[1] Univ Hosp Zurich, Dept Trauma, Zurich, Switzerland
[2] Univ Zurich, Harald Tscherne Lab Orthoped & Trauma Res, Zurich, Switzerland
[3] Univ Basel, Fac Med, Basel, Switzerland
[4] Univ Hosp Zurich, Dept Neurosurg, Zurich, Switzerland
[5] Univ Hosp Bern, Dept Orthoped Surg, Inselspital, Bern, Switzerland
[6] Univ Hosp Zurich, Dept Rheumatol, Zurich, Switzerland
[7] Osped Reg Lugano, Dept Neuroradiol, Neuroctr Southern Switzerland, Lugano, Switzerland
[8] Univ Hosp Bern, Dept Intervent & Diagnost Neuroradiol, Inselspital, Bern, Switzerland
[9] Malteser Waldkrankenhaus St Marien, Ctr Spinal & Scoliosis Surg, Erlangen, Germany
[10] Paracelsus Private Med Univ Nuremberg, Dept Orthoped & Traumatol, Nurnberg, Germany