[1] Hop Cantonal Fribourg, Hop Fribourgeois, Dept Rheumatol Phys Med & Rehabil, CH-1708 Fribourg, Switzerland
[2] Univ Geneva, Geneva, Switzerland
[3] Schulthess Klin, Spine Ctr, Dept Res & Dev, Zurich, Switzerland
[4] Univ Vall dHebron, Spine Unit Hosp, Barcelona, Spain
[5] Univ Geneva, Univ Hosp, Div Clin Pharmacol & Toxicol, Div Gen Med Rehabil, Geneva, Switzerland
[6] Univ Geneva, Univ Hosp, Div Clin Pharmacol & Toxicol, Ctr Multidisciplinary Pain, Geneva, Switzerland