1. Department of Orthopedics and Rehabilitation, University of Iowa, Iowa City, IA 52242, USA
2. College of Medicine, Northeast Ohio Medical University, Rootstown, OH 44272, USA
3. College of Medicine, American University of Beirut, Beirut 1107-2020, Lebanon
4. Department of Orthopaedic Surgery, Duke University, Durham, NC 27708, USA
5. Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI 48109, USA