1. Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
2. Translational Musculoskeletal Research Center, Philadelphia VA Medical Center, Philadelphia, Pennsylvania.
3. Department of Trauma Surgery, Regensburg University Medical Center, Regensburg, Germany.
4. Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania.
5. Collaborative Research Partner (CRP), Acute Cartilage Injury (ACI) Program of the AO Foundation, Davos, Switzerland.