1. Professor and Temporary Head, Orthopaedic Clinic, Medical Faculty RWTH Aachen, Pauwelsstraβe 30, D-52057 Aachen, Germany.
2. Orthopaedic Surgeon, Orthopaedic Clinic, Medical Faculty RWTH Aachen.
3. Resident, Orthopaedic Clinic, Medical Faculty RWTH Aachen.