Self-expanding inter-vertebral cage


Project ID D2013-73


Intervertebral cages are hollow implants used to treat spinal ailments that often emanate from degenerative disc disease. Surgeons can implant the cage using laparoscopy or through a small incision in the back or front of the spine. Expanding intervertebral cages were designed to reduce the size of the implant in minimally invasive surgeries. However, many of the expandable implants require a secondary activation force once the cage is in place. Therefore, it would be advantageous to have an intervertebral cage that could self-expand on demand.

Invention Description 

Researchers from the University of Toledo developed an intervertebral cage that utilizes shape memory alloy and an open loop design. The smaller, horizontal profile can be inserted into the patient in a condensed space and then expanded as a result of being released from installation or exposed to environmental conditions, such as electric or magnetic fields.


Treating spine related disease, such as degenerative disc disease.


  • Open loop design permits a smaller incision; eligible for use in minimally invasive techniques
  • Simplified and controlled activation; little to no force required
  • Decreased risk of complications/infections
  • Easier to achieve optical placement in the inter-vertebral space


IP Status:                           Issued US Patent 10,828,171

Publications:                     C.A. Chapman Design of an Expandable Intervertebral Cage Utilizing Shape Memory Alloys

Patent Information:
Medical Device
For Information, Contact:
Katherine Pollard
Licensing Associate
The University of Toledo
Anand Agarwal
Vijay Goel
Aakash Agarwal
David Dick
Degenerative bone disease
Intervertebral cage
Shape memory alloy