Patent ID: 8147547

Claim:
A spinal implant comprising: a body; an opening in the body that includes an inlet and a closed bottom opposite from the inlet, the opening comprising first and second opening sections each located a different distance from the inlet and a longitudinal axis that extends through the opening and the inlet and the bottom, said first opening section in closer proximity to the inlet than the second opening section and having a first back wall and one or more first sidewalls that define a first cross-sectional shape, the first opening section including a first width measured perpendicular to the longitudinal axis between the one or more first sidewalls, said second opening section disposed in the first back wall and having the closed bottom and one or more second sidewalls that define a different second cross-sectional shape, the second opening section including a second width measured perpendicular to the longitudinal axis between the one or more second sidewalls, the opening being positioned to be accessible by a surgical approach and releasably engagable by a surgical tool, the second width being smaller than the first width, wherein one of the first and second cross-sectional shapes is polygonal; and a plug removably securable in the opening, the plug closing the opening to prevent tissue growth into the opening; the plug including a distal end positioned adjacent to and facing the closed bottom when secured in the opening.