1. Department of Orthopaedic and Trauma Surgery,
University Hospital Bonn, Bonn
2. Department of Orthopaedic Surgery,
Zeisigwald Hospital Bethanien, Chemnitz
3. Department of Orthopaedic Surgery,
University Hospital Erlangen/Nürnberg, Erlangen
4. Department of Orthopaedic Surgery,
University Hospital Würzburg, Würzburg
5. Department of Orthopaedic Surgery,
Pius-Hospital Oldenburg, Oldenburg
6. Department of Orthopaedic Surgery,
Rummelsberg Hospital, Schwarzenbruck, Germany.