Total knee replacement can be one of the most grueling orthopedic procedures, its long and painful recovery period oftentimes overshadowing its successful long-term results. But the last two years have seen great improvements in this procedure, from minimally invasive techniques to more durable implants that better approximate the function of a natural knee. Patients are recovering faster than ever, with better overall results. Here's a look at some of the most critical advancements in knee surgery.