US Patent 8048134 Active compression to facilitate healing of bones

A bone fixation device includes one or more springs and one or more spacers disposed between two orthopedic structures. The orthopedic structures may comprise screws, rods, plates, or any other orthopedic devices configured to engage bone. The spacer may be absorbable or removable, and may serve to constrain the spring in a compressed or stretched state so that, upon absorption or removal of the spacer, the spring may apply tension or compression to surrounding bone. The device may thereby facilitate healing or bone or remodeling of soft tissues.