The era of Captain Hook's primitive prostheses -- hook replacing severed hand, wooden peg replacing severed leg -- is long over. Modern prosthetics benefit very heavily from advances in technology, advances that are increasingly resembling science fiction stories and movies from 40 years ago.
Where once prosthetic arms and legs were immobile, or partially mobile extensions of surviving limbs, increasingly they include technologies that make them more flexible and realistic, and more sensitive and responsive to the sensory responses of the human brain.
Sadly, there have been many military personnel returning from Iraq and Afghanistan with amputed limbs from mortars, bullets, improvised explosive devices, and vehicle accidents. The number of amputees in the United States has grown astronomically as a direct result of those wars. Because of the increasing number of military personnel requiring prosthetic devices, the Department of Defense has been a major source of funding for research into new technologies for prosthetics. The Defense Advanced Research Projects Agency (DARPA), the agency with the Department of Defense responsible for long-range research and development, has been developing technologies for this application. To quote directly from DARPA's homepage,
"After six years of development, the Revolutionizing Prosthetics program developed two anthropomorphic advanced modualr prototype prosthetic arm systems, including sockets, which offer increased range of motion, dexterity and control options."
Most significantly, DARPA refers to work it is performing on improving the connection of the prosthesis to the functioning of the brain:
"DARPA researchers have also attained promising initial results on achieving brain control of an advanced arm system developed by the Johns Hopkins University Applied Physics Lab, the second primary performer on Revolutionizing Prosthetics. This work...has demonstrated the potential to use advanced prostheses to improve the quality of life for victims of paralysis."
That, however, is a look into the future. Prosthetics that currently employ technologies are routinely observed every day. the South African sprinter Oscar Pistorius, was widely publicized for his skill at competitive running with prostheses on both legs -- prostheses that utilized carbon-fiber technology. A 2008 article in "Wired" detailed the current application of advanced technologies in the manufacture and use of prosthetic limbs, including what is called the i-limb, an "artificial hand with the super small motors is the closest thing to Luke's hand in Star Wars. One of the best wrap-around mechanical prosthesis, it includes five individually (sic) digits also powered by a two-input myoelectric signal. The individual fingers allow for the most dexterous, realistic replication." [Jose Fermoso, "Prosthetic Limb Research Could Lead to Bionic Athletes...," Wired, July 29, 2008]
In conclusion, many of the prosthetic limbs provided to wounded veterans today incorporate advanced technologies, both in their design and in their operation.