bodies. In the process, the fusion cage 80 changes the angle gradually to arrive at the predetermined angle.
If necessary, the operator can pull the flexible element 65 by the block ring 64 to adequately adjust the position of the fusion cage 80. After the fusion cage 80 is positioned (shown as
According to above mentioned structure, there are at least three advantages for applications listed as below: 1. expanding the gap between two vertebral bodies to shorten surgery time by the first dilatation barrel 22 with elliptic outer edge; 2. making the arc-shaped fusion cage 80 get forward along an arc path to between vertebral bodies and change the angle simultaneously to position almost at the status of bilateral symmetry relative to the vertebral bodies by the arc guiding hole 440 disposed at side of the second guiding tube 44; and 3. positioning the fusion cage 80 more exactly by the flexible element 65 extended in the hollow insert set 60.
Although the invention has been explained in relation to its preferred embodiment, it is not used to limit the invention. It is to be understood that many other possible modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the invention as hereinafter claimed.