The present application is directed to intervertebral implants. The implants may include a body with superior and inferior surfaces, and a sidewall. An interior section may be positioned within the body and sized to contain bone growth material. An opening extends through one or both of the superior and inferior surfaces to access the interior section. A cover may be attached to the body to extend across the opening. In some embodiments, the cover includes teeth that engage a vertebral member. The cover may further include a plate that extends across the opening, and an attachment mechanism to attach the cover to the body. One method of using the implant may include inserting bone growth material into the interior section and attaching the cover to close the opening. The implant may then be inserted into the intervertebral space.