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

An intervertebral spacer for spanning a space formed by upon removal of an intervertebral disc, the intervertebral spacer comprising:

• two end plates sized and shaped to fit within an intervertebral space between two vertebrae, each end plate having a vertebral body contacting surface and an inner surface,
• wherein the vertebral body contacting surfaces of one of the two end plates has at least one through hole therein that covers less than 40 percent of the vertebral body contacting surfaces, and wherein the at least one through hole therein extends longitudinally from one side of each end plate through the end plate to the other side of the end plate for bone growth therein;
• a connector interconnecting the inner surfaces of the two end plates in a rigid manner which limits motion between the end plates to less than a total of 5 degrees;
• and
• at least one fin projecting from one of the vertebral contacting surfaces, wherein the fin is configured to be inserted into a slot cut in the vertebra to inhibit rotation of the intervertebral spacer with respect to the vertebra.

A method of spanning a space formed 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 intervertebral spacer including:
• 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 to limits motion between the end plates;
• wherein the vertebral body contacting surfaces of one of the two end plates has at least one through hole therein, wherein the at least one through hole therein extends longitudinally from one side of each end plate through the end plate to the other side of the end plate for bone growth therein;
• placing a fin on one of the vertebral body contacting surfaces into the at least one slot, whereby the intervertebral spacer is inhibited from rotating;
• and
• maintaining the disc spaced between the two adjacent vertebral bodies with the intervertebral spacer without the use of bone graft or bridging bone.