An interbody device may include a main body and an arm movably connected thereto. The device may have a first end, a second end opposite the first end in a direction of a longitudinal axis of the device, a first side, a second side opposite the first side in a direction of a first transverse axis of the device, a third side, and a fourth side opposite the third side in a direction of a second transverse axis of the device. An overall distance between the first side and the second side may increase along at least a majority of a length of the device in a direction from the first end toward the second end, and an overall distance between the third side and the fourth side may increase along at least a majority of the length in a direction from the second end toward the first end.