Method and spacer device for spanning a space formed upon removal of an intervertebral disc

A method of spanning a space formed by upon removal of an intervertebral disc, the method comprising:

• performing a discectomy to remove disc material between two adjacent vertebral bodies;
• cutting at least one slot in at least one of the adjacent vertebrae;
• placing an intervertebral spacer between the two adjacent vertebral bodies, the spacer comprising:
• two end plates, each end plate having a metallic vertebral body contacting surface, an inner surface and a fin extending from the vertebral body contacting surface;
• a connector interconnecting the inner surfaces of the two end plates in a rigid manner which limits motion between the plates to less than a total of 5 degrees;
• wherein the vertebral body contacting surfaces of the end plates have no holes therein or have holes which cover less than 40 percent of the vertebral body contacting surfaces;
• wherein the intervertebral spacer including the two end plates and connector is formed of a single piece;
• placing a fin on one of the vertebral body contacting surfaces into the at least one slot, whereby the spacer is inhibited from rotating;
• maintaining the disc space between the two adjacent vertebral bodies with the intervertebral spacer without the use of bone graft or bridging bone, wherein no part of the intervertebral spacer extends outside the intervertebral disc space and slot.