An apparatus comprising an interbody fusion device and a fixation assembly (110, 210, 310, 410), the interbody fusion device comprising a housing, a first wedge member (14a, 14b), a second wedge member (16a, 16b), a first drive shaft, and second drive shaft, wherein the housing comprises a first shell member and a second shell member, the first and second shell members (32, 34) engaging the first wedge member (14a, 14b) along a first lateral area of the housing, engaging the second wedge member (16a, 16b) along a second lateral area of the housing, the first wedge member (14a, 14b) is provided with a through-opening configured to allow the first drive shaft to pass, the second wedge member (16a, 16b) is provided with a through-opening configured to allow the second drive shaft to pass, and the first drive shaft is operable to drive the first wedge member (14a, 14b) along the first lateral area of the housing, the second drive shaft is operable to drive second wedge member (16a, 16b) along the second lateral area of the housing, causing the first and second shell members (32, 34) to move relative to each other providing an expanded configuration of the interbody fusion device, the fixation assembly (110, 210, 310, 410) comprising a first fixation plate (120, 220, 320, 420) having a first aperture (124, 226, 326, 424) for insertion of a first fastener (122, 222, 322, 422), wherein the first fixation plate (120, 220, 320, 420) is modular configured to be attachable to the interbody fusion device, thereby allowing the first fixation plate (120, 220, 320, 420) to be attached to the interbody fusion device in the expanded configuration in situ and fastened to a first vertebral body to stabilize and/or prevent migration of the interbody fusion device. the interbody fusion device comprising a housing, a first wedge member (14a, 14b), a second wedge member (16a, 16b), a first drive shaft, and second drive shaft, wherein the housing comprises a first shell member and a second shell member, the first and second shell members (32, 34) engaging the first wedge member (14a, 14b) along a first lateral area of the housing, engaging the second wedge member (16a, 16b) along a second lateral area of the housing, the first wedge member (14a, 14b) is provided with a through-opening configured to allow the first drive shaft to pass, the second wedge member (16a, 16b) is provided with a through-opening configured to allow the second drive shaft to pass, and the first drive shaft is operable to drive the first wedge member (14a, 14b) along the first lateral area of the housing, the second drive shaft is operable to drive second wedge member (16a, 16b) along the second lateral area of the housing, causing the first and second shell members (32, 34) to move relative to each other providing an expanded configuration of the interbody fusion device, the housing comprises a first shell member and a second shell member, the first and second shell members (32, 34) engaging the first wedge member (14a, 14b) along a first lateral area of the housing, engaging the second wedge member (16a, 16b) along a second lateral area of the housing, the first wedge member (14a, 14b) is provided with a through-opening configured to allow the first drive shaft to pass, the second wedge member (16a, 16b) is provided with a through-opening configured to allow the second drive shaft to pass, and the first drive shaft is operable to drive the first wedge member (14a, 14b) along the first lateral area of the housing, the second drive shaft is operable to drive second wedge member (16a, 16b) along the second lateral area of the housing, causing the first and second shell members (32, 34) to move relative to each other providing an expanded configuration of the interbody fusion device, the fixation assembly (110, 210, 310, 410) comprising a first fixation plate (120, 220, 320, 420) having a first aperture (124, 226, 326, 424) for insertion of a first fastener (122, 222, 322, 422), wherein the first fixation plate (120, 220, 320, 420) is modular configured to be attachable to the interbody fusion device, thereby allowing the first fixation plate (120, 220, 320, 420) to be attached to the interbody fusion device in the expanded configuration in situ and fastened to a first vertebral body to stabilize and/or prevent migration of the interbody fusion device.