Like other hospitals in thinly populated areas, Sterling Regional Medical Center does a bit of everything. The 25-bed Colorado hospital has its own heliport, delivers about 200 babies a year and admits more than 1,200 patients for a variety of conditions and procedures. Replacing worn and painful hips and knees is among them. To patients, the surgery may seem perfectly routine. Joint replacements are anything but routine at hospitals that don't do many of them, a new U.S. News analysis shows. Sterling is among thousands of U.S. medical centers whose patients face a greater risk of death and complications because their surgical teams do too few procedures, even common ones, for doctors, nurses and technicians to maintain their skills.