When dozens of holes appeared in a patient’s femur alongside his hip prosthesis, experts were baffled as such a phenomenon had never been seen before. Over the first four decades of total hip surgery, the severe bone destruction multiplied, crippling many thousands of patients. Eventually identified as “periprosthetic osteolysis,” this devastating disease affected over 1 million patients and was the leading cause of failure in total hip surgery. Dr. William H. Harris and his colleagues played an important role in solving the mystery of this disease. William H. Harris, M.D., D.Sc., is an American orthopaedic surgeon, Founder and Director Emeritus of the Massachusetts General Hospital Harris Orthopaedics Laboratory, and creator of the Advances in Arthroplasty course held annually since 1970.