For more than 100 years, orthopedic surgeons have been repairing serious bone fractures by binding the fractures with screws, pins, and other fixation-type devices. Early on, these devices were often made from common metals such as iron or steel. Later on, they were made of highly sophisticated metal alloys of titanium, zirconium, niobium, and tantalum. Still the search continued for materials that would be more compatible with the human body, and that search led researchers to consider bioabsorbable polymers.