1. Department of Otorhinolaryngology–Head & Neck Surgery, Hospital of the University of Pennsylvania, Philadelphia
2. McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia
3. Surgical Service, Corporal Michael J. Crescenz Department of Veterans Affairs Medical Center, Philadelphia, Pennsylvania
4. Praxis am Hanse Viertel, Hamburg, Germany
5. Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Department of Veterans Affairs Medical Center, Philadelphia, Pennsylvania