The embodiments of the present disclosure relate to a spinal implant assembly having features to prevent or minimize fixation elements, such as screws, from being dislodged, or from backing out over time and with use. The spinal implant assembly may comprise an implantable body (10) having first apertures (24) for receiving fixation elements (40). A plate (60) configured to nest against the posterior portion (14) of the implantable body and comprising one or more second apertures can be provided. These second apertures permit access to the head portions (42) of the fixation elements. One or more locking elements (50) are then passed through the second apertures and engage the head portions (42) of the fixation elements. In addition, the plate (60) may comprise an adjustable arm to allow the plate to be used with implantable bodies of different size.