Filing Information

Inventor(s)	Bret A. Ferree ·
Assignee(s)	None listed in document.  View assignee updates
Attorney/Agent(s)	Gifford, Krass, Groh, Sprinkle, Anderson & Citkowski, PC ·
Primary Examiner	Nicholas D. Lucchesi ·
Assistant Examiner	Michael B. Priddy ·
Application Number	US9483805
Filing date	01/15/2000
Issue date	08/13/2002
Predicted expiration date	01/15/2020
U.S. Classifications	606/61  · 623/171.1  ·
International Classifications	--
Kind Code	B1
International Classifications	623 1711- 1716 · 606 61 · 606 90 ·

Patent Family

Abstract

Enhanced surface area spinal fusion devices have upper and lower sections which are implanted directly within the bodies of the vertebrae being fused, thereby surrounding the implanted sections with cancellous bone which is more conducive to ingrowth and permanent fusion. A preferred device comprises a frame-like structure composed of biocompatible material such as carbon fiber, the structure having a substantially hollow interior and open side walls or apertures to receive bone-graft material. The device is preferably used in conjunction with adjoining intervertebral cages, which may be rigidly joined to one another and/or to the inventive device. One or more physical features are also preferably provided to engage with surrounding bone or minimize back-out, such features including teeth, ridges, grooves, or outriggers. One or more shape-memory elements may also be used, each of which is preferably compressed for insertion then expanded when the device is in place. The inventive fixation device need not be employed between adjacent vertebra, but may be used between vertebra separated by one or more intermediate vertebra, in which case the device extends through the intermediate vertebra, preferably in intimate contact therewith. Multiple devices may also be implanted side by side between the same set of adjacent vertebra. In addition to these various alternative embodiments of the invention, a preferred method if installation is also disclosed.

Independent Claims | See all claims (22)

1. 1. An enhanced surface area spinal fusion device adapted for use between an upper vertebral body having an inferior vertebral endplate and a lower vertebral body having a superior endplate, wherein the interior of each body is composed of cancellous bone and each endplate is composed of cortical bone, with the distance between the endplates defining at least one intervertebral spacing, the device comprising: biocompatible structure having an outer surface conducive to bone ingrowth and two end surfaces; and wherein the structure is composed of one or more pieces of natural bone taken from the upper and lower bodies having been modified to receive the structure and the end surfaces of the structure define a height which is greater than the intervertebral spacing, such that when implanted, at least a portion of the device extends substantially beyond the superior endplate, the inferior endplate, or both, thereby penetrating into one or both of the upper and lower vertebra bodies and through the cortical bone, such that the end surface and outer surface of the penetrating portion are surrounded by cancellous bone.
2. 4. An enhanced surface area spinal fusion device adapted for use between an upper vertebral body having an inferior vertebral endplate and a lower vertebral body having a superior endplate, wherein the interior of each body is composed of cancellous bone and each endplate is composed of cortical bone, with the distance between the endplates defining at least one intervertebral spacing, the device comprising: a biocompatible structure having an outer surface conducive to bone ingrowth and two end surfaces defining a height which is greater than the intervertebral spacing, such that when implanted, at least a portion of the device extends substantially beyond the superior endplate, the inferior endplate, or both, thereby penetrating into one or both of the upper and lower vertebral bodies and through the cortical bone, such that the end surface and outer surface of the penetrating portion arm surrounded by cancellous bone; and one or more distraction devices positioned between the vertebral endplates.
3. 8. An enhanced surface area spinal fusion device adapted for use between an upper vertebral body having an inferior vertebral endplate and a lower vertebral body having a superior endplate, wherein the interior of each body is composed of cancellous bone and each endplate is composed of cortical bone, with the distance between the endplates defining at least one intervertebral spacing, the device comprising: a biocompatible structure having an outer surface conducive to bone ingrowth and two end surfaces defining a height which is greater than the intervertebral spacing, such that when implanted, at least a portion of the device extends substantially beyond the superior endplate, the inferior endplate, or both, thereby penetrating into one or both of the upper and lower vertebral bodies and through the cortical bone, such that the end surface and outer surface of the penetrating portion are surrounded by cancellous bone; and one or more intervertebral cages integrally formed with the device.
4. 9. An enhanced surface area spinal fusion device adapted for use between an upper vertebral body having an inferior vertebral endplate and a lower vertebra body having a superior endplate, wherein the interior of each body is composed of cancellous bone and each endplate is composed of cortical bone, with the distance between the endplates defining at least one intervertebral spacing, the device comprising: a biocompatible structure having an outer surface conducive to bone ingrowth and two end surfaces defining a height which is greater than the intervertebral spacing, such that when implanted, at least a portion of the device extends substantially beyond the superior endplate, the inferior endplate, or both, thereby penetrating into one or both of the upper and lower vertebral bodies and through the cortical bone, such that the end surface and outer surface of the penetrating portion are surrounded by cancellous bone; and one or more physical features to engage with surrounding bone to minimize back-out, at least one shape memory element which is compressed for insertion of the device and expanded when the device is in place.
5. 11. An enhanced surface area spinal fusion device adapted for use between an upper vertebral body having an inferior vertebral endplate and a lower vertebral body having a superior endplate, wherein the interior of each body is composed of cancellous bone and each endplate is composed of cortical bone, with the distance between the endplates defining at least one intervertebral spacing, the device comprising: a biocompatible structure having an outer surface conducive to bone ingrowth and two end surfaces defining a height which is greater than the intervertebral spacing, such that when implanted, at least a portion of the device extends substantially beyond the superior endplate, the inferior endplate, or both, thereby penetrating into one or both of the upper and lower vertebral bodies and through the cortical bone, such that the end surface and outer surface of the penetrating portion are surrounded by cancellous bone; and wherein the structure extends through one or more intermediate vertebra located between the upper and lower vertebra.
6. 12. A system for promoting fusion between an upper vertebra having an inferior vertebral endplate and a lower vertebra having a superior endplate, the distance between the endplates defining at least one intervertebral spacing, the system comprising: a biocompatible strut having an outer surface conducive to bone ingrowth and a height which is at least slightly greater than the intervertebral spacing, such that when the device is installed between the upper and lower vertebra, at least a portion of the device extends beyond the superior endplate, the inferior endplate, or both, thereby penetrating into cancellous bone; and one or more distraction devices positioned adjacent the strut without penetrating the vertebral endplates.