I've had three hip & knee replacements completed at HSS, the first at age 63 and the most recent (partial knee replacement) in Dec 2017. I'm 75, a hiker, and amateur nature photographer. Over a year ago, after failed attempts at physical therapy, I thought my outdoor activities were behind me, high pain level; balance &; flexibility were nil. Devastating! After several consults at HSS, I met with Dr. DiFelice. He listened to my interests and concerns about a 3rd full joint replacement and suggested a partial knee replacement less invasive and quicker rehab with an option for a full replacement IF it was needed. Yesterday, just ten weeks after Dr. DiFelice completed the partial, I took a slow 2 mile walk. No pain, no imbalance. While I won't be back on the Appalachian Trail, I will be on wooded trials shortly with my wife and camera, capturing the Spring in the air with a spring in my step. It has been a marvelous experience; it's literally given me back my life. Thank you HSS and Dr. DiFelice!