Photo 1: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012. AFP PHOTO / DAVID GANNON
Photo 2: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 3: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 4: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 5: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 6: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 7: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 8: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 9: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 10: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 11: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 12: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 13: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 14: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 15: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 16: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 17: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 18: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 19: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 20: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 21: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 22: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 23: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 24: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 25: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 26: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 27: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 28: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 29: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 30: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 31: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 32: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 33: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 34: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 35: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 36: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 37: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 38: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 39: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 40: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 41: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 42: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 43: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 44: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 45: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 46: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 47: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 48: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.
Photo 49: An operation replacinging an artificial knee is photographed at the Hygiea Clinic in Berlin's Schoeneberg district on July 11, 2012.