Knee replacement is a resurfacing procedure. Many patients think we remove the end of the thighbone and the top of the leg bone and put in a big piece of metal and plastic. We actually just resurface the ends of the bone. So we put a metal cap onto the end of the femur, which is the thighbone. We put a metal cap onto the end of the leg bone, the tibia, and there's a little plastic insert that goes in between. So it's really a joint resurfacing that we do when we replace a knee. Osteoarthritis is the most common indication for knee replacement. There are other indications just like with hip replacement. So really pain and functional limitations are the reasons that patients come in to see us in clinic and start wondering if knee replacement is the right option for them. We know that certain patients with knee pain tend to do very well with knee replacement. Those patients tend to have advanced objective radiographic arthritis. So those are patients who have bone rubbing on bone on their x-rays. We know that knee replacement is not a great operation for more mild forms of arthritis. If a patient has advanced arthritis, but they don't have severe pain, and functionally, they continue to do what they need to do on a day-to-day basis without many impairments or limitations, then it's reasonable to not have a knee replacement. So not every patient who has advanced knee arthritis needs knee replacement surgery. Knee surgery can be a little bit difficult to recover from. It is a painful operation. The first few days can be pretty tough. We have patients who are going home now the same day of surgery. A decade ago, patients would routinely stay in the hospital for three days, but we've been able to accelerate the recovery process. The first week or two really involves healing and some gentle physical therapy. Walking, getting moving again, allowing the incision to heal. The period after that, after the first couple of weeks, that's really when the physical therapy becomes critical where patients really work on getting their strength back and getting their motion back. For most patients, it's about a two to three month process to really feel like they've recovered from knee replacement surgery. The success rate of knee replacement is over 80%, so the overwhelming majority of our patients are satisfied that they had the operation and that they chose to have their joint replaced. We really have a very specialized group of people who do nothing but joint replacement. It's the whole package I think that we offer at UVA that I think really sets us apart and offers patients an excellent experience in getting their joint replacement surgery.