Spinal implant

Abstract

A spinal implant is disclosed which when placed within the spinal disc space stabilizes the spinal segment.

Description

[0001] The present application is a continuation of application Ser. No. 10 / 292,539, filed Nov. 12, 2002, now U.S. Pat. No. 7,066,961; which is a continuation of application Ser. No. 09 / 580,768, filed May 30, 2000, now U.S. Pat. No. 6,478,823; which is a continuation-in-part of application Ser. No. 29 / 056,996, filed Jul. 15, 1996, now U.S. Pat. No. D425,989; which is a continuation of application Ser. No. 29 / 023,922, filed Jun. 3, 1994, now abandoned; which is a continuation of application Ser. No. 08 / 052,211, filed on Apr. 22, 1993, now abandoned; which is a continuation of application Ser. No. 07 / 546,849, filed Jul. 2, 1990, now abandoned; which is a continuation of application Ser. No. 07 / 212,480, filed Jun. 28, 1988, now abandoned; all of which are incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] The present invention relates to an artificial fusion implant to be placed into the intervertebral space left after the removal of a damaged spinal disc. [0003] The p...

AI Technical Summary

Benefits of technology

[0046] The present invention comprises an artificial implant, the purpose of which is to participate in, and directly cause bone fusion across an intervertebral space following .the excision of a damaged disc. Said implants are structurally load bearing devices, stronger than bone, capable of withstanding the substantial forces generated within the spinal interspace. Such devices have a plurality of macro sized openings of 13 mm, which can be loaded with fusion promoting materials, such as autogenous bone, for the purpose of materially influencing the adjacent vertebrae to perform a bony bond to the implants and to each other. The implant casing may be surface textured or otherwise treated by any of a number of known technologies to achieve a “bone ingrowth surface” to further enhance the stability of the implant and to expedite the fusion. Further, said devices are so configured and designed so as to promote their own stability within the vertebral interspace to resist dislodgement, and furthermore, to stabilize the adjacent vertebrae.

[0050] It is another object of the present invention to provide for a means of achieving an interspace fusion and stabilization that is quicker, safer, and entails less blood loss than by any other known means.

[0051] It is another object of the present invention to provide for a means of achieving a one stage interspace fusion and stabilization without significant violation or removal of the adjacent vertebral bone stock.

[0052] It is another object of the present invention to provide for a method of intervertebral arthrodesis and stabilization of enhanced safety where the entire procedure is performed under direct vision.

[0053] It is another object of the present invention to provide for a method of intervertebral arthrodesis and stabilization of greater simplicity and requiring minimal specialized instrumentation or technique not already possessed by those doing such procedures by conventional means.

Problems solved by technology

If nothing is placed in the space the space may collapse which may result in damage to the nerves; or the space may fill with scar tissue and eventually lead to a reherniation.

The use of bone is less than optimal in that the bone obtained from the patient requires additional surgery and is of limited availability in its most useful form and if obtained elsewhere, lacks living bone cells, carries a significant risk of infection, and is also limited in supply as it is usually obtained from young accident victims.

Furthermore, regardless of the source of the bone, it is only marginal structurally and lacks a means to either stabilize itself against dislodgement, or to stabilize the adjacent vertebrae.

No such device has been found that is medically acceptable.

While the present invention is to be placed within the disc space, these prior devices cannot be placed within the disc space as at least one vertebra has already been removed and there no longer remains a “disc space.” Furthermore, all of these devices are limited in that they seek to perform as temporary structural members mechanically replacing the removed vertebra (not a removed disc), and do not intrinsically participate in supplying osteogenic material to achieve cross vertebrae bony fusion.

In summary, none of these devices are designed for or can be used within the disc space, do not replace a damaged disc, and do not intrinsically participate in the generation of a bony fusion.

Such bleeding, when it occurs, bears all the risks of blood loss (e.g. hypovolemic shock, transfusion transmitted diseases such as hepatitis and acquired immune deficiency syndrome, etc.), and all the complications arising from the resultant impaired visualization of the vital structures (e.g. nerves, blood vessels, and organs) due to such bleeding.

Implantation of a single implant of those dimensions from a posterior approach in the lumbar spine would otherwise be impossible because of the presence of the dural sac and spinal nerves.

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