Intervertebral implants with attachable flanges and methods of use

Vertebral implants for spacing apart vertebral members. The implants may include a spacer with a first side and a second side that contact the vertebral members. A sidewall may extend between the first and second sides. Two or more mounts are positioned along the sidewall. A flange may be connected to the spacer at the mounts. The flange extends beyond one or both of the first and second sides to position the spacer relative to the vertebral members. In some embodiments, the spacer further includes one or more insertion features that facilitate insertion of the spacer between the vertebral members.