1. Translational Musculoskeletal Research Center Corporal Michael J. Crescenz VA Medical Center Philadelphia Pennsylvania USA
2. Department of Orthopaedic Surgery, McKay Orthopaedic Research Laboratory, Perelman School of Medicine University of Pennsylvania Philadelphia Pennsylvania USA
3. Department of Biostatistics, Epidemiology & Informatics, Perelman School of Medicine University of Pennsylvania Philadelphia Pennsylvania USA
4. Department of Bioengineering University of Pennsylvania Philadelphia Pennsylvania USA