[1] Innovus, Stockholm, Sweden
[2] Karolinska Inst, Med Management Ctr, S-10401 Stockholm, Sweden
[3] Stockholm Sch Econ, Dept Orthoped, S-11383 Stockholm, Sweden
[4] Malmo Gen Hosp, S-21401 Malmo, Sweden
[5] Univ Lund Hosp, S-22185 Lund, Sweden
[6] Karolinska Inst, Stockholm Soder Hosp, S-10401 Stockholm, Sweden
[7] Umea Univ Hosp, S-90185 Umea, Sweden
[8] Helsingborg Hosp, Helsingborg, Sweden