The present invention describes an expandable vertebral implant and the method of use. The longitudinally expandable vertebral implant includes telescoping sections adapted for incremental expansion and ease of securement at any desired increment in situ, and constructed and arranged to engage opposing vertebrae. The corpectomy device is a distractible vertebral body replacement for the thoracic and lumbar spine. The device is cylindrical shaped having an inner and outer sleeve made adjustable by use of locking pads formed integral with the outer sleeve for use in engaging parallel circumferential locking grooves formed along the outer side surface of the inner sleeve.