The ALTERA is an articulating expandable interbody spacer designed for Transforaminal Lumbar Interbody Fusion (TLIF) procedures. Its primary function is to restore disc height and lumbar lordosis while maintaining sagittal balance. The spacer can be inserted at a significantly reduced height to minimize surgical impaction and preserve patient endplate integrity. Once positioned, it offers continuous expansion of up to 4mm to optimize the fit between vertebral endplates. An integrated articulation feature allows the surgeon to steer the device for optimal placement within the anterior disc space. As an interbody device, it requires supplemental posterior fixation for a complete fusion construct.