1 Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS), University of Oxford, Oxford, United Kingdom.
2 Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States.
3 Institute of Tendon and Bone Regeneration, Spinal Cord Injury and Tissue Regeneration Centre Salzburg, Paracelsus Medical University, Salzburg, Austria.