The most common organism in spinal infection is from the bacteria Staphylococcus aureus which typically exists on human skin, followed by Escherichia coli. Most spine infections occur in the lumbar spine because of the blood supply to this region of the spine.
Feudalism, a system of political and military relationships, evolved in western Europe. The feudal system was a simple but effective means of medieval government in which the king rented land to barons, who provided him knights and taxes
Characteristics of the Feudal World. 1  Timeline. The Middle Ages or medieval time is believed to have started with the fall of the Roman Empire in 476 and to have lasted about 1,000 years until about 1450. 2  The end of the Middle Ages in about 1450 led to the beginning of the Renaissance.