1. Orthopedic Surgery, Department of Surgery, Hôpital Sacré-Cœur de Montréal, 5400 Boul. Gouin O., Montréal, Québec H4J 1C5, Canada
2. Department of Orthopaedics and Traumatology, Lausanne University Hospital, Rue du Bugnon 46, CH-1011 Lausanne, Switzerland