[1] NU Sjukvarden, Dept Orthopaed, S-45180 Uddevalla, Sweden
[2] Danderyd Hosp AB, Dept Orthopaed, Stockholm, Sweden
[3] Norra Alvsborg Cty Hosp, Dept Orthopaed, Trollhattan Uddevalla, Sweden
[4] Fyrbodal Res Inst, Dept Orthopaed, Trollhattan Uddevalla, Sweden
[5] Sahlgrens Univ Hosp, Dept Orthopaed, S-41345 Gothenburg, Sweden