[1] Ruhr Univ Bochum, Marien Hosp Witten,Ctr Orthoped & Traumatol,St El, Ctr Spine Surg & Pain Therapy,Catholic Hosp Rhein, St Anna Hosp Herne,Marien Hosp,Herne Univ Hosp, Herne, Germany
[2] Ruhr Univ Bochum, Rheumazentrum Ruhrgebiet, Ctr Rheumatol, Herne, Germany
[3] Univ Med Greifswald, Clin Orthopaed & Orthopaed Surg, Greifswald, Germany
[4] Ruhr Univ Bochum, Marien Hosp Witten,Catholic Hosp Rhein Ruhr, Ctr Orthoped & Traumatol,St Elisabeth Grp, St Anna Hosp Herne,Marien Hosp,Herne Univ Hosp, Herne, Germany
[5] Univ Witten Herdecke, Ctr Spine Surg & Pain Therapy, Ctr Orthoped & Traumatol,St Elisabeth Grp, Catholic Hosp Rhein Ruhr,St Anna Hosp Herne, Herne, Germany