A method and
system for performing
bone fusion and / or securing one or more bones, such as adjacent
vertebra, are disclosed. The screws include a threaded tip connected to a main shaft and a threaded outer sleeve that rotates relative to the outer shaft until locked down. Independent rotation of the threaded outer sleeve relative to the threaded distal tip allows compression or
distraction to modify the gap between the vertebral bodies. The screws are passed from the inferior to superior
vertebra or superior to inferior, for example, through a trans-pedicular
route to avoid neurological compromise. At the same time, the path of screw
insertion is oriented to reach superior or inferior
vertebra. An intervertebral cage of the
system is configured for
lateral expansion from a nearly straight configuration to form a large
footprint in the
disc space. The screws and cage may be combined for improved fixation with minimal invasiveness.