The federal government for the first time is tracking the outcomes of hip and knee replacement surgeries, and it's naming names. An analysis by the Medicare program identifies 95 hospitals where elderly knee and hip surgery patients were more likely to suffer significant setbacks. The list includes two St. Louis-area hospitals, Des Peres Hospital and Mercy Hospital St. Louis, which both had high readmission rates. Medicare also named 97 hospitals where patients tended to have the smoothest recoveries. Barnes-Jewish Hospital, which scored better than average for complications, is the only St. Louis-area hospital included.