1. Department of Orthopaedics, Ste-Justine Hospital, Ste-Catherine, Montreal, Quebec, Canada.
2. Universite de Montreal, Montreal Quebec, Canada.
3. Department of Orthopaedics, Hôpital Sacré-Coeur, Montreal, Quebec, Canada.
4. Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada.
5. Department of Surgery, University of Toronto, Toronto, Ontario, Canada.