When the foot is twisted, the soft tissues can tear or the bones can break or both. Since the ankle joint is so tightly fitted together, even a displacement of the bones by as little as 1 mm can cause a significant increase in the abnormal forces across the joint, eventually leading to arthritis. When the bones break, swelling and instability occur. Ice, elevation and support are the initial steps. The definitive treatment is based on the fracture pattern and the degree of displacement. Early accurate reduction of the fracture and support with a splint or surgical plates and screws are extremely important. X-rays, MRI and CT scans are used to define the fracture patterns. Accuracy in diagnosis and treatment are the key to a successful outcome.
Knees do not necessarily wear out evenly, sometimes one part of the knee is perfectly fine while another part is completely destroyed. If only part of the knee joint is worn out, why replace all of it?
Metal has been used in patients since the time of Hippocrates (400 BCE) to repair broken bones and replace missing parts. The earliest metals included copper, tin or lead and often did not have the strength to last forever. Over the years, the metals we use have improved. They have become stronger and leach fewer ions into the body.