For 20 years, Barth Green struggled with his frustration, doctoring crushed and twisted spinal cords while knowing paralysis was permanent and irreversible. Spinal cord injuries doomed active, healthy people to spend the rest of their lives in wheelchairs. In the worst cases, they can't out of bed, pull on socks or underwear, brush their teeth, comb their hair, lift a forkful of food to their mouths or scratch an itch. But Green made a lousy fatalist. In 1985, he founded the Miami Project to Cure Paralysis, dedicated to reversing one of the most catastrophic conditions in medicine by solving the mystery of one of the most complex structures in biology. Today it is the country's largest and most comprehensive spinal cord research unit. ``No one's ever had the guts to say we want to cure paralysis, (but) I'm committed to eliminating wheelchairs. It's a world war against paralysis,'' said Green, a neurosurgeon. ``Our philosophy is to approach it like the Manhattan Project to split atoms to stop Hitler, or the Apollo Project to put a man on the moon in the space race.'' In an era when miracle drugs, transplant surgery, laser beams and artificial body parts have made medicine seem capable of solving almost anything, paralysis remains stubbornly unconquered. Researchers have made progress toward regenerating nerves in animals' spinal cords with transplants of cells from fetuses, electrical pulses and genetic engineering. But some say the challenge may be tougher than building atomic bombs or space ships. ``Those were engineering problems with a general consensus it could be done. Those guys had blueprints. We don't have any blueprints,'' said Dr. Walter Levy, a researcher at the Miami Project. ``We're in the Wright brothers stage. What's required is a space shuttle,'' said Dr. Michael Kliot, a neurosurgeon at Columbia Presbyterian Hospital in New York City. ``There's a ray of hope. But we're very, very far away from curing spinal cord injuries.'' An estimated 250,000 to 500,000 people in the United States are paralyzed as a result of injuries, according to the Department of Health and Human Services; an additional 10,000 to 15,000 people are hurt each year. No agency keeps precise count. Auto accidents account for about half the paralysis cases. Other causes are dives, falls, and accidents with guns and knives or while playing sports. The average age of victims is 19. Marc Buoniconti, son of former All-Pro football linebacker Nick Buoniconti of the Miami Dolphins, was 19 when his neck broke and crushed his spinal cord as he made a head-first tackle, paralyzing him from the neck down Oct. 26, 1985. ``I knew I broke my neck right away,'' said Buoniconti, who had played football since he was a 75-pound 7-year-old. ``My right arm flopped to the turf. I couldn't move. I couldn't get my breath back. I couldn't talk. ``In one second, I went from the best shape of my life to the worst,'' Buoniconti said. ``I was taking my last steps doing my favorite thing. It was on a football field, the place I love the most.'' Now, from his wheelchair at home in this Miami suburb, the 21-year-old Buoniconti is tackling paralysis as national spokesman for the Miami Project. The project's logo is a four-frame sequence of a stick figure standing up out of a wheelchair, matching the can-do grit of Buoniconti's personalized license plate that reads ``I'LL WALK.'' ``It's not a question of `if.' That's not in our vocabulary. It's a question of when,'' said Steve Towle, the project's executive director and a former Dolphins linebacker. ``I've seen what it takes to win. It can be done. It will be done.'' The spinal cord, encased in the bony armor of the spinal column, is as wide as a thumb and has the consistency of jellied candy.