1. Center of Experimental Orthopaedics and Saarland University Medical Center Homburg Germany
2. Department of Orthopaedic SurgerySaarland University Medical CenterHomburgGermany
3. Institute of Biology and Chemistry of ProteinsCentre National de la Recherche ScientifiqueLyonFrance
4. Department of Anesthesia and Children's Hospital BostonHarvard Medical SchoolBoston MassachusettsUSA
5. Department of SurgeryChildren's Hospital Boston, Harvard Medical SchoolBoston MassachusettsUSA