[1] Oslo Univ Hosp, Div Orthoped Surg, Post Box 4956 Nydalen, N-0424 Oslo, Norway
[2] Univ Oslo, Dept Interdisciplinary Hlth Sci, Fac Med, Oslo, Norway
[3] Univ Southern Denmark, Dept Sports Sci & Clin Biomech, Odense, Denmark
[4] Lund Univ, Fac Med, Dept Clin Sci, Orthoped,Clin Epidemiol Unit, Lund, Sweden
[5] Martina Hansens Hosp, Dept Orthoped Surg, Sandvika, Norway
[6] Univ Oulu, Res Unit Med Imaging Phys & Technol, Fac Med, Oulu, Finland
[7] Oulu Univ Hosp, Dept Diagnost Radiol, Oulu, Finland
[8] Norwegian Sch Sport Sci, Oslo Sports Trauma Res Ctr, Oslo, Norway
[9] Int Olymp Comm, Med & Sci Dept, Lausanne, Switzerland
[10] Akershus Univ Hosp, Dept Pathol, Lorenskog, Norway
[11] Norwegian Sch Sport Sci, Dept Sports Med, Oslo, Norway